Akkermansia muciniphila
Bacteroides thetaiotaomicron
Thiamine (VB1) biosynthesis protein ThiC in Bacteroides thetaiotaomicron contains a inverton that introduces a premature stop codon when inverted. Bacteroides thetaiotaomicron have the capacity to biosynthesize thiamine while at a large energetic cost. This work showed that at human intestine thiamine concentrations (0.02-2 μM), strain with inverted inverton was more fit than the prototrophic strain. However, they found thiamine availability does not promote rapid thiC inverton flipping and the inversions are probably stochastic. It fits a bet-hedging model.
Intragenic DNA inversions expand bacterial coding capacity
Cordycipitaceae
Defensive fungal symbiosis on insect hindlegs
Fusobacterium nucleatum
A distinct Fusobacterium nucleatum clade dominates the colorectal cancer niche
Salmonella enterica
Veillonella atypica
Scheiman et al. 2019 provides an example of a host-microbiome metabolic feedback loop, linking exercise-induced lactate to microbial propionate production and endurance performance. It’s an interesting example of how exercise shape the gut microbiome.