The researchers investigated relationships between the gut microbiome and mucosal immune measures while controlling for host, social and environmental factors in 199 samples from 158 wild spotted hyenas. The composition of the microbiome was assessed using a multi-amplicon approach and faecal immunoglobulin A and mucin were measured. ‘Probabilistic models showed that both immune measures predict the similarity of the microbiome between individuals in an age-dependent manner,’ explains study last author Susana C. M. Ferreira from the Research Institute of Wildlife Ecology (FIWI) at Vetmeduni Vienna.
Use of machine learning as an accurate predictor and identifier
These associations were strongest for bacteria, intermediate for parasites and weakest for fungal communities. Machine learning models accurately predicted both immune measures and identified the taxa responsible for these associations: symbiotic bacteria also found in humans and laboratory mice, unclassified bacteria, parasitic hookworms and fungi.
Wild animal populations harbour a hidden and largely unknown diversity in their guts, according to the researchers, and their immune systems must regulate these communities by maintaining mutualists and commensals while reducing harmful parasitic interactions. According to Ferreira, the study on the hyenas now provides important new information: ‘We were able to establish far-reaching and general relationships between immune measures and the various components of the gut microbiome and identify the taxa that determine these relationships.’
Co-adaptations in the microbiome as the next research goal
The study results point to the important role that the immune system plays in both defence and regulation of the microbiome. ‘We hypothesise that the identified taxa are closely linked to and involved in cross-talk, i.e. mutual exchange and communication, in the gut of wild hyena populations - a possible product of co-adaptation,’ says Ferreira. The next step, according to Ferreira, is to further investigate the genetic diversity and functional profile of gut microbiomes in natural populations to uncover evolutionary aspects of such potential co-adaptations.
The article „Mucosal immune responses and intestinal microbiome associations in wild spotted hyenas (Crocuta crocuta)“ by Susana P. Veloso Soares, Victor H. Jarquín-Díaz, Miguel M. Veiga, Stephan Karl, Gábor Á. Czirják, Alexandra Weyrich, Sonja Metzger, Marion L. East, Heribert Hofer, Emanuel Heitlinger, Sarah Benhaiem and Susana C. M. Ferreira was published in „Communications Biology“.
Scientific contact:
Susana Ferreira PhD.
Forschungsinstitut für Wildtierkunde und Ökologie (FIWI)
Veterinärmedizinische Universität Wien (Vetmeduni)
Susana.Ferreira@vetmeduni.ac.at