large-scale genetic study links carbohydrate malabsorption to irritable bowel syndrome

The study, coordinated by researchers at CIC bioGUNE and published in the journal Gastroenterology, has analysed the DNA of over 100,000 individuals.

A diet low in specific carbohydrates may potentially be beneficial for certain patient groups.

(Bilbao, 14 July 2021). Researchers at CIC bioGUNE, a member of the Basque Research & Technology Alliance (BRTA), have conducted a large-scale genetic study which links carbohydrate malabsorption to irritable bowel syndrome.

The study, published in the journal Gastroenterology, shows that DNA changes in the gene coding for sucrase-isomaltase, the enzyme responsible for the digestion of dietary sucrose and starch, are associated with an increased risk of irritable bowel syndrome in the general population.

Mutant forms of the sucrase-isomaltase gene cause congenital deficiency of this enzyme, and bring about a rare inherited carbohydrate malabsorption resulting from maldigested sucrose and starch. These molecules accumulate in the lower bowel, where they are fermented by bacteria causing diarrhea, abdominal pain and bloating”, explains Mauro D’Amato, Ikerbasque Research Professor and head of the Gastrointestinal Genetics Laboratory at CIC bioGUNE.

Previous research by Mauro D’Amato had shown that defective (hypomorphic) variants of sucrase-isomaltase can also be found at increased frequency in patients with irritable bowel syndrome, a common functional gastrointestinal disorder that affects a large fraction of the general population with symptoms similar to congenital sucrase-isomaltase deficiency. Prof. D’Amato’s research group had also shown that these variants are associated with a suboptimal response to the low-FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) diet, a popular approach to treating irritable bowel syndrome by limiting the intake of specific carbohydrates that are poorly absorbed in the intestine.

An international team led by Prof. D’Amato have analysed DNA sequencing data from over 100,000 individuals from the UK Biobank, one of the largest population-based cohorts in the world. By studying participants’ lifestyle questionnaire data and healthcare records, they have shown that the prevalence of rare  and common hypomorphic sucrase-isomaltase variants is increased in patients with irritable bowel syndrome diagnoses from hospital admissions, which possibly points to more severe forms of disease.

Our findings provide important additional evidence for a role of the sucrase-isomaltase gene in irritable bowel syndrome. This suggests potential for personalised treatment in a subgroup of patients based on their DNA profile, exploiting genetic information to guide beneficial dietary changes, including specific carbohydrate-restricted diets”, Mauro D’Amato points out.


About CIC bioGUNE
The Centre for Cooperative Research in Biosciences (CIC bioGUNE), based in the Bizkaia Technology Park, is a biomedical research organisation conducting cutting-edge research at the interface between structural, molecular and cell biology, with a particular focus on studying the molecular bases of disease, for use in the development of new diagnostic methods and advanced therapies.

About the BRTA
The BRTA is an alliance made up of 4 collaborative research centres (CIC bioGUNE, CIC nanoGUNE, CIC biomaGUNE and CIC energiGUNE) and 12 technology centres (Azterlan, Azti, Ceit, Cidetec, Gaiker, Ideko, Ikerlan, Lortek, Neiker, Tecnalia, Tekniker and Vicometch), with the aim of developing advanced technological solutions for Basque companies.

With the support of the Basque Government, the SPRI Group and the Provincial Councils of the three regional provinces, the alliance seeks to promote collaboration among its centres, to strengthen the conditions to generate and transfer knowledge to companies, thereby contributing to their competitiveness, and to spread Basque scientific and technological capacity.

BRTA has a staff of 3,500 professionals, accounts for 22% of the Basque Country’s R&D investment, generates an annual turnover of over EUR 300 million and files 100 European and international patents per year.

About Ikerbasque
Ikerbasque - the Basque Foundation for Science - was set up on the initiative of the Basque Government Department of Education to strengthen the commitment to scientific research by attracting, bringing back and consolidating researchers of excellence from all over the world. Today, Ikerbasque is a consolidated reality, with 290 researchers working in all fields of knowledge.

Spanish version

See a large version of the first picture


CIC bioGUNE, ONCE Foundation and Ikerbasque sign an agreement to promote the research career...

The successful candidates will conduct their research at CIC bioGUNE.