In the study researchers examined how the gut microbiome interacts with mucosal immune responses in wild African spotted hyenas analyzing 199 fecal samples from 158 individuals. They carefully accounted for host-specific social and environmental variables to isolate the effects of immune factors. The team used a multi-amplicon sequencing approach to characterize microbiome composition and measured key immune markers fecal immunoglobulin A (IgA) and mucin levels to assess mucosal immunity.

Using probabilistic modeling we found that both IgA and mucin significantly predict microbiome similarity between individuals and these effects vary with age explains Susana C. M. Ferreira senior author from the Research Institute of Wildlife Ecology (FIWI) at Vetmeduni Vienna. This study highlights the nuanced age-dependent interplay between immunity and gut microbial communities in a natural setting.

The study revealed that the strength of associations between immune markers and gut organisms varied by type being strongest for bacteria moderate for parasites and weakest for fungal communities. Using machine learning the researchers were able to accurately predict levels of both immune markers and pinpoint the microbial taxa responsible for these patterns. These included symbiotic bacteria common to humans and lab mice previously unclassified bacterial species parasitic hookworms and various fungi.

The findings underscore the vast and largely unexplored microbial diversity within wild animal guts. The researchers emphasize that host immune systems play a critical role in managing these communities nurturing beneficial mutualists and commensals while suppressing harmful parasites.

Our work with hyenas sheds light on these complex dynamics says Susana C. M. Ferreira. We uncovered broad generalizable links between immune function and different microbial groups and successfully identified the key taxa driving these relationships. This opens up exciting new avenues for understanding gut ecology and immunity in natural populations.

The findings of the study highlight the critical dual role of the immune system not only as a line of defense against harmful microbes but also as a key regulator that maintains balance within the gut microbiome. We believe the microbial taxa identified in our study are deeply intertwined with immune signaling and cross-talk within the gut suggesting a mutual exchange and communication that may have emerged through long-term co-adaptation explains Susana C. M. Ferreira.

This cross-talk points to a sophisticated relationship where the immune system doesn’t just fight pathogens but helps shape and sustain a diverse yet stable microbial community. Ferreira emphasizes that such interactions likely evolved over generations particularly in wild species like hyenas which face constant environmental and dietary pressures.

Looking ahead the researchers plan to explore the genetic diversity and functional capabilities of gut microbiomes in natural populations. Their goal is to unravel the evolutionary underpinnings of these immune-microbe interactions and better understand how co-adaptation has shaped gut ecosystem dynamics in the wild.

Source: https://www.vetmeduni.ac.at/en/university/infoservice/press-releases/press/austro-ai-decodes-gut-microbiome-of-african-hyenas