By Dr. Victor S. Sierpina
Germs are good for you. At least certain kinds and combinations of germs can be a positive contributor to your and your family’s health.
A recent article by Michael Pollan in The New York Times magazine, “Some of My Best Friends Are Bacteria,” summarized some amazing research I have been following for the past decade or so. It turns out that our lives are highly interdependent with the bacteria in our world, on our skin and in our gut ecology.
Bacterial DNA in our bodies, the microbiome, outnumbers our own human DNA by at least 100 times. The estimated 100 trillion bacteria inhabiting our bodies at any time is called our microbiota. Most of them are living in our gut.
Our vital interrelationships with these tiny living beings and their effect on health are slowly coming into focus. Because they multiply and mutate faster than our human genome, they can actually provide protection to us in quickly changing environments.
While in the past, infectious diseases were a major cause of death, it is now clear that various microorganisms actually reduce the risk of many diseases.
We have changed the environment and variety of the bacteria in our personal and collective ecology by — processing foods, treating farm animals with antibiotics to make them gain more weight, assiduously sterilizing our food and the wide use of antibiotics medically.
A round or two of antibiotics for a respiratory, urinary or other infection can significantly alter the kind of bacteria in our gut, leaving us prone to other infections, inflammation and immune risk.
On the other hand, exposure to dirt and a variety of germs early in life reduces the risk of such conditions as asthma, allergy and connective tissue disease.
In societies where intestinal parasites are common, inflammatory bowel disease is rare. The immunity the body mounts against the parasites is protective. The kinds of bacteria we have in our gut also affect metabolic regulation of intestinal absorption, detoxification and the interaction among friendly bacteria and pathogenic ones that cause disease.
Such interactions profoundly affect the immune system and inflammatory processes. Some alterations in gut bacterial ecology can lead to the kinds of diseases common in westernized society such as obesity, cardiovascular disease, metabolic syndrome, diabetes, allergy, immune problems and even cancer.
Infants have a sterile gut at birth but are inoculated with the mother’s bacterial mix as they pass through the birth canal. Those born by C-section, a sterile medical procedure, do not get this exposure and have a bacterial mix more like mom’s skin. These children have been found to have higher rates of asthma, allergy and immune disease.
Research on many of these topics remains in its infancy but is evolving quickly. The exact mix of bacteria in our inner ecosystem that contribute to good health remains a holy grail of scientists in this area.
According to Stanford microbiologist Justin Sonnenberg, eating abundant fiber and a variety of polysaccharides is the safest way to increase microbial biodiversity. Likely, there is no single Rosetta stone model of DNA, bacterial composition, human genomic patterns or diet that will be generalizable to all persons or genotypes.
So after a century of fighting infectious diseases, we are discovering that germs are not always bad for us. We are finding, too, that antibiotics are not always only good for us but might have a downside.
As Pollan said, we might not after all be individual human beings but complex superorganisms. We are living in dynamic equilibrium with the vibrant, information-rich ecology of the enormous microbiome active within and without us.
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At a glance
•Research is showing that the kinds of food we eat can have profound effects on our long-term health. Here are some suggestions that are precautionary, conservative and likely helpful:
•Avoid unnecessary antibiotics including foods containing them.
•If you must take an antibiotic, use a probiotic mixture containing such species as Lactobacillus and Bifidobacteria to help recolonize your body with helpful bacteria.
•Eat a diet high in fiber to help feed healthy gut bacteria. Such fiber acts as a “prebiotic” to nurture growth of healthy species. Fiber can be soluble like onions, nuts, root vegetables, insoluble like in whole grains, bran, avocados or resistant starch fiber like in bananas, oats and beans.
•Exposure of children to dirt, germs and pets can be good for their long-term health.
•If your child is born by C-section, try to breast feed, add probiotics to their diet and expose them to mother’s internal bacteria as soon as possible.
Dr. Victor S. Sierpina is the WD and Laura Nell Nicholson Family Professor of Integrative Medicine and Professor of Family Medicine at UTMB.