Microorganisms living inside the human body make crucial contributions to how the immune system combats disease, according to Prof. Rodney Dietert, immunotoxicology.
In a talk in Mann Library Thursday, Dietert discussed topics from his book with students in attendance, including the role the microbiome plays in human health.
The microbiome, according to Dietert, is defined as the bacteria, the viruses, fungi and parasites that live on and in the human body. Although his research on the subject has earned him several accolades, he said it is a topic he has only just begun to explore.
“I never focused on the microbiome in my career until very recently,” he said. “The book came about really through serendipity, dreams and what you might call gut instinct.”
The inspiration to write arose when Dietert decided to participate in a challenge posed in a physics journal, which asked respondents to identify a potential biomarker that could predict the long-term health of a newborn baby.
“That was just too good an invitation to pass up; that’s too intriguing,” Dietert said.
The answer he suggested with was the microbiome. In his submission to the journal, Dietert said he wrote that a baby born “as just the mammalian human” is incomplete.
“The baby is completed by the microbiome,” he said.
Although research on the human microbiome has only received attention recently, scientists have found that it serves an integral purpose in the human immune response, according to Dietert.
“Sixty to 70 percent of your immune system is in the gut. That’s where a lot of the microbiome is as well,” he said. “That immune system has to be trained how to interact with the environment … And that’s what happens postnatally, when the microbiome and the immune system commature together. If these things are missing, it’s analogous to missing an organ.”
He added that many major health complications — such as allergies, asthma and cancer — are much more commonplace today than they were decades ago, and that analyzing the microbiome is an important factor in addressing this “epidemic” of noncommunicable diseases.
“While this is a microbiome book, it is really a book about what’s killing us and what is disabling us and causing us to need more healthcare and medicine in our lives,” he said.
Because the microbiome has such a significant presence in the human body — more than 99 percent of the genes on and in a person are microbial — Dietert argued that further research on this subject will be crucial to the future of medicine.
“[These genes] are a rich target for modifying for our better health,” he said. “If we’re going to do precision medicine, this is the place to start, the 99 percent. And to ignore it would be, well that’s where we are at the moment, ignoring it.”
He stressed that much work needs to be done to discover the full potential of this area of biology.
“Good news, bad news for toxicology,” Dietert said. “We don’t know what’s safe, but [toxicologists have] work to do for decades, because we didn’t ever include the microbiome in the assessment of [the] safety of drugs, environmental chemicals, food.”