Probiotics for weight loss: do they work?

Do probiotics help you lose weight? Some research suggests probiotics for weight loss might be something to consider but there’s a lot more to the story. 

Your gut is home to tiny living organisms, often called the gut microbiome or gut flora. They help support digestion and overall health, and researchers are studying whether certain probiotics may also help with weight loss or weight management. Read on to learn about the evidence we have so far. 

It’s possible probiotics may help you lose weight, as some research shows promising results. However, you should look at probiotics as just one piece of the weight loss puzzle. Maintaining a healthy weight is a complex interplay between how much food you eat, what types of food you eat, exercise patterns, and your genetics. So, do probiotics help you lose weight? Here’s what some of the research says:

• In one review, scientists explored how a better balance of good bacteria (microbiome) in the digestive tract may influence weight, energy use and storage, inflammation, and  appetite signals. In the context of gut health, the scientists also said that some probiotics, either alone or in combination, could support weight loss by helping rebalance gut bacteria, improving how the body handles blood sugar, and increasing feelings of fullness.

• Another review found that some studies showed certain probiotic strains may help improve body weight, body mass index (BMI), waist size, inflammation, or gut bacteria. But the results were mixed, and more research is needed before probiotics can be recommended as a reliable weight-loss treatment.

• A meta-analysis of people with overweight and obesity plus related metabolic diseases suggested that supplementing with probiotics may reduce BMI and waist circumference. However, other data showed that probiotics didn’t result in overall weight loss. 

• Another systematic review examined studies on probiotics and overweight/obesity. In these studies, participants didn’t change their diets; they just added probiotics. In 67% of these studies, participants saw significant impacts on BMI and body weight. In 80% of the studies, participants saw decreased total body fat and waist circumference. The types of probiotics that showed the most promise were combinations of Lactobacillus and Bifidobacterium strains. 

These results are promising, but it’s important to note that in these studies, not all probiotics worked for weight loss and reducing body fat, even if the same strains were used. The authors of these reviews say more research is needed before making official recommendations on using probiotics for weight loss. 

If you want to lose weight, it’s best not to just rely on supplements like probiotics, but to make healthy lifestyle changes overall, like eating a healthy, balanced diet of whole foods, exercising regularly, and maintaining a calorie deficit, meaning you burn more calories than you take in. 

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Probiotics are live microorganisms. They’re usually bacteria that can help maintain a healthy balance in the gut when consumed in adequate amounts. The word itself gives a clue about their helpfulness — pro means for and bio means life.

A healthy gut has trillions of microorganisms, with different strains, species, and functions — often collectively referred to as the microbiome or gut flora. One of the most important jobs of your gut flora is to form a barrier against viruses, bacteria, and other infectious organisms, as well as dangerous substances that find their way into your body. 

It also plays a role in digestion, immunity, metabolism, blood sugar, cholesterol, gut-brain communication, and overall health. Adding certain probiotics through foods or supplements may support some gut and metabolic processes, but benefits depend on the specific probiotic and the person taking it. 

You could try taking a probiotic to lose weight, but it isn’t guaranteed to work. Three main reasons explain why we don’t really know yet whether probiotics can truly support weight loss:

1. Most probiotic supplements on the market haven't been well studied and dietary supplements do not need approval for safety or effectiveness by the United States Food and Drug Administration (FDA) before they are sold. This means many commonly sold probiotic supplements may be of questionable quality.

2. Scientists are still researching how the gut microbiome affects weight, body fat, and obesity, and it’s not clear how specific probiotics may influence that process. Studies would be needed, examining factors like probiotic strain, dose, and how long to take it, along with effects related to age, baseline body weight, and sex assigned at birth.

3. While there’s some good research on certain probiotic strains, there’s simply not enough specific research to know which probiotics, if any, should be routinely recommended for weight loss.

If you’re looking to lose weight, better options include following a healthy diet and exercise regimen, and paying attention to your stress levels and sleep quality. You can also speak to your healthcare provider to see if weight loss medications like Zepbound (tirzepatide) or Wegovy (semaglutide) are right for you.

There are several ways to take in probiotics: 

Fermented foods

The most common natural source of probiotics is fermented foods and beverages. Fermentation is a process where bacteria and yeast break down components in food and drinks, changing the texture, smell, taste, and appearance, as well as the structure of the food or drink. Many cultures have their own fermented foods and beverages. 

Some well-known fermented food and beverage products include:

• Yogurt and Kefir 

• Kimchi

• Miso

• Sauerkraut

• Kombucha

Almost all foods can undergo fermentation, and that includes fruits, vegetables, dairy and meat products, grains, and honey. It’s difficult to measure the exact amount of probiotics in natural food products, since it changes with fermentation.

Probiotic supplements

If you’re not a fan of fermented foods, you can also buy probiotic supplements, which come in different strains and doses. However, since these are dietary supplements, not drugs, they do not need FDA approval for safety or effectiveness before being sold. 

Probiotic supplement brands also can’t make any health benefit claims about their products (i.e., lowering your risk of diabetes or helping you lose weight). So, any supplements you see making those claims should raise some red flags.

Plant-based foods

One simpler approach is to feed the microbes you already have. Many of the beneficial bacteria we have in our gut feed on fiber that comes from plants. By incorporating a wide range of fruits, veggies, and other plants in your diet, you can help the naturally occurring microbes in your gut thrive.

When you first start taking probiotic supplements, you might experience some mild gastrointestinal side effects, including:

• Stomach cramps

• Nausea

• Increased gas

• Bloating

• Softer stools 

However, these side effects often subside once your body adjusts to the probiotics.

Most people can safely tolerate probiotic supplements, but some people are at higher risk for adverse effects, such as infection. These include:

• People who are immunocompromised

• Older people with health issues

• Preterm infants

If you fall into these categories, it’s crucial to consult a healthcare provider before starting any probiotic supplement.

Another risk is that many probiotic products are sold as dietary supplements, which do not need FDA approval for safety or effectiveness before they reach the market. This means they may contain other microorganisms not listed on the label, which could be potentially dangerous. If you take a probiotic supplement, make sure it’s from a reputable brand.

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Probiotics may play a role in helping you lose weight, but it’s certainly not a guarantee.

• Some research suggests that probiotics may support weight loss, reducing BMI, and decreasing waist circumference. 

• Other research shows inconsistent weight loss results from taking probiotics, so researchers don’t fully recommend them for weight loss at this stage. 

• Weight loss involves many factors like age, genetics, food intake, and activity level. It’s best to not just rely on any supplement or quick fix, including probiotics, if you’re trying to lose weight.

• Consult with a healthcare provider for more guidance before starting probiotics.