Author Interviews, Exercise - Fitness, Gastrointestinal Disease, Microbiome / 10.04.2017
Athletes’ Microbiome May Be Conditioned For Performance
MedicalResearch.com Interview with:
Dr. Orla O’Sullivan
Computational Biologist,
Teagasc Food Research Centre,
Moorepark, Co. Cork,
Ireland
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Previously we had demonstrated that professional rugby players had significantly increased microbial diversity compared to both low and high BMI controls. This microbial diversity correlated with creatine kinase levels in the blood (which we had used as a proxy for exercise) and protein intake. In this present study we went a step further and demonstrated that these same athletes had distinct functional potential in their gut microbes compared to controls and furthermore both the host derived ( urine) and bacterial derived ( faecal water) metabolites were also distinct in the athlete group. In particular we found that the athlete’s microbiome is primed for tissue repair and to harness energy from the diet, reflecting the significant energy demands and high cell-turnover evident in elite sport.
Thus, the state of physical fitness is not limited to the host alone; it appears to also include conditioning of the microbiota.


















Dr. Maria Luisa Alegre[/caption]
Maria-Luisa Alegre, MD, PhD
Professor of medicine
University of Chicago
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Most of the research that investigates why/how transplanted organs are rejected has focused on the genetic disparities between the donor and the recipient. Foreign proteins in the donor organ are recognized by the immune system of the host, which becomes activated to reject the transplanted organ. This is why transplant recipients need to take immunosuppressive medications for the rest of their lives.
Whether environmental factors, in addition to genetic factors, can also affect how the immune system is activated by the transplanted organ is much less understood. In particular, the microbiota, the communities of microbes that live on and in our body, is distinct in each individual and is known to affect the function of the immune system in diseases ranging from autoimmunity to cancer.
Using mouse models of skin and heart transplantation, we investigated if the microbiota was an environmental factor that could affect the speed at which the immune system rejects a transplanted organ.
We found that the microbial communities that colonize the donor and the host fine-tune the function of the immune system and control the strength with which the immune system reacts to a transplanted organ.
Dr. Katri Korpela[/caption]
Dr. Katri Korpela, PhD
University of Helsinki
Helsinki
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Korpela: Previous studies have shown that breastfeeding reduces the frequency of infections in the child and is associated with lower risk of childhood overweight. Conversely, antibiotic use in early life is associated with increased BMI. Both antibiotic use and breastfeeding are known to influence the infant's microbiota. However, these two factors have not been studied together and it was not known whether antibiotic use could modify the beneficial effects of breastfeeding. We collected data on lifetime antibiotic use, breastfeeding duration, and BMI in a group of daycare-attending children aged 2-6 years. We found that the beneficial effects on long breastfeeding, particularly as regards BMI development, were evident only in the children who did not get antibiotics in early life. Antibiotic use before or soon after weaning seemed to eliminate the protection against elevated BMI in preschool age and weaken the protection against infections after weaning.
Dr. W.H.Wilson Tang[/caption]
Dr. W.H. Wilson Tang M.D.
Department of Cellular and Molecular Medicine (NC10)
Cleveland Clinic Lerner Research Institute
Cleveland, Ohio 44195
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Our group has recently described the mechanistic link between intestinal microbe-generated phosphatidylcholine metabolite, trimethylamine N-oxide (TMAO), and the pathogenesis of atherosclerotic coronary artery disease (CAD) and its adverse clinical outcomes. Here in a separate, independent, contemporary cohort of patients undergoing coronary angiography, we demonstrated the association between elevated fasting TMAO levels and quantitative atherosclerotic burden (as measured by SYNTAX and SYNTAX II scores) in stable cardiac patients and is an independent predictor for the presence of diffuse (but not focal) lesion characteristics.
Ettje Tigchelaar[/caption]
Ettje Tigchelaar MSc
PhD student from department of Genetics
University of Groningen, Groningen
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: A gluten-free diet is used by celiac disease patients to alleviate their symptoms. Previous research in these patients has shown differences in gut microbiota composition when on habitual gluten containing diet (HD) compared to a gluten-free diet (GFD). Recently more and more individuals without celiac disease also started to adopt a gluten-free diet to improve their health and/or control weight. We studied changes in gut microbiota composition in these healthy individuals on a gluten-free diet.
We observed changes in the abundance of specific bacteria, for example the abundance of the bacterium family Veillonellaceae was much lower on a gluten-free diet versus HD, whereas it was higher for the family Clostridiaceae. We also looked at the function of the bacteria in the gut and found that many of those bacteria that changed because of the gluten-free diet played a role in metabolism of starch. This makes sense since starch is like gluten highly present in wheat containing products, thus when eliminating gluten from the diet, the intake of starch also changes and the gut bacteria processing this dietary starch change accordingly.
Jennifer Mahony, PhD and Prof Douwe Van Sinderen[/caption]
Jennifer Mahony, PhD and
Prof Douwe Van Sinderen
Dept of Microbiology
University College Cork
Cork, Ireland
MedicalResearch.com Editor's note: Dr Jennifer Mahony & Prof Douwe van Sinderen, of the APC (Alimentary Pharmbiotic Center) Microbiome Institute, University College Cork, Ireland, have received a Grand Challenges Explorations Grant from the Bill & Melinda Gates Foundation to study the microbiota (bacteria and viruses) of infants in developing countries. This study seeks to improve the gut health of infants which could potentially prevent/reduce the estimated 0.8 million infants who die annually in developing countries.
Dr. Mahony & Prof. van Sinderen answered several questions about the upcoming study for the MedicalResearch.com audience.
MedicalResearch.com: What is the background for this study? Would you briefly explain what is meant by a microbiome?
Response: The World Health Organisation promotes exclusive breast-feeding in infants until they are at least 6 months old. Early weaning in developing countries where sanitary conditions may be poor may lead to the introduction of microorganisms such as Shigella, which can cause intestinal infections and in extreme cases may be fatal. 0.8 million infant deaths in developing countries could be avoided annually according to UNICEF if exclusive breast-feeding is continued to the sixth month of life. Our intestinal tracts naturally contain many bacteria, called our microbiota, and the composition of this microbiota may have implications for our health and well-being. Just in the same way that drinking a probiotic drink every day is reported to promote a healthy gut microbiota, we will investigate how bacterial viruses (that specifically infect bacteria and not humans!) can change the gut bacterial population.
Dr. Susanne Asu Wolf[/caption]
Susanne Asu Wolf PhD
Max-Delbrueck-Center for Molecular Medicine
Berlin, Germany
MedicalResearch.com: What inspired you to research this link between Ly6Chi monocytes, antibiotics and neurogenesis?
Dr. Wolf: As a neuroimmunologist I research the communication between the immune system and the brain. Amongst other research groups we found almost 10 years ago that T cells are needed to maintain brain homeostasis and plasticity, namely neurogenesis. Since only activated T cells enter the brain, we were looking for a mouse model, where immune cells are not activated. My former supervisor Polly Matzinger (NIH), a well-known immunologist, suggested to use germ free mice, born and raised in an isolator without any contact to a pathogen or any bacteria. I did a pilot experiment with the germ free mice, but wanted to get closer to possible applications in humans. Since humans are rarely born and raised in a sterile environment, I was looking for another model. By chance I met with the group of Bereswill and Heimesaat (Berlin, Charite) who provided me with a model, where due to prolonged treatment with an antibiotic cocktail, the microbiota are below detection level and the mice are also virtually germ free. They got me into contact with the second senior author of the paper Ildiko Dunay (University of Magdeburg). Her expertise is the function of Ly6Chi monocytes during infection with malaria or toxoplasmosis.
Now we were ready to investigate the gut-immune-brain axis with the focus on neurogenesis and cognition. Meanwhile the impact of the microbiome on behavior was reported by several research groups using “sterile” germ free mice and I was also curious if we could see similar differences in our antibiotic treated mice.