Yogurt is famous for containing probiotics, but how many of them actually reach your gut? New research suggests that a common pantry ingredient may help beneficial bacteria pass through your intestinal tract intact.
Two separate studies conducted by researchers at the University of Illinois at Urbana-Champaign (UIUC) and published in The Journal of Nutrition in March and June 2024 found that adding honey, specifically clover honey, may help probiotics survive the intestinal stage of digestion. This may be a useful strategy to keep beneficial microbes alive, as digestive enzymes can kill them.
According to study author Hannah D. Holscher, PhD, R.D., an associate professor of nutrition at UIUC, her interest in honey's effects in yogurt began after she came across research showing that honey helps bifidobacteria survive in petri dish experiments.
“Bifidobacteria are a probiotic bacteria that are often added to yogurt, and plain yogurt is commonly eaten with honey, so we were interested in seeing whether this culinary combination would help probiotics survive both in vitro (in the laboratory) and in vivo (in humans),” she told Health. The results of both studies proved Holscher's suspicions correct.
Knapp/Getty Images
The first study by Holscher and his colleagues was a lab experiment analyzing how four types of honey affected the viability of probiotics in yogurt: Clover, alfalfa, buckwheat and orange blossom honey were added to yogurt containing the probiotic strain Bifidobacterium animalis.
The researchers then tested the effects of human digestion on the yogurt by adding simulated saliva, stomach acid, intestinal bile and enzymes. During the intestinal stage of this simulated digestion, the clover honey yogurt had the highest survival rate of the probiotics.
The reasons for clover's unique benefits are manifold, Holscher said: “For example, clover honey contained the highest amount of glucose, which may have acted as an energy source for the probiotic bacteria,” she noted.
Clover honey also has fewer enzymes that break down small chains of sugar called oligosaccharides that bacteria can use for energy, “so the lower enzyme concentrations in clover honey may provide more energy to fuel the probiotic bacteria on their long journey through the intestinal tract.”
Additionally, clover honey contains antioxidants that may protect the probiotics from the harsh environment in the small intestine, she added.
To see if these results applied to humans, Holscher's team conducted a second study. For two weeks, 66 healthy adults were asked to consume either yogurt with honey or heat-treated yogurt with added sugar. They provided stool samples, information about their bowel habits, and completed questionnaires about mood and cognition.
After two weeks, stool samples revealed that the honey yogurt increased B. animalis content throughout digestion. According to Holscher, one tablespoon of honey was enough to support the survival of the probiotic.
However, she noted that while honey appears to keep probiotics alive, it doesn't affect intestinal transit time or confer other measurable health benefits, such as improved bowel habits, mood or cognition.
Just because subjects in the second study didn't see a dramatic improvement in their gut health doesn't mean adding honey to yogurt isn't worthwhile, Holscher said.
“This may be because the digestive health of the study participants was fairly normal, so there wasn't much room for improvement,” she said. “People who suffered from constipation may have experienced benefits from adding honey to their yogurt, which sped up intestinal transit time.” Future studies may determine whether adding honey to yogurt can speed up digestion in people with constipation.
But adding sweeteners to yogurt is just a great way to make it taste better, says Amanda Sauceda, MS, RD, a lecturer at California State University, Long Beach and a nutritionist who specializes in gut health. And while some people might not like the taste of yogurt, at the end of the day, it's a healthy food that's packed with probiotics as well as protein, calcium, and other nutrients.
“Adding a little honey to help you get used to the tartness of the yogurt can be a beneficial and nutritious option,” she told Health. “Plus, honey is a little sweeter than regular sugar, so you don't need to add a lot to make it sweet.”
When consumed in moderation, honey is also a nutritious food in its own right. “What surprises people is that honey is not just a sugar, it's also a source of nutrients,” Sauceda says. “For example, one tablespoon of honey has 10 milligrams of potassium. It also contains phenols, which are being studied for how they affect the gut microbiome.”
Of course, honey is an added sugar, and added sugar in any form is known to have harmful effects, including contributing to weight gain and increased risk of cardiovascular disease.
“It's important not to have too much sugar in your diet,” Holscher says. “The Dietary Guidelines for Americans recommend that added sugars should make up less than 10% of your daily calories.”
On a 2,000-calorie-a-day diet, added sugars account for less than 200 calories. One tablespoon of honey contains about 64 calories, all of which come from sugar. If you decide to add honey to your yogurt, Sauceda recommends limiting other sources of added sugar on the same day.
According to both Holscher and Sauceda, yogurt with honey can be a healthy snack if eaten regularly.
“I think[this study]points to the fact that foods can complement each other,” Sauceda says. “Ultimately, this is a great reminder that the foods you probably have in your kitchen are powerful sources of nutrition for your body and gut health.”
