It is well known that huge quantity of microbes inhabit in the digestive tract of vertebrates and invertebrates where they establish symbiotic relationship with host.Literatures suggested that an important function for the commensal rnicrobiota in supplying essential nutrients, metabolizing indigestible compounds, defending against colonization by opportunistic pathogens.Therefore, the gut epithelium seemly tolerates the proliferation of resident bacteria to a certain extent to allow beneficial interactions to take place.