Gut homeostasis in wild tropical non-human primates

Abundance and diversity of microbial and helminth communities inhabiting the gastrointestinal tract are of critical importance to health in both humans and non-human animals. However, this micro-biodiversity has rarely been considered within a conservation framework. The Udzungwa red colobus monkey (Procolobus gordonorum) is an endangered and endemic primate species living in the Udzungwa Mountains of Tanzania, a global biodiversity hotspot. The monkeys are primarily arboreal and highly sensitive to hunting and habitat destruction. Therefore, they are an excellent model species for investigating the effect of habitat degradation on gut homeostasis. Two distinct studies have been conducted, separately, to understand both gut microbiota variability (31 faecal samples analysed) and helminth abundance and richness (251 faecal samples) across habitats with different levels of human disturbance, from either fragmented or unfragmented forests. The first study used barcoded 454 amplicon pyrosequencing of the 16S bacterial ribosomal RNA gene, while for the second study we recovered data via sodium nitrate floatation and faecal sedimentation. Our results in closely related, yet distinct, populations of red colobus showed that gut microbiota diversity was lowest within groups, higher between groups and highest across habitats. There was an increase of gut microbiota biodiversity in individuals living in the largest and more undisturbed forest range. This increase may be correlated with the higher diversity of available food resources. Similarly, helminth richness and abundance were also higher in larger and intact forests than in smaller and degraded areas. Our results suggest that human disturbance and degradation effects gut microbial and helminth communities and indicate that strict environmental protection is needed to preserve global natural diversity.