Research over the past few decades has revealed that we humans host a bewildering variety of invisible creatures, our microbiota. We can almost envision the collective genome of all these microbes, the microbiome, as a sort of second genome for human individuals. Unlike our human genome, the microbiome can be altered based on our diet and factors such as whether we have taken antibiotics.
The exact balance of microbes in our intestinal ecology varies from one person to another. It may be time to jettison the old notion that all microbes are “germs” that will do us harm and learn how to appreciate microbial diversity. How does our microbiota influence our health?
How does a baby acquire its intestinal inhabitants? How do they change throughout the life cycle? The microbiota has significant effects on behavior, cognition and the immune system, as well as digestive well-being. Since the health of our microbiota is intimately linked to our own health, how should we be caring for it?
Doctors begin to suspect that imbalances in the microbiota may be at the root of serious problems such as inflammatory bowel disease. The classic example of microbiota imbalance causing digestive disease is C diff infection. This diarrheal disease often occurs when many of the gut microbes are wiped out by antibiotic treatment. As a result, Clostridium difficile has an open niche to exploit. Once firmly established, these bacteria can be hard to eradicate. Recently, doctors have resorted to fecal microbiota transplant from healthy donors to treat serious C diff infections.
How do we take care of our microbiota so it can take good care of us? One approach is to make sure we eat what the microbiota wants. Mostly, that means a high-fiber plant-based diet with relatively little red meat or sugar. In addition, fermented foods can be helpful. When we consume foods with live bacteria such as kombucha, kimchi, kefir, sauerkraut, real pickles or yogurt, we are getting living probiotics that may bolster the microbiota. What else should you be doing?
Justin Sonnenburg, PhD, is currently an associate professor in the Department of Microbiology and Immunology at the Stanford School of Medicine.
Erica Sonnenburg, PhD, is currently a senior research scientist at the Stanford University School of Medicine in the Department of Microbiology and Immunology, where she studies the role of diet on the human intestinal microbiota.
Drs. Sonnenburg are co-authors of The Good Gut: Taking Control of Your Weight, Your Mood, and Your Long-Term Health.