The combination of gut microbiota-depleted treatment and fecal microbiota transplantation is an important strategy to verify the efficacy of Traditional Chinese Medicine though modulation of gut dysbiosis

To the Editors:

We read with great interest the study recently published by Sun et al¹ entitled “Electroacupuncture at Tianshu (ST25) and Zusanli (ST36) alleviates stress-induced irritable bowel syndrome in mice by modulating gut microbiota and corticotropin-releasing factor” in which the microbial details of electroacupuncture (EA)-induced protection in irritable bowel syndrome (IBS) were investigated. They showed that EA alleviated IBS mechanisms possibly involving the modulation of gut dysbiosis. The founding and its implications were interesting, however, the results presented in this paper were only descriptive. They showed that EA improved IBS, and alleviated the gut dysbiosis in mice, but the relationship between the gut microbiota and therapeutic effects of EA on IBS were still unclear. Did gut microbiota play a decisive leading role or a partial synergistic role in the process of EA relieving IBS? If the role of gut microbiota is not further defined, the conclusion would be unconvincing.

The combination of gut microbiota-depleted treatment and fecal microbiota transplantation (FMT) is the key to solve this scientific problem. It should be noted that germ-free mice are generally considered to be a model system to study effect of gut microbiota on host gastrointestinal physiology.² However, because of the high price and difficulty in breeding, scientists turn to utilize broad-spectrum antibiotic treatment models as a rapid, inexpensive, and accessible alternative. If the protective effects of interventions including traditional Chinese medicine are abolished or reduced due to the depletion of gut microbiota, it indicates that the interventions improve the diseases in a gut microbiota-dependent manner. Secondly, as an emergent technology, FMT is also another major and important strategy to determine the role of gut microbiota. As long as the fact that the protective effects of interventions are transferable from donors to the corresponding recipients by FMT is observed, we could conclude that altered microbiota plays a key role in modulating the effects of interventions on the certain diseases.³

Specifically, mice should be exposed to WAS for 10 days to induce the IBS model followed by one week treatment of EA in the presence or absence of antibiotics, if antibiotics treatment diminishes the beneficial effects of EA on IBS mice, it indicates that EA exerted therapeutic effect in a gut microbiota-dependent manner. For microbiota transplantation, the gut microbiota (mixture of stool pellets, cecal and colonic contents) would collected from water avoidance stress (WAS) group and WAS + EA mice and orally gavaged to the corresponding recipients pretreated with a 10-day WAS treatment, If this phenomenon that the microbiota from EA-treated donors recapitulated the protective effects of EA treatment on IBS mice occurs, the microbiota plays a functional role during IBS management.

Overall, targeted regulation of gut microbiota is the main way for Traditional Chinese Medicine to exert its efficacy. However, how to explain and verify this mechanism requires scientific methods, and the combination of gut microbiota-depleted treatment and fecal microbiota transplantation is the promised strategy.