Ask Dr. Bell — What’s the Microbiome?

About 100 trillion bacterial organisms too small to be seen by the naked eye live in our intestines and throughout our body. They outnumber human cells in the body 10 to 1.

These microbes — collectively known as the microbiome — are essential to your survival, helping with digestion and the absorption of nutrients, developing your immune system and protecting against harmful pathogens. They might even play a role in regulating stress and anxiety.

“The bacteria in our body is really driving the show,” says Robert Baldassano, MD, pediatric gastroenterologist and Director of the Center for Pediatric Inflammatory Bowel Disease at Children’s Hospital of Philadelphia, and a leading researcher of this new frontier in medicine. “We’re like a shell transporting the bacteria through the environment.”

But that doesn’t mean we are passive hosts. The food we choose to eat has an influence on our microbiome, and what we ingest can disrupt the environments where these organisms reside, possibly predisposing us to a wide range of chronic diseases, including obesity, inflammatory bowel disease, type 2 diabetes and even cancer.

Take antibiotics, for example. Not only are they the most prescribed drugs for humans in the United States, but they are also added to animal feed to fatten livestock. It wasn’t until recently that scientists uncovered why this works: Antibiotics alter the bacteria in the animals’ guts to make them obese. When you eat meat treated with antibiotics, the drugs are passed on to you and have the same effect on your gut bacteria.

Scientists now believe these two phenomena — people taking many antibiotics and eating meat containing the drugs — are contributing factors in the current obesity epidemic.

Emulsifiers — used in processed foods to keep ingredients from separating, improve texture and extend shelf life — have been found to alter the microbiome in a way that degrades the protective mucus layer in our intestines. This can cause intestinal inflammation, which in turn can lead to multiple diseases. A recent study found that when intestinal microbes metabolize a nutrient in red meat, they produce an organic compound that causes clogged arteries.

Working in our favor

The realization of these connections among our diet, our microbiome and our health, while alarming, has opened one of the most exciting new opportunities in drug development. Baldassano and other researchers are now investigating how we can use diet and drugs to alter the microbiome in ways that promote health instead of disease.

So what can you do about all this? While researchers are hesitant to make concrete recommendations just yet, Baldassano shares the following key takeaways:

• The first three years of life are the most critical in the evolution of the microbiome. Be aware of the risks of antibiotic overuse and judicious in their use during this time.
• Avoid eating foods treated with antibiotics.
• Reduce or eliminate food with emulsifiers. Instead, eat fresh food and bread from a bakery.