(02/09)

Dr Beate Niesler and her team at the Heidelberg Institute of Human Genetics have discovered that there may be a genetic element in irritable bowel syndrome.

Just as it affects sleep, mood, and blood pressure, serotonin plays an important role in the complex processes in the digestive tract. Various types of receptors are located in the intestine, to which serotonin attaches (like a key fitting into a lock) and transmits cellular signals.
‘Patients who suffer from irritable bowel syndrome with diarrhea show a higher frequency of certain mutations’, says Dr Niesler. These mutations appear to cause changes in the composition or number of receptors on the cell surface. The signal transduction in the digestive tract may be disturbed and this may lead to overstimulation of the intestine. Resulting disturbances in fluid balance could explain the occurrence of diarrhoea.’

The serotonin receptor blocker Alosetron is approved only in the US where it is effectively used in the treatment of women suffering from
diarrhoea-predominant IBS, but can only be prescribed with strict limitations due to its side effects.

Research of the serotonin system shows that serotonin receptors are located on, and influence, the nerve pathways involved in pain perception – which could explain why patients with irritable bowel syndrome often complain of severe pain although no infections or tumors are present. It has also been noted that persons with modified receptors suffer more frequently from depression.

Read more

J. Kapeller et al., First evidence for an association of a functional variant in the microRNA-510 target site of the serotonin receptor-type 3E gene with diarrhea predominant irritable bowel syndrome, Human Molecular Genetics, 2008, Vol.17, No.19, 2967-2977.

Click here for more research on IBS

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