Can Probiotics Help Reduce Sugar Cravings?

Companies promote the idea, but the science is based on mice studies.

Studies show that gut bacteria can influence sugar cravings in mice, and some companies claim probiotics can do the same for people.

For many people, sugar is hard to resist but could certain gut bacteria help curb those cravings? That’s what some probiotic brands claim.

Probiotic supplements have been marketed for years as a way to boost gut health, increase energy, and even “feel lighter.” Some brands go a step further, suggesting they can also help reduce sugar cravings.

But can a daily dose of bacteria really make you crave fewer sweets?

The idea isn’t entirely far-fetched. Research in mice has shown that lacking certain gut bacteria like, L. gasseri,

L. johnsonii, and Muribaculacecan lead to sugar binges. And it’s not just sugar mice missing L. johnsonii and Muribaculaceae tend to overeat high-fat foods, too. “Anything that’s pleasurable, the mice will eat more if they’re missing these organisms,” says Caltech microbiologist Sarkis Mazmanian. When these microbes are restored, the bingeing behavior decreases.

But does the same hold true for humans? That’s still up for debate.

A recent study in Nature Microbiology suggests that gut bacteria might play a bigger role in sugar cravings than we thought. Researchers in China found that Bacteroides vulgatus a common gut bacterium and a molecule it produces, vitamin B5 (pantothenate), can actually reduce sugar cravings in rodents.

The team studied mice that were genetically modified to lack FFAR4, a gut sensor for certain fatty acids. For reasons still unclear, losing this sensor also led to lower levels of B. vulgatus and vitamin B5, making the mice go on sugar binges. But when researchers gave them back the missing bacteria and vitamin, their sugar cravings dropped.

It all comes down to a chain reaction involving GLP-1, a protein that’s gained fame thanks to weight loss drugs like Ozempic, which mimic its effects to control blood sugar and appetite. While these findings are intriguing, it’s still unclear if the same mechanism works in humans.

Vitamin B5 (pantothenate) plays a key role in this process by stimulating GLP-1 production. In turn, GLP-1 triggers the release of a protein called FGF21, which somehow influences the hypothalamus the brain’s appetite control center to dial down sugar cravings. Scientists are still figuring out exactly how this works.

However, Bacteroides vulgatus only reduced sugar cravings in mice that lacked the FFAR4 sensor. That means this bacterium or vitamin B5 might not have the same effect in most people, since they already have a functioning FFAR4, says microbiologist Sarkis Mazmanian.

And in some cases, B. vulgatus might do more harm than good.“There’s some evidence that B. vulgatus has a dark side,” Mazmanian warns. In rats with certain genetic traits, this bacterium has been linked to intestinal inflammation. While most people don’t have those mutations, an overgrowth of B. vulgatus could still lead to digestive issues for some.

Even though animal studies suggest a link between gut bacteria and sugar cravings, there’s no solid proof that the same effect happens in people. So far, no one has tested whether the bacteria that curb sugar cravings in mice would do the same for humans and what works in lab mice doesn’t always translate to real world results.

Despite this uncertainty, companies can still market probiotics for sugar cravings without human trials. Pieter Cohen, an internal medicine doctor at Harvard Medical School who studies supplement safety, explains that probiotics are sold as dietary supplements, meaning they don’t need FDA approval or rigorous testing before hitting the shelves.

As long as brands avoid claiming to treat diseases, they have a lot of freedom in how they market their products. They do need some supporting evidence, but most of it comes from animal studies not human trials.

"There’s no real evidence that these probiotics work in humans,” Cohen says.

Even Sarkis Mazmanian, a microbiologist who specializes in gut bacteria, remains unconvinced. “It’s 2025, and I’m still skeptical of these claims,” he admits. Many probiotic products marketed for sugar cravings don’t even contain the specific bacteria that helped curb sugar intake in mice.

Even if probiotics did help curb sugar cravings in humans, the results would likely vary from person to person. Everyone’s biology, genetics, and gut microbiome are different, which means no single solution will work for everyone. “Any discovery we make in this field won’t apply universally,” Mazmanian explains.