Am J Physiol Gastrointest Liver Physiol 2025[Dec]; ? (?): ? PMID41389008show ga
A growing proportion of the non-celiac population experience adverse symptoms to gluten. The pathogenesis of non-celiac gluten sensitivity (NCGS) is unclear, but elevated duodenal eosinophils and altered mucosa-associated microbiota (MAM) populations have been reported. Given the microbiome's role in gluten digestion and its susceptibility to antibiotics, we hypothesised that altering the microbiome with antibiotics would modify immune responses to gluten in mice. BALB/C mice consuming gluten-free chow received amoxicillin/clavulanate (5mg/kg) or PBS-vehicle daily for 5-days. Mice were then treated with a 3mg wheat-gluten suspension, or vehicle, on days 4 and 5 before sacrifice on day 7. Duodenal immune cells were analysed by histology and flow cytometry, while the duodenal MAM and faecal microbiome were characterised via 16S rRNA and shotgun metagenomic sequencing, respectively. Antibiotic treatment followed by gluten reintroduction significantly reduced Staphylococcus in the duodenal MAM, enriched Bacteroides in faeces, and resulted in altered microbial carbohydrate and lipid metabolism, compared to vehicle controls. Treatment with antibiotics and gluten also increased duodenal eosinophils, which positively correlated with the genus Blautia. Flow cytometry revealed that sequential antibiotic and gluten treatment resulted in a greater proportion of active eosinophils and epithelial gammadelta T-cells, compared to vehicle control mice. This study demonstrated that modulating the microbiome with antibiotics was sufficient to alter the immune response to gluten in mice, suggesting that the microbiome may determine the capacity for gluten to induce immune responses. These findings contribute valuable insights into possible microbial mechanisms underlying NCGS, such as altered gluten metabolism or production of immunomodulatory metabolites.