## 3 Results and Discussion
### Antibacterial Activity of the Tablets  
The goal in administering probiotic products is to induce a balanced enteric microbiota, which will have a favorable impact on consumer health. Enteric microbiota include both beneficial and harmful microflora. As mentioned above, the tablets supplemented with Chinese ginseng and _P. sibiricum_ have a certain favorable effect on the activity of some lactobacilli. In order to investigate the antibacterial activity of the lactobacilli effervescent tablets, an in vitro bacteriostatic experiment against _S. aureus_ and _E. coli_ O157:H7, two common pathogens in clinical infection and food contamination, was conducted. After incubation with the control tablet for one hour, about 95.11% and 97.86% of _S. aureus_ and _E. coli_ O157:H7 were killed, respectively (Table 6). While the antibacterial ratio against both bacteria was decreased significantly with an increase in the content of the two herbs in the tablets (\(p<0.05\)), there was still a high antibacterial ratio for these tablets, which was more than 78% for the H-group. Because the treatment time of the antibacterial experiment was relatively short, which was 1 h, we considered that the disintegration progress of tablets may be an important factor affecting the antibacterial activity. As shown in Table 6, the dissolution time of the tablets was prolonged with increasing content of the two herbs (\(p<0.05\)), which is opposite to the change trend of antibacterial activity. The effervescence mediated by the citric acid and sodium bicarbonate ensures a rapid and complete distribution of the active ingredients in products to solutions [14], and can rapidly create an anaerobic microenvironment by released CO\({}_{2}\)[30], which can also decrease pH of the solution (Table 6). These features are harmful to bacteria which cannot withstand the environment. As the dissolution time of the tablets was prolonged with increased content of the two herbs (Table 6), this would decrease release rates of active ingredients and CO\({}_{2}\) with an increase in the content of the herbs, which may lower the antibacterial activity of the tablets with increased content of the herbs. Additionally, under the condition of the antibacterial experiment in this study, antagonist effects between antimicrobial and probiotic components of the herbs may lead to weak antibacterial activity of the tablets containing the herbs in a dose-dependent manner. Therefore, the antibacterial activity was highest for the control, which decreased significantly with an increase in the content of the two herbs in tablets under the condition of the antibacterial experiment in this study (Table 6). According to the previous results on the change of viability of lactobacilli after tablet disintegration for 48 h (Table 4), we deduced that the antibacterial activities of the four kinds of tablets against _S. aureus_ and _E. coli_ O157:H7 would be different when prolonged the treatment time.  
Meanwhile, the antibacterial activity of each kind of tablet was significantly higher against _E. coli_ O157:H7 than against _S. aureus_ (_p_ \(<\) 0.05) (Table 6). [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON] and [PERSON] [28] had found that ginseng causes bacterial death by directly destroying the membrane system. As we know, the cell wall of _S. aureus_ is thicker than that of _E. coli_ O157:H7, which will reduce the speed and content of CO\({}_{2}\) and active ingredients (such as saponins) reaching the cell membrane, causing higher antibacterial activity against _E. coli_ O157:H7 than against _S. aureus_ for each kind of tablet.