Abstract:
Compositions comprising a plurality of yeast cells, wherein said plurality of yeast cells are characterized by their ability to enhance the immune system (e.g., increase the activity of T and B lymphocytes and natural killer cells) in a mammal, said ability resulting from their having been cultured in the presence of an alternating electric field having a specific frequency and a specific field strength. Also included are methods of making and using these compositions.

Description:
FIELD OF THE INVENTION 
     The invention relates to compositions that can alleviate adverse immunological conditions in a mammal and are useful as dietary supplements (e.g., health drinks). These compositions contain yeast cells obtainable by growth in electromagnetic fields with specific frequencies and field strengths. 
     SUMMARY OF THE INVENTION 
     This invention is based on the discovery that certain yeast cells can be activated by electromagnetic fields having specific frequencies and field strengths to produce substances that are beneficial for the immune system. Compositions comprising these activated yeast cells can be used as dietary supplements (e.g., health drinks) for improving immunity in a subject in need thereof, e.g., human patients having cancer, viral infection or bacterial infection. 
     This invention embraces a composition comprising a plurality of yeast cells that have been cultured in an alternating electric field having a frequency in the range of about 17650-17850 MHz (e.g., 17690-17815 or 17696-17811 MHz), and a field intensity in the range of about 50 to 500 mV/cm (e.g., 70-470 or 80-460 mV/cm). The yeast cells are cultured in the alternating electric field for a period of time sufficient to substantially increase the capability of said plurality of yeast cells to produce substances beneficial for the immune system. For instance, the cultured yeast cells when ingested can increase (e.g., by at least 10% such as 20% and 200%) the number of T lymphocytes, the ability of B lymphocytes to proliferate in response to a mitogen (e.g., a lectin such as LPS), and/or the cytotoxicity of natural killer cells in a mammal. 
     In one embodiment, the frequency and/or the field strength of the alternating electric field can be altered within the aforementioned ranges during said period of time. In other words, the yeast cells can be exposed to a series of electromagnetic fields. An exemplary period of time is about 30-130 hours (e.g., 50 to 105 hours). 
     Yeast cells that can be included in this composition can all be obtained from the China General Microbiological Culture Collection Center (“CGMCC”), a depository recognized under the Budapest Treaty (China Committee for Culture Collection of Microorganisms, Institute of Microbiology, Chinese Academy of Sciences, Haidian, P.O. BOX 2714, Beijing, 100080, China). Useful yeast species include, but are not limited to,  Saccharomyces cerevisiae  and  Saccharomyces carlsbergensis, Schizosaccharomyces pombe, Saccharomyces sake, Saccharomyces urarum, Saccharomyces rouxii, Hansenula subpelliculosa , and  Rhodotorula aurantiaca . For instance, the yeast cells can be of the strain  Saccharomyces cerevisiae  Hansen AS2.375, IFFI1048, AS2.501, AS2.502, AS2.503, AS2.504, AS2.535, AS2.558, AS2.560, AS2.561, or AS2.562; or  Saccharomyces carlsbergensis  AS2.440, or AS2.420. 
     Also encompassed in the invention are methods of using these compositions to enhance the immune system in an individual and methods of making these compositions. 
     Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Exemplary methods and materials are described below, although methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention. All publications and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. The materials, methods, and examples are illustrative only and not intended to be limiting. Throughout this specification and claims, the word “comprise,” or variations such as “comprises” or “comprising” will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers. 
     Other features and advantages of the invention will be apparent from the following detailed description, and from the claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic diagram showing an exemplary apparatus for activating yeast cells using electromagnetic fields. 1: yeast culture; 2: container; 3: power supply. 
     FIG. 2 is a schematic diagram showing an exemplary apparatus for making yeast compositions of the invention. The apparatus comprises a signal generator and interconnected containers  1 ,  2  and  3 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     This invention is based on the discovery that certain yeast strains can be activated by electromagnetic fields (“EMF”) having specific frequencies and field strengths to produce agents useful in improving immunity. Yeast compositions containing the activated yeast cells can be used as dietary supplements, in the form of health drinks or dietary pills. In certain embodiments, the yeast compositions of this invention can improve immune functions, as indicated by restored activity levels of T cells, B cells and NK cells in immune-compromised subjects (e.g., a human subject). 
     Since the activated yeast cells contained in these yeast compositions have been cultured to endure acidic conditions (pH 2.5-4.2), the compositions are stable in the stomach and can pass on to the intestines. Once in the intestines, the yeast cells are ruptured by various digestive enzymes, and the anti-aging agents are released and readily absorbed. 
     Without being bound by any theory or mechanism, the inventor believes that EMFs activate or enhance the expression of a gene or a set of genes in the yeast cells such that the yeast cells become active or more efficient in performing certain metabolic activities which lead to the production of agents that are beneficial for the immune system. 
     I. Yeast Strains Useful in the Invention 
     The types of yeasts useful in this invention include, but are not limited to, yeasts of the genera Saccharomyces, Schizosaccharomyces, and Rhodotorula. 
     Exemplary species within the above-listed genera include, but are not limited to, the species illustrated in Table 1. Yeast strains useful in this invention can be obtained from laboratory cultures, or from publically accessible culture depositories, such as CGMCC and the American Type Culture Collection, 10801 University Boulevard, Manassas, Va. 20110-2209. Non-limiting examples of useful strains (with the accession numbers of CGMCC) are  Saccharomyces cerevisiae  Hansen AS2.501, AS2.502, AS2.503, AS2.504, AS2.535, AS2.558, AS2.560, AS2.561, and AS2.562. In general, yeast strains preferred in this invention are those used for fermentation in the food and wine industries. As a result, compositions containing these yeast cells are safe for human consumption. 
     Although it is preferred, the preparation of the yeast compositions of this invention is not limited to starting with a pure strain of yeast. A yeast composition of the invention may be produced by culturing a mixture of yeast cells of different species or strains. 
     
       
         
               
             
               
               
               
               
               
             
               
             
               
               
               
               
               
             
               
             
               
               
             
               
             
               
             
               
             
               
               
             
               
             
               
               
             
               
             
               
               
             
               
             
               
               
               
             
               
             
               
             
               
             
               
             
               
             
               
             
               
             
               
             
               
             
               
               
               
               
             
               
             
               
             
               
             
               
             
               
             
               
             
               
             
               
             
               
             
               
               
               
               
               
             
               
             
               
             
               
             
               
             
               
             
               
             
               
             
               
               
               
               
               
             
               
             
               
               
               
               
               
             
               
             
               
               
               
             
               
             
               
               
               
             
               
             
               
               
               
               
               
             
               
             
               
               
               
               
               
             
               
             
               
             
               
             
               
             
               
             
               
             
               
             
               
             
               
             
               
               
               
               
               
             
               
             
               
               
               
               
               
             
               
             
               
               
             
               
             
               
               
               
               
               
             
               
             
               
               
               
               
             
               
             
               
             
               
             
               
               
               
               
               
             
               
             
               
             
               
             
               
               
               
               
               
             
               
             
               
               
               
               
               
             
               
             
               
               
               
               
               
             
               
             
               
               
               
               
               
             
               
             
               
               
               
               
               
             
               
             
               
             
               
             
               
               
               
             
               
             
               
             
               
             
               
               
             
               
             
               
               
               
               
               
             
               
             
               
               
               
               
               
             
               
             
               
               
             
               
             
               
               
             
               
             
               
               
             
               
             
               
             
               
             
               
               
             
               
             
               
               
             
               
             
               
               
               
               
               
             
               
             
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                 Exemplary Yeast Strains 
               
               
                   
               
             
             
               
                   Saccharomyces cerevisiae  Hansen 
               
             
          
           
               
                 ACCC2034 
                 ACCC2035 
                 ACCC2036 
                 ACCC2037 
                 ACCC2038 
               
               
                 ACCC2039 
                 ACCC2040 
                 ACCC2041 
                 ACCC2042 
                 AS2.1 
               
               
                 AS2.4 
                 AS2.11 
                 AS2.14 
                 AS2.16 
                 AS2.56 
               
               
                 AS2.69 
                 AS2.70 
                 AS2.93 
                 AS2.98 
                 AS2.101 
               
               
                 AS2.109 
                 AS2.110 
                 AS2.112 
                 AS2.139 
                 AS2.173 
               
               
                 AS2.174 
                 AS2.182 
                 AS2.196 
                 AS2.242 
                 AS2.336 
               
               
                 AS2.346 
                 AS2.369 
                 AS2.374 
                 AS2.375 
                 AS2.379 
               
               
                 AS2.380 
                 AS2.382 
                 AS2.390 
                 AS2.393 
                 AS2.395 
               
               
                 AS2.396 
                 AS2.397 
                 AS2.398 
                 AS2.399 
                 AS2.400 
               
               
                 AS2.406 
                 AS2.408 
                 AS2.409 
                 AS2.413 
                 AS2.414 
               
               
                 AS2.415 
                 AS2.416 
                 AS2.422 
                 AS2.423 
                 AS2.430 
               
               
                 AS2.431 
                 AS2.432 
                 AS2.451 
                 AS2.452 
                 AS2.453 
               
               
                 AS2.458 
                 AS2.460 
                 AS2.463 
                 AS2.467 
                 AS2.486 
               
               
                 AS2.501 
                 AS2.502 
                 AS2.503 
                 AS2.504 
                 AS2.516 
               
               
                 AS2.535 
                 AS2.536 
                 AS2.558 
                 AS2.560 
                 AS2.561 
               
               
                 AS2.562 
                 AS2.576 
                 AS2.593 
                 AS2.594 
                 AS2.614 
               
               
                 AS2.620 
                 AS2.628 
                 AS2.631 
                 AS2.666 
                 AS2.982 
               
               
                 AS2.1190 
                 AS2.1364 
                 AS2.1396 
                 IFFI1001 
                 IFFI1002 
               
               
                 IFFI1005 
                 IFFI1006 
                 IFFI1008 
                 IFFI1009 
                 IFFI1010 
               
               
                 IFFI1012 
                 IFFI1021 
                 IFFI1027 
                 IFFI1037 
                 IFFI1042 
               
               
                 IFFI1043 
                 IFFI1045 
                 IFFI1048 
                 IFFI1049 
                 IFFI1050 
               
               
                 IFFI1052 
                 IFFI1059 
                 IFFI1060 
                 IFFI1062 
                 IFFI1063 
               
               
                 IFFI1202 
                 IFFI1203 
                 IFFI1206 
                 IFFI1209 
                 IFFI1210 
               
               
                 IFFI1211 
                 IFFI1212 
                 IFFI1213 
                 IFFI1214 
                 IFFI1215 
               
               
                 IFFI1220 
                 IFFI1221 
                 IFFI1224 
                 IFFI1247 
                 IFFI1248 
               
               
                 IFFI1251 
                 IFFI1270 
                 IFFI1277 
                 IFFI1287 
                 IFFI1289 
               
               
                 IFFI1290 
                 IFFI1291 
                 IFFI1292 
                 IFFI1293 
                 IFFI1297 
               
               
                 IFFI1300 
                 IFFI1301 
                 IFFI1302 
                 IFFI1307 
                 IFFI1308 
               
               
                 IFFI1309 
                 IFFI1310 
                 IFFI1311 
                 IFFI1331 
                 IFFI1335 
               
               
                 IFFI1336 
                 IFFI1337 
                 IFFI1338 
                 IFFI1339 
                 IFFI1340 
               
               
                 IFFI1345 
                 IFFI1348 
                 IFFI1396 
                 IFFI1397 
                 IFFI1399 
               
               
                 IFFI1411 
                 IFFI1413 
                 IFFI1441 
                 IFFI1443 
               
             
          
           
               
                   Saccharomyces cerevisiae  Hansen Var. ellipsoideus (Hansen) Dekker 
               
             
          
           
               
                 ACCC2043 
                 AS2.2 
                 AS2.3 
                 AS2.8 
                 AS2.53 
               
               
                 AS2.163 
                 AS2.168 
                 AS2.483 
                 AS2.541 
                 AS2.559 
               
               
                 AS2.606 
                 AS2.607 
                 AS2.611 
                 AS2.612 
               
             
          
           
               
                   Saccharomyces chevalieri  Guilliermond 
               
             
          
           
               
                 AS2.131 
                 AS2.213 
               
             
          
           
               
                 
                   Saccharomyces delbrueckii 
                 
               
             
          
           
               
                 AS2.285 
               
             
          
           
               
                   Saccharomyces delbrueckii  Lindner ver. mongolicus (Saito) Lodder 
               
               
                 et van Rij 
               
             
          
           
               
                 AS2.209 
                 AS2.1157 
               
             
          
           
               
                   Saccharomyces exiguous  Hansen 
               
             
          
           
               
                 AS2.349 
                 AS2.1158 
               
             
          
           
               
                   Saccharomyces fermentati  (Saito) Lodder et van Rij 
               
             
          
           
               
                 AS2.286 
                 AS2.343 
               
             
          
           
               
                   Saccharomyces logos  van laer et Denamur ex Jorgensen 
               
             
          
           
               
                 AS2.156 
                 AS2.327 
                 AS2.335 
               
             
          
           
               
                   Saccharomyces mellis  (Fabian et Quinet) Lodder et kreger van Rij 
               
             
          
           
               
                 AS2.195 
               
             
          
           
               
                   Saccharomyces mellis  Microellipsoides Osterwalder 
               
             
          
           
               
                 AS2.699 
               
             
          
           
               
                   Saccharomyces oviformis  Osteralder 
               
             
          
           
               
                 AS2.100 
               
             
          
           
               
                   Saccharomyces rosei  (Guilliermond) Lodder et Kreger van Rij 
               
             
          
           
               
                 AS2.287 
               
             
          
           
               
                   Saccharomyces rouxii  Boutroux 
               
             
          
           
               
                 AS2.178 
                 AS2.180 
                 AS2.370 
                 AS2.371 
               
             
          
           
               
                   Saccharomyces sake  Yabe 
               
             
          
           
               
                 ACCC2045 
               
             
          
           
               
                 
                   Candida arborea 
                 
               
             
          
           
               
                 AS2.566 
               
             
          
           
               
                   Candida lambica  (Lindner et Genoud) van. Uden et Buckley 
               
             
          
           
               
                 AS2.1182 
               
             
          
           
               
                   Candida krusei  (Castellani) Berkhout 
               
             
          
           
               
                 AS2.1045 
               
             
          
           
               
                   Candida lipolytica  (Harrison) Diddens et Lodder 
               
             
          
           
               
                 AS2.1207 
                 AS2.1216 
                 AS2.1220 
                 AS2.1379 
                 AS2.1398 
               
               
                 AS2.1399 
                 AS2.1400 
               
             
          
           
               
                   Candida parapsilosis  (Ashford) Langeron et Talice Var. intermedia 
               
               
                 Van Rij et Verona 
               
             
          
           
               
                 AS2.491 
               
             
          
           
               
                   Candida parapsilosis  (Ashford) Langeron et Talice 
               
             
          
           
               
                 AS2.590 
               
             
          
           
               
                   Candida pulcherrima  (Lindner) Windisch 
               
             
          
           
               
                 AS2.492 
               
             
          
           
               
                   Candida rugousa  (Anderson) Diddens et Lodder 
               
             
          
           
               
                 AS2.511 
                 AS2.1367 
                 AS2.1369 
                 AS2.1372 
                 AS2.1373 
               
               
                 AS2.1377 
                 AS2.1378 
                 AS2.1384 
               
             
          
           
               
                   Candida tropicalis  (Castellani) Berkhout 
               
             
          
           
               
                 ACCC2004 
                 ACCC2005 
                 ACCC2006 
                 AS2.164 
                 AS2.402 
               
               
                 AS2.564 
                 AS2.565 
                 AS2.567 
                 AS2.568 
                 AS2.617 
               
               
                 AS2.637 
                 AS2.1387 
                 AS2.1397 
               
             
          
           
               
                   Candida utilis  Henneberg Lodder et Kreger Van Rij 
               
             
          
           
               
                 AS2.120 
                 AS2.281 
                 AS2.1180 
               
             
          
           
               
                   Crebrothecium ashbyii  (Guillermond) 
               
               
                 Routein ( Eremothecium ashbyii  Guilliermond) 
               
             
          
           
               
                 AS2.481 
                 AS2.482 
                 AS2.1197 
               
             
          
           
               
                   Geotrichum candidum  Link 
               
             
          
           
               
                 ACCC2016 
                 AS2.361 
                 AS2.498 
                 AS2.616 
                 AS2.1035 
               
               
                 AS2.1062 
                 AS2.1080 
                 AS2.1132 
                 AS2.1175 
                 AS2.1183 
               
             
          
           
               
                   Hansenula anomala  (Hansen) H et P sydow 
               
             
          
           
               
                 ACCC2018 
                 AS2.294 
                 AS2.295 
                 AS2.296 
                 AS2.297 
               
               
                 AS2.298 
                 AS2.299 
                 AS2.300 
                 AS2.302 
                 AS2.338 
               
               
                 AS2.339 
                 AS2.340 
                 AS2.341 
                 AS2.470 
                 AS2.592 
               
               
                 AS2.641 
                 AS2.642 
                 AS2.782 
                 AS2.635 
                 AS2.794 
               
             
          
           
               
                   Hansenula arabitolgens  Fang 
               
             
          
           
               
                 AS2.887 
               
             
          
           
               
                   Hansenula jadinii  (A. et R Sartory Weill et Meyer) Wickerham 
               
             
          
           
               
                 ACCC2019 
               
             
          
           
               
                   Hansenula saturnus  (Klocker) H et P sydow 
               
             
          
           
               
                 ACCC2020 
               
             
          
           
               
                   Hansenula schneggii  (Weber) Dekker 
               
             
          
           
               
                 AS2.304 
               
             
          
           
               
                   Hansenula subpelliculosa  Bedford 
               
             
          
           
               
                 AS2.740 
                 AS2.760 
                 AS2.761 
                 AS2.770 
                 AS2.783 
               
               
                 AS2.790 
                 AS2.798 
                 AS2.866 
               
             
          
           
               
                   Kloeckera apiculata  (Reess emend. Klocker) Janke 
               
             
          
           
               
                 ACCC2022 
                 ACCC2023 
                 AS2.197 
                 AS2.496 
                 AS2.714 
               
               
                 ACCC2021 
                 AS2.711 
               
             
          
           
               
                   Lipomycess starkeyi  Lodder et van Rij 
               
             
          
           
               
                 AS2.1390 
                 ACCC2024 
               
             
          
           
               
                   Pichia farinosa  (Lindner) Hansen 
               
             
          
           
               
                 ACCC2025 
                 ACCC2026 
                 AS2.86 
                 AS2.87 
                 AS2.705 
               
               
                 AS2.803 
               
             
          
           
               
                   Pichia membranaefaciens  Hansen 
               
             
          
           
               
                 ACCC2027 
                 AS2.89 
                 AS2.661 
                 AS2.1039 
               
             
          
           
               
                   Rhodosporidium toruloides  Banno 
               
             
          
           
               
                 ACCC2028 
               
             
          
           
               
                   Rhodotorula glutinis  (Fresenius) Harrison 
               
             
          
           
               
                 AS2.2029 
                 AS2.280 
                 ACCC2030 
                 AS2.102 
                 AS2.107 
               
               
                 AS2.278 
                 AS2.499 
                 AS2.694 
                 AS2.703 
                 AS2.704 
               
               
                 AS2.1146 
               
             
          
           
               
                   Rhodotorula minuta  (Saito) Harrison 
               
             
          
           
               
                 AS2.277 
               
             
          
           
               
                   Rhodotorula rubar  (Demme) Lodder 
               
             
          
           
               
                 AS2.21 
                 AS2.22 
                 AS2.103 
                 AS2.105 
                 AS2.108 
               
               
                 AS2.140 
                 AS2.166 
                 AS2.167 
                 AS2.272 
                 AS2.279 
               
               
                 AS2.282 
                 ACCC2031 
               
             
          
           
               
                   Rhodotorula aurantiaca  (Saito) Lodder 
               
             
          
           
               
                 AS2.102 
                 AS2.107 
                 AS2.278 
                 AS2.499 
                 AS2.694 
               
               
                 AS2.703 
                 AS2.704 
                 AS2.1146 
               
             
          
           
               
                   Saccharomyces carlsbergensis  Hansen 
               
             
          
           
               
                 AS2.113 
                 ACCC2032 
                 ACCC2033 
                 AS2.312 
                 AS2.116 
               
               
                 AS2.118 
                 AS2.121 
                 AS2.132 
                 AS2.162 
                 AS2.189 
               
               
                 AS2.200 
                 AS2.216 
                 AS2.265 
                 AS2.377 
                 AS2.417 
               
               
                 AS2.420 
                 AS2.440 
                 AS2.441 
                 AS2.443 
                 AS2.444 
               
               
                 AS2.459 
                 AS2.595 
                 AS2.605 
                 AS2.638 
                 AS2.742 
               
               
                 AS2.745 
                 AS2.748 
                 AS2.1042 
               
             
          
           
               
                   Saccharomyces uvarum  Beijer 
               
             
          
           
               
                 IFFI1023 
                 IFFI1032 
                 IFFI1036 
                 IFFI1044 
                 IFFI1072 
               
               
                 IFFI1205 
                 IFFI1207 
               
             
          
           
               
                   Saccharomyces willianus  Saccardo 
               
             
          
           
               
                 AS2.5 
                 AS2.7 
                 AS2.119 
                 AS2.152 
                 AS2.293 
               
               
                 AS2.381 
                 AS2.392 
                 AS2.434 
                 AS2.614 
                 AS2.1189 
               
             
          
           
               
                 Saccharomyces sp. 
               
             
          
           
               
                 AS2.311 
               
             
          
           
               
                   Saccharomycodes ludwigii  Hansen 
               
             
          
           
               
                 ACCC2044 
                 AS2.243 
                 AS2.508 
               
             
          
           
               
                   Saccharomycodes sinenses  Yue 
               
             
          
           
               
                 AS2.1395 
               
             
          
           
               
                   Schizosaccharomyces octosporus  Beijerinck 
               
             
          
           
               
                 ACCC2046 
                 AS2.1148 
               
             
          
           
               
                   Schizosaccharomyces pombe  Lindner 
               
             
          
           
               
                 ACCC2047 
                 ACCC2048 
                 AS2.214 
                 AS2.248 
                 AS2.249 
               
               
                 AS2.255 
                 AS2.257 
                 AS2.259 
                 AS2.260 
                 AS2.274 
               
               
                 AS2.994 
                 AS2.1043 
                 AS2.1149 
                 AS2.1178 
                 IFFI1056 
               
             
          
           
               
                   Sporobolomyces roseus  Kluyver et van Niel 
               
             
          
           
               
                 ACCC2049 
                 ACCC20S0 
                 AS2.19 
                 AS2.962 
                 AS2.1036 
               
               
                 ACCC2051 
                 AS2.261 
                 AS2.262 
               
             
          
           
               
                   Torulopsis candida  (Saito) Lodder 
               
             
          
           
               
                 AS2.270 
                 ACCC2052 
               
             
          
           
               
                   Torulopsis famta  (Harrison) Lodder et van Rij 
               
             
          
           
               
                 ACCC2053 
                 AS2.685 
               
             
          
           
               
                   Torulopsis globosa  (Olson et Hammer) Lodder et van Rij 
               
             
          
           
               
                 ACCC2054 
                 AS2.202 
               
             
          
           
               
                   Torulopsis inconspicua  Lodder et Kreger van Rij 
               
             
          
           
               
                 AS2.75 
               
             
          
           
               
                   Trichosporon behrendii  Lodder et Kreger van Rij 
               
             
          
           
               
                 ACCC2056 
                 AS2.1193 
               
             
          
           
               
                   Trichosporon capitatum  Diddens et Lodder 
               
             
          
           
               
                 ACCC2056 
                 AS2.1385 
               
             
          
           
               
                   Trichosporon cutaneum  (de Beurm et al.) Ota 
               
             
          
           
               
                 ACCC2057 
                 AS2.25 
                 AS2.570 
                 AS2.571 
                 AS2.1374 
               
             
          
           
               
                   Wickerhamia fluorescens  (Soneda) Soneda 
               
             
          
           
               
                 ACCC2058 
                 AS2.1388 
               
               
                   
               
             
          
         
       
     
     II. Application of Electromagnetic Fields 
     An electromagnetic field useful in this invention can be generated and applied by various means well known in the art. For instance, the EMF can be generated by applying an alternating electric field or an oscillating magnetic field. 
     Alternating electric fields can be applied to cell cultures through electrodes in direct contact with the culture medium, or through electromagnetic induction. See, e.g., FIG.  1 . Relatively high electric fields in the medium can be generated using a method in which the electrodes are in contact with the medium. Care must be taken to prevent electrolysis at the electrodes from introducing undesired ions into the culture and to prevent contact resistance, bubbles, or other features of electrolysis from dropping the field level below that intended. Electrodes should be matched to their environment, for example, using Ag—AgCl electrodes in solutions rich in chloride ions, and run at as low a voltage as possible. For general review, see Goodman et al.,  Effects of EMF on Molecules and Cells , International Review of Cytology, A Survey of Cell Biology, Vol. 158, Academic Press, 1995. 
     The EMFs useful in this invention can also be generated by applying an oscillating magnetic field. An oscillating magnetic field can be generated by oscillating electric currents going through Helmholtz coils. Such a magnetic field in turn induces an electric field. 
     The frequencies of EMFs useful in this invention range from about 17650 MHz to 17850 MHz. Exemplary frequencies include 17696, 17702, 17709, 17806 and 17811 MHz. The field strength of the electric field useful in this invention ranges from about 50 to 500 mV/cm (e.g., 70-90, 160-190, 150-180, 350-380, 440-470, 320-350, 350-400, and 340-380 mV/cm). Exemplary field strengths include 82, 175, 168, 367, 452, 332, 352, 362, 177, 206, and 115 mV/cm. 
     When a series of EMFs are applied to a yeast culture, the yeast culture can remain in the same container while the same set of EMF generator and emitters is used to change the frequency and/or field strength. The EMFs in the series can each have a different frequency or a different field strength; or a different frequency and a different field strength. Such frequencies and field strengths are referably within the above-described ranges. Although any practical number of EMFs can be used in a series, it may be preferred that the yeast culture be exposed to a total of 2, 3, 4, 5, 6, 7, 8, 9 or 10 EMFs in a series. 
     Although the yeast cells can be activated after even a few hours of culturing in the presence of an EMF, it may be preferred that the activated yeast cells be allowed to multiply and grow in the presence of the EMF(s) for a total of 30-130 hours, e.g., 30-100, 30-75 or 50-105 hours. 
     FIG. 1 illustrates an exemplary apparatus for generating alternating electric fields. An electric field of a desired frequency and intensity can be generated by an AC source ( 3 ) capable of generating an alternating electric field, preferably in a sinusoidal wave form, in the frequency range of 5 to 20,000 MHz. Signal generators capable of generating signals with a narrower frequency range can also be used. If desired, a signal amplifier can also be used to increase the output. The culture container ( 2 ) can be made from a non-conductive material, e.g., glass, plastic or ceramic. The cable connecting the culture container ( 2 ) and the signal generator ( 3 ) is preferably a high frequency coaxial cable with a transmission frequency of at least 30 GHz. 
     The alternating electric field can be applied to the culture by a variety of means, including placing the yeast culture ( 1 ) in close proximity to the signal emitters such as a metal wire or tube capable of transmitting EMFs. The metal wire or tube can be made of red copper, and be placed inside the container ( 2 ), reaching as deep as 3-30 cm. For example, if the fluid in the container ( 2 ) has a depth of 15-20 cm, 20-30 cm, 30-50 cm, 50-70 cm, 70-100 cm, 100-150 cm or 150-200 cm, the metal wire can be 3-5 cm, 5-7 cm, 7-10 cm, 10-15 cm, 15-20 cm, 20-30 cm and 25-30 cm from the bottom of the container ( 2 ), respectively. The number of metal wires/tubes used can be from 1 to 10 (e.g., 2 to 3). It is recommended, though not mandated, that for a culture having a volume up to 10 L, metal wires/tubes having a diameter of 0.5 to 2 mm be used. For a culture having a volume of 10-100 L, metal wires/tubes having a diameter of 3 to 5 mm can be used. For a culture having a volume of 100-1000 L, metal wires/tubes having a diameter of 6 to 15 mm can be used. For a culture having a volume greater than 1000 L, metal wires/tubes having a diameter of 20-25 mm can be used. 
     In one embodiment, the electric field is applied by electrodes submerged in the culture ( 1 ). In this embodiment, one of the electrodes can be a metal plate placed on the bottom of the container ( 2 ), and the other electrode can comprise a plurality of electrode wires evenly distributed in the culture ( 1 ) so as to achieve even distribution of the electric field energy. The number of electrode wires used depends on the volume of the culture as well as the diameter of the wires. 
     III. Culture Media 
     Culture media useful in this invention contain sources of nutrients that can be assimilated by yeast cells. Complex carbon-containing substances in a suitable form (e.g., carbohydrates such as sucrose, glucose, dextrose, maltose and xylose) can be the carbon sources for yeast cells. The exact quantity of the carbon sources can be adjusted in accordance with the other ingredients of the medium. In general, the amount of carbohydrate varies between about 1% and 10% by weight of the medium and preferably between about 1% and 5%, and most preferably about 2%. These carbon sources can be used individually or in combination. Amino acid-containing substances such as beef extract and peptone can also be added. In general, the amount of amino acid containing substances varies between about 0. 1% and 1% by weight of the medium and preferably between about 0. 1% and 0.5%. Among the inorganic salts which can be added to a culture medium are the customary salts capable of yielding sodium, potassium, calcium, phosphate, sulfate, carbonate, and like ions. Non-limiting examples of nutrient inorganic salts are (NH 4 ) 2 HPO 4 , CaCO 3 , KH 2 PO 4 , K 2 HPO 4 , MgSO 4 , NaCl, and CaSO 4 . 
     IV. Electromagnetic Activation of Yeast Cells 
     To activate or enhance the ability of yeast cells to produce agents beneficial for the gastrointestinal system, these cells can be cultured in an appropriate medium under sterile conditions at 20-35° C. (e.g., 28-32° C.) for a sufficient amount of time (e.g., 10-150 hours) in an alternating electric field or a series of alternating electric fields as described above. 
     An exemplary set-up of the culture process is depicted in FIG. 1 (see above). An exemplary culture medium contains the following per 1000 ml of sterile water: 20 g of sucrose, 40 μg of Vitamin B12 (sterilized and cooled to 45° C. before being added to the solution), 50 μg of Vitamin C (sterilized and cooled to 45° C. before being added to the solution), 0.2 g of KH 2 PO 4 , 0.2 g of MgSO 4 .7H 2 O, 0.25 g of NaCl, 0.1 g of CaSO 4 .2H 2 O, 3 g of CaCO 3 .5H 2 O, and 2.5 g of peptone. Yeast cells of the desired strain(s) are then added to the culture medium to form a mixture containing 1×10 8  cells per 1000 ml of culture medium. The yeast cells can be of any of the strains listed in Table 1. The mixture is then added to the apparatus shown in FIG.  1 . 
     The activation process of the yeast cells involves the following steps: (1) maintaining the temperature of the activation apparatus at 24-33° C. (e.g., 28-32° C.), and culturing the yeast cells for 25-42 hours (e.g., 32 hours); (2) applying an alternating electric field having a frequency of 17696 MHz and a field strength of 160-190 mV/cm (e.g., 175 mV/cm) for 14-18 hours (e.g., 15 hours); (3) then applying an alternating electric field having a frequency of 17702 MHz and a field strength of 150-180 mV/cm (e.g., 168 mV/cm) for 30-35 hours (e.g., 32 hours); (4) then applying an alternating electric field having a frequency of 17709 MHz and a field strength of 350-380 mV/cm (e.g., 367 mV/cm) for 25-30 hours (e.g., 28 hours); (5) then applying an alternating electric field having a frequency of 17806 MHz and a field strength of 440-470 mV/cm (e.g., 452 mV/cm) for 16-20 hours (e.g., 18 hours); and (6) then applying an alternating electric field having a frequency of 17811 MHz and a field strength of 320-350 mV/cm (e.g., 332 mV/cm) for 10-14 hours (e.g., 12 hours). The activated yeast cells are then recovered from the culture medium by various methods known in the art, dried (e.g., by lyophilization) and stored at 4° C. Preferably, the concentration of the dried yeast cells are no less than 10 10  cells/g. 
     V. Acclimatization of Yeast Cells To the Gastric Environment 
     Because the yeast compositions of this invention must pass through the stomach before reaching the small intestine, where the effective components are released from these yeast cells, it is preferred that these yeast cells be cultured under acidic conditions to acclimatize the cells to the gastric juice. This acclimatization process results in better viability of the yeasts in the acidic gastric environment. 
     To achieve this, the yeast powder containing activated yeast cells can be mixed with a highly acidic acclimatizing culture medium at 10 g (containing more than 10 10  activated cells per gram) per 1000 ml. The yeast mixture is then cultured first in the presence of an alternating electric field having a frequency of 17806 MHz and a field strength of 350-400 mV/cm (e.g., 367 mV/cm) at about 28 to 32° C. for 38 to 42 hours (e.g., 40 hours). The resultant yeast cells are further incubated in the presence of an alternating electric field having a frequency of 17811 MHz and a field strength of 340-380 mV/cm (e.g., 352 mV/cm) at about 28 to 32° C. for 20 to 25 hours (e.g., 22 hours). The resulting acclimatized yeast cells are then either dried and stored in powder form (≧10 10  cells/g) at room temperature or in vacuum at 0-4° C. 
     An exemplary acclimatizing culture medium is made by mixing 700 ml of fresh pig gastric juice and 300 ml of wild Chinese hawthorn extract. The pH of acclimatizing culture medium is adjusted to 2.5 ml of 0.1 M HCl or 0.2 M potassium biphthalate (C 6 H 4 (COOK)COOH). The fresh pig gastric juice is prepared as follows. At about 4 months of age, newborn Holland white pigs are sacrificed, and the entire contents of their stomachs are retrieved and mixed with 2000 ml of water under sterile conditions. The mixture is then allowed to stand for 6 hours at 4° C. under sterile conditions to precipitate food debris. To prepare the wild Chinese hawthorn extract, 500 g of fresh wild Chinese hawthorn is dried under sterile conditions to reduce the water content (≦8%). The dried fruit is then ground (≧20 mesh) and added to 1500 ml of sterile water. The mixture is allowed to stand for 6 hours at 4° C. under sterile conditions. The supernatant is collected to be used in the acclimatizing culture medium. 
     VI. Manufacture of Yeast Compositions 
     To manufacture the yeast compositions of the invention, an apparatus depicted in FIG. 2 or an equivalent thereof can be used. This apparatus includes a first container ( 1 ), a second container ( 2 ), and a third container ( 3 ), each equipped with a pair of electrodes ( 4 ). One of the electrodes is a metal plate placed on the bottom of the containers, and the other electrode comprises a plurality of electrode wires evenly distributed in the space within the container to achieve even distribution of the electric field energy. All three pairs of electrodes are connected to a common signal generator. 
     The culture medium used for this purpose is a mixed fruit extract solution containing the following ingredients per 1000 L: 300 L of wild Chinese hawthorn extract, 300 L of jujube extract, 300 L of Wu Wei Zi ( Schisandra chinensis  (Turez) Baill seeds) extract, and 100 L of soy bean extract. To prepare hawthorn, jujube and Wu Wei Zi extracts, the fresh fruits are washed and dried under sterile conditions to reduce the water content to no higher than 8%. One hundred kilograms of the dried fruits are then ground (≧20 mesh) and added to 400 L of sterile water. The mixtures are stirred under sterile conditions at room temperature for twelve hours, and then centrifuged at 1000 rpm to remove insoluble residues. To make the soy bean extract, fresh soy beans are washed and dried under sterile conditions to reduce the water content to no higher than 8%. Thirty kilograms of dried soy beans are then ground into particles of no smaller than 20 mesh, and added to 130 L of sterile water. The mixture is stirred under sterile conditions at room temperature for twelve hours and centrifuged at 1000 rpm to remove insoluble residues. To make the culture medium, these ingredients are mixed according to the above recipe, and the mixture is autoclaved at 121° C. for 30 minutes and cooled to below 40° C. before use. 
     One thousand grams of the activated yeast powder prepared as described above (Section V, supra) is added to 1000 L of the mixed fruit extract solution, and the yeast solution is transferred to the first container ( 1 ) shown in FIG.  2 . The yeast cells are then cultured in the presence of an alternating electric field having a frequency of 17806 MHz and a field strength of about 330-380 mV/cm (e.g., 362 mV/cm) at 28-32° C. under sterile conditions for 14 hours. The yeast cells are further incubated in an alternating electric field having a frequency of 17811 MHz and a field strength of 330-380 mV/cm (e.g., 352 mV/cm). The culturing continues for another 12 hours. 
     The yeast culture is then transferred from the first container ( 1 ) to the second container ( 2 ) (if need be, a new batch of yeast culture can be started in the now available the first container ( 1 )), and subjected to an alternating electric field having a frequency of 17806 MHz and a field strength of 130-180 mV/cm (e.g., 177 mV/cm) for 8 hours. Subsequently the frequency and field strength of the electric field are changed to 17811 MHz and 200-210 mV/cm (e.g., 206 mV/cm), respectively. The culturing continues for another ten hours. 
     The yeast culture is then transferred from the second container ( 2 ) to the third container ( 3 ), and subjected to an alternating electric field having a frequency of i17806 MHz and a field strength of 90-120 mV/cm (e.g., 115 mV/cm) for 8 hours. Subsequently the frequency and field strength of the electric field are changed to 17811 MHz and 70-90 mV/cm (e.g., 82 mV/cm), respectively. The culturing continues for another 10 hours. 
     The yeast culture from the third container ( 3 ) can then be packaged into vacuum sealed bottles for use as dietary supplements, e.g. tonic drinks. If desired, the final yeast culture can also be dried within 24 hours and stored in powder form. The dietary supplement can be taken three to four 30˜60 ml doses daily for a three-month period, preferably 10-30 minutes before meal and bedtime. 
     In some embodiments, the compositions of the invention can also be administered intravenously or peritoneally in the form of a sterile injectable preparation. Such a sterile preparation can be prepared as follows. A sterilized health drink composition is first treated under ultrasound ( 1000  Hz) for 10 minutes and then centrifuged for another 10 minutes. The resulting supernatant is adjusted to pH 7.2-7.4 using 1 M NaOH and subsequently filtered through a membrane (0.22 μm for intravenous injection and 0.45 μm for peritoneal injection) under sterile conditions. The resulting sterile preparation is submerged in a 35-38 ° C. water bath for 30 minutes before use. 
     The yeast compositions of the present invention are derived from yeasts used in food and pharmaceutical industries. The yeast compositions are thus devoid of side effects associated with many pharmaceutical compounds. 
     VII. Examples 
     The following examples are meant to illustrate the methods and materials of the present invention. Suitable modifications and adaptations of the described conditions and parameters which are obvious to those skilled in the art are within the spirit and scope of the present invention. 
     The activated yeast compositions used in the following experiments were prepared as described above, using  Saccharomyces cerevisiase  Hansen AS2.503 cells cultured in the presence of an alternating electric field having the electric field frequency and field strength exemplified in the parentheses following the recommended ranges listed in Section IV, supra. Control yeast compositions were those prepared in the same manner except that the yeast cells were cultured in the absence of EMFs. 
     Example 1 
     Esterase Staining 
     Mature T lymphocytes express alpha-naphthyl acetate estarase (ANAE) on their cell surface. The level of ANAE expression is positively correlated to T lymphocyte functions. 
     In this experiment, 30 NfH mice (6-8 weeks old) were divided into groups A, B and C, each having 10 mice. Mice in these groups were each given 2.5 ml of the activated yeast composition, the control yeast composition and saline, respectively, for 10 consecutive days. On day 10, four hours after the composition administration, 0.5 ml of blood was drawn from the animals from the vena orbitalis, smeared onto a glass slide and blown dry using room temperature air. The slide was then immersed in a 37° C. incubation buffer for 3 hours, rinsed with water to remove debris, and dried carefully with filter paper. 
     The incubation buffer was prepared as follows. Two grams of α-naphthyl acetate was dissolved in 100 ml of methyl glycol and stored at 4° C. Then 4 g of pararosaniline was dissolved in 100 ml of 2 M HCl. The solution was then warmed up to 60-80° C., filtered, and stored at 4° C. Right before use, 3 ml of freshly made 4% sodium nitrite was added drop-wise to 3 ml of the pararosaniline solution while shaking, until the color changed from brown to light yellow. This solution was a hexazonium pararosaniline solution, usable as an incubation buffer. 
     The slide was then placed in 89 ml of PB buffer (prepared by mixing 1M NaH 2 PO 4  and 1M Na 2 HPO 4  at a 1:1 ratio; pH 7.6), to which 6 ml of the hexazonium pararosaniline solution was slowly added and gently mixed. Then 2.5 ml of the α-naphthyl acetate solution was slowly added while gently mixing the solution. The pH of the solution was subsequently adjusted to 6.4 with acetic acid. Then a 1% malachite green solution was added to the slide and the slide was further incubated for 5-10 seconds. The slide was then rinsed with water, pat dried with filter paper and blown dry with a heat dryer. 
     The slide was then examined under oil microscope. For each slide, 200 lymphocytes were examined for the presence of red granules in the cytoplasm. A lymphocyte with fine red granules distributed in the cytoplasm was recorded as one (+). A lymphocytes with a single or more larger red granules was recorded as (++). These cells were considered ANAE-positive. A lymphocyte with no red granules was recorded as (−). The percentage of ANAE-positive cells was calculated by dividing the number of (+) cells and (++) cells by 200. The results were shown in Table2 below. 
     
       
         
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                   
                   
                 % of esterase-stained T 
               
               
                 Group 
                 Number of Animals 
                 lymphocytes 
               
               
                   
               
             
             
               
                 A 
                 10 
                 48.89 
               
               
                 B 
                 10 
                 34.12 
               
               
                 C 
                 10 
                 34.24 
               
               
                   
               
             
          
         
       
     
     The data thus demonstrate that the activated yeast composition significantly increased T lymphocyte levels as indicated by ANAE positive cells, as compared to the control yeast composition and saline. 
     Example 2 
     Regulation of B Lymphocyte Proliferation 
     Forty NIH mice (18-22 g) were divided for equal groups A, B, C and D. Mice in group A were orally administered 3 ml of the activated yeast composition per animal daily for 42 consecutive days. Starting on day 14, the mice were placed in an atmosphere with 0.94 ppm ozone for the remaining 28 days. Mice in groups B and C were treated in the same manner except that they were given the control yeast composition and preservative ethyl-p-hydroxy benzoate, respectively. Mice in group D were treated in the same manner as group C except that no ozone treatment was given. 
     On day 42, the mice were sacrificed by bloodletting from eyeballs. The blood cells were suspended in RPMI-1640 to reach a concentration of 1×10 8  cells/ml. Then monoclonal antibodies against Thy-1.2 was added to the cell suspension at a ratio of 1:1000. The sample was incubated at 4° C. for 30 seconds and washed once with double distilled water. Then complement was added at a antibody:cell suspension ration of 1:10. The sample was then incubated at 37° C. for 45 minutes, and washed 3 times. The remaining intact cells were counted and suspended in RPMI-1640 at 2.5×10 6  cells/ml. The cells were then seeded on a 96-well plate, with 0.2 ml in each well. Cells isolated from each mouse were seeded in three duplicate wells. To each well was added 10 μg of lipopolysaccharide (LPS), and the plate was incubated at 37° C. in a humidified atmosphere with 5% CO 2  for 72 hours. Sixteen hours before the end of the incubation,  3 H-TdR was added at 0.5 μCi/well. The radioactivity from each well was measured by standard methods. The data are shown in Table 3 below. 
     
       
         
               
               
               
             
           
               
                 TABLE 3 
               
               
                   
               
               
                 Group 
                 Number of Animals 
                 cpm 
               
               
                   
               
             
             
               
                 A 
                 10 
                 64339 ± 4765  
               
               
                 B 
                 10 
                 5221 ± 2141 
               
               
                 C 
                 10 
                 5219 ± 1221 
               
               
                 D 
                 10 
                 65532 ± 5476  
               
               
                   
               
             
          
         
       
     
     These data demonstrate that while ozone markedly inhibited B cell proliferation, the activated yeast composition of this invention significantly reverses that inhibition. 
     Example 3 
     Activity of NK Cells 
     L929 cells are adherent mouse fibroblasts that can uptake neutral red. Thus, the amount of the neutral red uptake after placing NK cells in contact with L929 cells indicates the cytotoxic activity of the NK cells. 
     In this experiment, 30 NIH mice were divided into three equal groups. Mice in group A were each orally administered 3 ml of the activated yeast composition daily for 14 days. Mice in groups B and C were treated in the same manner, except that they were administered the control yeast composition and preservative ethyl-p-hydroxy benzoate, respectively. On day 14, splenocytes from these animals were prepared using standard techniques. Red blood cells were lysed by suspending the collected splenocytes in 0.4 ml of double-distilled water and gently vortexing the cell sample for 30 seconds. Then 0.4 ml of 1.7% saline was added to restore the osmotic balance of the cell sample. The cells were spun down, washed with serum-free RPMI-1640, and suspended in RPMI-1640 supplemented with 10% fetal bovine serum (FBS) to reach a concentration of 1×10 7  cells/ml. This preparation contained an enriched population of NK cells. 
     To prepare target L929 cells, the cells were grown to near confluence one day before the cytotoxicity experiment, and the cell culture medium was replaced with fresh medium. The next day, the cells were trypsinized with 1-2 ml of 0.25% trypsin. The cells were washed off from the culture container with RPMI-1640 and centrifuged at 1000 rpm for 5 minutes. The pellet was resuspended in RPMI-1640 supplemented with 10% FBS at 2×10 5  cells/ml. The L929 cells were then plated on a flat-bottom 96-well plate at 0.1 ml/well and incubated at 37° C. in a humidified atmosphere with 5% CO 2  for at least 1 hour (e.g., 6 hours). Then 0.1 ml of the NK cell solution was added to each well such that the ratio of NK cells to L929 cells was 50:1. Four duplicate wells were used for each sample. RPMI-1640 supplemented with 10% FBS was added to the control wells. The plate was replaced in the 37° C. incubator for at least 20 hours (e.g., 36 hours). The culture medium was then removed, and the wells were washed three times with saline. Then 0.1 ml of 0.1% neutral red was added to each well and incubated at 37° C. for 30 minutes. The dye solution was then removed, and the wells were washed three times with saline. Next, 0.1 ml of a cell lysis solution (50% HCl and 50% ethanol) was added to each well to release neutral red from the L929 cells. Optical density (OD) was measured of each well at 429 nm, with 450 nm as the reference wavelength. Cytotoxic activity of the NK cells was indicated by [(OD of control sample—OD of test sample)/OD of control sample] X 100%, where OD of control sample was the OD of wells with L929 cells only and OD of test sample was the OD of wells with L929 cells and NK cells. The data are shown in Table 4 below. 
     
       
         
               
               
               
               
               
             
           
               
                   
                 TABLE 4 
               
               
                   
                   
               
               
                   
                   
                 Number of 
                   
                   
               
               
                   
                 Group 
                 Animals 
                 NK cells O.D. 
                 Cytotoxicity (%) 
               
               
                   
                   
               
             
             
               
                   
                 A 
                 10 
                 0.102 ± 0.021 
                 91.2 
               
               
                   
                 B 
                 10 
                 0.188 ± 0.042 
                 68.3 
               
               
                   
                 C 
                 10 
                 0.186 ± 0.022 
                 67.9 
               
               
                   
                   
               
             
          
         
       
     
     These data demonstrate that the activated yeast composition of the invention can significantly enhance the cytotoxic activity of NK cells. 
     While a number of embodiments of this invention have been set forth, it is apparent that the basic constructions may be altered to provide other embodiments which utilize the compositions and methods of this invention.