Thanks to Louis Pasteur, a cornerstone of our modern medicine has been based on the notion of 'killing germs'. But current science is telling us that struggling against germs is not an accurate portrayal of what it means to be healthy. Rather than thinking of our bodies as a battlefield, humans and microbes must now be seen as a co-evolved system for the mutual benefit of both the host and resident microbes. Health is the result of balanced harmony between resident microbes and human cells....