Veillonella

Veillonella are Gram-negative bacteria (Gram stain pink) anaerobic cocci, unlike most Bacillota, which are Gram-positive bacteria. This bacterium is well known for its lactate fermenting abilities. It is a normal bacterium in the intestines and oral mucosa of mammals. In humans they have been implicated in cases of osteomyelitis and endocarditis, for example with the species Veillonella parvula.

Veillonella dispar is the most nitrate-reducing bacterium in the oral cavity, which is beneficially anti-bacterial.

When Veillonella is responsible for clinical infections in humans, it should be kept in mind that more than 70% of the strains are resistant to penicillin, while more than 95% of the strains are susceptible to amoxicillin/clavulanate.

Previous studies have shown that exercise is associated with changes in microbiome composition. Specifically, Veillonella, Bacteroides, Prevotella, Methanobrevibacter, and Akkermansiaceae are in more abundance in endurance athletes. Specifically, one study has proposed that V. atypica is beneficial for endurance performance because the high-lactate environment of the athlete provides a selective advantage for colonization by lactate metabolizing organisms, such as Veillonella. Previous studies in mice have shown that propionate increases heart rate variability (HRV) and VO2 max. It also raises the resting energy expenditure and lipid oxidation in fasted humans. These modifications are beneficial for athletes because an increase in HRV indicates that the body is adapting to the exercise stimuli, indicating an increase in fitness. Also, a higher VO2 max allows the athlete to produce more energy which allows them to do more work and an increase in lipid oxidation delays glycogen depletion.