MC lecture to focus on how food, lifestyle affect the body

The term “ecosystem” brings to mind vast and complex interacting environments such as forests or sea beds, but the individual bodies of humans also are ecosystems.

Dr. Jack Gilbert has made the human microbiome his life’s study, with research in recent years showing that our bodies are more than they appear, consisting not only of the parts and chemicals detailed in medical books but also of an entire, integrated living and interdependent community of organisms unique to every person.

“There are about 40 trillion bacterial cells in our bodies – put them all together and they’d weigh about a pound,” he said. “They produce chemicals we rely on, and the work we’ve done is to understand what they do, what goes wrong when they’re disturbed by things such as antibiotics, diets, sedentary behavior, and what’s useful to rebalance that equation.”

Gilbert will be in Marietta Tuesday to participate in a noon-hour panel discussion on food allergies and in the evening to deliver the annual Krause Lecture in Science at the Alma McDonough Auditorium on the Marietta College campus. Both events are free and open to the public.

Public health authorities, doctors and scientists have been increasingly concerned about the widening occurrence of autism, Alzheimer’s disease, various sorts of allergies, obesity and other conditions. The microbiome appears to be a critical influence.

Gilbert is a professor in pediatrics at University of California-San Diego and a professor with the Scripps Institution of Oceanography, as well as group leader in microbial ecology at Argonne National Laboratory near Chicago and a visiting professor of surgery at the National University of Singapore. For eight years he was professor of surgery and director of the Microbiome Project at the University of Chicago, and he is a doctoral graduate of Unilever and Nottingham University in the U.K. and received postdoctoral training at Queens University in Canada.

He is the author of “Dirt is Good: The Advantage of Germs for Your Child’s Development.”

The research in which he has been involved blurs the line most people think exists between their bodies and the world around them.

“The microbiome is actually more numerous than the human cells we have,” he said. “They spread around us, we release 30 million cells every hour. Wherever we go, we leave behind our microbial selves all the time. The interaction between our microbiome and the environment has a big impact, for instance, on how your immune system works.”

Gilbert said microbiome research could hold the answers to many medical mysteries.

“It’s going toward understanding why different people respond differently to drugs, foods, lifestyles,” he said. “We’ve seen dramatic increases in chronic diseases in our population – autism, asthma, behavioral disorders, cancers – and ask, why are these things getting worse?”

The microbiomic galaxies within each of us could hold the key to that, he said.

“We’re trying to operationalize the evidence to give people the best lives they can have,” he said.

The lecture Tuesday night will include information that is useful.

“Most of the work we do is easily applied solutions, and much of it is diet, encouraging the good bacteria – like consuming fiber – and discouraging the bad,” he said. “If, for instance, you eat fiber and polyphenyls (colored vegetables), you promote growth of bacteria that produce neurotransmitters, such as dopamine. We used to think nutrition stopped with the gut, but the way the food feeds your bacteria has big downstream effects. Each of us has unique blood sugar response, for one thing – some people can eat ice cream and not gain weight, others do gain weight, and that’s due to the bacteria that live in your intestines.”

Mark Miller, associate provost for Marietta College, said he met Gilbert at a conference on food allergies, something he has a personal interest in, and invited him to come to Marietta to speak.

“I heard Dr. Gilbert talk and thought he would be great for the Krause Lecture,” Miller said.

In addition to delivering the Krause Lecture at 7 p.m. Tuesday in the Alma McDonough Auditorium, Gilbert will also sit on a public panel Tuesday at noon in the Dyson Baudo Recreation Center to discuss food allergies. He also is scheduled to meet with masters students in the physicians assistant program and will speak to any science students who are interested in hearing about the process of getting into graduate school and have questions about the life of a scientist, Miller said.

Dr. Jack Gilbert at Marietta College, Tuesday

•Noon to 1:30 p.m. – Panel discussion on food allergies, second floor trustee conference room, Dyson Baudo Recreation Center (event is free but RSVP requested online at

•7 p.m. – Krause Lecture, Human and Environmental Microbial Health: A Global Perspective, Alma McDonough Auditorium.

Both events are free and open to the public.