Lynn Margulis and Emily Case in Orion Magazine:
Babies rely on milk, food, and finger-sucking to populate their intestines with bacteria essential for healthy digestion. And microbial communities thrive in the external orifices (mouth, ears, anus, vagina) of mammals, in ways that enhance metabolism, block opportunistic infection, ensure stable digestive patterns, maintain healthy immune systems, and accelerate healing after injury. When these communities are depleted, as might occur from the use of antibacterial soap, mouthwash, or douching, certain potentially pathogenic fungi—like Candida or vaginal yeast disorders—can begin to grow profusely on our dead and dying cells. Self-centered antiseptic paranoia, not the bacteria, is our enemy here.
But in our ignorance, we also miss a larger lesson. Bacteria offer us evidence that health depends on community, and independence is an ecological impossibility. Whenever we treat isolated medical symptoms or live socially or physically isolated lives, we ignore warnings from our more successful planetmates.