Impact of Physical Exercise on Gut Microbiome, Inflammation, and the Pathobiology of Metabolic Disorders

Abstract

BACKGROUND: The gastrointestinal tract (GIT) harbors a complex and diverse microbial composition that outnumbers our own body cells and their gene contents. These microbes play a significant role in host metabolism and energy homeostasis. Emerging evidence suggests that the GIT microbiome significantly contributes to host health and that impairments in the microbiome may cause the development of metabolic diseases. The microbiome architecture is shaped by several genetic and environmental factors, including nutrition and physical activity. Physical exercise has preventive or therapeutic effects in respiratory, cardiovascular, neuroendocrine, and muscular diseases. Yet, we still have little information of the beneficial effects of physical exercise on GIT health and microbial composition. Furthermore, we are not aware whether exercise-derived benefits on microbiome diversity can beneficially influence other tissues and body organs. OBJECTIVES: The aim of this article is to review the available literature on exercise-induced microbiome changes and to explain how these changes may induce inflammatory, immune, and oxidative responses that may contribute to the improvement of metabolic disorders. METHODS: A systemic and comprehensive search of the relevant literature using MEDLINE and Google Scholar databases was conducted during fall 2018 and spring 2019. The search identified sixty-two research and review articles that discussed exercise-induced microbiome changes. RESULTS: The review of the relevant literature suggests that exerciseinduced microbial changes affect the host's immune pathways and improve energy homeostasis. Microbes release certain neuroendocrine and immune-modulatory factors that may lower inflammatory and oxidative stress and relieve patients suffering from metabolic disorders. CONCLUSIONS: Exercise-induced changes in microbial diversity are able to improve tissue metabolism, cardiorespiratory fitness, and insulin resistance.

Gut Microbiome Analysis Reveals Characteristics Decrease in Bifidobacterium Count in the Adult Type 2 Diabetes Mellitus Patients

“…Here we observed that microbial community diversity, as revealed by alpha-and beta-diversity indexes were not signi cantly different between the study groups. These observations resemble with our previous ndings [9], where we report no statistical differences between the salivary microbiome diversity of obese pre-diabetic and healthy lean controls. Contrary to our observations, many researchers hypothesize that the diabetic phenotype is associated with a decline in gut microbial diversity, characterized as species richness and abundance [8,17,37].…”

“…These studies concluded that diverse gut microbiome could have a protective effect against systemic in ammation and metabolic disorders. Similarly, no difference was observed between Firmicutes to Bacteroidetes ratio in the study groups, another critical parameter, most often emphasized as a prodrome for metabolic disorders development [9]. However, no signi cant differences in quanti cations of taxonomic composition at phylum were observed in this study among the study groups.…”

“…Microbial dysbiosis, characterized by a decline in bacterial richness and diversity, may enhance intestinal permeability, glucose homeostasis, and elicit systemic in ammation [7]. Previous diabetes-microbiome studies demonstrate several vital changes in gut microbiome composition, including a decline in microbial diversity and relative richness of speci c microbial taxa at different hierarchical levels [5,6,[8][9][10]. Literature review also reveals a rise in Firmicutes to Bacteroidetes ratio (F/B) in the subjects with T2DM compared to the healthy controls.…”

A Review of the Role of the Gut Microbiome in Personalized Sports Nutrition

“…Numerous reviews have been published highlighting the effect of exercise on the gut microbiota (39)(40)(41)(42)(43)(44)(45)(46)(47)(48)(49)(50)(51)(52)(53)(54)(55)(56). However, the primary focus of these reviews has been the implications for aspects of host health, such as the immune system and risk of chronic diseases.…”

Profiling the Oral Microbiome and Plasma Biochemistry of Obese Hyperglycemic Subjects in Qatar

“…Hyperglycemia in the pre-diabetic stage is correlated with obesity, blood pressure, and dyslipidemia [4]. However, like diabetes, obesity also does not have a well-defined etiology or pathogenesis and, in many cases, obesity is considered as a prodrome of insulin resistance (IR) in diabetes [5].…”