Evidence of a physical cause for the symptoms of irritable bowel syndrome (IBS) have long eluded medical science but now a team of researchers has identified signs of low level inflammation of the gut wall in sufferers.
The previous lack of any signs of physical disease has resulted in the medical profession being skeptical of the existence of IBS and patients have often found doctors to be dismissive of their symptoms, adding to their suffering. This new study is likely to go a long way to change all this while also pointing the way for future research and treatment.
The research was carried out by biologists, led by Professor Michael Schemann, at Germany's Technische Universitaet Muenchen (TUM). Schemann and his team in TUM's Department for Human Biology discovered low-level inflammation, referred to as "micro-inflammation", in the mucosa of the gut in IBS patients. The micro-inflammation is thought to result in sensitization of the nervous system in the gut (the enteric nervous system) which leads to the symptoms experienced by sufferers.
These symptoms include constipation and diarrhea (some IBS patients alternate between the two extremes), flatulence, bloating and distention, nausea and abdominal pain. IBS is estimated to affect as much as 10% of the population in developed nations and in Germany alone, some seven million people struggle with the condition.
Due to the lack of physical signs of the disorder there has been no routine test available to identify IBS and it has therefore been a diagnosis of exclusion. Along with leading doctors to be somewhat dismissive this has also meant treatment options have been hit and miss and currently many patients are simply left to manage their symptoms on their own through dietary changes, stress management and various complementary and alternative medicine (CAM) treatments such as hypnotherapy.
The researchers at TUM used ultrafast optical measuring techniques to demonstrate that in areas where micro-inflammation occurs, chemical mediators released by mast cells (best known for releasing histamine during allergic reactions) and enterochromaffin cells (which release hormones and neurotransmitters) directly activate the nerve cells in the bowel. This hypersensitivity of the enteric nervous system upsets communication between the gut's mucosa and its nervous system. Professor Schemann explains: "The irritated mucosa releases increased amounts of neuroactive substances such as serotonin, histamine and protease. This cocktail produced by the body could be the real cause of the unpleasant IBS complaints."
The team at TUM researchers have put themselves at the forefront of IBS research with this study. Their focus has now moved on to trying to determine the extent to which nerve sensitisation correlates with the severity of symptoms in the condition. Working with colleagues from Amsterdam, they have already substantiated the clinical relevance of their results - showing that IBS symptoms improve after treatment with an antihistamine known for its immune-stabilising effect in the treatment of allergic reactions such as hay fever. Thanks to funding from the German Research Foundation (DFG), the scientists are now investigating whether the improved symptoms are accompanied by a normalisation of nerve activity.
Successful identification of the source of the micro-inflammation of the gut wall and the active compounds produced by the enteric nervous system could enable the development of much more targeted and effective treatments for IBS, be they drugs or natural alternatives.
In the short-term many IBS patients will simply be heartened to hear that medical science is finally starting to prove what they already know, that their symptoms are not merely "in their heads."
Source: Technische Universitaet Muenchen