Without germs, we're nothing Health Nikki Tundel · St. Paul, Minn. · Apr 4, 2007 Bring on the bacteria Dennis Kunkel Bacteria outnumber us a trillion to one. So it's a good thing most of them are friendly. Gerald Callahan, the author of Infection: The Uninvited Universe, talks about why we need bacteria to survive. Stay Informed The news on your schedule from MPR News Update Email Address* Zip Code MPR News Update AM Edition MPR News Update PM Edition See our Privacy Policy. Must be age 13.