Is there gold in bugs? Scientists and natural health experts say yes. The burgeoning field of the microbiome—the bacteria, fungi, viruses, and archaea that live in our guts (our stomachs and intestinal tracts)—is becoming the health issue to watch.
The gut microbiome, evidence says, is linked to numerous aspects of health—from inflammation and autoimmune diseases to weight gain and mood. As part of this gamut of connections, researchers are also eyeing its role in digestive disorders, including the vast and still perplexing universe of gluten sensitivity. “There’s been a big explosion in funding a lot of microbiome research, and of course gluten sensitivity is a huge area to study,” says Florence Comite, MD, a personalized medicine physician in New York City.
With rapidly evolving science around both the microbiome and gluten sensitivity, the landscape is likely to be dynamic, shifting toward targeted treatments that could prove to be effective.
The gluten connection
When Fortune named 2015 The Year of the Microbiome, it was onto something big—or, if you prefer: many things that are very, very small. Encouraging research indicates we’re just beginning to learn how the microbiome affects human health. In 2013, scientists announced that they were able to conquer severe bacterial infections known as Clostridium difficile (or C. diff) in 90 percent of patients by giving them a transplant of a healthy person’s microbes—results that have spurred confidence and hope in those who are interested in unlocking many more of the gut microbiome’s mysteries.
Food sensitivities are a logical fit for microbiome research. Gluten sensitivity—which can generate a variety of symptoms, including abdominal pain, bloating, upset stomach, and headaches, along with myriad nongastrointestinal effects—is still hotly debated. If you have celiac disease, a blood test and biopsy can provide a definitive diagnosis. “Beyond that, you get into a gray zone,” says Joseph Murray, MD, a gastroenterologist at Mayo Clinic in Rochester, Minnesota, who specializes in gluten sensitivity and intestinal inflammation. No reliable test exists—yet—to determine if someone has nonceliac gluten sensitivity. “I think of it on a spectrum,” Comite says. The science might also be somewhat askew; though gluten is found in several grains, including barley and rye, many “gluten” studies to date have focused on wheat-based foods rather than gluten specifically.
Nonceliac gluten sensitivity: Still uncharted territory
People with celiac disease show different gut microbiome patterns from that of the general population. But little research has been done on nonceliac gluten sensitivity, specifically. This is, in part, because the population is so difficult to define. Murray points out that many people who identify as gluten sensitive have already changed their diets (which in turn changes their microbe populations), making sound gut studies even more difficult to achieve.
“The main determinant of our flora is what [the flora] eat,” Murray says. Food can rapidly impact gut microbe populations. “Your bacteria can change by tomorrow if you eat something different,” he says. A recent study found that shifting healthy volunteers’ diets could drastically alter their microbiome profiles—even nudging them toward patterns of disease—in a matter of just a few days.
“Your bugs change when you go gluten free,” Murray explains. A recent animal study showed that feeding mice a gluten-free diet did, indeed, alter their microbiota. What this could mean in humans is that a diet-induced shift in microbe populations may trigger or even increase a food sensitivity, explains Daniel Leffler, MD, a gastroenterologist and director of clinical research at the Celiac Center at Beth Israel Deaconess Medical Center in Boston. “It may be that some diets modulate gastrointestinal symptoms because the type of food you eat modulates your microflora, and not because of the food directly,” he says.
Just how microbes could reduce symptoms of gluten sensitivity itself is still a guessing game—even for top physicians and researchers. In his own practice, Leffler finds that probiotics do improve some people’s symptoms, but there is no telling which person will benefit and which probiotic strains will work. “[Prescribing probiotics involves] a lot of trial and error—there’s no way around that right now,” he says.
One bug, two bugs …
Probiotic products were once the domain of natural foods stores, but now you can find them in mass-market outlets such as Starbucks and Target. But how do you know if something—whether a snack food or supplement—labeled “probiotic” will actually benefit you?
One of the greatest challenges in finding a useful probiotic product is that bacteria are extraordinarily diverse—much more so than types of wheatgrass powder or forms of vitamin D. It will be some time before health practitioners are able to prescribe particular species of probiotics, combinations, or doses tailored to a specific health issue. This makes probiotic product formulation still, to a large extent, as much art as science.
Further understanding of probiotics is particularly pressing for those looking to alleviate gluten sensitivity. Leffler suspects that new research will zero in on types of probiotics that don’t necessarily break down gluten itself, but rather modulate the gut response or the immune system—in other words, strains that “do something to make the gut a little more tolerant.”
Also, prebiotics—compounds that feed the beneficial microbes—could complement probiotics by boosting gut health for gluten-free eaters, Murray says. “If you’re taking a lot of wheat out of your diet, you’re reducing the materials available for the good, fermenting bugs in the colon,” he notes. “You need to think about replacing them.”
Probiotic therapies and beyond
About 1 percent of the U.S. population must avoid all gluten because of celiac disease. “They’re not trending or trying it out,” says Murray, who authored the book Mayo Clinic Going Gluten Free (Oxmoor, 2014). But we all know people who are cutting out gluten for nonspecific health reasons. In fact, as of early 2013, about one-third of all U.S. adults were trying to reduce or remove gluten from their diet, according to the NDP, a market research company.
Interestingly, and perhaps related to the increase in gluten-free eaters, “more and more patients are coming in asking about probiotics,” says Melinda Dennis, RD, a registered dietitian and nutritional coordinator for the Celiac Center at Beth Israel Deaconess Medical Center. “More people are interested in learning ‘How are my gut bacteria responding?’ and ‘Is there something I should be doing?’”
In her practice, Dennis attempts to alleviate gluten-sensitivity symptoms by turning to anything she can use to heal the gut and restore it to its proper functioning order, she says. Therapies can include probiotics, as well as vitamins, omega-3s, calcium, and digestive enzymes (not to break apart gluten but to handle other symptoms, such as bloating). Dennis, who coauthored the book Real Life with Celiac Disease (AGA, 2010) notes that many people do not want to take a pill or medication. Therefore, her first recommendation is usually food—drink kefir instead of taking probiotic pills, or eat asparagus instead of using prebiotic powders, for example.
It may not be the gluten
As knowledge about the role of the microbiome in health increases, will the gluten-free movement start to fade? “There’s a lot of hype about gluten-free diets. There are a lot of promises,” Murray notes. “As those promises are not fulfilled, there is going to be swingback the other way. The big challenge and direction is to make something that’s both gluten free and healthy.” Thanks to the beneficial-bacteria news, probiotics will likely play a role in that effort, whether the good bugs come from food—such as kefir or a probiotic-fortified cheese—or in a pill.
Gluten—as a sole point of sensitivity—might also be challenged as new research and different dietary approaches emerge. In fact, for many people, the symptoms of gluten sensitivity may actually result from something called “fructose malabsorption” or overgrowth of bacteria in the small intestine, says Dennis.
Enter the recent emergence and popularity of the low-FODMAP diet: reducing foods with Fermentable Oligosaccharides, Disaccharides, Monosaccharides, And Polyols, which include not only wheat products, but also some dairy, legumes, stone fruits, other fruits such as apples and pears, and some sweeteners. People and scientists alike are beginning to ask: Is it gluten or is it FODMAPs?
But as with any diet, Murray says, given the early nature of the research, “if it doesn’t work, don’t keep at it.” And consider the overall nutritional value of any diet you adopt, he adds. The low-FODMAP diet, for example, is low in fiber and can starve some of the good bugs that live in your gut.
When it comes to identifying which foods cause an individual to experience negative effects, finding the specific links between trigger and symptom will be key. “The next frontier is not just identifying who [gut microbes] are,” Murray says. The gut “is a community of interacting bacteria. Understanding what that community is doing and how it’s interacting with us is a huge challenge.” Comite agrees: “I think it’s naive to assume one strain of bacteria is going to be enough,” she says.
Despite all of the scientific excitement and market hype, many experts remain realistic. “There will never be a silver-bullet probiotic [for gluten sensitivity],” Leffler says. In the future, however, health practitioners will have more confidence when it comes to prescribing probiotics and finding strain combinations that do a good job of relieving symptoms.