Isolated Grauer's gorilla populations differ in diet and gut microbiome

Area of Science:

• Ecology
• Microbiology
• Evolutionary Biology

Background:

• The gut microbiome influences host biology, including digestion, behavior, and local adaptation in animals.
• Studies on wild animal gut microbiomes often lack comparisons across ecologically distinct populations and simultaneous diet analysis.
• Understanding diet-microbiome interactions is crucial for assessing adaptation potential in wild populations.

Purpose of the Study:

• To investigate the relationship between diet and gut microbiome composition in three distinct populations of Grauer's gorillas (Gorilla beringei graueri).
• To determine if gut microbiome profiles are population-specific and covary with dietary patterns in this critically endangered species.
• To explore the role of the gut microbiome in facilitating local adaptation in Grauer's gorillas.

Main Methods:

• Genomic analysis to confirm genetic differentiation among geographically isolated Grauer's gorilla populations.
• Metagenomic sequencing to characterize gut microbial communities.
• Dietary analysis based on sample analysis to assess food consumption patterns.
• Statistical modeling to identify correlations between diet, microbiome, population, social group, age, sex, and genetic relatedness.

Main Results:

• Significant population- and social group-specific differences were observed in both diet and gut microbiome composition.
• A clear covariation between dietary intake and gut microbial profiles was detected across the populations.
• Core microbial taxa were present across all groups, but community structure varied.
• Dietary diversity differed significantly, with high-altitude populations consuming fewer plant types, likely due to availability.
• Age had no detectable effect, while sex and genetic relatedness showed only marginal influences on the microbiome.

Conclusions:

• The gut microbiome of Grauer's gorillas exhibits substantial plasticity, adapting to population-specific diets.
• Covariation between diet and microbiome is likely shaped by long-term environmental and social factors.
• The adaptable nature of the gut microbiome supports flexible feeding strategies, potentially contributing to local adaptation in Grauer's gorillas.
• This study highlights the importance of considering gut microbiome dynamics in conservation efforts for endangered species.