“We’re more microbial than human,” said Suzanne Devkota, PhD, an assistant professor of gastroenterology and a member of Cedars-Sinai Precision Health‘s core team. “The bacteria in our gut alone outnumber all of our cells in our entire body.”
The collection of microscopic organisms—including bacteria, fungi and viruses—that lives in our bodies is called the microbiome. Each person’s microbiome is as unique as a fingerprint.
That means we each have two genomes in our bodies—the set of genes we’re born with and the set of genes that make up the organisms in our microbiomes. When determining how to treat a specific patient’s disease, many scientists propose we actually consider the two genomes as one, the so-called hologenome.
Both halves of this unified genome affect diseases such as cancer, diabetes, and obesity, as well as our body’s response to treatment.
And while we can’t change the genome we’re born with, changing our microbiome can be as simple as changing what we eat.
“That’s where precision medicine comes in,” Devkota said. “If we can manipulate that microbial part of our genome, we may actually change how someone responds to a drug, and potentially eliminate side effects.”