The Effects of Host Taxon, Hybridization, and Environment on the Gut Microbiome of Callithrix Marmosets

Microbiome studies show that host taxon, diet, and environment influence gut bacteria. However, these factors are rarely studied in animal hybrids and exudivores (which nutritionally exploit indigestible oligosaccharides). To investigate the effects of host taxon, hybridization, and environment on gut microbiota, we conducted 16S V4 ribosomal sequencing of the gut microbiome of marmosets (Callithrix), non-human primate (NHP) specialist exudivores that also hybridize. We sampled 59 wild, translocated, and captive pure and hybrid Callithrix, including endangered C. aurita. Gut microbiome diversity differed significantly between hybrids and non-hybrids, but host environment had the strongest overall effect on the gut microbiome. Captive marmosets showed relatively reduced gut microbiome diversity. Wild Callithrix had the highest relative abundance of Bifidobacterium, which process host-indigestible carbohydrates, while captive marmosets had the highest relative abundance of Enterobacteriaceae, a family containing several pathogenic bacteria. The wild marmoset gut microbiome was enriched predictively for carbohydrate metabolism functions, while that of captive marmosets was enriched for nucleotide and amino acid metabolism function. Our findings show that carbohydrate metabolism is integral to the composition and function of the wild exudivore gut microbiome. Further, captivity perturbs the exudivore gut microbiome, raising implications for captive host health and endangered exudivore conservation.