Glucose Parameters, Inflammation Markers, and Gut Microbiota Changes of Gut Microbiome-Targeted Therapies in Type 2 Diabetes Mellitus: a Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Purpose: This meta-analysis aims to summarize the effects of gut microbiome-targeted therapies (MTTs) on glucometabolic, inflammatory factors and gut microbiota in patients with type 2 diabetes mellitus (T2DM).

Methods: 4 databases were searched for randomized controlled trials (RCTs) that included subjects with T2DM who received MTTs. All results were presented as standardized mean difference (SMD)/MD and 95% confidence intervals (95% CIs). In addition, subgroup analyses were performed according to region, type of MTTs, number of probiotic strains, probiotics dose, prebiotics dose, duration of MTTs, mean age, and baseline body mass index.

Results: Fifty-four RCTs were included, encompassing 60 groups and 3,390 subjects. Overall, MTTs intervention decreased fasting plasma glucose (MD = -7.97 mg/dL, 95%CI =-10.82, -5.12; p ＜0.00001), 2h-postprandial blood glucose (MD = -43.30 mg/dL, 95%CI = -75.83, -10.77; p = 0.009), fasting insulin (MD = -1.73uU/ml, 95%CI = -2.63, -0.84; p = 0.0001), HbA1c (MD = -0.28%, 95%CI = -0.39, -0.17; p ＜0.00001), and Homeostatic Model Assessment of Insulin Resistance (MD =-0.53, 95%CI = -0.85, -0.20; P=0.0002). Furthermore, MTTs supplementation reduced high-sensitivity C-reactive protein, tumor necrosis factor alpha, and lipopolysaccharides. Meanwhile, the levels of Interleukin-10 were increased. Moreover, the abundance of Actinobacteria, Lactobacillus, and Lactobacillus casei subgroup increased.

Conclusion: MTTs modestly improved glucometabolic parameters, reduced pro-inflammatory cytokines, and enriched beneficial microbes (e.g., Actinobacteria, Lactobacillus) in T2DM. However, heterogeneity and limited long-term data highlight the need for large-scale RCTs.