Functional changes in gut microbiota across the hibernation cycle of Ictidomys tridecemlineatus examined by stable isotope-assisted labeling

Abstract

The hibernation cycle of the 13-lined ground squirrel, which includes fasting during winter months, drives changes in taxonomic composition of the gut microbiota. This study employs stable isotope-assisted labeling (SlAL) as a novel approach to investigate, in vivo, functional capacities of changing microbiotas across the hibernation cycle. Capacity to degrade 13C-inulin and 13C-mannitol, as indicated by change in breath 𝛿13C02 after oral gavage, was greater in summer than winter. Prior antibiotic (ABX) treatment reduced 𝛿13C02 in summer after 13C-inulin or 13C-mannitol gavage. Results suggest that SIAL effectively tracks seasonal changes in functional capacity of the microbiota to degrade substrates, and that ABX treatment depletes bacterial populations as indicated by significant reductions in 𝛿13C02. This has validated SlAL as a technology to determine the functional ability of a microbiota to degrade various substrates.