Probiotic Supplementation and its Potential Benefits in Type 2 Diabetes: A Meta-analysis

This meta-analysis aims to evaluate the efficacy and safety of probiotic supplementation as an adjunct to standard therapy in patients with type 2 diabetes (T2D), with a focus on its effects on plasma glucose, HbA1c, and insulin levels.

Specific keywords such as "Type 2 Diabetes", "Probiotics", and "Blood Sugar" were employed to identify relevant clinical and randomized controlled trials. A comprehensive search of PubMed, Scopus, and Web of Science, conducted between September 2010 and October 2024, retrieved 48 studies, of which only 9 met the predefined inclusion criteria. Studies were excluded if they did not involve patients with T2D, failed to specify the probiotic strains used, lacked a placebo-controlled arm, were not written in English, were not freely accessible, or did not report outcomes of interest.

Three separate meta-analyses were conducted to evaluate the primary and secondary outcomes of interest: plasma glucose, HbA1c, and insulin concentrations. Each analysis revealed statistically significant effects. The magnitude of the effect of probiotic supplementation in patients with T2D is expressed by a promising reduction in fasting plasma glucose levels (MD = -17.68; 95% CI: -21.72 to -13.63; p < 0.0001; I² = 0%; p for heterogeneity = 0.76); HbA1c (MD = -0.42; 95% CI: -0.67 to -0.17; p = 0.0009; I² = 0.5%; p for heterogeneity = 0.40) and insulin (MD = -2.26; 95% CI: -2.87 to -1.65; p < 0.0001; I² = 0%; p for heterogeneity = 0.67).

This meta-analysis included a total of 649 patients with T2D, who showed a reduction in levels of some clinical indicators at the end of the intervention period. These findings provide evidence supporting the use of probiotic supplementation as an adjunct to standard therapy for the management of this condition.