The GI functions are progressively acquired during development and are largely sensitive to the environment, especially the intestinal luminal content. Indeed, probiotics and prebiotics have shown beneficial effects upon GI functions of newborns. One of the metabolite of the gut flora potentially involved is the butyrate. Butyrate is a short chain fatty acid produced in the colon by the microbiota (carbo-hydrates degradation). The colonic amount of butyrate increases gradually after birth. The beneficial effects of butyrate are related to its properties upon the epithelial barrier (anti-inflammatory, antioxidant, barrier repair) and upon the enteric nervous system (network of neurons and glial cells) that regulate GI functions and in particular colonic motility.