Small intestinal microbial fiber metabolism dysfunction in celiac disease

Area of Science:

• Gastroenterology
• Microbiology
• Immunology

Background:

• Celiac disease (CeD) is an immune-mediated disorder triggered by gluten, managed by a strict gluten-free diet (GFD).
• The GFD can cause nutrient deficiencies, including fiber, and duodenal microbiota alterations are observed in CeD patients.
• The impact of CeD on microbial fiber metabolism within the small intestine remains unclear.

Purpose of the Study:

• To investigate microbial fiber metabolism in the small intestine of CeD patients.
• To explore the role of Prevotella spp. in fiber degradation and short-chain fatty acid (SCFA) production.
• To assess the therapeutic potential of dietary fiber supplementation in a mouse model of CeD.

Main Methods:

• Analysis of duodenal microbiota and fiber metabolism in CeD patients and controls.
• Colonization of germ-free mice with Prevotella spp. to assess SCFA production.
• Utilizing a gluten-sensitized HLA-DQ8 mouse model with inulin supplementation during GFD to evaluate mucosal healing.

Main Results:

• CeD patients exhibited impaired microbial fiber metabolism, associated with reduced Prevotella spp. abundance, irrespective of GFD status.
• Prevotella spp. colonization in germ-free mice enhanced small intestinal SCFA levels.
• Inulin supplementation in mice accelerated small intestinal mucosal healing during GFD by promoting microbial saccharolytic function and SCFA production.

Conclusions:

• Small intestinal microbial fiber metabolism is impaired in celiac disease, linked to Prevotella depletion.
• Dietary fiber supplementation and enhanced microbial fiber degradation show promise for improving GFD efficacy in CeD.
• Further clinical studies are warranted to explore fiber supplementation strategies for CeD management.