Moxibustion and the gut microbiota–inflammation axis: a systematic review and meta-analysis of clinical and preclinical studies

Abstract

Background Gut dysbiosis and aberrant inflammatory signaling are increasingly implicated in the pathogenesis of intestinal and extra-intestinal disorders. Moxibustion has been reported to modulate gut microbiota composition and inflammatory responses, but its overall effects remain incompletely characterized. Objective: To evaluate the effects of moxibustion on gut microbiota-related outcomes and inflammatory mediators in clinical and preclinical studies. Methods PubMed, Web of Science, the Cochrane Library, CNKI, WanFang Data, and VIP were searched from database inception to December 31, 2024. Clinical and preclinical studies investigating moxibustion and reporting at least one gut microbiota-related outcome were included. Clinical and preclinical evidence was synthesized separately, with quantitative meta-analysis restricted to eligible preclinical animal outcomes. Microbiota outcomes were pooled using ratios of means (ROMs), whereas inflammatory mediators were synthesized using standardized mean differences (SMDs) under random-effects models. Metabolite- and pathway-related findings were narratively synthesized. Results Thirty-one reports representing 30 unique studies were included, comprising 25 preclinical animal studies (26 reports) and 5 clinical studies. In animal studies, moxibustion increased Chao1 (ROM = 1.079, 95% CI [1.034–1.127]; P = 0.0005), ACE (ROM = 1.100, 95% CI [1.044–1.160]; P = 0.0004), and Shannon diversity (ROM = 1.047, 95% CI [1.015–1.080]; P = 0.0037), whereas Simpson diversity was not significantly altered. No significant pooled effects were detected for the major phyla. Ruminococcus decreased (ROM = 0.643, 95% CI [0.426–0.972]; P = 0.0364), whereas the other taxa retained in the main analysis showed no statistically significant pooled effects. Moxibustion reduced TNF-α (SMD = −1.648, 95% CI [−2.659 to −0.637]; P = 0.0014) and IL-1β (SMD = −1.861, 95% CI [−2.419 to −1.303]; P < 0.0001), whereas IL-6 and IL-10 were not significantly altered. Clinical findings were sparse and directionally inconsistent. Certainty of evidence for the evaluable prespecified primary microbiota outcomes was very low. Three studies further suggested potential modulation of short-chain fatty acids, amino acid metabolism, and microbial functional pathways. Conclusion Preclinical evidence indicates that moxibustion is associated with increased microbial richness and diversity and reduced selected pro-inflammatory mediators, while taxon-specific responses are highly heterogeneous and clinical confirmation remains insufficient. Systematic review registration https://www.crd.york.ac.uk/PROSPERO/ , identifier CRD42025639714.