Beta-Glucans & The Intestinal Microbiome | Highlighting SCFAs

Fibers, including but not limited to inulin, cereal-derived β-glucans, resistant starch, pectin, and more, can influence host physiology through their interactions with the intestinal microbiome (3). Among these, β-glucans have attracted significant attention for their diverse biological activities potentially spanning metabolic regulation, immune modulation, and gut barrier support (1-4). Their effects stem from both their unique structural properties and their capacity to serve as fermentable substrates for beneficial gut microbes, positioning them at the intersection of nutrition and microbial ecology.

In more detail, β-glucans are non-starch polysaccharides composed of D-glucose monomers linked by β-glycosidic bonds; though, it may be noted that β-glucan structure varies by biological source. It may also be noted that a glycosidic bond is the covalent bond that connects a monosaccharide (sugar) molecule to another group. β-glucan molecules can be found within various dietary sources, including mushrooms, oats, and barley (1,3).

In shifting to prebiotics, prebiotics can be regarded as "nondigestible food ingredients that, when administered, exert a beneficial effect on host health"(2). Moreover, β-glucans have demonstrated prebiotic effects and may modulate the composition of the intestinal microbiome (1-4). In more detail, the fermentation of β-glucans by colonic microbiota yields short-chain fatty acids (SCFAs)—primarily acetate, propionate, and butyrate, and these metabolites can play essential roles in both intestinal and systemic health (3,4).

In summary, β-glucans can be regarded as structurally diverse non-starch polysaccharides that interact with the gut microbiome and reflect both their molecular configuration and biological origin. Their relationship with intestinal microbes highlights the broader role of dietary fibers in shaping metabolic and gastrointestinal processes through microbiota-mediated mechanisms.