Poster: The impacts of soil as a probiotic in altering the gut microbiome of the Ōkārito kiwi (Apteryx rowi) in hatcheries
Stephen Rowe1, Matthew Stott1, Manpreet Dhami2
1 University of Canterbury, Christchurch
2 Manaaki Whenua Landcare Research, Lincoln
The Ōkārito kiwi, or rowi, is the rarest of the kiwi species and among the least studied. With less than a thousand birds left in the wild, captive rearing has become a critical tool in the conservation of this species. However, many challenges in captive rearing remain, including exposure to diseases, unnatural diets, antimicrobial usage and the potential long-term effects these factors may have on the microbial communities that live in symbiosis with the rowi – their microbiome. Recent research has begun to highlight the importance of managing the microbiome of captive animals in an effort to improve their overall well-being and prepare them for release into the wild. The gut microbiome in particular could offer a uniquely impactful avenue of mitigating disease and bolstering the health of captive animals, through the development of direct probiotics or more natural diets.
This research aimed to analyse the impact of natal soils, lifted from the Ōkārito reserve, as a direct probiotic and a source of environmentally relevant microorganisms for the captive rowi gut microbiome. In doing so, this study would also provide an overview of the composition of bacterial and fungal communities in the gut microbiome of rowi, using 16S rRNA and ITS gene sequencing to identify the key taxonomic groups present. The health outcomes of rowi were monitored to identify any differences between the control and treatment group.
Results showed a distinct microbial profile of rowi in captivity that diversifies as the birds’ age, with the relative abundances of major taxonomic groups changing over time. A majority of the microorganisms present were of the bacterial phyla Firmicutes, Proteobacteria and Actinobacteria, and the fungal orders Malasseziales and Trichosporon. Exposure to natal Ōkārito soils did have an effect on the composition of the gut microbiome in rowi. Treated birds harboured a more specialised set of microbial taxa, with the key organisms in this diversity shift being the bacteria Escherichia/Shigella, Faecalibacterium, Burkholderia, Terrisporobacter and Liquorilactobacillus, and the fungi Malassezia. The fungal component of the rowi gut microbiome was especially responsive to outside influence, with the majority of treatment bird gut communities directly reflecting the fungi they were exposed to. No significant changes to rowi growth rates or overall health were found between rowi control and treatment groups.
The findings of this study represent the first exploration of the gut microbiome of Apteryx rowi using next-generation sequencing methods, and a positive indication that mediation of the gut microbial communities of captive rowi can be achieved through the introduction of natal soils.