"High dietary live microbe intake is correlated with reduced risk of depressive symptoms: A cross-sectional study of NHANES 2007-2016".

Background: Recent research indicated that levels of dietary live microorganisms were inconsistently associated with the prevalence of depressive symptoms. This study aimed to investigate the correlation between consumption of live microorganisms and symptoms of depression.

Methods: Data on 21,653 study participants were obtained from the National Health and Nutrition Examination Survey (NHANES). Dietary information was assessed using a self-report questionnaire. Depressive status was assessed using the Patient Health Questionnaire (PHQ-9). Generalized linear model, restricted cubic spline (RCS), and subgroup analyses were performed in this study.

Results: After full adjustment for confounders, participants in the moderate-dietary microbe intake group had a lower prevalence of depressive symptoms than those in the lowest intake group [odds ratio (OR): 0.813, 95 % confidence interval (CI): 0.678-0.974, P = 0.026, and pseudo R = 0.12]. Participants in the highest-dietary microbe intake group had a lower prevalence of depressive symptoms than those in the lowest intake group (OR: 0.714, 95 % CI: 0.586-0.870, P = 0.001, and pseudo R = 0.12). An L-shaped dose-response relationship was observed in the RCS (the P value for nonlinear relationship = 0.007). In subgroup analyses, participants with male identity, normal weight, and high physical activity (PA) level showed a substantial correlation between dietary live microbe consumption and depressive symptoms (all P values for interaction <0.050).

Limitations: This study was limited by its cross-sectional study design, and self-reported dietary live microbe consumption and depressive symptoms.

Conclusions: A high dietary live microbe intake was nonlinearly correlated with a lower prevalence of depressive symptoms.