Short-chain fatty acids as a target for prevention against food allergy by regulatory T cells.

Objective: Food allergy (FA) has become a public health issue of global concern. Short-chain fatty acids (SCFAs) are one of the most important biomarkers of intestinal metabolites. SCFAs may affect the occurrence and development of FA. Currently, no studies have been reported on the mechanism of FA in response to SCFAs. In this study, the common food allergen ovalbumin (OVA) was used for intestinal sensitization in Balb/c mice to study the effect of FA on intestinal barrier function and regulatory T cells in mice, thus providing a new target for the prevention and treatment of FA.

Methods: Twenty BALB/c mice were randomly divided into the experimental group and control group. The experimental group was given OVA, and the control group was given an equal amount of physiological saline. On the 31st day of modeling, the levels of secretory immunoglobulin A (sIgA) and serum total IgE and diamine oxidase (DAO) were determined using enzyme linked immunosorbent assay (ELISA). At the same time, after in vitro stimulation with different concentrations of SCFAs and histone acetylase inhibitor trichostatin A (TSA), the frequency and function of Treg in OVA-sensitized mice were detected by flow cytometry.

Results: Different concentrations of SCFAs and TSA selectively proliferate Treg cells in a dose-dependent manner. SCFAs and TSA-pretreated PBMCs that were injected intravenously into the OVA-sensitized mice through the tail vein can significantly reduce the expression of IgE, DAO, and sIgA.

Conclusion: SCFAs and TSA can selectively proliferate Tregs and upregulate the expression of anti-inflammatory cytokines, thereby suppressing allergic reactions.