A gut punch against COVID-19?

“You are what you eat.”

Jean Anthelme Brillant-Savarin, a French lawyer, epicurean, and father of the low carbohydrate diet, penned these words in the 18th century. As we struggle through the COVID-19 pandemic, we search for personal ways to influence our health and our immune system to combat this pestilence. Food choices are an overlooked variable that may alter our fate.

Our human engagement with infections is played out daily through our immune system. Ironically, we are dependent upon our commensal microbes that happily reside in our bodies to assist in the fight against environmental, viral, and bacterial invaders.  Over one hundred trillion bacteria and untold fungi, archaea, and microscopic multicellular microbes take up residence in the gut after birth.  These microbes are a virtual army responsible for innate immunity and the initial fighting response to pathogenic agents. Furthermore, these bacteria contribute forty times more genes in the gut than human genes in the entire body. The exact role of these genes is uncertain, but they may produce proteins that may influence the bodies fighting power.  It is believed this gut bacterial diversity and their metabolites protect us by establishing an intact mechanical barrier, facilitating the release of bacterial and human antimicrobial chemicals, and competing with pathogens for nutrients. They trigger the inflammasome, a coordinated release of immune-stimulating chemicals (cytokines) that arm the lymphocytes, macrophages, neutrophils, dendritic, and plasma cells that produce the coordinated inflammatory response.  A delayed innate response can result in a virus that gains a foothold that cannot be stopped. Similar to friendly fire, an over-exuberant immune response can injure tissue from toxic inflammatory chemicals long after the pathogen has been vanquished.

Older age, diabetes, and obesity are clearly risk factors for severe adverse outcomes with COVID-19. The common metric of these risks is a dysfunctional immune response. A slow initial response or an unregulated and injurious inflammatory reaction can result in devastating consequences for the infected host.  The gut microbes and their genes, the so-called microbiome, are fundamental for a proper defense to infectious agents. A healthy microbiota is still being defined, but with new molecular biological techniques, a diverse population of organisms is critical to drive down the middle lane of life — away from infectious disease and autoimmune/allergic disorders. Altered microbiota or dysbiosis, is the hallmark of obesity and diabetes. And our country is flush with these risks. Over 40 percent of the U.S. is obese, representing a four-fold increase in prevalence since the 1960s.

The microbiota can be malleable and is dictated by food for good or bad. And, food choices in our country may have steered us into more fatal outcomes with COVID-19. Processed food, hydrogenated and trans fats, high fructose corn syrup, larger portion size with higher calories, and antibiotic tainted meats have assaulted the beneficial microbes in us. Could this be one of the reasons we are the leading country in COVID-19 cases and deaths?

Social distancing and masks are first-line defenses against the coronavirus fight.  Food choices may be another volitional pathway to maintain health. Fermented foods can select for beneficial commensal bacteria that make-up one’s microbiota. Greek yogurt, sauerkraut, tempeh, kimchi, and miso can favor the growth of Lactobacilli and Bifidobacter genera, both known to be healthy members of the microbiome.  Germany, Korea, and Japan have low per capita rates of disease, attributed to timely public health measures and widespread COVID-19 testing. Might these differences be partly explained by eating sauerkraut in Germany, kimchi in Korea, and miso in Japan?  Do some long-standing cultural food preferences select for a healthier microbiome that is protective for coronavirus infection or helps to modulate an appropriate immune response?  It seems to this clinician that it’s worth a clinical study as we, the people of every culture and nation, come together to collectively look to each other for any possible clue to mitigate the ravages of this virus.

Lawrence Hurwitz is a gastroenterologist.

Image credit: Shutterstock.com

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