The impact of exercise-induced muscle damage, inflammation and oxidative stress on the intestinal microbiota in athletes.
Soft tissue injuries are one of the key determinants of the training process effectiveness. Recent developments and reports in the field of soft tissue injuries prompted us to extend those studies on the gut microbiome (GM) analysis. The role of gut microbiota in health maintaining and better results in the field of sport has already been studied. Furthermore some research underlying changes in microbial diversity after severe injury has been published in last few years. However, there is still lack of knowledge regarding the correlation of microbiota composition with sport specification, clinical features, course and outcomes related to the soft tissue injuries occurring during training. Due to the nature of this relations it is difficult to find information referring to those relationships depending on intensity of physical activity. In this study, we will investigate whether anaerobic exercise and induced by maximal intensity exercises muscle damage alters gut microbial communities and whether there is an association between gut microbiota, inflammation response and iron metabolism. The main aim of the proposed project is a detailed and combined characteristics of bacteria affecting those features by using novel technique (NGS) and correlating them with molecular and biochemical biomarkers. The project aimed to: 1) Demonstrate whether Wingate Anaerobic Test (WAnT) will affect the microbiome and hepcidin concentration; 2) Indicate whether and how skeletal muscle damage induced by maximal intensity exercise influence human microbiome; 3) Show whether WAnT test or Bruce test will induce a higher change of microbiome, iron metabolism and the concentration of inflammation markers; 4) Demonstrate whether Bruce test (aerobic) will cause changes in microbiome concentration and whether these changes will correlate with changes in iron metabolism and inflammation process. 5) Indicate whether circulating free DNA (cfDNA) may be used as a new early-stage biomarker of muscle damage and training overload.  In order to achieve objectives of that study, 80 people were recruited and divided into groups with a very strict criteria. They were subjected to a WAnT test and Bruce test (at least 2 weeks later). Blood and stool samples were collected for biochemical, genetic and microbiome analysis before and after tissue-damaging tests in very precisely defined timepoints. Extracted material was checked for a proper quality and quantity. For microbiome analysis the shotgun sequencing was performed using NovaSeq Illumina platform with 2x150 reads. After bioinformatical analysis, all results were analysed statistically in order to look for correlations regarding to the influence of typical exercise (WanT, Bruce test), microbiome diversity, cfDNA level and biochemical data between analysed groups of young men.  The measurable effect of this study will be a discovery of relationship between specific adaptations induced by physical training, type of tissue injury and microbiome status among analysed groups of people. In combination with conventional methods for determination of a person's load during and after physical exercise, data obtained from this study can lead to more accurate understanding of processes happening during and after the exercise, and how biochemical changes in the parameters associated to a physical exercises can effect human's microbiome status. That can result in a more tailored training program which will stimulate the development of desired bacteria and reduce the risk of soft tissue injuries. This may serve also to identify species helpful for athletic achievement. A better understanding of the nature of these postinjury changes may lead to the ability to intervene in otherwise pathological clinical trajectories.