Beneficial effects of probiotic and synbiotic supplementation on some cardiovascular risk factors among individuals with prediabetes and type 2 diabetes mellitus: A grade-assessed systematic review, meta-analysis, and meta-regression of randomized clinical trials

Previous studies suggested that probiotics/synbiotics administration exerts some beneficial effects on cardiometabolic risk factors. However, the results from trials have been inconsistent. This study aimed to identify the impact of probiotic and synbiotic supplements on cardiovascular health factors in patients with type 2 diabetes mellitus (T2DM) and prediabetes We searched PubMed/MEDLINE, Web of Science, and Scopus up to February 2022 to identify eligible RCTs. Estimating 95 % confidence (CI) and the weighted mean difference (WMD) for weight, body mass index (BMI), waist circumferences (WC), triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), systolic blood pressure (SBP), and diastolic blood pressure (DBP), the random-effects model was used. In the current meta-analysis, 54 RCTs were included. With the probiotic/synbiotics intervention, several parameters changed significantly, including weight (WMD: -0.38, 95 % CI: -0.63 to -0.12 Kg), TG (WMD:-19.08, 95 % CI: -27.65 to-10.51 mg/ dl), TC (WMD: -10.46, 95 % CI: -15.19 to-5.72 mg/dl), LDL-C (WMD: -4.87, 95 % CI: -7.65 to-2.09 mg/dl), HDL-C (WMD: -2.70, 95 % CI: 1.33-4.07 mg/dl), SBP (WMD: -3.81, 95 % CI: -6.24 to-1.38 mmHg), and DBP (WMD: -2.01, 95 % CI: -3.12 to-0.91 mmHg). In the subgroup analysis, probiotics/synbiotics supplementation resulted in a greater change in lipid profile components in T2DM patients. Weight and BMI reduced only after synbiotic supplementation. We found that the administration of probiotics and synbiotics had beneficial effects on lipid profiles, anthropometric indices, and blood pressure in individuals with T2DM.