Background: Gut microbiota is considered to have a great impact on human health and disease. While it is widely recognized that the gut microbiota of healthy individuals differs from those with obesity, inflammatory bowel disease, metabolic syndrome, and other chronic diseases, the alterations of gut microbiota with physical activity are not fully understood. Accordingly, we performed this systematic review to address the question regarding the effects of mild and intense exercise on the gut microbiota in humans. Methods: The comparative analyses of gut microbiota were conducted following the PRISMA protocol to determine the differences in the active vs. non-active individuals (phenotypes) (n = 11), including the influence of physical activity intervention on the human gut microbiota (n = 13); the differences in the gut microbiota of athletes vs. non-athletes (n = 8); and the microbiota status at different stages of athletic performance or intervention (n = 7), with various of physical activities, sport disciplines, and activity duration. Literature searches were completed using four databases: PubMed, Web of Science, Scopus, and EBSCO, and 2090 articles were retrieved by using appropriate keywords. The low heterogeneity of the studies hasn’t allowed us to prepare a meta-analysis. After excluding 2052 articles, we ultimately selected 38 articles that met the eligibility criteria for this review. Results: The data analyses revealed that in non-athletes rising physical activity markedly influenced the relative abundance of short-chain fatty acid (SCFA). Aerobic training that lasted 60 min, and physical activity that characterized 60% HRmax or more also influenced beta diversity indexes. The results showed that athletes harbor a more diverse type of intestinal microflora than non-athletes, but with a relatively reduced abundance of SCFA- and lactic acid-producing bacteria, thereby suggesting an adverse effect of intense exercise on the population of gut microbiota. Conclusion: It is concluded that the level of physical activity modulates the gastrointestinal microbiota in humans. For a long period, increasing the intensity and volume of exercise may lead to gut dysbiosis. Perhaps, proper supplementation should be considered to keep gut microbiota in large biodiversity and richness, especially under unfavorable gut conditions associated with intense exercise. Trial registration: Prospero CRD42021264064.

This study aimed to evaluate the changes in the erythropoietin level and hematological variables in wrestlers after intermittent hypoxic exposure (IHE). Twelve wrestlers were assigned into two groups: hypoxia (sports training combined with IHE, n=6) and control (sports training, n=6). An IHE was performed for 10 days, with one day off after 6 days, once a day for about an hour. The concentrations of hydrogen peroxide (H(2)O(2)), nitric oxide (NO), vascular endothelial growth factor (VEGF) and erythropoietin (EPO), as well as total creatine kinase activity (CK) were measured. Also, the hematological markers (Hb -hemoglobin, Ht - hematocrit, RBC - red blood cell, WBC - white blood cell, Ret - reticulocytes) were analyzed. The 6-day IHE caused an increase in the levels of H(2)O(2), NO and VEGF. Similarly, the EPO level and WBC count reached the highest value after 6 days of IHE. The total Ret number increase constantly during 10 days of IHE. The hypoxia group showed a higher CK activity compared to the control. In conclusion, 10-day IHE in combination with wrestling training elevates levels of H(2)O(2), NO and VEGF, and improves the oxygen transport capacity by the release of EPO and Ret in circulation.

Bovine colostrum supplementation has been suggested as a potential factor in reducing oxidative stress and inflammation. The primary objective of this study was to evaluate the effects of six months of bovine colostrum supplement intake (3.2 g; four capsules/day) in highly trained female athletes on changes in oxidative stress level, inflammation, and iron metabolism biomarkers after intense exercise. In this study, 20 trained female athletes were recruited. Participants were divided into two groups: 11 in the bovine colostrum (6-month supplementation) and 9 in the placebo group (6-month placebo supplementation). All participants completed an intense exercise test at the beginning of the experiment and after six months post-treatment. Blood samples were taken before, following exercise, and after 3 h recovery. Compared to the placebo group, the colostrum group showed a significant decrease in TBARS level (p< 0.01) at all time points, whereas a marked increase was observed in IL-6 (p < 0.01; pre-exercise) and SOD activity (p < 0.01), and transferrin (p < 0.01; rest period) and lactoferrin (p < 0.05; post-exercise) levels. The results suggested that 6-months of bovine colostrum supplementation is beneficial in the reduction of the harmful effects produced by free radicals (ROS), oxidative stress, and inflammation. In consequence, alleviation of the inflammatory response by bovine colostrum supplementation may also cause positive action on iron homeostasis in female athletes.

Background: Bovine colostrum (BC) contains a myriad of bioactive molecules that are renowned for possessing unique medicinal benefits in children and adults, and BC supplements are considered safe and cost-effective options to manage/prevent the incidence of upper respiratory tract infections and gut-related problems in athletes. In this review, we will try to answer the question: How will BC supplementation ameliorate gut permeability problems among athletes? Methods: Literature searches were performed using PRISMA guidance to identify studies assessing the influence of BC supplements on gut permeability. Studies were selected using four databases: PubMed, Web of Science, Scopus, and EBSCO, and a total number of 60 articles were retrieved by using appropriate keywords. Results: Nine studies were selected that met the eligibility criteria for this review. The data analysis revealed that vigorous exercise profoundly increases intestinal permeability, and BC supplementation helps to reverse gut permeability in athletes. Conclusion: BC supplementation may be highly beneficial in improving gut permeability in athletes. However, well-designed, placebo-controlled, and randomized studies are needed to evaluate the long-term safety and efficacy and to determine the optimal dose schedules of BC supplementation in high-performance athletes.

The scientific literature indicates that chokeberry is widely used as a supplement to support the maintenance of the body’s homeostasis by reducing inflammation and oxidative stress. In recent years, positive effects of chokeberry on intestinal parameters have also been observed. Oxidative stress, inflammation and, according to recent reports, also the gut microbiome are closely related to the overall well-being and health of the population. This study, therefore, attempts to summarise all the health benefits of black chokeberry supplementation. This study was registered in PROSPERO (International Prospective Register of Systematic Reviews) under registration number CRD42023395969. Additionally, the systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method. Electronic databases were searched in Web of Science, PubMed, Scopus and EBSCO using the following combination of the words ‘chokeberry or aronia’ and ‘inflammation or oxidative stress or microbiota or microbiome or permeability or gut’. Ultimately, fifty-seven studies were summarised in the review. Data analysis showed that black chokeberry has a positive effect on the reduction of inflammation, oxidative stress and intestinal microflora, but the size of the changes varies and depends on many variables. Therefore, the researchers concluded that the compounds found in black chokeberry play a pivotal role in maintaining the overall balance within the system. This is a crucial consideration given the tendency for disturbances in organismal homeostasis to accompany disease processes and various disorders. However, further research is necessary to elucidate the mechanisms and optimise its use fully.

Intermittent exposure to hypoxia (IHE) increases the production of reactive oxygen and nitrogen species as well as erythropoietin (EPO), which stimulates the adaptation to intense physical activity. However, several studies suggest a protective effect of moderate hypoxia in cardiovascular disease (CVD) events. The effects of intense physical activity with IHE on oxi‐inflammatory mediators and their interaction with conventional CVD risk factors were investigated. Blood samples were collected from elite athletes (control n = 6, IHE n = 6) during a 6‐day IHE cycle using hypoxicator GO2 altitude. IHE was held once a day, at least 2 hours after training. In serum, hydrogen peroxide (H₂O₂), nitric oxide (NO), 3‐nitrotyrosine (3‐Nitro), proinflammatory cytokines (IL‐1β and TNFα), high sensitivity C‐reactive protein (hsCRP), and heat shock protein 27 (HSP27) were determined by the commercial immunoenzyme (ELISA kits) or colorimetric methods. Serum erythropoietin (EPO) level was measured by ELISA kit every day of hypoxia. IHE was found to significantly increase H₂O₂, NO, and HSP27 but to decrease 3NT concentrations. The changes in 3NT and HSP27 following hypoxia proved to enhance NO bioavailability and endothelial function. In the present study, the oxi‐inflammatory mediators IL‐1β and hsCRP increased in IHE group but they did not exceed the reference values. The serum EPO level increased on the 3^rd day of IHE, then decreased on 5^th day of IHE, and correlated with NO/H₂O₂ ratio (r_s = 0.640, P < 0.05). There were no changes in haematological markers contrary to lipoproteins such as low‐density lipoprotein (LDL) and non‐high‐density lipoprotein (non‐HDL) which showed a decreasing trend in response to hypoxic exposure. The study demonstrated that IHE combined with sports activity reduced a risk of endothelial dysfunction and atherogenesis in athletes even though the oxi‐inflammatory processes were enhanced. Therefore, 6‐day IHE seems to be a potential therapeutic and nonpharmacological method to reduce CVD risk, especially in elite athletes participating in strenuous training.