Sticking to starch

Not all starches in the human diet are created equal: “resistant starches” are consolidated aggregates of the α-glucan polysaccharides amylose and amylopectin, which escape digestion by salivary and pancreatic amylases. Upon reaching the large intestine, resistant starches become fodder for members of the human gut microbiota, impacting the metabolism of both the symbionts and the host. In a recent study, Koropatkin et al. provided new molecular insight into how a keystone bacterium in the human gut microbiota adheres to resistant starches as a prelude to their breakdown and fermentation.