Who Benefits from Fermented Food Consumption? A Comparative Analysis between Psychiatrically Ill and Psychiatrically Healthy Medical Students

Abstract

Probiotic therapies and fermented food diets hold promise for improving mental health. Although in this regard psychiatric patients appear to benefit more than healthy individuals, no research has been performed to directly evaluate this hypothesis. The present study examined a cohort of medical students facing a stressful event, and some of the students reported suffering from chronic psychiatric diseases. The amount of fermented food consumption was calculated with the use of seven-day dietary records, while depressive and anxiety symptoms were assessed with the use of the Patient Health Questionnaire-9 and Generalized Anxiety Disorder-7, respectively. In psychiatrically healthy medical students under psychological stress (n = 372), higher fermented food consumption was associated with more depressive and anxiety symptoms. In contrast, psychiatrically ill medical students (n = 25, 6.3% of all the participants) were found to present a negative association between the amount of fermented food consumed and the severity of depressive symptoms (adjusted β −0.52, 95% CI −0.85 to −0.19, p = 0.0042); however, this relationship was insignificant for anxiety symptoms (adjusted β −0.22, 95% CI −0.59 to 0.15, p = 0.22). A significant interaction was found between the consumption of fermented food and psychiatric diagnosis in predicting depressive symptoms (p = 0.0001), and a borderline significant interaction for anxiety symptoms (p = 0.053). In conclusion, psychiatrically ill people, but not healthy ones, may benefit from fermented food consumption in terms of alleviation of depressive symptoms. Our findings require cautious interpretation and further investigation.

A Review: Exploring Nutrition Approaches to Improve Mental Health Among Athletes: Focus on Depression and Disordered Eating

“…Finally, enriching diets with fermented foods containing probiotic microorganisms along with their healthpromoting bioactives, such as probiotic yogurt, kefir, kimchi, and sauerkraut, can improve gut health, promote better mental health, lower depression risk, as well as improve sleep and reduce perceived stress. Interestingly, probiotic-rich diets have been associated with lower depression severity, particularly in men, and fermented dairy products like yogurt and cheese have demonstrated a significant correlation with lower depression risk (Karbownik et al, 2022;Kim & Shin, 2019;Luo et al, 2023;Şanlier et al, 2019).…”

Personality traits and health-related behaviors in medical students facing a stressful event

“…All the participants gave their informed consent in an electronic manner. The study partially represents a secondary analysis of already published results (14,15), however, it also includes new data.…”

Diet and the microbiota–gut–brain-axis: a primer for clinical nutrition

“…1 ). For example, a healthy diet (with varied sources of dietary fibre [ 20 ▪ , 21 ], phytochemicals [ 22 ], or live bacteria [ 3 ▪▪ , 23 ]) can promote increased microbial diversity and production of SCFA and other bioactive compounds with beneficial physiological effects from gastrointestinal and metabolic health to brain processes [ 3 ▪▪ , 13 , 16 ▪ , 20 ▪ , 21 , 23 ]. On the contrary, a western-like pattern comprising processed foods lacking the recommended quantity of dietary fibre and with higher content of saturated fats, salt and sugars can result in suboptimal gut microbiota composition and a low-grade systemic inflammation associated, for example, with mental illness, gastrointestinal pathology and metabolic disorders [ 11 ] and obesity [ 24 , 25 ] (Fig.…”

“…Finally, in a prospective study of healthy medical students under psychological stress (academic exams), higher fermented foods consumption was associated with the severity of depressive and anxiety symptoms [ 37 ], which was not found for food-derived prebiotics. In contrast, higher consumption of fermented foods was associated with lower severity of depressive symptoms in medical students with psychiatric illness, while no association was found for anxiety symptoms [ 23 ]. These results suggest that interventions with fermented foods can modulate brain processes through changes in the gut microbiome and gut–brain-axis pathways, which are worthy of further investigation.…”