Can Probiotics Help You Lose Weight? Here’s What the Science Says

Probiotics are often claimed to be helpful for a range of issues, from colic and allergies to cognitive decline. Recently, research has shown a possible link between probiotics and weight loss. 

So, what does the science say? Is this just hype, or can taking probiotics actually help you lose weight? Here we’ll review what the evidence shows about gut bacteria and how probiotics might help tip the scales when it comes to finding a comfortable weight.

What are probiotics?

Probiotics are live microorganisms — like bacteria and yeast — that may offer health benefits when you consume them. Some foods naturally contain probiotics, while others have them added during the manufacturing process. You can also get probiotics through supplements as pills, powders, or liquids. 

When you consume probiotics, they join the rest of the microorganisms in your gut (called the gut microbiome). They encourage “good” bacteria to grow while keeping harmful microorganisms under control. Your gut microbiome affects how your gut functions and also seems to have health effects beyond your gut. 

Probiotics may benefit your body in many ways, including: 

• Keeping your gut healthy

• Boosting your immune system

• Helping your body make essential vitamins and hormones

They’ve also shown promise in preventing or treating many health conditions, like digestive disorders, allergies, and high cholesterol. 

Can probiotics help you lose weight?

It’s possible that probiotics can help you lose weight. So far, the research has been promising but somewhat mixed. Some studies have found no change in weight with probiotics, while others have found that taking probiotics helped with weight loss. 

A 2023 meta-analysis shed new light on this question. Researchers looked at over 200 studies on probiotics and/or synbiotics and their impact on weight loss. They found that taking probiotics or synbiotics can lead to lower weight, a smaller waist size, and a lower body mass index (BMI). 

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In a 2024 literature review, the authors also found evidence that probiotics lower body weight, waist size, and body fat in people with larger body sizes. 

But the answer might not be so simple. Whether probiotics help with weight management may depend on a lot of things — not just whether or not you’re taking a probiotic. These things include:

• What probiotic strain(s) you take

• The dose of probiotic you take

• How long you take the probiotics

• Your age

• Your biological sex

• Your starting body weight

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The truth is that more research is still needed before we can know for sure whether probiotics work for weight management and how exactly to use them.  

What type of probiotic supplements are best for weight loss?

It’s hard to say. When it comes to probiotic supplements, scientists are still researching which strains are most effective for weight loss. 

In clinical trials, some probiotic strains that may help with weight loss include: 

• Lactobacillus gasseri (L. gasseri)

• Lactobacillus plantarum (L. plantarum)

• Bifidobacterium species

But even with this information, it’s still hard to choose the “best” supplement.

Many products use multiple strains of probiotics. And when it comes to the right dose, there aren’t clear guidelines for how much to take. Some studies show that higher doses work better for weight management, but experts don’t know if this is true for everyone.

If you’re interested in taking probiotics, talk to a healthcare professional. They can help you understand which probiotic might be right for you. 

Which probiotic foods are best for weight loss?

Again, it’s hard to say for sure. But eating foods with probiotics is a great way to get health benefits without spending extra money on supplements.

Foods rich in probiotics include:

• Yogurt

• Sauerkraut

• Kimchi

• Pickled vegetables

• Kefir

• Tempeh or miso

If you’re trying to change your body weight, consider eating more probiotic-rich foods. Look for products that list live microorganisms like L. gasseri, L. plantarum, or Bifidobacterium on the ingredients label. 

And remember, other small changes in your daily routine can also help you find a comfortable weight. These include practicing stress management, getting good sleep, and exercising.  

How do probiotics affect your weight?

Scientists are still uncovering all the links between gut bacteria and body weight. So far, there’s evidence that your gut microbiome may affect your weight in several ways:

• Appetite: Some bacteria make molecules that affect your brain and make you feel fuller. 

• Fat storage: Some bacteria affect enzymes that encourage your body to store fat. 

• Chronic inflammation: Certain bacteria cause ongoing inflammation in your body, which is often linked to a higher weight. 

• Circadian rhythm: Some bacteria can mess with your body’s normal circadian rhythm, which can lead to weight gain. 

• Energy absorption: Certain types of bacteria absorb more calories and fat from the food in your gut.

Probiotics may work to lower weight by influencing these pathways and mimicking the natural good bacteria that line your gut. 

Do people with different weights have a different gut microbiome?

It’s not totally clear if your body size affects your gut microbe. Some of the first insights into the link between weight and probiotics came from studies in mice. Researchers noted that mice raised in germ-free environments ate more food but gained less weight than conventionally raised mice. These germ-free mice had no bacteria in their gut. 

When scientists transplanted gut bacteria from humans considered obese (BMI over 30) into germ-free mince, the mice began gaining more weight. But when bacteria from humans with smaller body sizes were transplanted, the mice gained less weight. 

It turns out that humans might also have important differences in their gut microbiome depending on body size. And it’s possible that gut health and weight could be linked, at least in part. More research is needed before experts can say for sure. 

Potential risks when taking probiotics

Probiotics are safe for most people and usually don’t cause side effects. If you do experience side effects, they’re likely to be mild digestive symptoms, like gas or bloating, that go away as your body gets used to the probiotic.

However, some people are at higher risk of more serious side effects when taking probiotics, including:

• Premature infants

• People of any age with a serious or critical or illness

• People with a weakened immune system, such as those getting treatment for autoimmune disease or cancer 

• People with short bowel syndrome

Whether you’re at risk for more serious side effects from probiotics, it’s best to talk with a healthcare professional before trying probiotic supplements.

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Written by:

Karen Hovav, MD, FAAP

Karen Hovav, MD, FAAP, has more than 15 years of experience as an attending pediatrician. She has worked in a large academic center in an urban city, a small community hospital, a private practice, and an urgent care clinic.

Edited by:

Alex Eastman, PhD, RN

Alex Eastman, PhD, RN, is a California-based registered nurse and staff medical editor at GoodRx, where he focuses on clinical updates and Latino health.

Reviewed by:

Mandy Armitage, MD

Mandy Armitage, MD, has combined clinical medicine with her passion for education and content development for many years. She served as medical director for the health technology companies HealthLoop (now Get Well) and Doximity.

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