Association of eating habits and Firmicutes/Bacteroidetes ratio among Japanese female university students: A cross-sectional study

Background & Aims: University students are prone to changes in their health status and lifestyle due to changes in their living environment and associated stress and anxiety. These changes may affect them in later life. This study utilized a cross-sectional study among Japanese female university students to examine dietary factors affecting their fecal microbiota. Methods: Sixty-eight healthy female university students were evaluated using an eating behavior assessment and diet history questionnaire. The 12-component Japanese diet index (JDI-12) was then calculated. A quantitative real-time PCR method was used to analyze the predominant bacterial species in the gut, and the Firmicutes/Bacteroidetes ratio (F/B ratio) at the phylum level was calculated. The partial correlation between the fecal microbiota and eating behavior abnormality score was assessed, and dietary habits associated with the F/B ratio were analyzed. Results: A significant correlation was identified between F/B ratios and the eating behavior abnormality score (r = 0.26, FDR = 0.064). Additionally, multiple regression analysis identified a negative correlation trend between the F/B ratio and JDI-12 score (beta = -0.22; p = 0.091), and exploratory analysis found a negative association between the F/B ratio and consumption of beef and pork, one of the less beneficial JDI-12 components (beta = -0.33, FDR = 0.120). Conclusion: In healthy female university students, there was a positive correlation between eating behavior abnormality and the F/B ratio, indicating that adherence to the Japanese diet pattern may be associated with a lower F/B ratio.