Fecal Short Chain Fatty Acid ratios are related to both Depressive and Gastrointestinal Symptoms in Young Adults

Objective Short chain fatty acids (SCFAs) are produced by the gut microbiota and may reflect health. Gut symptoms are common in individuals with depressive disorders and recent data indicates relationships between gut microbiota and psychiatric health. We aimed to investigate potential associations between SCFAs and self-reported depressive and gut symptoms in young adults. Method Fecal samples from 164 individuals, of which 125 were patients with psychiatric disorders, were analyzed for the short chain fatty acids (SCFA) acetate, butyrate and propionate by nuclear magnetic resonance (NMR) spectroscopy. We then compared SCFA ratios to dimensional measures of self-reported depressive and gut symptoms. Results Depressive symptoms showed a positive association to acetate levels and negative associations to both butyrate and propionate levels in relation to total SCFA levels. Furthermore, symptoms of diarrhea and bloating showed positive associations to acetate and negative associations to propionate in relation to total SCFA levels. Cluster analysis revealed a heterogeneous pattern where shifts in SCFA ratios were seen for individuals with either elevated levels of depressive symptoms, elevated levels of gut symptoms or both. Conclusion Shifts in SCFAs may have relevance for both depressive symptoms and gut symptoms in young adults.