A decrease in consumption of major dietary components (e.g., fibre) has led to changes in the microbial community composition and an increase in the incidence of metabolic and immune-related diseases such as colitis (Desai et al., 2016, Koh et al., 2016). Resistant starch (RS) is a type of fibre that is resistant to digestion in the small intestine. Instead, it is fermented by the microbiota in the lower gastrointestinal tract, and thus represents a useful tool to modulate the gut microbiota in experimental settings. Colonic fermentation leads to multiple effects on the host including production of the short-chain fatty acids (SCFAs) acetate, propionate, and butyrate (Tan et al., 2017). These metabolites are key mediators of the gut microbiota on host immunity. SCFAs exert their effects not only in the gut but also in distant organs by dampening immune responses that are uncontrolled in patients on a low-fibre Western diet (Thorburn et al., 2014). High-fibre diets have been shown to ameliorate metabolic and allergic diseases mainly through their microbiota-dependent fermentation to SCFAs that promote tissue barrier integrity, mucus production, immunoglobulin A (IgA) secretion, and regulatory T cell (Treg) differentiation, thereby supporting an anti-inflammatory environment (Mariño et al., 2017, Thorburn et al., 2014). https://www.sciencedirect.com/science/article/pii/S1931312818305912?via%3Dihub
WHAT IS RESISTANT STARCH
Resistant starch has characteristics of both insoluble and soluble fibre. Much like insoluble fibre, it's “resistant” to digestion and passes into the colon undigested, but once there, it behaves like soluble fibre and is fermented (digested) by the good bacteria that live there.