Introduction The microbiome consists of microorganisms that are both helpful and potentially harmful. Most are symbiotic (where both the human body and microbiota benefit) and some, in smaller numbers, are pathogenic (promoting disease). In a healthy body, pathogenic and symbiotic microbiota coexist without problems.Gut microbiota have a crucial immune function against pathogenic bacteria colonization inhibiting their growth, consuming available nutrients and/or producing bacteriocins,the antibacterial protein. Gut microbiota also prevent bacterial invasion by maintaining integrity of the intestinal epithelium.The gut microbiota has broad impacts, including effects on colonization, resistance to pathogens, maintaining the integrity of intestinal epithelium, metabolizing dietary and pharmaceutical