3 / 2019-06-20 14:23:35

Gut microbiota--a new target for active regulation of brain function by exercise

Gut microbiota； exercise；brain function ；brain-gut axis

Purpose:Exercise offers extensive mental health benefits that merit its regular use as a low-cost, low-risk intervention. Physical exercise is a powerful tool in nervous system disease,numerous studies have demonstrated that regular moderate exercise is beneficial to preventing, recovering or improving various brain diseases, reducing psychological stress, depression and anxiety-like behavior, cognitive defects ,improving learning and memory in various conditions by means of the promotion of an anti-inflammatory state, reinforcement of the neuromuscular function,activation of the hypothalamic–pituitary–adrenal (HPA) axis and augment of the brain derived neurotrophic factors (BDNF) levels.In addition, The human body is composed of a complex biological system; with over 90% of microbiota cells and 10 million microbiota genes,gut microbiota appears to be closely related to health and disease. There is considerable and growing evidence implicating the gut microbiome in the normal development and function of the nervous system ,regulating neurophysiological-governed behaviors, such as affective disorders,autism spectrum disorders (ASD), chronic pain,multiple sclerosis and Parkinson's disease.Preclinical and clinical studies have shown bidirectional interactions within the brain-gut-microbiome axis.As a novel therapeutic target,Gut microbiota is found to regulate the neurophysiological behaviors through immune, endocrine and neural pathways .So based on the brain-gut axis (BGM) effect,changes in the microbial community affecting behavior,gut microbiota may also play an important role in protecting brain function during exercise. According to previous studies,The purpose of this review is to explore several mechanisms which physical exercise might cause changes in brain function by regulating gut microflora .

Method:Systematic English literature retrieval was conducted in PubMed, MEDLINE and SCI databases (January 2000 to  March 2019).Search keywords include “gut microbiota”,“gut microbiome”, “exercise”,“training”,“physical fitness”,“physical activity”,“Brain-Gut-Microbiome Axis”,“BGM”,“Depression”,“Anxiety”,“Cognitive Disorders”,“brain function”refering to the electronic original and follow up the references cited in the relevant papers.After being extracted and readed, these articles were divided into three categories: 1. The effect of exercise on gut microbiota; 2. Relationship between gut microbiota and brain function;3. How to use sports intervention measures to promote brain function by regulating gut microbiota.

Result: The mechanisms whereby physical fitness promotes increased resilience and well-being and positive psychological and physical health are diverse and complex. Review of data presented in this review suggests that regular moderate exercise,as a steady-state stimulus, can optimize the structure of intestinal flora and promote intestinal health,regulate beneficial metabolites of intestinal flora(such as SCAFs ,bile acids and tryptophan),reduce inflammation and improve immunity,which is good for lower HPA axis,Sympathetic Nervous System(SNS) and inflammatory activity ,greater neuroplasticity, higher levels of neurotrophic factors.The role of the gut microbiota as a “peacekeeper” in regulating the brain-controlled function and behavior,through the brain-gut axis,regular exercise may be an especially effective intervention in treating and/or preventing a variety of mental disorders (depression, anxiety) and neurological disorders (Parkinson's disease, autism spectrum disorders).

Conclusion:The regulation of intestinal microflora by moderate physical exercise can optimize microbial composition, regulate metabolites, strengthen immune system and promote health. We can conclude that intestinal microbiota has a positive effect on brain function through the mechanisms of the neurobiochemical, neuroendocrine, and neuroimmune systems of the brain-gut axis.On the basis of the brain-gut axis effect, these mechanisms can further improve mental illness and neurological dysfunction.But few controlled studies of humans have attempted to confirm the results of animal studies.Therefore, in the future more human studies need to be done. A number of aspects of the effects of exercise on brain function remain unresolved. For example, the exact mechanism of the neuroprotective effect of exercise and how gut microbiota communicated to the brain are still uncertain and warrant further exploration.In addition,How to regulate intestinal microbiota and provide treatment for nervous system diseases through appropriate exercise patterns, intensity and duration remains to be further studied.