# Range‐Wide Assessment of the Tasmanian Devil Gut Microbiome

## TL;DR

This study examines gut microbiome variation in wild Tasmanian devils across Tasmania, finding that diet has a smaller impact than expected, suggesting other factors like environment and immunity are more important.

## Contribution

The study provides the first range-wide assessment of the Tasmanian devil gut microbiome and challenges the assumption that diet is the primary driver of microbiome variation in this species.

## Key findings

- The five most abundant phyla and genera in the gut microbiome were consistent across all 10 locations in Tasmania.
- Dietary differences explained only a small amount of variation in microbial communities, contrary to expectations.
- Environmental factors and immune system development are suspected to have a stronger influence on gut microbiome variability than diet.

## Abstract

The gut microbiome is an important component of host health and function and is influenced by internal and external factors such as host phylogeny, age, diet, and environment. Monitoring the gut microbiome has become an increasingly important management tool for wild populations of threatened species. The Tasmanian devil (
Sarcophilus harrisii
) is the largest extant carnivorous marsupial from the island state of Tasmania, Australia. Devils are currently endangered due to devil facial tumor disease. Previous assessments have shown differences between captive and wild devil gut microbiomes and changes during translocations. However, wild gut microbiome variability across Tasmania and the drivers of these differences are not well understood. We conducted a range‐wide assessment of gut microbiomes at 10 locations across Tasmania, via 16S rRNA sequencing, and tested the influence of diet (12S vertebrate sequencing), location, sex, and cohort. We show that the five most abundant phyla and genera were consistent across all 10 locations. Location, cohort, and sex impacted bacterial richness, but location did not impact diversity. While there were differences in diet across the state, there was no strong evidence of differences between juveniles and adults, nor between males and females. Contrary to our hypothesis, the vertebrate diet explained a small amount of variation in microbial communities. We suspect that other variables, such as environmental factors and immune system development, may have a stronger influence on gut microbiome variability. Dietary components missed by our 12S primer, including invertebrates and plants, may also contribute to these patterns. Adjustments to dietary supplementation are not recommended when preparing devils for translocation to different sites. Future research should prioritize collecting environmental samples for microbial analysis and integrating metabolomics to elucidate functional differences associated with Tasmanian devil gut microbiome variability.

We conducted a comprehensive assessment of gut microbiomes at 10 locations across Tasmania, utilizing molecular methods such as 16S rRNA amplicon sequencing and diet metabarcoding to investigate the influences of diet, location, sex, and age. Contrary to the prevailing notion that diet is a main driver of gut microbiome differences, we found that dietary differences accounted for only a small proportion of microbial variation, suggesting that other ecological and physiological factors play a more pivotal role.