Due to a lack of internal thermoregulation, all aspects of ectotherm physiology are highly temperature dependent including development, immunity, digestion, and metabolism. Despite a long history of research directed at understanding the impacts of temperature on ectotherm physiological performance, little attention has been focused on the interplay between environmental temperature and the gut microbiome. However, understanding this relationship will be important moving forward, as ectothermic vertebrates are highly threatened under global climate change.
 
Work from the lab has shown that fluctuations in environmental temperature are capable of reducing the diversity and altering the community composition of the amphibian gut microbiome, in both tadpoles [1] and salamanders [2]. Further, increasing temperature is associated with the loss of bacterial taxa that perform functions potentially important for host nutrition [2]. We have also found that the response to temperature varies across species, such that the gut microbiome of invasive bullfrog tadpoles responds more rapidly than green frog tadpoles [3]. Future work in this area will focus on identifying the mechanism by which temperature alters the gut microbiome and elucidating how these changes directly influence host physiology.
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1. Kohl, K.D. and J. Yahn. 2016. Effects of environmental temperature on the gut microbial communities of tadpoles. Environmental microbiology, 18(5): 1561-1565.
2. Fontaine, S.S., A.J. Novarro, and K.D. Kohl. 2018. Environmental temperature alters the digestive performance and gut microbiota of a terrestrial amphibian. Journal of Experimental Biology, 221(20): jeb187559.
3. Fontaine, S.S., Kohl, K.D. (2020) Gut microbiota of invasive bullfrog tadpoles responds more rapidly to temperature than a non-invasive congener. Molecular Ecology. 29: 2449-2462. [link]