As humans we are essentially living communities – with our microbiomes. A microbiome is a mixture of millions of microrganisms, mainly bacteria, living in every body cavity and on our skin. Many of these useful "roommates" live in our intestines.

"Only ten percent of our cells are 'ours' – the rest is a cluster of germs", says Peter Holzer, a professor for experimental neurogastroenterology at the Medical University Graz. He is one of the top scientists from twelve institutions, which are participating in the "MyNewGut"-project. The project is subsidized by the EU with nine million Euros and its goal is to examine the microbiome's effects on our physical and mental health.