[Irritable Bowel Syndrome; gut microbiota and probiotic therapy]

Irritable bowel syndrome (IBS) is characterized by symptoms of abdominal pain and altered bowel habits. This common disorder is managed by varying clinical styles as no dominant therapeutic strategy has emerged. The pathophysiology of IBS remains unknown, but several lines of evidence link this disorder with the gut microbiota. Although controversy exists, gut microbiota is likely contributing to symptoms of IBS, at least in some patients, through an altered fermentation process, an impaired intestinal barrier function, a harmful modulation of enteric sensorimotor function, a promotion of low-grade inflammation without tissue damage, and a harmful modulation of the brain-gut axis. Probiotic therapy has a modest effect on IBS symptomatic relief, but the actual evidence is not strong enough to support a general recommendation of use. The best results are achieved, in children, with Lactobacillus rhamnusus GG, which moderately improves abdominal pain, while in adults the benefit appears to be greatest employing Bifidobacterium species.