Bioactive Metabolites from Yeasts Presumptively Qualified as Safe as Functional Agents in the Management of Type 2 Diabetes

Microbial metabolites offer a multitude of mechanisms for alleviating diabetes, particularly type 2 diabetes (T2D). However, the metabolites of yeasts recognised as safe remain under-explored and are receiving less attention in the treatment of T2D. In addition to the recognised probiotic status of certain yeasts, their genetic feature is responsible for many of the effects observed. Branched and non-branched short-chain fatty acids, bioactive peptides, carotenoids, and polysaccharides (β-glucans, mannans, and peptides derived from them) have vital properties that modulate intestinal permeability, soothe inflammation, and directly influence insulin sensitivity. Their action mechanism ranges from hepatic lipogenesis via the induction of hormone-sensitive lipase and the inhibition of α-glucosidase or DPP-IV to promoting the secretion of GLP-1 (Glucagon-Like Peptide-1) and GIP (Gastric Inhibitory Polypeptide), orchestrating immune modulation, and nourishing the gut microbiota. The richness of the yeast metabolome suggests that a concentrated fermentate could be developed to potentiate the functional effects in vitro in the treatment of T2D. The purpose of this review is to take stock of the current state of knowledge of probiotic yeast metabolites and outline their potential for the treatment of diabetes via the development of food supplements or nutraceuticals.