Move over, gluten-free: Probiotics are the new darling on the food-fad scene. With science suggesting that these friendly intestinal bacteria fight colds, ease irritable bowel syndrome, and lower LDL cholesterol, food companies have leaped onto the probiotics bandwagon and busted yogurt’s former monopoly: Ice cream, sauerkraut, and fruit juice are now among the foods touting probiotic content, and that list promises to grow in 2014.

Refereeing the probiotics parade is Centennial-based Mary Ellen Sanders, one of America’s foremost probiotics experts. Over the past 23 years, Sanders, who holds a doctorate in food science with an emphasis in microbiology, has helped steer worldwide debate on the topic and assisted the country’s biggest food and supplement companies in understanding the dark, mysterious world of “good” bacteria.

What fascinates you about probiotics?

Twenty years ago, probiotics research was just starting to take off, so I’ve been able to see this whole field develop from its infancy. Now, the international community is looking not only at probiotics but at all the microbes that colonize the human body. We’re starting to understand how influential those microbes are to people’s overall health. And how unique: Your microbiome is as distinctive as your fingerprint.

Are probiotics worth the money?

Assuming you maintain the basic principles of a healthy diet, increasing the amount of fermented and probiotic-rich foods you eat is a good thing. Certainly our ancestors from Paleolithic times—and earlier—were eating a lot of live microbes, more than we eat today because our food supply has become so clean [thanks to pasteurization and refrigeration]. But we’re learning that you need your gut microbiota (microbes in the intestines) to be balanced and intact to keep you healthy.

What’s emerging in probiotics research?

Preliminary research has established a link between people’s microbiota and chronic health problems, such as obesity and diabetes. We don’t know yet whether that relationship represents a cause or an effect, but the link is clear. And it’ll be interesting to watch what we learn about probiotics’ impact on gut-brain interactions. We already know, from pilot studies and research on animals, that certain probiotics have an effect on anxiety and stress. We could potentially use probiotics to treat those issues, and maybe even pain, through the brain’s pain receptors.