The study here is carried out in horses, but it is reasonable to expect to find very similar mechanisms in other mammals. The beneficial populations of the gut microbiome provide metabolites that steer cell function and exist in symbiosis with the host animal. Mitochondria, the power plants of the cell, are the evolved descendants of ancient symbiotic microbes, now an integral part of cellular processes. It is reasonable to think that the one can influence the other directly via signaling processes, as researchers discuss in these materials and elsewhere. In humans, for example, researchers have found that propionate generated by some populations of gut microbes can enhance athletic performance. There are no doubt other signals and metabolites at work as well, yet to be cataloged.
Mitochondria, which can be briefly described as the energy provider of cells, have been shown in recent studies to be interdependent with gut bacteria. In fact, many diseases associated with mitochondrial dysfunction in humans, such as Parkinson's and Crohn's have been linked to changes in the gut microbiome in many previous studies.
"Studying horses is a good way to assess the link between gut bacteria and mitochondria, because the level of exercise, and thereby mitochondrial function, performed by a horse during an endurance race is similar to that of a human marathon runner. For this study we took blood samples from 20 healthy horses of similar age and performance level, at the start and end of the International Endurance Competition of Fontainebleau, an 8-hour horse race in France. These samples provided information about the chemical signals and expression of specific genes, which is the process by which DNA is converted into instructions for making proteins or other molecules. To understand the composition of the horse's gut bacteria metabolites, we obtained fecal samples at the start of the race."
The researchers found that certain bacteria in the gut were linked to the expression of genes by the mitochondria in the cells. Furthermore, the genes that were expressed, or "turned on", were linked to activities in the cell that helped it to adapt to energetic metabolism.
"Interestingly, mitochondria have a bacterial origin - it is thought they formed a symbiotic relationship with other components to form the first cell. This may explain why mitochondria have this line of communication with gut bacteria. Improving our understanding of the intercommunication between the horse and the gut microbiome could help enhance their individual performance, as well as the method by which they are trained and dietary composition intake. Manipulating the gut microbiota with probiotic supplements as well as prebiotics, to feed the good bacteria, could be a way for increasing the health and balance of the microbiome and horses, to better sustain endurance exercise."