Unabsorbed fructose may fuel anxiety via gut-brain inflammation

New multi-part research links unabsorbed dietary fructose to increased anxiety indicators and brain inflammation. In a healthy male cohort, breath tests showed about 60% had fructose malabsorption; those individuals had higher inflammatory proteins, more bacterial toxins in blood, and distinct gut bacteria, with anxiety scores elevated though not clinically diagnostic. In a mouse model lacking the intestinal fructose transporter, a 5% fructose diet induced anxiety- and depression-like behaviors and strong microglial inflammatory responses, alongside significant gut microbiome shifts. Limitations include male-only participants and observational human data; the findings suggest fructose malabsorption could trigger gut-driven immune signals that affect the brain, warranting trials on fructose-free diets or anti-inflammatory approaches to mood disorders.