Table 2.

Summary of the effects of traditional Chinese medicine on the composition of the gut microbiome in T2D patients.

TCM	Year	Patients	Period	Study design	Microbes	Outcomes
Berberine	Zhang et al., 2020 (57)	409 Patients with T2D treated with either berberine alone, probiotic+berberine, probiotic alone or placebo.	12 weeks	Randomized, double-blind, placebo-controlled trial	Berberine ↓ Ruminococcus bromi	Berberine reduced HbA1c, fasting and postprandial plasma glucose, fasting plasma triglyceride, total and low-density lipoprotein cholesterol
GQD	Xu et al., 2015 (58)	187 patients with T2D treated with either GQD or placebo	12 weeks	Randomized double-blinded placebo-controlled clinical trial	GQD ↑ Faecalibacterium prausnitzii	GQD reduced the mean fasting plasma glucose and HbA1c
AMC	Tong et al., 2018 (59)	100 patients with T2D treated with either the metformin or AMC	12 weeks	Randomized, open labelled randomized study RCT	AMC ↑ Faecalibacterium spp.	AMC reduced plasma glucose and lipids

GQD, Gegen Qinlian Decoction; AMC, specifically designed herbal formula (no full name provided).