Probiotics Attenuate Food Allergy via Short-Chain Fatty Acids-Mediated Immune Modulation and Gut Barrier Restoration

The rising global prevalence of food allergy (FA) necessitates innovative therapeutic strategies. This study investigates the protective effects of three probiotic strains, Lacticaseibacillus rhamnosus HN001 (HN001), Bifidobacterium lactis HN019 (HN019), and Lactobacillus acidophilus NCFM (NCFM) against FA in a murine model. Probiotic administration significantly alleviated allergic symptoms and suppressed the Th2 response, reducing IgE, histamine, and cytokines (TNF-α, IL-2/5), while concurrently enhancing CD4+CD25+ regulatory T cell (Treg) activity and TGF-β1 expression. Treatment also restored intestinal integrity by upregulating tight junction proteins (ZO-1, claudin-1). 16S rRNA sequencing revealed that protection was underpinned by microbiota remodeling, marked by increased α-diversity and enrichment of SCFA-producing taxa (Lachnospiraceae and Muribaculaceae), which correlated with elevated acetate, butyrate, and propionate levels. Spearman analysis linked these microbial shifts to improved immune and barrier markers. Collectively, these findings demonstrate that probiotics mitigate FA through a convergent mechanism of immune rebalancing, barrier reinforcement, and SCFA-mediated microbiota-immune crosstalk, offering a promising microbiome-targeted therapy.