Abstract
Effects of vertebrate-associated microbiota on physiology and health are of significant interest in current biological research. Most previous studies have focused on host-microbiota interactions in captive-bred mammalian models. These interactions and their outcomes are still relatively understudied, however, in wild populations and non-mammalian taxa. Using deep pyrosequencing, we described the cloacal microbiome (CM) composition in free living barn swallows Hirundo rustica, a long-distance migratory passerine bird. Barn swallow CM was dominated by bacteria of the Actinobacteria, Proteobacteria and Firmicutes phyla. Bacteroidetes, which represent an important proportion of the digestive tract microbiome in many vertebrate species, was relatively rare in barn swallow CM (< 5%). CM composition did not differ between males and females. A significant correlation of CM within breeding pair members is consistent with the hypothesis that cloacal contact during within-pair copulation may promote transfer of bacterial assemblages. This effect on CM composition had a relatively low effect size, however, possibly due to the species’ high level of sexual promiscuity.
Highlights
Vertebrate digestive tracts are inhabited by a taxonomically and functionally diverse community of bacteria, usually dominated by obligatory anaerobes [1,2]
We focus on cloacal microbiome (CM) composition in a free-living population of barn swallows (Hirundo rustica), an insectivorous long-distance migratory passerine bird
The level of inter-individual variation in CM composition was pronounced as just four operational taxonomic units (OTUs) were detected in all samples and only 52 OTUs in more than 50% of individuals
Summary
Vertebrate digestive tracts are inhabited by a taxonomically and functionally diverse community of bacteria, usually dominated by obligatory anaerobes [1,2]. The cell and active gene count of this community may exceed that of the host genome by at least one order of magnitude [3]. It is no surprise that gastrointestinal tract microbiota (GTM) interact with a broad range of host physiological systems and provide ecosystem services of considerable value. GTM affect metabolism efficiency [4,5], modulate the host’s immune system [6], play a significant role in defence against pathogens [7,8] and enable synthesis of substances that cannot be synthesised by enzymes encoded by the host’s genome [9,10]. GTM dysbiosis is often associated with metabolic [11,12], autoimmune [13] and neurological disorders [10,14] and can increase the risk of pathogen invasion [7,8].
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
