The natural history of Caenorhabditis elegans

Does Hydra have an associated microbiome? Yes, it does. Like the human gut, Hydra is home to an array of bacterial residents. The composition of the microbiome for a particular strain of Hydra seems to be quite stable. How the microbiome is maintained and what it contributes to the host are important questions that are starting to be addressed. Hydra is a much simpler model for studying host/microbe interaction than vertebrate models such as humans and mice.