We spoke with gut health expert Will Bulsiewicz, M.D., M.S.C.I., to see just how useful probiotic supplements and fermented foods can be for weight loss and reducing belly fat.
feet with slippers on, standing on a scale
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Probiotic supplements and fermented foods like kombucha and kimchi are all the rage these days as more research finds associations between our microbiomes and (pretty much) every aspect of our health. Among improved skin and more regular digestion, weight loss is also one of the touted benefits of adding probiotics into your diet.

While there is some research out there to connect probiotics with weight loss and belly fat reduction, we wanted to get an expert opinion on the subject. We spoke with Will Bulsiewicz, M.D., M.S.C.I., a South Carolina-based gastroenterologist and renowned gut health expert to find out the facts. We were pretty surprised by what he said.

Should You Try Probiotics for Weight Loss?

"There are studies out there suggesting some strains could help with weight loss—Lactobacillus and Lactobacillus gasseri—but it's just really not that simple," Bulsiewicz said. "If probiotics were that effective, we would all be using them."

Bulsiewicz explains that while gut health is relevant to our metabolism, energy balance and weight, that doesn't mean upping your intake of probiotics—either through a supplement or food—will necessarily give you the results you want. He says this is in part to two major things—the first being that every strain affects us differently.

"There is no one-size-fits-all probiotic," Bulsiewicz says. "We each have our own unique microbiome, as unique as your fingerprint, so there's no guarantee for how a person will respond to any given strain."

Secondly, Dr. B says that we can't expect for one small lifestyle change to drastically affect our weight if we don't change our other lifestyle habits. While he does say probiotics can help with bloating, heal previous damage to your microbiome and relieve constipation, it's not going to give you the long-term results that eating healthy and exercising regularly will.

Consider Prebiotics

While "probiotic" is the buzzword of the wellness industry today, Bulsiewicz says we need to consider another crucial part of achieving better gut health—prebiotics. Prebiotic is also a fancy word for soluble fiber and are what the good probiotic gut bacteria feed on to give our bodies the impressive health benefits like reduced inflammation, clearer skin, improved heart health and many others.

"Ninety-seven percent of Americans aren't getting enough fiber," Dr. B says. "We are totally ignoring this and our microbes are starving."

Dr. B prioritizes putting his patients on prebiotic fiber supplements, as he says pretty much all people can benefit from them. Unlike probiotics, prebiotics are guaranteed to make an impact on your health for the better (and at a much better price). Prebiotic supplements are much more cost-effective—Dr. B says about $10 per month versus $40—and you don't have to risk trying several strains that may not work until you find one that does.

"If your goal is weight loss, taking a prebiotic supplement with each meal will help tell you when you are full. You simply take it as a pill, and it will help fill your stomach up and keep you from overeating."

The Bottom Line

Dr. B is very clear that there's no magic supplement or pill that can replace a healthy, plant-rich diet and regular exercise. He says simply walking for thirty minutes a day can help jumpstart your fitness and weight loss journey—and if you want to take a probiotic, do it!

Upping your intake of fiber-rich prebiotic foods, such as whole grains, fruits, nuts, seeds and veggies is a surefire way to get closer to your weight-loss goals and improve your overall health. On top of that, it may be worth talking to your doctor about adding a prebiotic supplement to your mealtime routine to see if that can help give you the push you need. Just be sure to consult your medical professional before making any lifestyle changes.