Close, tightly orchestrated interactions between the intestinal epithelium and the mucosa-associated immune system are critical for normal intestinal absorptive and immunological functions. Recent data indicate that commensal intestinal microbiota represents a major modulator of intestinal homeostasis. This review analyses the process of intestinal colonisation and the interaction of microbiota with the intestinal epithelium and mucosal immune system, with special reference to the first years of extrauterine life. Dysregulation of the symbiotic interaction between intestinal microbiota and the mucosa may result in a pathological condition with potential clinical repercussions. Based on the concept that there is a beneficial and symbiotic relation between the host and endogenous microbiota, strategies aimed at directly modulating intestinal microbiota with regard to disease prevention or treatment have been developed. One strategy involves administering viable probiotic bacteria. Clinical evidence for the beneficial effect of probiotics in the prevention and/or treatment of necrotising enterocolitis, infectious and antibiotic-associated diarrhoea, allergic diseases, and inflammatory bowel disorders is reviewed herein.
Ruemmele FM, Bier D, Marteau P, Rechkemmer G, Bourdet-Sicard R, Walker WA, Goulet O. Clinical evidence for immunomodulatory effects of probiotic bacteria. J Pediatr Gastroenterol Nutr. 2009 Feb;48(2):126-41. View Abstract