First aired on Quirks & Quarks (16/11/13)
Jason Tetro wants us to build a better relationship with germs. Tetro is a microbiologist, science writer and broadcaster in Toronto, and in his new book, The Germ Code: How to Stop Worrying and Love the Microbes, he argues it's time to stop the war on germs, because we can't win it. In a recent interview on Quirks and Quarks, he explained that the huge majority of germs have no interest in us, and a large number are actually beneficial. Only a tiny few are harmful, and we need to control them while living peacefully with the others.
We may consider ourselves top of the food chain, but germs outnumber humans on Earth by an unimaginable number. They are vastly more diverse, and can live in every possible ecological niche. In fact, there are 10 times as many germs cells in your body as there are your own cells.
Tetro told Quirks host Bob McDonald that the title of his book refers to "a phenomenon that germs undergo in order to essentially survive and thrive in our environment. The germ code is really about evolution." He went on to say that human beings evolve about every 20 years. But germs can evolve about once every 20 minutes, which gives them a 200,000-times advantage over us. "So if we think we can ignore or put to the side the germ code we are definitely not doing ourselves a favour. And we really are harming ourselves in our relationship with them."
Germs are "microscopic organisms that can exist anywhere in the environment," and include bacteria, viruses, fungi, single-celled organisms known as protozoa and multicellular creatures known as nematodes.
Tetro's aim in writing his book is to change how we see germs. He pointed out that our approach in the last 25 years or so has been to "go to war against them, and try to dispose and get rid of them for the sake of our health." There are about 2.5 million germs, most of which don't have anything to do with us. There are also "tens of thousands" that are good, and help maintain our health and environment. There are about 1,450 harmful germs, and as individuals we "may only see about a dozen of those. We have a war on germs -- that we know we can't win -- essentially to get rid of about a dozen harmful germs." As Tetro puts it, "the world needs germs-relationship therapy," and his book is "the first step in that therapy."
In the 1950s and '60s, it was believed that we had won the war on germs, because the use of antibiotics and vaccines led to reductions in infections such as tuberculosis and gonorrhoea, and the eradication of smallpox and polio. But in the 1970s, we realized not only had we not won the war, we had actually made things worse. Tetro cited the widespread use of antibiotics in agriculture and the emergence of antibiotic-resistant bacteria in hospitals. "By 2011, it became very clear when gonorrhea that was completely antibiotic-resistant emerged, that we're in deep trouble," he said, adding that we have to start making significant changes "not only in health care but also in the entire society."
In particular, "we have to move away from the use of antibiotics simply because as these bacteria continue to evolve rapidly, they can share that resistance with other germs. They use the body as an incubator, where they can colonize and develop different types of toxins." One example of this is Clostridium difficile, which emerged in 2003 and "now is rampant and endemic."
One alternative is the use of bacteriaphages, which we've known about for almost a century. "But the whole idea of drinking germs to combat germs never really got off the ground back then, so it went nowhere," Tetro said. He went on to add that people use bleach or other chemical disinfectants that could develop resistance, but in fact "the most natural disinfectant isn't bleach, it's steam." He believes that we have to rely on "good germs and natural technologies" to help combat bad germs.
That is what's involved in fecal transplants. It may be difficult to believe that something the body excretes can actually have a therapeutic value, but Tetro explained that infections like C. difficile are "colonizing your gut. When you put the good germs in, they're essentially the cavalry. They kill off the bad ones, [and] shove the bad bacteria out of the way, because they love the intestinal lining more than the bad germs do."
The best thing for our health, Tetro said, is to be exposed to "a diversity of microbes in our lives." He contends that "it really comes down to us appreciating the relationship we have with germs," and respecting the fact that "that they outnumber us and out-evolve us." The key thing is "to make sure that you're surrounded by good germs, and the bad ones are either kept away or killed."