When sweetness overflows: fructose influences microbial and metabolic dysregulation

Over the past decades, global consumption of industrially processed fructose has surged, increasingly separating this sugar from its natural, fiber-rich context. Fructose provides a striking example that not all calories are metabolically equivalent, regardless of their source. Fructose is particularly detrimental to intestinal and hepatic homeostasis, with mounting evidence implicating the gut microbiota as key contributors. Under contemporary dietary patterns, fructose increasingly reaches intestinal regions-and their resident microbial communities-that would normally be spared in healthier nutritional contexts. Here, we review recent advances in understanding gut-liver fructose metabolism and the role of the gut microbiota in linking excess fructose to host dysmetabolism.