Probiotic food consumption is associated with lower severity and prevalence of depression: A nationwide cross-sectional study

•Probiotics have the potential to improve brain function in humans through the gut–brain axis.•Probiotic food intake from fermented dairy products and vegetables was inversely associated with depressive symptoms in the general population.•Probiotic food showed decisive effects on lowering the risk for self-reported diagnosis of clinical depression. It has been suggested that probiotics have beneficial effects on a variety of health problems including immunologic diseases and metabolic disorders, however, the effects on brain function are yet to be fully studied. The aim of this study was to evaluate the association between probiotic food consumption and depression status through a cross-sectional analysis of a nationwide, large population-based data. The study population included 26 118 individuals 19 to 64 y of age who participated in the Korean National Health and Nutrition Examination Survey (KNHANES, 2012–2016). A food frequency questionnaire was used to assess probiotic food consumption. Depression status was determined by two different methods including a Patient Health Questionnaire (PHQ-9) and self-reported clinical diagnosis. Compared with the lowest tertile of probiotic food consumption, the highest tertile had significantly lower odds in PHQ-9 depression severity (odds ratio [OR], 0.48; 95% confidence interval [CI], 0.28–0.81; P = 0.0065) and self-reported clinical depression (OR, 0.59; 95% CI, 0.35–0.96; P = 0.0129). Although there was no significant association between probiotic food consumption and clinical depression in women (OR, 0.85; 95% CI, 0.47–1.54; P = 0.3081), men showed a significantly lower prevalence of clinical depression (OR, 0.24; 95% CI, 0.06–0.92; P = 0.0256) in the highest tertile. These results suggest that probiotic food consumption might have beneficial effects on depression, particularly in men. Further studies are required to identify the mechanistic relations between probiotics and depression.