How different is the gut makeup of that of an athlete as opposed to that of an inactive person? In a new study the gut microbiome of marathoners was given to mice and the result was an increase in activity. There has been an increased interest by scientists on how the huge population of gut flora affects our health and well-being but now this study takes it even a step further. How intertwined is our outside with the inside of our bodies? Until recently scientists have been studying the effect of transferring gut microbiome from thin to obese mice and people and the results have been varied. A new study published in Nature Medicine which was done by the researchers from the Joslin Diabetes Center of Harvard University is focused more on the flora of active as opposed to sedentary subjects. In studying runners, they discovered a high number of a certain microbiome called Veillonella. They all had a different diet, but activity was the only common thread. Veillonella is a microbe that is responsible for metabolizing lactate in our gut and can influence blood sugar levels, oxygen consumption and inflammation. If the transfer of this microbe is successful it may be a new way of attacking the obesity problem. That is in combination with the motivation to be more active.