# Pondering Ponds: Exploring Correlations Between Cloacal Microbiota and Blood Metabolome in Freshwater Turtles

## TL;DR

This study explores how the gut microbiota of freshwater turtles is influenced by their environment and how it relates to their blood metabolome.

## Contribution

This is the first investigation into cloacal microbiota and serum metabolome correlations in chelonians.

## Key findings

- Location significantly influenced microbial composition and metabolic profiles in turtles.
- Turtles from one pond had an unusually high proportion of Actinomycetota.
- Microbiota diversity was clearly connected to the metabolome, indicating impacts on host physiology.

## Abstract

The gut microbiota of vertebrates significantly influences host physiology, yet little is known about how habitat factors shape microbiotas in non-human species, especially freshwater turtles. This study explores the relationship between cloacal microbiota and serum metabolome in eastern longneck turtles (Chelodina longicollis), marking the first such investigation in chelonians. By comparing microbiotas from two distinct pond environments, we applied a multi-omics approach combining 16S rRNA sequencing and metabolomic profiling. Results showed that location influenced microbial composition and metabolic profiles, with dominant bacterial phyla Pseudomonadota, Actinomycetota, and Bacillota, and distinct families linked to differences in microbial diversity. Notably, turtles from one pond displayed an unusually high proportion of Actinomycetota. We also found a clear connection between microbiota diversity and metabolome, suggesting certain bacterial combinations impact host physiology. These findings offer important insights into the complex interaction between microbial communities and metabolism in freshwater turtles, a highly threatened group. This research emphasises the value of integrating microbiota and metabolomic data in conservation strategies and highlights the need for further longitudinal studies to explore the dynamic host-microbiota relationship in these understudied species.

The online version contains supplementary material available at 10.1007/s00248-025-02556-7.