Understanding the Role of the Gut Microbiome in Diabetes and Therapeutics Targeting Leaky Gut: A Systematic Review

Abstract

The gut microbiota has been studied and continues to be a developing area in the pathognomic development of metabolic diseases like diabetes. Treatment with diet changes, the addition of supplements like prebiotics/probiotics, and the impact of fecal microbial transplantation can be correlated to targeting changes in dysbiosis. Understanding the impacts of various anti-hyperglycemic agents such as metformin and the implications of post-bariatric surgery on the gut microbiota diversity has emerged. These areas of study are crucial to understanding the pathognomic aspects of diabetes disease progression at the microbial level of metabolic and inflammatory mechanisms, which may give more insight into focusing on the role of diet prebiotic/probiotic supplements as potential forms of prospective management in diabetes and the development of more agents that target gut microbiota, which harbors low-grade inflammation. Intestinal dysbiosis was consistently observed in the mechanism of gut microbial change in diabetic individuals, contributing to reduced insulin sensitivity and poor glycemic control. This systematic review was carried out using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) 2020 checklist. We performed a literature search using the PubMed, Google Scholar and Science Direct databases in accordance with the eligibility criteria and ultimately selected 14 articles for final analysis. The Scale for the Assessment of Narrative Review Articles (SANRA) and the PRISMA 2020 checklist were used to assess the quality of selected articles for cross-sectional studies, traditional literature reviews, and systematic reviews, respectively. We collected papers from 2012 to 2022 for this review. We gathered articles from databases, such as this study, which show there is a strong connection between microbiota and diabetes that appears to exist. The objective is to assess and identify any dietary and therapeutic agents that may alter the microbiota and potentially target and modulate insulin sensitivity. This review article will discuss the pathophysiological effects of gut microbiota in diabetes management and the impact of various gut biodiversity therapeutics that can aid in reversing insulin sensitivity.

Keywords: diabetes; glucose metabolism; gut microbiome; insulin resistance; microbial transplantation; prebiotics; probiotics; type 2 diabetes.

Figure 1. PRISMA flow chart of this systematic review.

PRISMA: Preferred reporting items for systematic reviews and meta-analysis

Figure 2. A descriptive figure of a healthy gut model (green model) surrounded by various metabolic mechanisms vs. pathological mechanisms (red model) associated with gut integrity in dysbiosis (leaky gut) noted in diabetic individuals alters molecular mechanisms and interactions with host factors.

SCFA: Short chain fatty acids, LPS: Lipopolysaccharides This figure is the author’s own creation.

Figure 3. Plant-based diets (which are fiber-rich) vs. Animal-based diets (which have more fat and protein-rich components) have inverse relations in terms of inflammatory cytokine activation, LPS activation, SCFA activation, and beneficial and opportunistic bacteria composition, which is shown in detail.

SCFA: Short-chain fatty acids, LPS: Lipopolysaccharides This figure is the author’s own creation.