Effect of Probiotic Bifidobacterium bifidum TMC3115 Supplementation on Psychosocial Stress Using a Sub-Chronic and Mild Social Defeat Stress in Mice.

Atsushi Toyoda,Natsuki Ohsawa,Kazutoyo Yoda,Mizuho Sato,Gaku Harata,Fang He,Kenji Miyazawa

doi:10.3390/nu14050970

Abstract

With the accumulation of knowledge on the relation between psychological stress and gut microbiota, there is growing interest in controlling stress and/or mood disorders via probiotic supplementation. We aimed to examine the effect of probiotic Bifidobacterium bifidum TMC3115 (TMC3115) supplementation using a sub-chronic and mild social defeat stress murine model in this study. TM3115 supplementation maintained body weight gain and alleviated a polydipsia-like symptom induced by the stress. In the analyses of fecal and cecal bacterial profiles, expansions of Proteobacteria in stressed mice and increases in Actinobacteria and Bifidobacterium in mice supplemented with TMC3115 were observed. There was no marked difference in the diversity of cecal bacteria between the tested mice. Elevated serum levels of inflammatory markers such as tumor necrosis factor (TNF)-α and interleukin (IL)-6 were observed in the stressed mice, while TMC3115 only reduced the IL-6 level. These findings suggest that TMC3115 supplementation confers tolerance to psychosocial stress in the host through modulation of the gut microbiota and alleviation of stress-induced inflammatory responses. Furthermore, it may be expected to exert prevention and treatment of disorders related to peripheral IL-6, including depression.

Highlights

Stressful life events often lead to a variety of disorders, such as depression, posttraumatic stress disorder, and cardiovascular disease [1]
A significant lower food intake was observed in the St group compared with the Ct group during the sCSDS period (p = 0.027, Figure 2C)
We examined the effect of TMC3115 supplementation on psychosocial stress using an sCSDS murine model and demonstrated to influence some aspects of stress-induced symptoms

Summary

Introduction

Stressful life events often lead to a variety of disorders, such as depression, posttraumatic stress disorder, and cardiovascular disease [1]. Stress induces psychological and physiological changes, including activation of the hypothalamic–pituitary–adrenal axis and sympathetic nervous system [2], which can significantly affect mood, behavior, and health. The recent growing research interest in the brain–gut axis has revealed that stress alters the gut microbiota [3,4]. Alleviating stressful conditions and protecting ourselves from stress, and maintaining good intestinal conditions, could be effective approaches to reducing the risk of developing these disorders. As one of the definitions of probiotics is “A live microbial feed supplement which beneficially affects the host animal by improving its intestinal microbial balance” [5], the current strategy of probiotics restores microbial diversity and alters the perturbed intestinal microbiota [6]. Many pieces of research have shown that probiotics have a wide range of health benefits [7], for instance, the alleviation and/or prevention of allergies [8,9]

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