Relationship Between Dietary Habits and Stress Responses Exerted by Different Gut Microbiota

Background/Objectives: A number of studies have reported on the improvement in physical and psychological diseases through diet; however, the findings for these ameliorative effects have differed. Such differences may be due to the varying metabolism of the nutrient content in food among subjects. It has been reported that differences in the enterotypes of gut microbiota are associated with metabolic differences, and enterotypes vary between countries and regions. This study investigated whether differences in gut microbiota affect the relationship between dietary habits and stress responses. Methods: We administered a questionnaire to 810 subjects who participated in the "Sukoyaka Health Survey" regarding their dietary habits and stress reactions. We also performed an analysis of the gut microbiota from fecal samples. Results: The gut microbiota was grouped into four clusters based on the abundance of genus strains. The relationship between dietary habits and stress responses revealed two patterns of eating: one where more frequent intakes were associated with a lower stress response, and another with a higher stress response. We investigated the relationship between dietary habits and stress responses for each gut microbiota cluster. The results showed that the relationship between dietary habits and stress responses differed for each cluster. Conclusions: Our analysis showed that dietary habits affect stress responses, but the relationship varies depending on the gut microbiota. This finding suggests that one of the factors for the difference in the ameliorative efficacy of physical and psychological diseases through diet is the difference in the abundance ratio of the gut microbiota (enterotype).