A gut feeling: how your gut and brain changes your risk and time preferences

Abstract

Recent research has shown that the gut microbiota can influence the interaction between the central and the enteric nervous systems via the gut-brain axis (GBA). Animal models and human neuroimaging studies have revealed that changes in the gut microbiota affect neural activity in brain regions linked to basic emotional and cognitive processes. Whether the gut microbiota also affect human decision-making and, more specifically, risk and time preferences, however, remains largely unknown. Here, we examine the role of the gut-brain axis in decision-making in the face of risk and intertemporal choices. In a placebo-controlled double-blinded design, with two sessions separated by 28 days, during which participants received daily doses of probiotics (or a placebo), we investigate whether the prolonged and controlled intake of probiotics affects risk-taking behavior and intertemporal choices using incentivised economic tasks. We found a significant decrease in risk-taking behavior and an increase in future-oriented choices in the probiotics group as compared to the placebo group. These findings provided the first direct experimental evidence suggesting a potential functional role on the part of the microbiota-gut-brain axis in decision-making, creating a path for potential clinical applications and allowing for a better understanding of the underlying neural mechanisms of risk-taking behavior and intertemporal choices.