Potential role of the intestinal microbiota in programming health and disease.

The composition of the microbiota varies according to prenatal events, delivery methods, infant feeding, infant care environment, and antibiotic use. Postnatal gut function and immune development are largely influenced by the intestinal microbiota. Emerging evidence has shown that early microbiota colonization may influence the occurrence of later diseases (microbial programming). The vast majority of microbial species (commensals) give rise to symbiotic host-bacterial interactions that are fundamental for human health. However, changes in the composition of the gut microbiota (dysbiosis) may be associated with several clinical conditions, including obesity and metabolic diseases, autoimmune diseases and allergy, acute and chronic intestinal inflammation, irritable bowel syndrome (IBS), allergic gastroenteritis (e.g., eosinophilic gastroenteritis and allergic IBS), and necrotizing enterocolitis. Based on recent advances, modulation of gut microbiota with probiotics, prebiotics, or fermented dairy products has been suggested as a treatment of, or prevention for, different disorders such as IBS, infectious diarrhea, allergic disease, and necrotizing enterocolitis.