Navigation
Fructose malabsorption induces dysbiosis and increases anxiety in male human and animal models
Understanding the consequences of excessive fructose consumption is becoming increasingly important in public health discussions. While many people struggle to absorb fructose adequately, this malabsorption can lead to chronic conditions that may have significant health implications. Specifically, this study investigates how fructose malabsorption might influence the gut microbiota and, consequently, relate to mood disorders.
The research was conducted on a cohort of healthy male volunteers, who underwent breath hydrogen testing to assess fructose malabsorption. Alongside this, levels of plasma lipopolysaccharide (LPS), IL8, and TNFα were measured, and anxiety traits were evaluated using the State-Trait Anxiety Inventory (STAI). Additionally, 16S rRNA sequencing was employed to analyze gut microbiota composition, while dietary fructose intake was meticulously recorded.
In parallel, a preclinical study utilized GLUT5 knockout (GLUT5_KO) mice, which lack the ability to transport fructose in their intestines. These mice were placed on a diet containing 5% fructose for four weeks. Their behavior was assessed for anxiety- and depressive-like traits, alongside evaluations of gut microbiota and gene expression related to microglia.
The results revealed that approximately 60% of the volunteers exhibited fructose malabsorption, a condition characterized by elevated plasma levels of LPS, IL8, and TNFα. Participants also showed increased anxiety traits, which correlated with distinct shifts in gut microbiota, partially linked to their fructose consumption patterns. Throughout the study, the average daily intake of fructose was found to be 30 g, with notable variability stemming from different dietary sources.
In the GLUT5_KO mouse model, the introduction of a 5% fructose diet resulted in heightened anxiety- and depressive-like behaviors. This was accompanied by significant alterations in gut microbiota composition and changes in microglia-associated gene expression. These findings underscore the intricate relationship between dietary fructose, gut microbiota, and inflammatory responses, suggesting that chronic fructose malabsorption could contribute to mood disorders through mechanisms involving gut dysbiosis and neuroinflammation. Such insights underscore the need for further exploration of dietary interventions as potential strategies to improve mental health outcomes. [NPID: Fructose, anxiety, depression, dysbiosis, neuroinflammation].
Year: 2026
