2.1. Study design
The aim of this study was to evaluate the efficacy of SAAT on the abundance and biological structure of gut microbiota in healthy Asian adults. This is a randomized controlled trial that participants will be randomly divided into 2 groups (A receiving the SAAT with herbal compound and B receiving placebo). The protocol was approved by the Institutional Review Board of XinDu Hospital of Traditional Chinese Medicine and Chengdu Hanhe Traditional Chinese Medicine Hospital for Preventive Treatment (Approval No. 201801). All participants provided verbal and written consent, and this study conformed to the standards set by the latest revision of the Declaration of Helsinki. The study adheres to the CONSORT guidelines for reporting randomized trials. After participants were enrolled in the study, they were assigned either to study group A or group B on the basis of random numbers generated by an independent investigator. The acupuncturist would give the participant the corresponding intervention according to the random number. All acupuncturists in the study have Chinese medicine practitioner licenses with at least 5 years of clinical experience. The subjects received 3 treatment sessions per year on the hottest days in summer (“Sanfu” Days), according to the lunar calendar, for 24 consecutive months, which was followed by a follow-up period of 6 months. After enrollment, no additional drugs or interventions were allowed during the treatment period. The obligatory acupoints included BL13 (Feishu), BL17 (Geshu), BL20 (Pishu), and BL23 (Shenshu). Fecal samples were collected twice before and after the treatment in both groups and then frozen at −80°C within half an hour after sampling. Specifically, the first sample was collected in the morning before administering the first SAAT or placebo and the second sample was collected in the morning 6 months after the end of treatments. The specimens underwent DNA extraction and 16S rDNA sequencing, which are described below.