FIG 1.

Functional adaptations in the gut microbiome of western lowland gorillas across seasons of variable dietary intake and in humans under two different subsistence strategies. (a) Principal-coordinate analysis using Bray-Curtis distances generated from the relative abundances of KEGG pathways shows functional distinctions between the microbiome of gorillas across dry (dark wheat) and wet (light wheat) seasons and between BaAka hunter-gatherers and Bantu agriculturalists (PERMANOVA: R² = 0.14, P = 0.01**). The amplified ordination panel on the left specifically shows functional distinctions between gorillas across seasons (PERMANOVA: R² = 0.10, P = 0.05*). (b) Ordination scores along PCo2 reflect functional similarities between BaAka hunter-gatherers and gorillas in dry seasons and between Bantu agriculturalists and gorillas in wet seasons. (c) Higher interindividual variations were observed in Bantu agriculturalists and gorillas during the wet season. (d) Relative abundances of significantly discriminating pathways identified using gene set enrichment analysis further highlights the similarity between Bantu and gorillas during the wet season and BaAka and gorillas during the dry season. The square root (sqrt) of cumulative abundance is shown on the y axes. The color key in panel a applies to all panels. A nonparametric two-sided Wilcoxon rank sum test was used for testing the box plot distributions. The center values indicate the median values, and error bars depict the standard deviations (SD). ns, not significant; *, P < 0.05; **, P < 0.01.