RSSIrritable bowel syndrome caused by bacteria

Posted on Wed, 25 Jun 14

Irritable bowel syndrome caused by bacteria

A remarkable study has found that transferring the gut bacteria from people with irritable bowel syndrome to a healthy digestive system can cause pain and sensitivity, suggesting that bad gut bacteria alone could cause digestive problems.  

A lot of research has shown that people suffering from irritable bowel syndrome (IBS) – characterized by pain, distension, bloating, constipation and/ or diarrhea – have important differences in their gut bacteria when compared to people who have no symptoms.

However, despite considerable research it has been unclear if changes in gut bacteria can directly cause symptoms, until now. In an important experiment the gut bacteria from people with IBS was transplanted into rats with a healthy digestive system and subsequently shown to directly cause digestive pain and sensitivity. These IBS symptoms occurred without any major changes to the digestive tissue, suggesting that certain changes in gut bacteria can directly cause IBS.

The disruption in healthy gut bacteria, termed dysbiosis, resulted in more sulfate-reducing bacteria (which can cause fermentation, gas, distention, sensitivity and pain) and less bifidobacteria (which may prevent symptoms).

This important study suggests changes in gut bacteria may be a key cause of digestive symptoms for some people and helps explain why prebiotics and probiotics can sometimes relieve symptoms.


Crouzet L, Gaultier E, Del'Homme C, et al. The hypersensitivity to colonic distension of IBS patients can be transferred to rats through their fecal microbiota. Neurogastroenterol Motil. 2013 Apr;25(4):e272-82.

Tags: Digestive Health, Irritiable Bowel Syndrome, Probiotics

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