Metagenomic analysis revealed the effects of goat milk feeding and breast feeding on the gut microbiome of Amur tiger cubs

Ingredients in breast milk can help establish a healthy community of microorganisms in the infant gut, but no research exists regarding the effects of goat milk feeding and breast feeding on the gut microbiome of the Amur tiger, which is one of the most endangered species in the world. In this study, we used whole-metagenome shotgun sequencing to analyze the effects of two different feeding patterns, goat milk feeding and breast feeding, on the composition and functional structures of gut microbiota in Amur tiger cubs. Goat milk-fed cubs have fewer beneficial bacteria and more pathogenic bacteria and a higher microbial diversity in their gut than breastfed cubs. A total of 15 genera showed statistically significant differences; the relative abundances of Streptomyces scabiei, Streptomyces avermitilis and Streptomyces davawensis were significantly decreased, whereas those of Niabella soli, Aeromonas media and Brochothrix thermosphacta were significantly increased in the goat milk-fed group compared with those in the breastfed group. At the functional level, carbohydrate metabolism, translation and replication and repair decreased, and amino acid metabolism, membrane transport and metabolism of cofactors and vitamins increased in the gut microbiota of goat milk-fed cubs compared with breastfed cubs. Our results indicate for the first time that the different milk feeding patterns of goat milk feeding and breast feeding can change the composition and functional structures of gut microbiota in Amur tiger cubs and that breastfed tiger cubs and goat milk-fed tiger cubs have distinct microbiotas in their guts.