Genetic Variations May Influence IBS Patients’ Response to Certain Diets

A recent international study has uncovered that genetic variations in carbohydrate-digesting enzymes may affect how patients with irritable bowel syndrome (IBS) respond to carbohydrate-reduced diets. Published in Clinical Gastroenterology & Hepatology, this research highlights the potential for using genetic markers to create personalized dietary treatments for IBS.

Led by Mauro D’Amato, PhD, of CIC bioGUNE and LUM University in Italy, the study found that IBS patients with defects in their carbohydrate-active enzymes (hCAZymes) were more likely to experience significant improvements when following a low-FODMAP diet, which reduces fermentable carbohydrates. This could revolutionize IBS management by allowing healthcare providers to tailor treatments based on a patient's genetic makeup.

IBS is a prevalent digestive disorder, affecting up to 10 percent of people worldwide. Characterized by abdominal pain, bloating, diarrhea, and constipation, treating IBS has long been challenging due to the highly variable responses to dietary and pharmacological treatments. Many IBS patients report that certain foods, particularly carbohydrates, trigger their symptoms, making dietary modifications, such as low-FODMAP diets, a common treatment approach. However, not all patients benefit equally from these diets.

“These findings suggest that genetic variations in hCAZyme enzymes, which play a key role in digesting carbohydrates, could become critical markers for designing personalized dietary treatments for IBS,” said Dr. D’Amato. “The ability to predict which patients respond best to a carbohydrate-reduced diet has the potential to strongly impact IBS management, leading to better adherence and improved outcomes”.

The study included 250 IBS patients who were either given a low-FODMAP diet or treated with antispasmodic medication. Of the 196 patients on the diet, those with defective hCAZyme genes showed a marked improvement, especially those with diarrhea-predominant IBS (IBS-D), who were six times more likely to respond positively to the diet. Interestingly, this genetic influence was not observed in patients treated with medication, highlighting the role of individual genetic predisposition in dietary treatment success.

“These data need to be further validated by future studies,” added study author Maura Corsetti, PhD of Nottingham Digestive Diseases Centre at the University of Nottingham in England. “If confirmed, this approach opens the way to personalized dietary and treatment strategies.”

The study’s results point toward a future where IBS treatments could be tailored based on a patient's genetics, bringing precision medicine into gastroenterology. However, the researchers caution that further studies are needed to validate these findings and fully understand how genetic markers can be used in clinical practice.