Excerpt: When you take a broad-spectrum antibiotic, which is the kind most commonly prescribed, it may be that rare microbes occasionally get wiped out entirely. And once the population hits zero, there is no bouncing back. For your body, that species is now extinct. My worry is that some of these critical residential organisms — what I consider “contingency” species — may disappear altogether.
Why might it matter? Those puny species may not be so inconsequential. Microbes multiply. Any small population of, say, 50 cells can explode into a billion or more in one week. The trigger for their massive bloom could be a food you’ve eaten for the first time, which only they have the enzymes to digest. In the presence of this food, the rare microbe goes into overdrive, doubling every 12 or 20 minutes, multiplying by a million percent or more. Read more….