The animal gut microbiome consists of a complex community of microbes with potentially large effects on host health and fitness. Unfortunately, we know very little about when this bacterial community colonizes the gut and how it matures in juveniles, especially in birds and non-model organisms. To evaluate these questions, we sampled juvenile ostriches in South Africa over time, from one-week-old chicks to 12 weeks of age.

A fascinating picture of microbial development emerged. As chicks grew older, the microbial community generally became more diverse. However, some microbes colonized juveniles immediately after hatching only to go locally extinct a few weeks later, others persisted through development, and some did not establish until older ages. We found certain bacteria that were associated with yolk nutrition in the weeks after hatching, and some bacteria that were negatively associated with juvenile growth several weeks later. Interestingly, several of the bacteria that were more abundant in chicks with reduced growth, have also been associated with reduced weight in mice and humans. These results enable a better understanding of microbiome development in animals, and highlight specific microbial groups important for host fitness.

See the complete paper here: https://onlinelibrary.wiley.com/doi/full/10.1111/mec.15087

– Elin Videvall, Smithsonian Institution and Charlie Cornwallis, Lund University