Understanding the Human Microbiome

By Jodi Rawson
Reader Contributor

Back in biology class, in the late ‘90s, I learned that our bodies were made of cells containing tiny “brains” called nuclei, with 46 chromosomes. Every cell that made me, I learned, contained human DNA.

A National Geographic I picked up nearly a decade ago threw out this teaching. Scientists were beginning to research the “human microbiome,” the organisms that live within us that contain no human DNA.

“We couldn’t do this 10 to 15 years ago, and that is why we were ignoring (gut microbes) — we couldn’t understand how many there were, and what they were doing down there,” said microbiologist Javier Ochoa-Reparaz of Eastern Washington University.

Estimates now suggest that only around 10 percent of the cells in our bodies are human. Ninety percent of the cells in our bodies our a complex community of bacteria, yeasts, and other mini organisms that are just being introduced to us.

“… Scientists have begun thinking about them (our microbiome) as another organ. Indeed about three pounds of every person’s biomass is microbial; that is roughly the same weight as a human brain,” wrote Lydialyle Gibson in UTNE Reader in 2015.

It all reminds me of “Horton Hears a Who,” by the wise Dr. Suess. Humans have been trying to eliminate bacteria since they first witnessed them through a microscope.

“But today, doctors are talking about how the antibiotic era may already be ending. Antibiotics are powerful weapons to fight disease — but they are powerful weapons that lose their effectiveness the more they are used. Like the Borg from Star Wars, bacteria begins to adapt,” wrote Daniel Waters for the Inlander.

Over 23,000 people die annually from antibiotic resistance, according to the Centers for Disease Control and Prevention.

“The paradigm has to change. Because we’ve been killing things for a long time, and now we have a lot of new problems: multiple sclerosis, neurological disease, Alzheimer’s, autism, inflammatory bowel disease, anastomatic leaks,” said John Alverdy, a microbial ecologist at the University of Chicago and Argonne National Laboratory.

There has been experiments in “fecal transplants” that are showing promising results. Transplanting the feces of a healthy human microbiome through an enema is beginning testing. In one test subject, not only did the the man’s health improve, but he began to grow hair where he had been balding. While this is exciting for some scientists and companies that hope to capitalize on fecal transplants, this type of research is disgusting to others, and companies are trying to hone in on the magic of feces in a “cleaner” way … perhaps as powder in a pill?

It makes me wonder about the robust health of my chicken-crap-eating dogs. According to Jack Gilbert, who partners with Alverdy in studying microbial ecology, “a dog can exponentially increase the microbial diversity of a home — they bring the outside inside.”

Years ago I was studying bacteria through cheese and kefir making. I developed a goat chevre that was fool proof because I worked with the raw milk rather than against it. Instead of pasturizing it and adding a single bacteria, as many of the recipes suggest, I added the culture (cheese bacteria or kefir) to the milking pot itself and the process of multiplying the right bacteria happened immediately, without compromising the benefits of the raw milk.

When a baby enters the world raw, they “have elvolved to get their starter microbial culture, their ‘sourdough bread,’” as Gilbert calls it, from their mothers’ birth canals. But that only happens if they’re delivered vaginally.” According to Cathryn Nagler, an immunologist that collaborates with Gilbert at the University of Chicago, “Cesarean section is a major environmental factor associated with allergic disease.”

Another environmental factor is the overuse of antibiotics, which I was on almost indefinitely during the months I trained in the National Guard. I was always ill and on drugs, it seemed, while I was training, ironically to be a medic. Since then I have developed food allergies.

Thankfully, I have been able to avoid antibiotics since 2003, and in my home I clean with products that do not genocide my microbiome. I have also consumed pounds of raw goat cheese and gallons of kefir in the last decade because I craved it, and it helped rebuild me. The North Idaho lakes and rivers that I have bathed in, rich in bacterial flora, and the black earth that squishes between my toes and fingers, feed me (and the tiny friends I host). I think my microbiome is happy because nowadays I feel healthy.

Science is only beginning to study our human microbiome. While we wait for understanding, it might be wise to be grateful. Yeah, bacteria! We love you.