Irritable Bowel Syndrome linked to chilli pepper pain receptor

Researchers have discovered that those suffering from Irritable Bowel Syndrome have a higher number of chilli pepper pain receptors than normal and say the findings may lead to better treatments.

The study was published yesterday in the journal Gut and was carried out by researchers at Imperial College London.

Irritable Bowel Syndrome (IBS) is the most commonly diagnosed gastrointestinal disorder in the UK and is estimated to affect up to 20% of the population. Despite this it is also one of the least understood digestive diseases and patients are often left trying to cope with treatments which are only partially effective at best.

Professor Subrata Ghosh, one of the authors of the study from the Division of Medicine at Imperial College London, agreed saying: "At the moment patients don't have a lot of options for managing their condition and the treatments we can offer can give disappointing results. We hope that our findings will lead to better treatments to help people with IBS."

One of the main symptoms of IBS is abdominal pain and discomfort. The Imperial College London researchers may now have discovered at least one reason why sufferers experience such symptoms.

To look for differences between IBS patients and those without the condition the researchers recruited 23 patients and 22 controls from the Gastroenterology clinics and the endoscopy department at Imperial College Healthcare NHS Trust. They then took biopsies of colon tissue from all 55 study participants which were then studied in the Division of Neuroscience and Mental Health at Imperial College London.

After comparing the biopsies of IBS patients to those of the controls it was found that those with IBS had more nerve fibres expressing the pain receptor TRPV1. This receptor is also referred to as the 'chilli pepper pain receptor' as it is responsible for the burning sensation felt when people eat chilli peppers.

The researchers believe their findings may explain why some people's IBS symptoms worsen after eating spicy food. Many sufferers find that they must stay away from certain foods if they want to avoid aggravating their symptoms. Spicy foods such as curry are amongst the most frequently troublesome. It is hoped that the research will lead to treatments which relieve the pain of IBS through blocking this receptor

The study authors also suggest that the presence of higher numbers of chilli pepper pain receptors might mean that IBS patients are more susceptible to pain in general. This would appear to fit with other research that finds that those with IBS are more likely than the general population to suffer with other pain conditions such as fibromyalgia.

Currently those with severe pain from IBS which isn't controlled by dietary and lifestyle modifications, alternative therapies, or over the counter painkillers such as paracetemol and ibuprofen are often prescribed opiate painkilling drugs. These can of coursehave serious side-effects. New painkillers to target the TRPV1 receptor are currently being developed and the new findings suggest that these could tackle some of the symptoms of IBS without the side-effects.

Professor Praveen Anand, an author of the study from the Division of Neuroscience and Mental Health at Imperial College, said: "Up to 50 pharmaceutical and biotech companies world-wide are developing drugs that block the chilli pepper receptor TRPV1, and our published studies on this receptor in a number of chronic pain and hypersensitivity conditions provide hope for millions of suffering patients."