FRIDAY, Sept. 11, 2026 (HealthDay News) — The use of probiotic supplements has skyrocketed in the United States, but people’s pursuit of a healthy gut still doesn’t extend to their daily diet, a new study says.

Probiotics increased by 287% among U.S. adults from 2009 to 2023, and by 786% among those younger than 20, researchers reported Sept. 7 in the journal Clinical Gastroenterology and Hepatology.

But those same folks did not increase their intake of fiber, which acts as fuel for gut microbes, researchers found.

Likewise, the average consumption of foods rich in healthy microbes — yogurt or kombucha, for example — rose only slightly, the study found.

“We have known that probiotic supplement use is increasing across all ages, but this is the first time we have looked closely at it in relation to other microbiome-focused health behaviors,” lead researcher Dr. Kira Newman said in a news release. She’s a clinical assistant professor of internal medicine at the University of Michigan Medical School.

“Dietary fiber and fresh produce have well-established health benefits for the gut microbiome,” Newman said. “However, our findings suggest that people are not making changes to what they eat, even though an increasing number are concerned enough about their microbiome to take a probiotic supplement.”

For the study, researchers analyzed data from seven rounds of the National Health and Nutrition Examination Survey, a regular federal study of Americans' diet and health. The data ran from 2009 to 2023.

Results showed that the proportion of adults 20 and older taking probiotics rose from 1.8% to nearly 7% during that period, and from 0.6% to 5.6% among those younger than 20.

However, there also was a small but significant decrease in fiber intake, and a minimal increase in average intake of microbe-rich foods.

People might see probiotics as an alternative to healthy diet habits or a high-quality diet, which could cost their health long-term, researchers said.

“A diet with plenty of vegetables, fruits, legumes and whole grains provides not just fiber, but also a wealth of other beneficial vitamins, minerals and plant-derived compounds,” Newman said. “This helps support a diverse range of beneficial gut microbes.

“Prebiotic supplements alone do not contain the same variety or richness. It’s like picking one color out of a rainbow,” she said.

More information

The Mayo Clinic has more on probiotics and prebiotics.

SOURCES: University of Michigan, news release, Sept. 8, 2026; Clinical Gastroenterology and Hepatology, Sept. 7, 2026