# Subpopulations and Stability in Microbial Communities

## TL;DR

This paper investigates how phenotypic diversity within microbial species affects ecological stability, revealing that phenotypic variation can both destabilize and stabilize communities, challenging classical stability theories.

## Contribution

It introduces a detailed analysis of phenotypic switching effects on stability, highlighting the stabilizing role of rare phenotypes like bacterial persisters.

## Key findings

- Phenotypic variation can destabilize microbial communities.
- Rare phenotypes such as persisters can stabilize communities.
- Phenotypic diversity influences stability under large perturbations.

## Abstract

In microbial communities, each species often has multiple, distinct phenotypes, but studies of ecological stability have largely ignored this subpopulation structure. Here, we show that such implicit averaging over phenotypes leads to incorrect linear stability results. We then analyze the effect of phenotypic switching in detail in an asymptotic limit and partly overturn classical stability paradigms: abundant phenotypic variation is linearly destabilizing but, surprisingly, a rare phenotype such as bacterial persisters has a stabilizing effect. Finally, we extend these results by showing how phenotypic variation modifies the stability of the system to large perturbations such as antibiotic treatments.