15.10.2024 16:02
Research results, scientific publications
European study shows that genetic defects in carbohydrate breakdown influence the extent to which those affected with irritable bowel syndrome benefit from a change in diet. Publication in Clinical Gastroenterology & Hepatology.
Irritable bowel syndrome (IBS) is a digestive disorder characterized by abdominal pain, bloating, diarrhea or constipation. It affects up to 10% of the world’s population. Despite its prevalence, treatment of irritable bowel syndrome remains challenging because symptoms and response to dietary or pharmacological interventions are highly variable. A European research team involving members of the Cluster of Excellence “Precision Medicine in Chronic Inflammation” (PMI) has now shown that nutritional measures are more effective in IBS patients with defects in carbohydrate digestion genes than in those affected without these changes. They published their results in the journal Clinical Gastroenterology & Hepatology.
IBS patients often associate their symptoms with the consumption of certain foods, especially carbohydrates. Avoiding these foods has been proven to be an effective treatment option, but not all sufferers receive the same benefits. Nutrigenetics, the science that studies the combined effect of genetics and nutrition on human health, has shown how changes in DNA can affect the way we process food. A well-known example is lactose intolerance, in which the loss of function of the enzyme lactase hinders the digestion of dairy products. The now published work suggests that genetic changes in human carbohydrate-active enzymes (hCAZymes) may similarly influence how people with irritable bowel syndrome respond to a low-carbohydrate (low-FODMAP) diet.
Research work involving the Institute for Clinical Molecular Biology (IKMB) at the Christian Albrechts University of Kiel (CAU) and the University Hospital Schleswig-Holstein (UKSH), Kiel Campus, has examined the role of hCAZymes in relation to irritable bowel syndrome. In a large-scale European research network, the GenMalCarb consortium, the team has now been able to show that people with defective variants in hCAZyme genes are more likely to benefit from a low-carbohydrate diet. The study, which involved 250 patients with irritable bowel syndrome, compared two treatments: a diet low in fermentable carbohydrates (FODMAPs) and the antispasmodic drug otilonium bromide. Of the 196 affected people who took part in the low-FODMAP diet, those who were carriers of a defective hCAZyme gene showed a significant improvement compared to non-carriers. The effect was particularly pronounced in those affected with predominantly diarrheal irritable bowel syndrome (IBS-D); they were six times more likely to respond to the diet. In contrast, this difference was not observed in patients receiving medication.
“The hCAZyme enzymes play a key role in the digestion of carbohydrates. “Our results suggest that genetic variants of these enzymes could become critical markers for the development of personalized nutrition-based treatments for irritable bowel syndrome,” says Dr. Britt Sabina Löscher from IKMB, co-author of the study and member of the PMI Cluster of Excellence. “In the future, knowledge of the hCAZyme genotype could be incorporated into clinical practice and enable doctors to identify in advance which patients are most likely to benefit from specific nutritional measures.”
Not only would this avoid unnecessary restrictive diets for those who are unlikely to benefit from them, but it would also open the door to personalized medicine for irritable bowel syndrome. The research team emphasizes that further studies are needed to validate these results and to explore the biological mechanisms that play a role. If confirmed, this approach could significantly improve the treatment of irritable bowel syndrome and similar gastrointestinal diseases by making nutritional and therapeutic strategies more precise and effective.
The study involved researchers and clinicians from Spain (CIC bioGUNE), Italy (LUM University and University of Naples), Germany (IKMB and University of Hannover), Belgium (TARGID) and the United Kingdom (University of Nottingham). The study was supported by the Spanish government MCIN/AEI/10. 13039/501100011033 (PCI2021-122064-2A), the German Federal Ministry of Education and Research BMBF (01EA2208B and 01EA2208A) and the Medical Research Council MRC (MR/W031213/1), under the umbrella of the European Joint Programming Initiative “A Healthy Diet for a Healthy Life” (JPI HDHL) and the ERA-NET Cofund ERA-HDHL (GA N° 696295 of the EU Horizon 2020 Research and Innovation Program), the Spanish government MCIN/AEI/10. 13039/501100011033 (PID2020-113625RB-I00), the German Research Foundation DFG (NA331/13-1 and 390884018) and the Belgian Health Care Knowledge Center (ref number: 16001).
The Cluster of Excellence “Precision Medicine in Chronic Inflammation” (PMI) is funded from 2019 to 2025 by the Federal and State Excellence Strategy (ExStra). It follows the inflammation research cluster “Inflammation at Interfaces”, which has already been successful in two funding periods of the Excellence Initiative (2007-2018). Around 300 members are involved in the new association in eight supporting institutions at four locations: Kiel (Christian Albrechts University of Kiel, University Hospital Schleswig-Holstein, Muthesius Art University, Institute for the World Economy and Leibniz Institute for the Pedagogy of Natural Sciences and Mathematics), Lübeck (University of Lübeck, University Hospital Schleswig-Holstein), Plön (Max Planck Institute for Evolutionary Biology) and Borstel (Borstel Research Center – Leibniz Lung Center).
The aim is to increasingly transfer the diverse research approaches to chronic inflammatory diseases of barrier organs in their interdisciplinarity into health care and to advance the fulfillment of previously unmet needs of those affected. Three points are important in connection with successful treatment and are therefore the focus of PMI’s research: the early detection of chronic inflammatory diseases, the prediction of disease progression and complications and the prediction of the individual response to therapy.
Cluster of Excellence Precision Medicine for Chronic Inflammatory Diseases
Scientific office, management: Dr. habil. Susanne Holstein
Postal address: Christian-Albrechts-Platz 4, D-24118 Kiel
Telephone: (0431) 880-4850
Press contact:
Frederick Buhse
Telephone: (0431) 880 4682
Email: [email protected]
Scientific contact person:
Dr. Britt-Sabina Löscher
Medical school
Institute of Clinical Molecular Biology, CAU and UKSH
Tel.: 0431 500-15255
Email: [email protected]
Original publication:
Andreea Zamfir-Taranu et al.: Functional variation in human CAZyme genes in relation to the efficacy of a carbohydrate-restricted diet in IBS patients. Clin Hepatol Gastroenterol, 2024.
