Loading ...

TOPLINE:

Cooperative breeding interactions among Seychelles warblers were associated with increased sharing of anaerobic gut bacteria in those interacting directly at nests: Dominant breeders and their helper partners — who cooperate in nest care — had more similar anaerobic gut microbiomes than noncooperative pairs involving non‑helping subordinates.

METHODOLOGY:

• Social transmission of microbes strongly affects disease dynamics and host health; however, its role in wild populations — particularly for commensal gut microbes — remains poorly understood.
• Researchers used a wild population of cooperatively breeding Seychelles warblers to examine how social interactions shape the gut microbiome and analyzed 648 fecal samples from 345 individually marked birds between 2017 and 2022 across 10 breeding seasons.
• DNA was extracted from fecal samples, and 16S ribosomal RNA (rRNA) sequencing was performed to characterize gut microbiome composition; bacterial genera were assigned as aerotolerant (able to survive in oxygen-rich environment) or anaerobic (requiring oxygen-free conditions).
• Individuals were categorized on the basis of cooperative breeding interactions as dominant-dominant breeding pair, dominant breeders-helpers, dominant breeders-other subordinates, helpers-other subordinates, and subordinates-subordinates, reflecting different levels of social interaction.
• Gut microbiome composition was compared between birds within the same breeding group and across different breeding groups and also across various types of cooperative breeding interactions.

TAKEAWAY:

• Pairs within the same breeding group had significantly more similar overall gut microbiome composition than those from different breeding groups (P < .001); both aerotolerant and anaerobic bacterial genera showed greater gut microbiome similarity within the same breeding groups than across different breeding groups (aerotolerant, P < .001; anaerobic, P = .003).
• Anaerobic gut microbiota composition was significantly more similar in dominant-dominant pairs than in helper-subordinate pairs (P = .034) and subordinate-subordinate pairs (P = .014); differences also existed with dominant-subordinate pairs, but they were not significant (P = .051).
• Nest-sharing pairs (dominant-dominant and dominant-helper pairs) had significantly more similar anaerobic gut microbiome composition than non-nest-sharing pairs (dominant-subordinate, helper-subordinate, and subordinate-subordinate pairs; P = .003); however, aerotolerant gut microbiome composition did not differ significantly by social status categories.
• Genetic relatedness was not a significant predictor of gut microbiome composition similarity, both within and across the breeding groups.

IN PRACTICE:

“This work reveals how cooperative social interactions lead to microbial transmission and thus contribute to shaping specific components of a host’s gut microbiome,” the authors of the study wrote.

SOURCE:

This study was led by Chuen Zhang Lee, University of East Anglia, Norwich, England. It was published online in Molecular Ecology.

LIMITATIONS:

Samples were not consistently collected from all individuals within each breeding group during the same field period. The study relied on 16S rRNA sequencing rather than shotgun metagenomics. Global Positioning System‑based tracking data were not available due to technologic limitations.

DISCLOSURES:

Some authors reported receiving funding from the UK Biotechnology and Biological Sciences Research Council, Norwich Research Park Biosciences Doctoral Training Partnership, and other sources. The authors declared having no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.