Growth capacity and mortality burden shape microbial persistence under osmotic stress in Bacteroides thetaiotaomicron
- 1University of British Columbia
Abstract
Microbial persistence in the gut is central to sustaining beneficial host-microbiota interactions; however, characterizing determinants of persistence in vivo can be challenging due to the complexity of native microbial communities interacting with the host. Here, we used a defined microbial consortium to demonstrate that intrinsic in vitro growth capacity becomes increasingly predictive of in vivo relative abundance as intestinal osmolality increases. In Bacteroides thetaiotaomicron, in vivo abundance was higher than predicted from growth capacity alone, indicating that additional physiological factors contribute to persistence. We identify mortality as one such determinant: adaptation to prolonged osmotic stress markedly reduced cell loss without enhancing growth capacity. This adaptive phenotype was associated with rapid and reversible phase variation in cell surface-associated PUL78/80 rather than fixed de novo mutations, with the PUL78/80-OFF state becoming progressively enriched among surviving cells as mortality increased. Our findings demonstrate that in addition to growth capacity, reduced cell loss can provide a distinct route to microbial persistence during environmental perturbation.
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BibTeX
@misc{ghezzi2026growth,
title = {{Growth capacity and mortality burden shape microbial persistence under osmotic stress in Bacteroides thetaiotaomicron}},
author = {H. Ghezzi and R. Wolff and A. Jain and J. Burckhardt and M. Hunter and K. Ng and S. Carasso and N. Geva-Zatorsky and N. Garud and C. Tropini},
howpublished = {bioRxiv},
year = {2026},
month = sep,
doi = {10.64898/2026.09.08.750096},
url = {https://www.biorxiv.org/content/10.64898/2026.09.08.750096v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Growth capacity and mortality burden shape microbial persistence under osmotic stress in Bacteroides thetaiotaomicron
AU - H. Ghezzi
AU - R. Wolff
AU - A. Jain
AU - J. Burckhardt
AU - M. Hunter
AU - K. Ng
AU - S. Carasso
AU - N. Geva-Zatorsky
AU - N. Garud
AU - C. Tropini
PY - 2026
DA - 2026/09/08
PB - bioRxiv
DO - 10.64898/2026.09.08.750096
UR - https://www.biorxiv.org/content/10.64898/2026.09.08.750096v1
AB - Microbial persistence in the gut is central to sustaining beneficial host-microbiota interactions; however, characterizing determinants of persistence in vivo can be challenging due to the complexity of native microbial communities interacting with the host. Here, we used a defined microbial consortium to demonstrate that intrinsic in vitro growth capacity becomes increasingly predictive of in vivo relative abundance as intestinal osmolality increases. In Bacteroides thetaiotaomicron, in vivo abundance was higher than predicted from growth capacity alone, indicating that additional physiological factors contribute to persistence. We identify mortality as one such determinant: adaptation to prolonged osmotic stress markedly reduced cell loss without enhancing growth capacity. This adaptive phenotype was associated with rapid and reversible phase variation in cell surface-associated PUL78/80 rather than fixed de novo mutations, with the PUL78/80-OFF state becoming progressively enriched among surviving cells as mortality increased. Our findings demonstrate that in addition to growth capacity, reduced cell loss can provide a distinct route to microbial persistence during environmental perturbation.
ER -