Microbes ‘R’ Us - Olivia Judson Blog - NYTimes.com
But it’s the bacteria in the digestive tract, especially the gut, that intrigue me most. Many of these appear to be true symbionts: they have evolved to live in guts and (as far as we know) are not found elsewhere. In providing their habitat — a constant temperature, some protection from hostile lifeforms and regular influxes of food — we are as essential to them as they are to us.
I'm intrigued by germ-phobes. Why do they fear germs when 99.9999 percent of them cause us no harm, and in fact some are beneficial to us?