Small intestinal microbial fiber metabolism dysfunction in celiac disease

Area of Science:

• Gastroenterology
• Immunology
• Microbiome Research

Background:

• Celiac disease (CeD) is an immune-mediated disorder triggered by gluten, leading to small intestinal inflammation.
• The only treatment is a strict gluten-free diet (GFD), which can cause nutrient deficiencies like low fiber intake.
• Alterations in duodenal microbiota are observed in CeD, but their fiber metabolic capacity remains unclear.

Purpose of the Study:

• To investigate the microbial fiber metabolic capacity in the small intestine of celiac disease patients.
• To explore the role of Prevotella spp. in gut health and short-chain fatty acid (SCFA) production.
• To assess the impact of dietary fiber supplementation on mucosal healing in a mouse model of CeD.

Main Methods:

• Analysis of microbial fiber metabolism in duodenal biopsies from active and treated CeD patients.
• Colonization of germ-free mice with Prevotella spp. to study SCFA production.
• Utilizing a mouse model (HLA-DQ8) with gluten sensitization, treated with an inulin-supplemented diet during GFD.

Main Results:

• Both active and treated CeD patients exhibited impaired microbial fiber metabolism.
• A depletion of carbolytic taxa, specifically Prevotella spp., was associated with impaired metabolism.
• Prevotella spp. colonization increased small intestinal SCFAs in mice.
• Inulin supplementation in mice enhanced microbial carbolytic function, SCFA production, and accelerated mucosal healing during GFD.

Conclusions:

• Impaired microbial fiber metabolism is a feature of celiac disease.
• Prevotella spp. play a role in gut microbial fiber metabolism and SCFA production.
• Dietary fiber supplementation shows promise for enhancing GFD efficacy and promoting mucosal healing in CeD.