Unlocking a novel determinant of athletic performance:The role of the gut microbiota,short-chain fatty acids,and“biotics”in exercise

The gut microbiota refers to the collection of trillions of intestinal microorganisms that modulate central aspects of health and disease through influential effects on host physiology.Recently,a connection has been made between the gut microbiota and exercise.Initial investigations demonstrated the beneficial effects of exercise on the gut microbiota,with cross-sectional studies revealing positive correlations between exerciseassociated states,and healthy gut microbiota and exercise interventions showed post-intervention increases in the abundance of beneficial bacterial taxa.More recent investigations have focused on exploring the reverse relationship:the influence of the gut microbiota on exercise performance.Murine investigations have revealed that certain bacterial taxa may enhance endurance exercise performance by augmenting various aspects of lactate metabolism.Further,short-chain fatty acids—which modulate metabolism at various organ sites,including within skeletal muscle—have been shown to enhance endurance exercise capacity in mice.This review highlights what is currently known about the connection between the gut microbiota and exercise,with a particular focus on the ergogenic potential of the gut microbiota and how it may be leveraged to enhance endurance exercise performance.

Gut microbiota and obesity:Impact of antibiotics and prebiotics and potential for musculoskeletal health

Obesity is a complex disease with multiple contributing factors.One of the most intensely studied factors during the past decade has been the gut microbiota,which is the community of all microbes in the intestinal tract.The gut microbiota,via energy extraction,inflammation,and other actions,is now recognized as an important player in the pathogenesis of obesity.Dysbiosis,or an imbalance in the microbial community,can initiate a cascade of metabolic disturbances in the host.Early life is a particularly important period for the development of the gut microbiota,and perturbations such as with antibiotic exposure can have long-lasting consequences for host health.In early life and throughout the life span,diet is one of the most important factors that shape the gut microbiota.Although diets high in fat and sugar have been shown to contribute to dysbiosis and disease,dietary fiber is recognized as an important fermentative fuel for the gut microbiota and results in the production of short-chain fatty acids that can act as signaling molecules in the host.One particular type of fiber,prebiotic fiber,contributes to changes in the gut microbiota,the most notable of which is an increase in the abundance of Bifidobacterium.This review highlights our current understanding of the role of gut microbiota in obesity development and the ways in which manipulating the microbiota through dietary means,specifically prebiotics,could contribute to improved health in the host,including musculo skeletal health.

Impact of age on host responses to diet-induced obesity:Development of joint damage and metabolic set points

Background:Osteoarthritis is one of the leading causes of pain and disability worldwide,and a large percentage of patients with osteoarthritis are individuals who are also obese.In recent years,a series of animal models have demonstrated that obesity-inducing diets can result in synovial joint damage(both with and without the superimposition of trauma),which may be related to changes in percentage of body fat and a series of low-level systemic inflammatory mediators.Of note,there is a disparity between whether the dietary challenges commence at weaning,representing a weanling onset,or at skeletal maturity,representing an adult onset of obesity.We wished to evaluate the effect ofthe dietary exposure time and the age at which animals are exposed to a high-fat and high-sucrose(HFS) diet to determine whether these factors may result in disparate outcomes,as there is evidence suggesting that these factors result in differential metabolic disturbances.Based on dietary exposure time,we hypothesized that rats fed an HFS diet for 14 weeks from weaning(HFS Weanling) would demonstrate an increase in knee joint damage scores,whereas rats exposed to the HFS diet for 4 weeks,starting at 12 weeks of age(HFS Adult) and rats exposed to a standard chow diet(Chow)would not display an increase in knee joint damage scores.Methods:Male Sprague-Dawley rats were fed either an HFS diet for 14 weeks from weaning(HFS Weanling) or an HFS diet for 4 weeks,starting at 12 weeks of age(HFS Adult).At sacrifice,joints were scored using the modified Mankin Criteria,and serum was analyzed for a defined subset of inflammatory markers(Interleukin-6,leptin,monocyte chemoattractant protein-1,and tumor necrosis factorα).Results:When the HFS Weanling and HFS Adult groups were compared,both groups had a similar percent of body fat,although the HFS Weanling group had a significantly greater body mass than the HFS Adult group.The HFS Weanling and HFS Adult animals had a significant increase in body mass and percentage of body fat when compared to the Chow group.Although knee joint damage scores were low in all 3 groups,we found,contrary to our hypothesis,that the HFS Adult group had statistically significant greater knee joint damage scores than the Chow and HFS Weanling groups.Furthermore,we observed that the HFS Weanling group did not have significant differences in knee joint damage scores relative to the Chow group.Conclusion:These findings indicate that the HFS Weanling animals were better able to cope with the dietary challenge of an HFS diet than the HFS Adult group.Interestingly,when assessing various serum proinflammatory markers,no significant differences were detected between the HTS Adult and HFS Weanling groups.Although details regarding the mechanisms underlying an increase in knee joint damage scores in the HFS Adult group remain to be elucidated,these findings indicate that dietary exposure time maybe less important than the age at which an HFS diet is introduced.Moreover,increases in serum proinflammatory mediators do not appear to be directly linked to knee joint damage scores in the HFS Weanling group animals but may be partially responsible for the observed knee joint damage in the adults over the very short time of exposure to the HFS diet.