The effects of SCFAs on glycemic control in humans: a systematic review and meta-analysis

Abstract

Background Non-communicable disease development is related to impairments in glycaemic and insulinemic response, which can be modulated by fiber intake. Fiber's beneficial effect upon metabolic health can be partially attributed to the production of short-chain fatty acids (SCFAs) via microbial fermentation of fiber in the gastrointestinal tract. Objective We aimed to determine the effect of the SCFAs, acetate, propionate, and butyrate on glycemic control in humans. Methods CENTRAL, Embase, PubMed, Scopus and Web of Science databases were searched from inception to the 07/12/2021. Papers were included if they reported a randomized, controlled trial measuring glucose and/or insulin compared to a placebo in adults. Studies were categorized by the type of SCFA and intervention duration. Random effects meta-analyses were performed for glucose and insulin for those subject categories with ≥3 studies, or a narrative review was performed. Results We identified 43 eligible papers, with 46 studies within those records (n = 913), 44 studies were included in the meta-analysis. Vinegar intake decreased acute glucose response, standard mean difference (SMD) and (95% CI) –0.53 (–0.92, –0.14) (n = 67) in individuals with impaired glucose tolerance or type 2 diabetes and in healthy (SMD) –0.27 (–0.54, 0.00) (n = 186). The meta-analyses for acute acetate as well as acute and chronic propionate studies had no significant effect. Conclusions Vinegar decreased glucose response acutely in healthy and non-healthy. Acetate, propionate, butyrate, and mixed SCFAs had no effect on blood glucose and insulin in humans. Significant heterogeneity, risk of bias, and publication bias were identified in several study categories, including acute vinegar glucose response. As evidence was very uncertain, caution is urged when interpreting these results. Further high-quality research is required to determine the effect of SCFAs on glycemic control.

Beneficial effect of the short-chain fatty acid propionate on vascular calcification through intestinal microbiota remodelling

“…In contrast, some studies have shown that propionic acid improves islet β cell function, regulates insulin secretion [33], reduces digestibility by inhibiting amylase activity [34] and delays gastric emptying and glucose absorption from the diet [35,36], all of which maintain blood glucose balance. Furthermore, a meta-analysis showed that acute or chronic propionate interventions had no significant effect on fasting glycaemia or fasting insulin, postprandial glucose or postprandial insulin levels [37]. In addition, propionate also has a crucial effect on body weight.…”

Integrated Bacteria-Fungi Diversity Analysis Reveals the Gut Microbial Changes in Buffalo With Mastitis

“…Notably, Ruminococcus is also a potential producer of SCFAs ( 53 ). Numerous pieces of evidence indicated that SCFAs play a fundamental role in gut microbial homeostasis and host metabolism ( 54 , 55 ). Furthermore, SCFAs were also involved in the regulation of intestinal permeability, immunologic function, and cell proliferation ( 56 , 57 ).…”

The role of short-chain fatty acids on insulin sensitivity: a systematic review and meta-analysis

“…To date, there have been no reports of any adverse side effects of SCFAs on human health. A very recent systematic review and meta-analysis assessed the effects of acute and chronic administration of SCFAs and vinegar on glycemic control 71 . Interestingly, they did not observe a significant effect of acute acetate and propionate as well as chronic propionate treatment on glucose and insulin concentrations.…”