Effects of Moxibustion at ST36 on Body Temperature, Gut Microbiota, and Gut Microbiota in Healthy Females: A Pilot Study Exploring the Gut-Brain Axis

Background: In traditional East Asian medicine, moxibustion is widely used for thermal therapy and gastrointestinal regulation. While clinical evidence supports its efficacy, the underlying scientific mechanisms remain unclear. This study investigated the physiological, psychological, and microbiological impacts of pedal moxibustion. Methods: Ten healthy, moxibustion-naive female volunteers participated in a two-week winter study. Participants applied pedestal-type moxibustion cones to the bilateral Zusanli (ST36) acupoint daily. Physiological changes were evaluated via core (axillary) and cutaneous temperatures (forehead, hand, and foot). Psychological anxiety was assessed using the State-Trait Anxiety Inventory (STAI). Fecal samples were collected before and after the intervention for 16S rRNA gene-based gut microbiota analysis, alongside qualitative feedback on somatic conditions. Results: Due to pronounced individual variations, no statistically significant group-level differences were observed in STAI scores or body temperatures, although state anxiety showed a downward trend and axillary temperature tended to increase. In contrast, microbiota analysis revealed distinct shifts in microbial profiles across all participants, including an increased relative abundance of the beneficial genus Faecalibacterium in half of the subjects. Furthermore, qualitative feedback indicated notable improvements in somatic symptoms: six participants reported increased bowel movement frequency, six noted altered stool consistency, three experienced longer sleep duration, and two reported reduced menstrual pain. Conclusion: A two-week pedal moxibustion intervention induced distinct, individualized shifts in gut microbiota profiles alongside qualitative improvements in bowel habits, sleep, and menstrual discomfort. These findings suggest that traditional moxibustion may influence host homeostasis through the gut-brain axis, potentially driven by mild thermogenesis. Large-scale, randomized controlled trials are required to validate these preliminary insights.