The Benefits and Risks of Probiotic, Prebiotic and Symbiotic interventions in the Care of patients with Diabetes Mellitus

Introduction: Probiotics, prebiotics and synbiotics are thought to affect the pathophysiology of diabetes mellitus including gut dysbiosis, intestinal barrier permeability and modulator of gut-brain axis and oxidative stress. This systematic review examined if their interventions resulted in improved clinical outcomes and were safe to administer. Methods: An electronic search was conducted in August 2020 of CINAHL, EMBASE, MEDLINE, and PUBMED databases as well as using Google Scholar using keyword searches combined in a formal search strategy. The studies extracted were then filtered through an inclusion and exclusion criteria and assessed for risk of bias. Results: Twenty-four studies met the inclusion criteria, with 20 studies involving participants with type 2 diabetes, 1 study a mixed cohort of type 1 and 2, and 3 involving prediabetes participants. Meta-analysis was not appropriate due to the heterogeneity in populations, methods and presented results. One trial was limited due to unclear risk of bias and was excluded. Four key themes were identified across the studies: improvements to glycaemic control; improvements in oxidative stress, inflammation and gut permeability; lipid profile, anthropometric parameters and blood pressure; and adverse events and tolerability. Conclusions: Probiotics improved glycaemic control, oxidative stress, inflammation and gut permeability and lipid profile in T2DM participants. There was no evidence of improvements to T1DM due to lack of studies and insufficient studies on pre-diabetes. Synbiotics are also promising but prebiotics have insufficient evidence.