Individualized elimination diets guided by leukocyte activation tests reduced symptoms of irritable bowel syndrome better than a sham diet in a randomized controlled trial.
Researchers concluded that this dietary strategy may enable patients with IBS to alleviate their symptoms with less food restrictions than those required by the low FODMAP diet, which could improve long-term adherence.
“We didn’t expect results like this,” Ather Ali, ND, MPH, MHS, assistant professor of pediatrics and of medicine at Yale School of Medicine, said in a press release. “The people who consumed the diet consistent with the test did significantly better than people on the sham diet.”
In a parallel-group, double-blind trial, Ali and colleagues analyzed blood samples from 58 adults with IBS (mostly white women) using a leukocyte activation test to measure immune response to individual foods. Then they randomly assigned participants to adhere to a diet restricting foods consistent with the test results, or to a sham diet restricting foods inconsistent with the test results, for 4 weeks.
An average of 13 foods were eliminated among all participants out of a possible 200 that were tested, the most common of which included strawberries and cinnamon (low FODMAP foods) followed by almonds, apples, onions and pears (high FODMAP foods).
Additionally, overall diet adherence rates were statistically comparable, and patients reported no adverse effects related to the intervention.
Patients on the individualized diet showed significantly greater increases in IBS Global Improvement Scale (GIS) scores compared with those on the sham diet, which served as the primary endpoint. At 4 weeks, the mean difference in scores between groups was 0.86 (95% CI, 0.05-1.67), and at 8 weeks it was 1.22 (95% CI, 0.22-2.22).
Both groups showed significant improvements in IBS Symptom Severity Scale scores, but those on the individualized diet showed significantly greater reductions relative to the sham diet. At 4 weeks, the mean difference in score change from baseline between groups was –61.78 (95% CI, –4.43 to –119.14), and at 8 weeks it was –66.42 (95% CI, –5.75 to –127.09).
Both groups experienced statistically comparable changes in mean IBS Adequate Relief and quality of life scores.
Further analysis of plasma samples from strong responders showed that reduced levels of a single protein (neutrophil elastase) were associated with reduced symptoms.
The investigators concluded that this study provides novel data supporting the strategy of using leukocyte activation testing to develop individualized diets for IBS.
“If these intriguing results can be replicated in larger and more diverse samples they can provide insight into another way to treat a condition that can often be very frustrating,” Ali said in the press release. “It can be debilitating and patients are often looking for dietary approaches to it.” – by Adam Leitenberger
Disclosures: The researchers report no relevant financial disclosures.