The protective effect of probiotic/prebiotic consumption against fatigue in the general population is modulated by BMI: an analysis of mediating and moderating effects based on NHANES.

Objectives: Fatigue is closely linked to gut microbiota dysbiosis, making probiotics and prebiotics promising candidates for interventions related to fatigue. This study explores the relationship between probiotic/prebiotic consumption and fatigue in the general population, focusing on potential moderating and mediating factors, as most prior research has centered on clinical populations with secondary fatigue.

Methods: This study is a cross-sectional analysis using data from the National Health and Nutrition Examination Survey (NHANES) from 2009 to 2018, and it included 3,791 US residents without underlying health conditions. Fatigue was assessed using the Patient Health Questionnaire-9 (PHQ-9), and probiotic/prebiotic consumption was evaluated via a 30-day dietary supplement questionnaire. Statistical analyses included weighted logistic regression to examine associations, and mediation/moderation models to assess the roles of BMI, sleep duration, depression scores, and exercise hours.

Results: A total of 3,791 participants were included in the study, with 46.6% self-reporting fatigue. Probiotic/prebiotic consumers had a significantly lower fatigue risk (OR = 0.738, 95% CI 0.735-0.741, p < 0.001). Among the mediating and moderating factors analyzed, only BMI was found to weakly but significantly moderate the association between probiotic/prebiotic consumption and fatigue, with higher BMI strengthening the association of probiotics and/or prebiotics intake with reduced fatigue odds (p = 0.039).

Conclusions: These findings indicate that the consumption of probiotics/prebiotics is correlated with a decreased risk of fatigue in the general population, and this association is further reinforced in individuals with a higher BMI.