Gut microbiome is affected by gut region but robust to host physiological changes in captive active-season ground squirrels

Kirsten Grond; Courtney C Kurtz; Jasmine Hatton; Michelle M Sonsalla; Khrystyne N Duddleston

doi:10.1186/s42523-021-00117-0

Gut microbiome is affected by gut region but robust to host physiological changes in captive active-season ground squirrels

Anim Microbiome. 2021 Aug 13;3(1):56. doi: 10.1186/s42523-021-00117-0.

Authors

Kirsten Grond¹, Courtney C Kurtz², Jasmine Hatton³, Michelle M Sonsalla², Khrystyne N Duddleston³

Affiliations

¹ Department of Biological Sciences, College of Arts and Sciences, University of Alaska Anchorage, 3211 Providence Dr., Anchorage, AK, 99508, USA. kgrond@alaska.edu.
² Department of Biology, College of Letters and Science, University of Wisconsin-Oshkosh, 800 Algoma Blvd., Oshkosh, WI, 54901, USA.
³ Department of Biological Sciences, College of Arts and Sciences, University of Alaska Anchorage, 3211 Providence Dr., Anchorage, AK, 99508, USA.

Abstract

Background: Thirteen-lined ground squirrels (Ictidomys tridecemlineatus) are obligate hibernators and are only active 4-5 months annually. During this period, squirrels rapidly acquire fat for use during hibernation. We investigated how the gut microbiome changed over the active season in the mucosa and lumen of two gut sections: the cecum and ileum. We sequenced the 16S rRNA gene to assess diversity and composition of the squirrel gut microbiome and used differential abundance and network analyses to identify relationships among gut sections.

Results: Microbial composition significantly differed between the cecum and ileum, and within the ileum between the mucosa and lumen. Cecum mucosa and lumen samples did not differ in alpha diversity and composition, and clustered by individual squirrel. Ileum mucosa and lumen samples differed in community composition, which can likely be attributed to the transient nature of food-associated bacteria in the lumen. We did not detect a shift in microbiome diversity and overall composition over the duration of the active season, indicating that the squirrel microbiome may be relatively robust to changes in physiology.

Conclusions: Overall, we found that the 13-lined ground squirrel microbiome is shaped by microenvironment during the active season. Our results provide baseline data for new avenues of research, such as investigating potential differences in microbial function among these physiologically unique gut environments.

Keywords: Firmicutes:Bactoidetes ratio; Gastrointestinal tract; Hibernation; Ictidomys tridecemlineatus.

Abstract

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