Diet and phylogeny shape the gut microbiota of Antarctic seals: a comparison of wild and captive animals

• Published in: Environmental Microbiology
• Main Authors: Nelson, Tiffanie M., Rogers, Tracey L., Carlini, Alejandro R., Brown, Mark V.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2012
• Subjects: Antarc*; Antarctic; Elephant Seal; Elephant Seals; Leopard Seals; Southern Elephant Seal; Southern Elephant Seals
• Online Access: http://dx.doi.org/10.1111/1462-2920.12022; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2F1462-2920.12022; http://onlinelibrary.wiley.com/wol1/doi/10.1111/1462-2920.12022/fullpdf

Summary The gut microbiota of mammals underpins the metabolic capacity and health of the host. Our understanding of what influences the composition of this community has been limited primarily to evidence from captive and terrestrial mammals. Therefore, the gut microbiota of southern elephant seals, M irounga leonina , and leopard seals, H ydrurga leptonyx , inhabiting A ntarctica were compared with captive leopard seals. Each seal exhibited a gut microbiota dominated by four phyla: F irmicutes (41.5 ± 4.0%), F usobacteria (25.6 ± 3.9%), P roteobacteria (17.0 ± 3.2%) and B acteroidetes (14.1 ± 1.7%). Species, age, sex and captivity were strong drivers of the composition of the gut microbiota, which can be attributed to differences in diet, gut length and physiology and social interactions. Differences in particular prey items consumed by seal species could contribute to the observed differences in the gut microbiota. The longer gut of the southern elephant seal provides a habitat reduced in available oxygen and more suitable to members of the phyla B acteroidetes compared with other hosts. Among wild seals, 16 ‘core’ bacterial community members were present in the gut of at least 50% of individuals. As identified between southern elephant seal mother–pup pairs, ‘core’ members are passed on via vertical transmission from a young age and persist through to adulthood. Our study suggests that these hosts have co‐evolved with their gut microbiota and core members may provide some benefit to the host, such as developing the immune system. Further evidence of their strong evolutionary history is provided with the presence of 18 shared ‘core’ members in the gut microbiota of related seals living in the A rctic. The influence of diet and other factors, particularly in captivity, influences the composition of the community considerably. This study suggests that the gut microbiota has co‐evolved with wild mammals as is evident in the shared presence of ‘core’ members.