High cellulose diet aggravates food allergy through gut homeostasis disruption

This study investigated the impact of a high cellulose diet (HCD) on intestinal homeostasis and food allergy development in BALB/c mice. While soluble fibers are known to mitigate FA via short-chain fatty acid (SCFA) production, the role of insoluble fibers like cellulose remains unclear. Mice fed HCD exhibited gut dysbiosis, characterized by increased Proteobacteria, decreased tight junction protein expression, and intestinal barrier impairment, despite unchanged SCFA levels. RNA sequencing revealed HCD-induced upregulation of immune pathways, including the positive regulation of B and T cells differentiation and antigen receptor-mediated signaling pathway. Following ovalbumin (OVA) sensitization, HCD-fed mice displayed exacerbated allergic symptoms, including elevated OVA-specific IgE, IgG, histamine, and mMCP-1 levels. Gut microbiota analysis highlighted enrichment of potentially pathogenic taxa in HCD+OVA groups. Fecal microbiota transplantation (FMT) from HCD donors to antibiotic-treated recipients showed severe food allergy responses, confirming microbiota-mediated effects. These findings demonstrate that HCD exacerbates food allergy through gut microbial dysbiosis, intestinal barrier disruption, and intestinal immune disorder.