Effects of probiotics on lipid profile in patients with type-۲ diabetes mellitus: A narrative review

Background and Aim : Probiotic supplementation seems to be an effective approach in treatment and management of type-۲ diabetes mellitus (T۲DM). Dyslipidemia is a major concern in T۲DM, affecting the cardiometabolic status in these patients. A growing number of studies suggest that modification of the gut microbiome through probiotics may improve the lipid profile in T۲DM. The effectiveness of probiotic interventions and the underlying mechanisms are still unclear. Therefore, in this review, we aimed to evaluate the effects of probiotics on lipid profile among patients with T۲DM.Methods : A search was conducted on PubMed, Cochrane Library, and Web of Science databases from ۲۰۱۱ to ۲۰۲۱ using the terms "probiotics", "lipid profile", "type-۲ diabetes", and " gastrointestinal microbiome". Results : Probiotics supplementation significantly decreased total cholesterol, LDL-c, VLDL, LDL/HDL ratio, and triglycerides and increased HDL-c in patients with T۲DM, although there is still some recent evidence showing no effects of probiotics on the lipid profile of these patients. Furthermore, the most common probiotics strains were lactobacilli acidophilus and Bifidobacterium. These probiotics also significantly reduced the levels of systemic endotoxin through modifying the gut microbiome composition and strengthening the intestinal epithelial barrier function, which is regarded as a potential underlying mechanism of probiotics effect on lipid profile. Longer trials and multi-strain probiotics were more efficient and modified a higher number of lipid and cardiometabolic factors. Conclusion : Finally, our findings suggest that probiotic supplementation is a potential candidate for adjuvant therapy in managing dyslipidemia of patients with T۲DM. Lack of microbial and gene expression data assessments, different probiotic doses, small sample sizes, and combination with drug therapy were among the most important challenges leading to discrepancies between different studies. Therefore, further human studies are required to overcome these challenges, confirm these findings, and provide optimized protocols to manage lipid profile in T۲DM patients.