Comparative study on static and dynamic digest characteristics of oat β-Glucan and β-Gluco-Oligosaccharides

Both oat β-glucans (OGs) and their hydrolyzed counterparts, oat β-gluco-oligosaccharides (OGOs), are dietary fibers indigestible by humans. They serve as substrates for the colonic intestinal flora, exhibiting potential prebiotic properties. This study, through in vitro digestion simulation, found that OGs and OGOs are not degraded and can safely pass through the upper digestive tract to reach the colon. Anaerobic fermentation was conducted using fecal microbiota in an anaerobic tube and gastrointestinal reactor to investigate their impact on the structure and metabolism of intestinal flora. The research revealed that OGs and OGOs distinctly influence the fermentation characteristics and the intestinal flora's metabolic profile. Specifically, in static fermentation, OGs notably increased butyric acid production in both healthy individuals and those with type 2 diabetes, whereas OGOs more effectively enhanced acetic and propionic acid production in type 2 diabetics. Moreover, OGs and OGOs variably affected the composition of intestinal flora. In dynamic fermentation, there was a marked improvement in the production of short-chain fatty acids (SCFAs), with OGs significantly boosting butyric acid and OGOs enhancing acetic acid production. This study lays a theoretical foundation for employing specific dietary fibers to selectively improve intestinal flora and supports the development of functional ingredients that modulate intestinal microorganisms, utilizing in vitro research methodologies.