Maryam Hadian - Department of Microbiology, Shahr-e-Kord Branch, Islamic Azad University, Chaharmahal and Bakhtiari, Iran

Probiotic products contain useful bacteria that have significant effects on the health of consumers. Thesemicroorganisms generally cause general health in the functioning of the body's organs, includingimproving the functioning of the digestive system and brain, reducing blood cholesterol, strengthening thebody's immune system, and increasing bone density through high calcium absorption. They are alsouseful in improving diabetes, cancer, liver, skin, and metabolic syndrome. Research shows thatLactobacillus and Bifidobacterium species are generally recognized as the most abundant probiotics. Onthe other hand, prebiotics, which are indigestible food components, can have a beneficial effect onmaintaining and improving human health due to the selective stimulation of the growth and activity ofone or a limited number of bacterial species. Probiotics increase the health of the host by stimulating orregulating the immune system and can destroy pathogens, and the presence of prebiotics certainlyincreases the antimicrobial effect of probiotics. Researchers call the microbial species present in differentparts of a person's body, microbiota, and the collection of their genes, microbiome. The composition ofmicrobiota is specific to each person, which is related to genetic and environmental factors, includinglifestyle and the use of some types of drugs. Therefore, microbiota is a complex ecosystem ofmicroorganisms (bacteria, viruses, and fungi) that live in different areas of the human body, such as thedigestive tract, skin, mouth, and respiratory tract.It is hoped that by clarifying the importance of the antimicrobial effect of probiotics and prebiotics, aswell as the positive effect of microbiota and microbiome on the functioning of the body's immune system,a useful planning path will be paved to replace and use them instead of chemical drugs with high sideeffects. Because this issue, in addition to affecting human health, can also be effective in reducing thecosts of excessive use of chemical drugs and improving the country's economy. Therefore, the purpose ofthis review is to examine the clinical and research evidence related to the antimicrobial effect ofprobiotics and prebiotics in treating diseases and strengthening the immune system. Also, the protectiveand metabolic role of microbiota and microbiome on pathogens is also investigated

Antimicrobial properties, Microbiota, Prebiotic, Probiotic