Overview of modification of the gut microbiota for irritable bowel syndrome

The gut microbiota is increasingly implicated in the pathophysiology of irritable bowel syndrome (IBS)Ianiro, 2019El-Salhy, 2020Halkjaer, 2018. The most convincing evidence for this is the finding that some patients develop IBS after acute infectious gastroenteritis. At the time of writing, there is insufficient evidence to determine a clear pattern of changes in gut microbiota in patients with IBS—commercial stool testing is not recommended because it is unlikely to influence therapeutic interventionsHugerth, 2020.

The gut microbiota may contribute to IBS symptoms through bacterial fermentation of carbohydrates, small intestinal bacterial overgrowth (SIBO), and activation of innate mucosal immune responses. These can increase intestinal permeability, activate nociceptor sensory pathways and dysregulate the enteric nervous system.

The gut microbiota can be affected by diet (particularly fibre), probiotics or antibiotics.