Doctor's Tip: How lifestyle affects our microbiome - Glenwood Springs Post Independent

This is the fifth in a series of columns based on Dr. Dean Ornish’s recent book “Undo It.” The book makes the case that our health is not determined so much by the genes we’re born with but by whether these genes are turned on or off. And to a large extent, that process is determined by our lifestyle.

Our microbiome — particularly our gut microbiome — is a key player in our health, and should be thought of as another organ system, similar to our brain, kidneys, liver, etc. Dr. Ornish is currently doing research with a leading microbiome scientist “to understand how the four components of our lifestyle medicine program — eat well, move more, stress less, love more — interact with our microbiome in healing ways.”

Humans have over 100 trillion organisms (bacteria, viruses and fungi) residing in our mouth, nose and gut; and on our skin (there is also a vaginal microbiome). The genes in all the organisms in our microbiome outnumber all the genes in our own cells by at least 100 to 1. Depending on our lifestyle, our microbiome can keep us healthy or make us sick. Here are some examples:

• Obesity: Diets high in fat, sugar or refined carbohydrates adversely affect the type of microbes in our gut microbiome, as well as their diversity (a health-promoting microbiome has many different species). These foods cause “the growth of microbes that harvest energy more efficiently — in other words, you gain more weight eating the same amount of calories.”

• More obesity: A high-fat diet causes gut microbes to modulate our genes that affect fat storage, making us more efficient at storing calories as fat — not good if you are overweight or don’t want to be.

• Inflammation: A diet based on animal products increases the number of microbes that cause chronic inflammation — and inflammation contributes to cardiovascular disease, diabetes and cancer.

• Depression: Gut bacteria manufacture neurotransmitters like serotonin and norepinephrine, “which can help keep you from feeling anxious, depressed and tired.”

• Dementia: There is evidence that inflammation plays a role in Alzheimer’s disease. According to Dr. Ornish, Alzheimer’s disease patients have a lower number of gut bacteria that have anti-inflammatory activity, and a higher number of bacteria that cause inflammation.

• Cardiovascular disease: A healthy mouth microbiome helps prevent dental plaque buildup, cavities and gum disease — all of which cause chronic inflammation, leading to many diseases including heart attacks and strokes.

• Cancer: A prevalence of certain species of gut bacteria increase risk of colon cancer.

How can you develop a health-promoting gut microbiome?

• Eat well: The bacteria in our gut microbiome feed on fiber, which is found in only in plants. Animal products encourage disease-causing gut bacteria. Fruit, vegetables and whole grains encourage health-promoting gut microbes.

• Move more: Studies show that exercise increases microbes that produce short-chain fatty acids, which reduce disease-causing inflammation.

• Stress less, love more: Dr. Ornish has shown that avoiding negative emotions such as stress and loneliness (even a pet helps) cuts down on the number of interleukin-producing gut bacteria — interleukins cause inflammation, harmful activation of your immune system, and depression.

• Avoid antibiotics unless absolutely necessary. One weeklong course of antibiotics “can change your gut microbiome for up to a year.”

• For a healthy mouth microbiome, avoid antibacterial mouthwashes and toothpaste.

In summary, be kind to you’re the trillions of organisms that make up your microbiome — they can be your friends, or your enemies.

Greg Feinsinger, M.D. is a retired family physician who has a nonprofit: Prevention and Treatment of Disease Through Nutrition. He gives a free presentation at 7 p.m. the first Monday of the month at the Third Street Center in Carbondale; is available by appointment for free consultations (379-5718); and conducts a shop-with-a-doc session at 10 a.m. the first Saturday of the month at Carbondale City Market.