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

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, Mirounga leonina, and leopard seals, Hydrurga leptonyx, inhabiting
Antarctica were compared with captive leopard seals. Each seal exhibited a
gut microbiota dominated by four phyla: Firmicutes (41.5 ± 4.0%),
Fusobacteria (25.6 ± 3.9%), Proteobacteria (17.0 ± 3.2%) and Bacteroidetes
(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 Bacteroidetes 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 Arctic. 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.