PT  - JOURNAL ARTICLE
AU  - Darka Labavić
AU  - Claude Loverdo
AU  - Anne-Florence Bitbol
TI  - Hydrodynamic flow and concentration gradients in the gut enhance neutral bacterial diversity
AID  - 10.1101/2021.05.14.444143
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.05.14.444143
4099  - http://biorxiv.org/content/early/2021/05/16/2021.05.14.444143.short
4100  - http://biorxiv.org/content/early/2021/05/16/2021.05.14.444143.full
AB  - The gut microbiota features important genetic diversity, and the specific spatial features of the gut may shape evolution within this environment. We investigate the fixation probability of neutral bacterial mutants within a minimal model of the gut that includes hydrodynamic flow and resulting gradients of food and bacterial concentrations. We find that this fixation probability is substantially increased compared to an equivalent well-mixed system, in the regime where the profiles of food and bacterial concentration are strongly spatially-dependent. Fixation probability then becomes independent of total population size. We show that our results can be rationalized by introducing an active population, which consists of those bacteria that are actively consuming food and dividing. The active population size yields an effective population size for neutral mutant fixation probability in the gut.Competing Interest StatementThe authors have declared no competing interest.