Introduction. Probiotics are live microorganisms which, administered in appropriate amounts, have a beneficial effect on human health. Food products that contain these microorganisms are known as natural probiotics. Probiotic food include the group of dairy products in which fermented milk products are majority. Objective. The aim of the study is to review current data and summarize knowledge on the effects of consumption of dairy probiotics on human health. The review also aims at discussing the potential of these health-supporting microorganisms as a prevention factor against civilization diseases. State of knowledge. Consumption of probiotic food, especially natural dairy probiotic food, may have a positive effect on health due to the presence of probiotic bacteria or by the presence of their metabolites (postbiotics) demonstrating bioactive effects. The intake of these products is associated with the improvement of parameters such as lipid profile, insulin sensitivity, cardiovascular risk parameters, or presents protective effect on bones. Studies show a correlation between the consumption of natural probiotics and reduction in duration of diarrhea or alleviation of the course of inflammatory bowel diseases. Conclusion. The influence of natural dairy probiotics consumption on the state of health has recently been broadly investigated. Regular consumption of these products has shown beneficial effect on gut microbiota and on a wide range of health parameters. However, further studies are necessary to draw a precise conclusion.

Fermented food is a source of microorganisms. Numerous strains present in fermented products have probiotic characteristics. Probiotic strains can reverse dysbiosis due to the ability to modify gut microbiota. Regular consumption of fermented products may positively affect the composition and diversity of the intestinal microbiota. Numerous studies focus on the health effects of fermented dairy products. The range of non-dairy fermented products is large and includes, among others, vegetables, meat, fish, and eggs. The main ingredient and method of fermentation determine the presence and amount of bacterial strains. Lactic acid bacteria (LAB) present in sauerkraut, kimchi, and pickled cucumbers have a positive effect on the immune system activity, lipid metabolism, and anti-carcinogenic activity. The introduction of sauerkraut to the diet of irritable bowel syndrome (IBS) patients improved their quality of life. Soy sauce strains alleviate allergic rhinitis. Other fermented soy products show a beneficial effect on lipid profile or haematological parameters in animal models. Strains present in kombucha have not yet been tested for effects on consumer health. In summary, regular consumption of fermented non-dairy products can have a multidirectional impact on health improvement. However, more studies in this range, especially on appropriate daily intake of fermented food, are necessary to formulate a precise conclusion.