TOPLINE

Increased consumption of beta-glucan and inulin was associated with a roughly 30% lower risk for Crohn’s disease (CD) in first-degree relatives (FDRs) of affected patients. These fiber subtypes were also linked to preserved gut barrier function, lower levels of systemic inflammation markers, and favorable changes in gut microbiome composition.

METHODOLOGY

• The impact of specific fibers on the risk for CD in humans remains unknown, and prior epidemiologic studies have predominantly focused on total fiber intake without accounting for the marked heterogeneity among fiber subtypes.
• Researchers included 3314 asymptomatic FDRs of patients with CD (median age at recruitment, 17.5 years; 52.9% female individuals) enrolled in the Crohn’s and Colitis Canada (CCC)-Genetic, Environmental, Microbial Project from North America and Israel (2008-2020) to assess the link between intake of total fiber or specific dietary fiber subtypes and the risk for incident CD.
• Habitual dietary intake over the previous 12 months was assessed using validated region-specific food frequency questionnaires (FFQs), with the estimated daily intake calculated for five fiber subtypes: inulin, fructooligosaccharides, beta-glucan, pectin, and arabinoxylan.
• A nested case-control subset was constructed, comprising 94 participants who developed CD over a median follow-up duration of 8.5 years and up to four matched control individuals per case (n = 382).
• The baseline biomarkers assessed included fecal calprotectin levels, serum C-reactive protein (CRP) levels, the urinary lactulose-to-mannitol ratio (LMR) for intestinal permeability, and gut microbial composition via 16S ribosomal RNA sequencing of stool samples, and detailed proteomic analysis was performed targeting 446 proteins.

TAKEAWAY

• Higher beta-glucan and inulin intakes were independently associated with a lower risk for CD (hazard ratio [HR], 0.70; P = .009 and HR, 0.68; P = .028, respectively), with no significant associations observed for fructooligosaccharides, pectin, or arabinoxylan.
• Increased consumption of inulin correlated with reduced CRP levels (estimate, -0.172; P = .02), as did increased intake of beta-glucan (estimate, -0.158; P = .019). No association was observed between the intake of any fiber subtype and fecal calprotectin levels.
• A higher intake of both beta-glucan (adjusted odds ratio [aOR], 0.827; P = .002) and inulin (aOR, 0.799; P = .004) was linked to lower odds of abnormal intestinal permeability, defined as having an LMR > 0.025.
• Higher intakes of both inulin and beta-glucan were inversely associated with the abundance of Ruminococcus torques, a taxon identified as the top contributor to a microbiome-derived risk score predictive of CD development up to 5 years before diagnosis.

IN PRACTICE

“Although these associations cannot yet justify specific clinical recommendations, they do highlight dietary patterns that are plausibly supportive of barrier function and microbial metabolism in individuals at risk for [Crohn’s disease],” the authors of the study wrote.

SOURCE

The study was led by Mingyue Xue, Zane Cohen Centre for Digestive Diseases, Mount Sinai Hospital, Toronto, Ontario, Canada. It was published online in Gastroenterology.

LIMITATIONS

Fiber subtype intake estimation depended on food datasets that often lack information on many foods and fiber types. The analysis might not have fully considered the differences in the properties of fibers. Dietary information gathered through FFQs may be subject to recall bias.

DISCLOSURES

CCC, the Canadian Institutes of Health Research (CIHR), and the Helmsley Charitable Trust provided grants to support the study. One author disclosed being the recipient of a Canada Research Chair in Inflammatory Bowel Diseases. Some authors disclosed receiving support from CIHR and Mount Sinai fellowships or receiving support from the Temerty Centre for Artificial Intelligence Research and Education in Medicine at the University of Toronto through the AI in Medicine Summer Student Research Program, as well as from the Department of Medicine at Mount Sinai Hospital. The authors declared having no competing interests.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.