Just over a decade ago, Tamara Duker Freuman, MS, RD, CDN, left her business career to pursue a degree in dietetics. During one of her courses, Freuman’s professor showed the class an annotated diagram of the intestine, indicating what is happening in each section of the digestive tract.

“For me, it was a lightbulb moment, that the human digestive tract is literally a road map,” Freuman recalls. “If you can understand disease and where the problem is, there’s a direct correlation to diet and nutrition. I felt that this was an area where a nutritionist could have such a profound impact. I was so attracted to that from day one.”

When patient after patient kept seeking her out for the same problem—unexplained bloating—that no doctor could fix, Freuman realized it was time to put her findings about digestive health over the last eight years into an easy-to-use guide for patients and health professionals. In December, the digestive health expert released her first book, “The Bloated Belly Whisperer” (St. Martin’s Press, 2018).

“I wrote my findings down to equip patients to take matters into their own hands and narrow down the most likely causes of their problems so that they can facilitate a diagnosis with their own doctor faster,” Freuman says. “I also wrote it for my colleagues—because I get calls from other dietitians all across the country all the time—to help them help their patients better.”

24Life sat down with Freuman just in time for the new year to discuss all things gut health—including why that New Year’s resolution diet might actually be doing you more harm than good.

24Life: Gut health is all the rage right now. People are mapping their gut biomes. What do you think of this phenomenon?

Tamara Freuman: I will caveat this by saying we don’t really know how to define the health of the microbiota yet. A healthy microbiota does seem to be connected to a wide variety of other health outcomes, both digestive (inflammatory bowel disease, irritable bowel syndrome) and otherwise (other autoimmune diseases, Parkinson’s disease, diabetes risk, obesity). It does seem that there is a relationship between the health of your gut microbiota and many other things in your life. What’s problematic is we don’t yet understand the nature of that relationship. What is a healthy gut microbiota? It’s not like there’s one model of what a healthy ecosystem is. The researchers studying microbiota are seeing tremendous diversity. And while there are common characteristics of what a healthy microbiota is—it’s really contextual. A healthy microbiota for someone in urban New York City might be really different [from] someone in rural China. I think there’s this idea among consumers that there’s a well-defined archetype of a healthy microbiota, but that doesn’t exist. So this idea that we all should be working toward a specific archetype is, I think, not really grounded in fact. This idea that we can even manipulate or micromanage our gut microbiota is also a really big question mark.

24Life: What about probiotics? Should we be taking them?

TF: There’s this idea that we need to have more good bacteria, so we should take pills and we’ll have a healthy microbiota. That’s really not well-established. It’s not clear that probiotics really do much at all to manipulate the gut microbiota. I feel that the probiotics we currently have available are probably not relevant for most people and probably don’t promote much by way of good health for most people. I think we will reach a point in our understanding of the microbiota and how to manipulate it, and we may well find a version of probiotics that is relevant and that is health-promoting and maybe will be individualized for people or tailored in a certain way. Right now, taking some random product off the shelf because you want to have “a better balance” or promote immunity—I wouldn’t bother.

I was interviewing a bunch of experts, including the scientific director at one of the country’s biggest labs studying the human microbiome. They have 17,000 samples of poop and are mapping out the variation of microbes in Americans’guts  and how they correlate to diet. I asked him if any of the microbiome researchers in the lab take a probiotic. He said no, but almost all of them eat fermented food. That’s really telling, that the people who know this stuff the best don’t bother taking probiotics, but they recognize that there does seem to be some health-promoting benefits to eating fermented food. I think it’s reasonable and probably beneficial for people to seek out more cultured foods.

24Life: What else can we eat for a healthier gut microbiota?

TF: The best way we know how to manipulate gut microbiota—the only real way we know—is to eat a diet that’s high not just in total fiber but in a diverse array of different types of fiber. If you’re eating a diet that’s high in fiber from 10 different types of fiber, you’re going to feed a lot greater variety of different species of microorganisms in your gut.

I tell people really you’re looking for diversity. Eat the most diverse types of plant foods you can comfortably tolerate. Any food that creates a lot of gas, by definition, feeds bacteria really well. [What’s] making that gas? The bacteria are making that gas when they ferment the food. The gassiest foods you can think of are the ones that feed your microbiota the best—cauliflower, beans, Brussels sprouts—all those really healthy but really gassy fiber-rich foods. Now, if those foods aggravate you and cause distress, obviously, don’t eat them. If they don’t bother you, those are great foods to eat.

There’s another category, and these are foods rich in prebiotic fiber. Prebiotic fiber is a type of fiber that is known to feed beneficial species of bacteria very well. Foods that have prebiotic fiber are things like onions, garlic, artichokes, jicama, leeks. Those types of foods are great, if you can tolerate them, and may have a really nice beneficial effect on promoting the growth of known beneficial species of bacteria in the gut.

24Life: It sounds like plant-based is the way to go for gut health?

TF: I think plant-heavy, not necessarily plant-based. I think a lot of people hear plant-based and think they have to be vegan. That’s not true. I’m an omnivore. I follow the Mediterranean diet, but I have a very plant-heavy diet. Whatever dietary pattern you follow, the way to promote a diverse, robust, healthy gut microbiota is to eat a diverse array of lots of plant foods. If you’re not eating a lot of plant foods, it’s going to be really hard to optimize the health of your gut’s ecosystem.

By way of background, I’ll say I’m not a dogmatic proponent of any one way of eating. I think there are many dietary patterns that are consistent with good health, as long as your dietary pattern is rich in a lot of different plant foods. The dietary pattern only tells me so much about what’s going in your mouth. I have vegetarian patients who don’t eat vegetables because they don’t like them. Those are the macaroni and cheese, Diet Coke vegetarians. You tell me you’re vegetarian, I still don’t know anything about what you actually eat. So from my perspective, you should follow the healthiest diet that meets your food preferences and convenience. Are you someone who can cook or not? If you’re someone who doesn’t cook, you probably shouldn’t be a vegan. That’s not a great plan for you. I think you want to find a plant-heavy diet that matches your preferences, lifestyle, cultural heritage or beliefs.

24Life: How can healthy diets become the cause of constipation, bloating and gut distress?

TF: Sometimes what happens is people will adopt what they call a “clean-eating protocol.” A lot of the leading clean-eating protocols are grain-free. They really limit fruit because of sugar. You’re only allowed to have berries. People are eating vegetables, nuts, berries and protein. Some people might feel great on that diet. If you had a junky diet, many people find it [helps them be regular] and they’re so happy. But the opposite thing can happen. [Those are] the patients I see. When you go to a diet like that, you inadvertently cut out a specific type of fiber called soluble fiber.

Soluble fiber is a type of fiber found in grains, fruit and root vegetables. Soluble fiber holds onto water and fluid in the gut and retains it like a sponge. If you’re someone who might tend on the slower side of digestive transit time, which some people are, if you don’t have enough soluble fiber in the waste stream, there’s nothing to hold onto moisture in the waste while it’s moving slowly through the gut. By the time it makes it to the end of the colon, it’s completely dried out and hard as a rock. That can be really constipating.

It’s just something I point out in my book and articles I write, which is sometimes a really objectively healthy diet can have an unanticipated, unintended consequence on your digestive function. It doesn’t mean you’re doing something wrong. It doesn’t mean your diet’s not healthy. It means you changed the composition of your diet and your new diet is going to be behave differently in the GI tract. It means this particular dietary pattern doesn’t agree with your body.

24Life: What advice do you have to help people avoid bloat in the new year?

TF: I would say ease into diet change. I think it’s our tendency to just dive in headfirst to dramatic overhaul of the way we eat and live. That’s human nature, but dramatic changes in your diet can have unintended consequences. That is especially so if you go on a diet where you really are eliminating a large number of foods that used to be your staples and making foods central that previously might have been peripheral in your diet. [A good example is] cauliflower—you used to have it once a week, and now it’s replaced the rice and bread and pizza crust in your diet.

If you’re able to, take a step back and ask, “What is the goal diet I want to get to, and can I give myself three months to work my way there gradually?” Making incremental changes as you go, see how you feel so if you introduce a big change and feel miserable, now you know what [made you feel bad]. When you change everything at once and it’s dramatic and you feel terrible, you have no idea what caused it. And frankly, it’s more sustainable to change gradually. How many people stick with a completely dramatic overhaul to their diet for more than a month or two? Pick something discrete, achievable that you can work and habituate into your life until it doesn’t take effort to do it anymore. Once that’s automatic, you’re ready to take on a new discrete goal. You do it in that incremental way. By the time the three months rolls around, you’ve gotten to the dramatic change. You’ve done it in a way that makes it more likely you’ll stick with it and makes it more likely that you already vetted the individual changes and know they agree with you.

Photo credit: Dawit, Unsplash; Courtesy of Tamara Freuman