Journal Article

Rapid evolution of a novel protective symbiont into keystone taxon in Caenorhabditis elegans microbiota

King, Kayla, Bates, Kieran, University of Guelph [Guelf, Ontario, Canada], Wu-Chuang, Alejandra, ANR-10-LABX-0062,IBEID,Integrative Biology of Emerging Infectious Diseases, Biologie moléculaire et immunologie parasitaires et fongiques (BIPAR) ; École nationale vétérinaire d'Alfort (ENVA)-Laboratoire de santé animale, sites de Maisons-Alfort et de Normandie ; Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (ANSES)-Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (ANSES)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Universidad de Zaragoza = University of Zaragoza [Saragossa University] = Université de Saragosse, University of Oxford, Cabezas Cruz, Alejandro, Estrada-Peña, Agustín, Obregon, Dasiel

2022

Overview

Abstract Protective microbes have a major role in shaping host–pathogen interactions, but their relative importance in the structure of the host microbiota remains unclear. Here, we used a network approach to characterize the impact of a novel, experimentally evolved ‘protective microbial symbiont’ ( Enterococcus faecalis ) on the structure and predicted function of the natural microbiota of the model organism Caenorhabditis elegans . We used microbial network analysis to identify keystone taxa and describe the hierarchical placement of protective and non-protective symbionts in the microbiota. We found that early colonization with symbionts produce statistically significant changes in the structure of the community. Notably, only the protective E. faecalis became a keystone taxon in the nematode microbiota. Non-protective lineages of the same bacterial species remained comparatively unimportant to the community. Prediction of functional profiles in bacterial communities using PICRUSt2 showed that the presence of highly protective E. faecalis decreased the abundance of ergothioneine (EGT) biosynthesis pathway involved in the synthesis of the antioxidant molecule EGT, a potential public good. These data show that in addition to direct antagonism with virulent pathogens, keystone protective symbionts are linked to modified bacterial community structure and possible reductions in public goods, potentially driving decreased antioxidant defense. We suggest that this response could suppress infection via wholesale microbial community changes to further benefit the host. These findings extend the concept of protective symbionts beyond bodyguards to ecosystem engineers.

• Publisher: Nature Publishing Group,CCSD,Nature Publishing Group UK,Nature Portfolio
• Subject: 631/181/2475 / 631/181/2481 / 631/326/171 / 631/326/2565 / 631/326/41 / 631/326/421 / 704/158 / Animals / Antagonism / Antioxidants / Bacteria / Bacteria - genetics / Biosynthesis / Caenorhabditis elegans / Caenorhabditis elegans - microbiology / Community structure / Enterococcus faecalis / Host-pathogen interactions / Humanities and Social Sciences / Life Sciences / Microbiology and Parasitology / Microbiota / multidisciplinary / Nematodes / Pathogens / Science / Science (multidisciplinary) / Statistical analysis / Structure-function relationships / Symbionts / Taxa
• ISBN: 0008419427000