Large-scale genetic study finds new link between irritable bowel syndrome and cardiovascular system

One in ten people suffer from irritable bowel syndrome (IBS) worldwide, but therapeutic options are scarce and generally limited in their efficacy due to unknown aetiology.

A new study, published in the journal Cellular and Molecular Gastroenterology and Hepatology, has revealed that some of the biological mechanisms that cause IBS may be common to cardiovascular disease (CVD).

An international research team, coordinated by Professor Mauro D’Amato, from theGastrointestinal Genetics Research group at CIC bioGUNE– a BRTA member – and LUM University, and including scientists from Monash University (Australia), IRGB-CNR, CEINGE and the University of Naples Federico II (Italy), and the University of Groningen (The Netherlands), have identified DNA changes found in the general population that are associated with an increased risk of irritable bowel syndrome IBS, defined according to Rome Foundation expert consensus criteria.

The researchers studied 24,735 people with IBS and 77,149 individuals without symptoms from two large European population-based cohorts(UK Biobank and Lifelines) and compared their DNA profiles across the human genome. They identified four genomic regions, including two not previously reported, where certain DNA changes are more common in people with IBS. The results, published in Cellular and Molecular Gastroenterology and Hepatology, together implicate genes involved in important physiological processes such as control of gastrointestinal motility, intestinal mucosal integrity and circadian rhythm. “While we cannot yet conclusively pinpoint individual genes and specific mechanisms,” says lead and corresponding author Dr Leticia Camargo Tavares, Postdoctoral Research Fellow in the Hypertension Research Laboratory in the School of Biological Sciences at Monash University, “these findings offer new insight into the pathophysiology of IBS and highlight potential therapeutic targets, and we hope that future research will build on these findings.”

The team also analysed similarities between the genetics predisposing to IBS and those of other common diseases: in addition to the known overlap with mood and anxiety disorders as in previous studies, they identified a new link with several conditions and diseases of the cardiovascular system, including hypertension, ischaemic coronary heart disease and angina pectoris. “I find this the most exciting result of our study,” comments lead author and study supervisor, Ikerbasque Research Professor Mauro D’Amato, “the realisation that the genetic makeup underlying IBS contributes similarly to CVD tells us that some drugs and therapeutic approaches used to treat either condition may in fact find applicability to treat both.”

An important by-product of their research, the study also showed that the heritability of IBS (the weight of genetics in determining a person’s risk of disease) is much stronger than previously recognised. This may be due to the fact that they focused on more standardised and structured classifications of IBS patients and their symptoms according to theRome Criteria, the authors explain.