Insights into the nematobiome in gut of a helminth, Teladorsagia circumcincta

To describe the composition and structure of the intestinal microbial population of Teladorsagia circumcincta. We extracted genomic DNA from entire helminths and carried out amplicon sequencing targeting the 16 S rRNA gene. The resulting microbial profile was then compared to that of the ovine host (abomasum). Additionally, we cultured and isolated unique bacterial strains to define the functional microbiome of the helminth. Alpha diversity analysis revealed significant differences in the Shannon and Chao 1 indices. Principal component analysis (PCA) of Aitchison distances revealed a distinct clustering for T. circumcincta, confirming differences in microbial composition between helminths and hosts (PERMANOVA R2 = 0.12, P-value = 0.001). The Microbiome Multivariable Association with Linear Models revealed nine genera were significantly abundant in the parasite. Using bacterial culture and whole genome sequencing (WGS), we identified three putative new species isolated from the parasite. Metabolite prediction revealed the mechanisms of antioxidant defense, adeptness at iron scavenging, and utilisation, describing a cooperative, commensal microbial community collectively defined as the nematobiome. For the first time we characterised the innate intestinal microbiota of T. circumcincta and identified unique bacterial species that suggest a co-evolved mutualism. The discovery of three presumptive novel bacterial species has implications for biotechnology, livestock management, and broader microbiome, and ecological research.