Acetate, a molecule produced from fermentation of dietary fiber in the colon, leads to increase anorectic signaling in the hypothalamusCERAN AND PEREZResearchers have long realized that consuming a fiber-rich diet can suppress appetite and reduce food intake in mice and humans alike, a phenomenon previously attributed to the release of gut hormones. Writing in Nature Communications today (April 29), Imperial College London’s Gary Frost and his colleagues showed that small amounts of the short-chain fatty acid acetate, released as a result of the fermentation of dietary fiber in the mouse gut , accumulates within certain neurons in the animal’s hypothalamus, a part of the brain that helps regulate hunger.
For the first time, the researchers have traced “a link between fermentation in the lower part of the gut—the colon—with activity in the brain,” said Patrice Cani, who co-leads the Metabolism and Nutrition Research Group at Université Catholique de Louvain in Belgium, and was not involved in the work. “The originality was to show that acetate can in fact circulate and reach the brain . . . and affect appetite.”
Frost’s team was among the many that had been focusing on gut hormones, such as peptide YY and glucagon-like peptide-1, finding that these could directly affect neurons within the hunger-regulating hypothalamus. But using manganese-enhanced MRI (MEMRI) the researchers found “unusual brain signaling” in appetite-suppressed mice fed a fiber-rich diet, Frost said. “You’d usually expect that ...
