60 second summary
- Scientists investigated the abundance of Veillonella bacteria in high performance athletes
- Veillonella abundance was significantly increased post exercise
- This bacterium plays a key role in breaking down lactate which is the causative factor in muscle cramps
- The products of lactate breakdown by this bacterium may increase maximal oxygen consumption during exercise.
An introduction to Veillonella
Veillonalla is a genus of bacteria commonly be found in the intestines and mouth of mammals. It is most commonly known for its ability to breakdown the molecule lactate.
Genus- a type of ranking in biological classification
What is lactate?
Lactate is a by product of respiration, the release of energy, without oxygen.
In order for energy to be supplied to our muscles for exercise, glucose must be broken down via a pathway called glycolysis. The quantity of energy released is dependent on whether oxygen is present. If it is present up to 38 molecules of ATP may be produced where ATP is the currency of energy in cells and in termed aerobic respiration. During long or intense bursts of exercise our body’s oxygen consumption does not meet the heightened demand so nerobic respiration, the release of energy without oxygen, occurs. This pathway leads to the formation of lactate which is what causes muscle cramps.
Veillonella bacteria increased in athlete gut microbiomes
In a study on marathon runners and Olympic trail rowers researchers found a significant increase in the genus Veillonella post exercise. Furthermore, changes at the genetic level were seen too- every single gene in the methylmalonyl-CoA pathway, which breaks down lactate, was more abundant.
Effects of lactate breakdown.
The scientists then investigated the specific effect of Veillonella compared to another strain of bacteria which does not break down lactate (Lactibacillus bulgarsis) . The experiment involved injecting mice with either one of bacteria and then testing their treadmill performance;
The Veillonella group performed significantly better.
How can a microbe alter your fitness?
As mentioned above, Veillonella breakdown lactate via the methylmalonyl CoA pathway. This Lactate is broken down into acetate and propionate.
Methylmalonyl- Co-A pathway=
3 Lactate → acetate + 2 propionate + CO 2+ H 2O
These 2 products are a class of molecules called short chain fatty acids (SCFA’s) which are absorbed into the bloodstream rectum ( lower digestive tract) and drain directly into the vena cava via the pelvic plexus.
Vena cava- large vein which returns blood to the heart
pelvic plexus- a bundle of nerves in the pelvic area
In terms of exercise the SCFA propionate has shown to increase resting energy expenditure as well as maximum oxygen consumption- the latter being crucial in prolonging the body’s ability to utilize oxygen during exercise. These effects of propionate were confirmed as when the scientists administered a group of mice with this molecule compared to salt solution
~their treadmill performance increased accordingly. 
suggests one day scientists might be able to create an exercise probiotic- a
fermented drink or food with the potential to enhance one’s aerobic capacity
important for people with activity heavy lives such as soldiers. 
 Springer Link. (2016). Microbiota metabolite short chain fatty acids, GPCR, and inflammatory bowel diseases. [online] Available at: https://link.springer.com/article/10.1007/s00535-016-1242-9 [Accessed 14 Jul. 2019].
 Research Gate. (2019). Meta-omics analysis of elite athletes identifies a performance-enhancing microbe that functions via lactate metabolism. Available at: https://www.researchgate.net/publication/333985452_Meta-omics_analysis_of_elite_athletes_identifies_a_performance-enhancing_microbe_that_functions_via_lactate_metabolism [Accessed 14 Jul. 2019].
 Live science. (2019). Athlete’s gut bacteria boost performance. Available at: https://www.livescience.com/65780-athletes-gut-bacteria-boost-performance.html [Accessed 14 Jul. 2019].