Bacteria and cancer: Feeding your microbiome

How does what you eat affect your chances for cancer? Some new answers may be hidden in the millions of bacteria that live in your gut. 

These bacteria make up your gut microbiome -- the largest collection of bacteria in your body. It starts forming when you’re born, then grows and changes as you age.

Your diet sustains these bacteria. In turn, they help you digest food and absorb essential vitamins and nutrients.

Carrie Daniel-MacDougall, Ph.D., M.P.H., is a nutritional epidemiologist at MD Anderson. She’s about to begin studies to learn more about how a person’s diet and microbiome jointly contribute to the risk of obesity and cancer.

Microbiome research uncovers clues

“Having a healthy mix of gut bacteria may lower a person’s risk of obesity or weight gain,” Daniel-MacDougall says. “Obesity is a known risk factor for many cancers, including colorectal cancer.”

Your gut bacteria play a vital role in how much energy or calories your body extracts from food. They also help your body decide how many calories to store as fat.

“A lot of unknowns exist about which bacteria make up an ideal microbiome and which are truly harmful,” Daniel-MacDougall says. “But, we are learning that a diverse community of gut bacteria is beneficial to a person’s health.”

Keep a healthy diet, rich in plant foods

“A diet that includes a variety of plant foods seems to fill your body with a healthy balance of bacteria,” Daniel-MacDougall says.

Plant foods, like fruits, beans and vegetables, also tend to be rich in fiber. And, fiber helps nurture a robust community of gut bacteria.

Eating a variety of fiber-rich plant foods can also help reduce your risks for many cancers, including colorectal cancer.

Include healthy pre and probiotic foods in your diet

Eating pre and probiotic foods may introduce new bacteria in your body. It also can change existing bacteria to ensure you keep a healthy mix.

Prebiotic foods feed the bacteria already living in your gut. They include asparagus, bananas, oatmeal and beans or legumes.

Probiotic foods contain live bacteria. It’s considered “good” bacteria because it helps prevent the growth of harmful bacteria in your gut. Yogurt with live or active cultures is a probiotic food.

Stick with a stable diet

“It’s your long-term choices that matter most when it comes to a healthy microbiome and lowering your cancer risk,” Daniel-MacDougall says. “So, the first step is to choose a healthy diet that satisfies you. Then, you’ll be more likely to stick with it over time.”

Remember, you are what you eat.