Adjunctive Bifidobacterium longum SX-1326 improves the therapeutic efficacy of Acupotomy in post-stroke dysphagia: A randomized, double-blind, placebo-controlled study

Post-stroke dysphagia (PSD) is a frequent, disabling complication of ischemic stroke. Because acupotomy has limited effects on swallowing and gut–brain axis modulation with probiotics may support neural repair, we performed a single-center, randomized, double-blind (for probiotic/placebo allocation), placebo-controlled trial to test whether adjunctive Bifidobacterium longum (B. longum) SX-1326 enhances swallowing recovery in ischemic PSD. Between September 2023 and September 2024, 100 patients with confirmed PSD were randomized (1:1) to receive acupotomy plus B. longum SX-1326 (2 g twice daily) or acupotomy plus placebo for 4 weeks. Swallowing outcomes were assessed using WST, standardized swallowing assessment (SSA), and SWAL-QOL; secondary endpoints included nutritional indices, neuro-injury and neurotrophic biomarkers (NSE, NPY, IGF-1, BDNF, GFAP, GDF-15), inflammatory cytokines (IL-1β, IL-6, TNF-α, CRP), and fecal microbiota profiles (16S rRNA sequencing). Compared with placebo, the probiotic group achieved greater improvements in WST, SSA, and SWAL-QOL, higher cure rates, better nutritional recovery, reduced neuro-injury and inflammatory markers, and increased neurotrophic factors (all P < 0.05). Fecal microbiota profiling (16S rRNA sequencing) showed increased microbial diversity and an enrichment of Bifidobacterium, Coprococcus, and Collinsella in the probiotic group. 16S-based in silico functional inference suggested a relative increase in the pyruvate-to-L-lactate fermentation pathway. These microbiome and predicted functional shifts were associated with clinical improvement and should be considered hypothesis-generating; causality cannot be inferred from correlation-based analyses, and direct metabolite quantification (e.g., SCFAs, lactate) in future studies is required to validate these functional predictions.Trial Registration: Chinese Clinical Trial Registry (ChiCTR2300075164, http://www.chictr.org.cn/), registered on August 28, 2023.