Clinical study on efficacy and mechanism of separated moxibustion in the treatment of rheumatoid arthritis and related negative emotions based on gut microbiota

To investigate the clinical efficacy of separated moxibustion in the treatment of rheumatoid arthritis (RA) and related negative emotions based on gut microbiota, so as to explore its potential mechanism of action.

A total of 70 RA patients were randomly divided into a control group (n=35, 2 cases dropped off, 3 cases were excluded) and an observation group (n=35, 3 cases dropped off, 2 cases were excluded), and 30 healthy participants who underwent physical examination during the same period were randomly enrolled as the normal group. The control group was given conventional drug therapy; the observation group was additionally treated with separated moxibustion at bilateral Zusanli (ST36), Shenshu (BL23) and Ashi points on the basis of the control group, once every other day, 3 times a week, for 5 consecutive weeks. The scores of disease activity score in 28 joints (DAS28), visual analogue scale (VAS) for pain, morning stiffness, gastrointestinal symptom rating scale (GSRS), self-rating anxiety scale (SAS), and self-rating depression scale (SDS) were compared between the control group and observation group before and after treatment. 16S ribosomal RNA (rRNA) gene sequencing was used to detect the composition structure and relative abundance of gut microbiota in the 3 groups before and after treatment. ELISA was adopted to measure the serum contents of lipopolysaccharide (LPS), lipopolysaccharide-binding protein (LBP), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β), 5-hydroxytryptamine (5-HT), and insulin-like growth factor-1 (IGF-1) in the control and observation groups before and after treatment.

Compared with the baseline in the same group, the scores of DAS28, VAS, GSRS, SAS, SDS, as well as serum contents of LPS, LBP, TNF-α, IL-1β and IL-6 were significantly decreased in both the control and observation groups after treatment (P<0.05, P<0.01), and the reductions in the observation group were more significant than those in the control group (P<0.05, P<0.01). In contrast, morning stiffness score was significantly decreased, and serum contents of 5-HT and IGF-1 were significantly increased in the observation group after treatment compared with baseline and those in the control group after treatment (P<0.05, P<0.01). Before treatment, compared with the normal group at the same time point, the α -diversity of gut microbiota (Chao1, Ace, Sobs, Shannon indices) and the abundances of beneficial bacteria (Bacteroidota, Faecalibacterium, Bacteroides, Bifidobacterium) in the observation and control groups were significantly lower (P<0.01), while the Firmicutes/Bacteroidota (F/B) ratio and the abundances of opportunistic pathogenic bacteria (Firmicutes, Prevotella, Proteobacteria, Actinobacteriota, Escherichia-Shigella, Klebsiella) were significantly higher (P<0.01). Microbiota clustering analysis showed significant differences between the observation/control groups and the normal group. After treatment, all the above indicators were improved in observation/control groups, and the observation group showed significantly better outcomes in increasing α-diversity, restoring beneficial bacteria abundance, and reducing F/B ratio and pathogenic bacteria abundance than the control group (P<0.01, P<0.05).

Separated moxibustion combined with conventional drugs exerts superior clinical efficacy to monotherapy with conventional drugs in relieving joint pain, improving gastrointestinal symptoms, and alleviating anxiety and depression in RA patients. Its mechanism may be associated with regulating gut microbiota diversity, optimizing microbiota structure, reducing inflammatory factor levels, and improving neurotransmitter metabolism.