Jianpi Yiqi Busui Formula attenuates immune dysregulation in myasthenia gravis: Associations with gut microbiota remodeling and the Treg LDHA-lactate-H3K18la-PD-1 axis.
BACKGROUND Myasthenia gravis (MG) is an autoimmune neuromuscular disorder in which immune dysregulation and altered T-cell homeostasis contribute to pathogenic autoantibody production. Jianpi Yiqi Busui Formula (JPYQBSF) is used as an adjunctive traditional Chinese medicine, but its immunometabolic mechanisms remain incompletely defined. PURPOSE To evaluate the clinical and preclinical effects of JPYQBSF and to examine whether gut microbiota remodeling and the regulatory T-cell (Treg) LDHA-lactate-H3K18la-PD-1 axis are associated with its immunomodulatory activity. STUDY DESIGN An exploratory prospective clinical cohort, an experimental autoimmune myasthenia gravis (EAMG) rat model, and multi-omics and mechanistic experiments were integrated. METHODS Thirty-one anti-acetylcholine receptor antibody-positive MG patients receiving stable conventional therapy were assessed before and after 24 weeks of adjunctive JPYQBSF, with 31 age- and sex-matched healthy participants as a reference group. EAMG rats underwent functional, electrophysiological, immunological, 16S rRNA, serum metabolomic, and TMT-proteomic analyses. Fecal microbiota transplantation, human Treg-cell experiments, pharmacological LDH inhibition, LDHA knockdown, ChIP-qPCR, CUT&Tag, and reporter assays were used to interrogate candidate pathways. RESULTS In the clinical cohort, adjunctive JPYQBSF was associated with lower AChR-Ab levels and partial normalization of inflammatory and immunoregulatory markers; the uncontrolled design precludes attribution of these changes to JPYQBSF alone. In EAMG rats, JPYQBSF improved motor and electrophysiological outcomes, reduced inflammatory mediators, and shifted the Treg/Th17 balance. Microbiome, metabolomic, and proteomic analyses identified treatment-associated community and metabolic changes, including aromatic lactic-acid derivatives and LDHA. In cultured Tregs, JPYQBSF exposure increased LDHA expression, lactate, H3K18la enrichment near the PDCD1 promoter, and PD-1 expression. Oxamate and LDHA knockdown attenuated several of these changes, whereas healthy-donor FMT partially reproduced selected immunometabolic effects. CONCLUSION The findings support a coordinated model in which gut microbiota remodeling and LDHA-dependent Treg immunometabolic changes contribute to the effects of JPYQBSF. They do not establish a direct linear causal pathway from specific microbial metabolites to H3K18 lactylation, PD-1 regulation, or independent clinical efficacy.