# The Effect of Selected Herbal Extracts on Lactic Acid Bacteria Activity
The name of the herb is derived from the Latin word \"valere\", which means \"to be healthy\" [1,2]. Sage (_Salvia officinalis_ L.) contains compounds that inhibit lipid peroxidation, and also exhibit antibacterial, antiallergic, antiviral, and analgesic properties. In addition, sage is used in medicine to fight rheumatism and arthritis, and sometimes to prevent the general weakening of the body [3, 4, 5]. Chamomile (_Matricaria chamomilla_ L.) has been used for centuries as a poulice for healing wounds and burns, and as an eyewash to treat conjunctivitis. This herb has not lost its relevance [6, 7, 8]. It is known to have anti-inflammatory, antibacterial, bacterial toxin-binding, disinfect, antiapsmodic, choleretic, sedative, and laxative effects, and is hence used widely in medicine. Furthermore, it is used in the food industry for the production of liqueurs and in the cosmetic industry for the production of creams, lotions, soaps, bath liquids, and toothpastes [6, 7, 8]. Cistus (_Cistus_ L.) acts as an antioxidant and removes free radicals and prevents the formation of new ones [9, 10]; it also has antibacterial, anti-inflammatory, antiviral, and antifungal effects [9, 10]. Linden blossom (_Tilia_ L.) exhibits a high healing effect and was therefore used by our ancestors for generations. In traditional medicine, the linden flower is commonly used for nervous tension and excessive nervous excitability. In some cases, it is used as a prophylactic against atherosclerosis and hypertension [11, 12, 13, 14, 15, 16]. Linden flowers are also characterized by anti-inflammatory, antipyretic, diaphoretic, diuretic, mildly astringent, and analgesic properties [11, 12, 13, 14, 15, 16]. Since ancient times, infusions prepared from linden or sage have been used to treat respiratory diseases. Ribwort plantain (_Plantago lancoleata_ L.) has also been used in folk medicine. Its leaves are used to treat cuts, bruises, bites, and burns, as well as for chronic gastrointestinal catarrh, acidity, and damage to the gastric and intestinal mucosa (e.g., by bacterial toxins or other chemical compounds) [17, 18, 19, 20]. This herb has bacteriostatic, antimicrobial, anti-inflammatory, antispasmodic, and expectorant properties. It also improves blood clotting and has astringent and sealing effects on blood vessels [17, 18, 19, 20]. Marshmallow (_Althaea_ L.) was valued for its prohealth properties by Egyptians and Syrians in ancient times. The generic name Althaea comes from the Greek word \"althe\" which means \"to heal\". Both the root and leaves of marshmallow are rich in mucus, which is the basic ingredient of this plant used in medicine [21, 22, 23, 24]. Marshmallow has anti-inflammatory, protective, coating, and antiussive properties [21, 22, 23, 24]. In food production, the use of herbs can stabilize the microflora of products, by preventing the development of harmful microorganisms and supporting the growth of desired bacteria. Only few scientific reports have shown that when selected plant extracts are used in appropriate portions, they can have a beneficial effect on lactic acid bacteria (LAB) [25, 26]. Bifidobacteria and some lactobacilli can transform polyphenols into important metabolites that have important functions in the human body is known to be [25, 26]. Moreover, observations of market trends suggest that plant extracts are used or can be used as food additives in the production of flavored fermented dairy products (including yoghurts or other fermented milks, sour cream, acid and rennet cheses), and many products derived from them. Only limited studies have analyzed the influence of phenolic compounds on the growth and viability of other lactic acid bacteria such as _Streptococcus thermophilus_ used in the production of yogurt. The present study aimed to investigate the effect of selected herbal additives on the activity and growth of lactic acid bacteria (LAB) during fermentation and passage of milk through the digestive system model.