Probiotics have never been hotter, thanks in large part to the pandemic. In May of 2020, Americans increased their use of probiotic supplements by 66 percent compared to six months earlier, according to one survey, for both digestive and immune health. Probiotics have also been touted for weight loss, but do they really work to help you shed pounds? Here is everything you need to know about taking a probiotic for gut health, immunity and weight loss.

What are probiotics?

Probiotics are live microorganisms that “when administered in adequate amounts, confer a health benefit on the host,” according to a study in the journal Frontiers in Microbiology. Often referred to as healthy gut bacteria, probiotics are naturally found in foods like yogurt, kefir, kimchi, kombucha, miso, tempeh, or other fermented foods. You can also find probiotics in supplements.

How do probiotics help your gut?

Your body is home to an estimated 10 to 100 trillion microorganisms, most of which live in your digestive tract, says Raphael Kellman, M.D., physician of integrative and functional medicine and founder of Kellman Wellness Center in New York City. Together, they make up what’s called your gut microbiome, which is where anywhere from 70 to 90 percent of your immune system lies.

Those microorganisms include bacteria, and while that sounds ominous, not all bacteria is bad. “There are good bacteria, and they compete with the bad bacteria,” says Joan Salge Blake, Ed.D., R.D.N., a nutrition professor at Boston University in Massachusetts and host of the award-winning podcast Spot On!. “Ideally, you want more good bacteria in your gut so they overpower the bad bacteria to help support a healthy immune system and overall good health.”

By consuming probiotics, you’re essentially adding more bacteria to your gut that could benefit your health, says Lisa Moskovitz, R.D., CEO of NY Nutrition Group and author of The Core 3 Healthy Eating Plan. Not only can probiotics support your immune system, but they can also fight bacterial infections, treat diarrhea and potentially improve the entire digestive system. They’ve even been linked to improving acne, fighting yeast infections, increasing energy, and improving heart health and mental health.

Can you lose weight with probiotics?

Whether probiotics can help with weight loss is an ongoing area of research. Yet it seems likely that probiotics could help, given that your gut microbiome is crucial to your health and in the end, your weight. “Because your microbiome plays a significant role in your ability to appropriately digest and assimilate nutrients, as well as maintain a healthy weight, it likely plays a central role in obesity,” Kellman says.

Several studies have also linked obesity to an imbalance in gut microbiota, and research has shown that people who are obese tend to have a less diverse gut microbiome. What’s more, persistent inflammation, which is associated with numerous chronic conditions including obesity, can lead to something called "leaky gut."

“This happens when the intestinal mucosa, which lines the gastrointestinal tract, becomes damaged over time, resulting in small food particles, bacteria, and other toxins leaking out of the gastrointestinal tract and into the bloodstream, thereby causing an immune response,” Kellman says. As a result, your ability to properly digest food and assimilate nutrients will be affected, resulting in metabolic imbalances and most likely, weight issues.

Enter probiotics, which studies have shown can help balance the gut microbiome and aid in weight loss, even address obesity, Kellman says. In one study from the British Journal of Nutrition, for instance, obese women who took probiotic supplements and followed a low carbohydrate diet for 24 weeks experienced statistically significant weight loss when compared to a placebo group. They also had lower levels of leptin, a hormone that controls hunger.

Why might probiotics aid with weight loss? For starters, people often eat differently when they have digestive issues. “If they resolve those issues (through probiotics), they may find it easier to eat more weight loss-friendly foods like lower-calorie, nutrient-dense fresh vegetables, fruit, and fiber-rich grains and legumes,” Moskowitz says.

Studies also suggest that probiotics can increase nutrient absorption and produce short-chain fatty acids that support a healthy metabolism. “This can also assist with blood sugar control, which can regulate appetite and reduce cravings,” Moskovitz says.

Do probiotics aid weight loss?
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Should you get probiotics through supplements or food?

Getting your nutrients through food is always the first line of defense. Moskovitz recommends eating a balanced, varied diet not only with fermented foods but also unfermented fiber-rich foods, which includes all plant foods (animal products contain no fiber). “Fiber is another key player for gut health, as certain types of fiber act as a prebiotic which feeds the beneficial bacteria in your gut,” she says.

For many individuals, though, taking probiotic supplements can fill in some gaps. “Because it’s harder to find and consume probiotic-rich foods on a regular basis, probiotic supplements can introduce a larger amount of different types of beneficial bacteria,” Moskovitz says. They’re also packaged in a way that will enhance absorption and effectiveness. Plus, if probiotic-rich foods are heated, the heat will destroy the probiotics, she adds. The fact that probiotics are so fragile makes another compelling reason to pop them in supplement form.

Of course, this doesn’t mean probiotic supplements are the panacea you might be seeking. For starters, because supplements aren’t regulated by the FDA, you can’t be entirely sure you’re getting what the label says. Plus, not all probiotic supplements are the same, especially given that each supplement contains different types of probiotics.

“For those reasons, it’s impossible to predict whether you’ll feel better or benefit from taking a probiotic supplement,” says Moskovitz, adding that it depends on variables like the strains of probiotics in the supplement and your symptoms. That’s why she recommends monitoring any symptoms you’re trying to treat to see if they change after taking a probiotic supplement.

What should you look for when buying a probiotic supplement?

There are dozens of probiotic supplements on the market, each one featuring different types of bacteria. Knowing which one your body needs will be difficult to determine, but here are some tips to keep in mind when shopping for a probiotic supplement:

  • If weight loss is your main goal, seek supplements with specific strains of Lactobacillus, including L. plantarum, L. rhamnosus and L. gasseri, which research has shown to be effective in aiding in weight loss, Kellman says.
  • Look for high colony forming units (CFU) counts: Probiotic dosage is measured in CFUs and ideally, adults should aim for 10 to 20 billion CFUs per day, Kellman says. Yet because the recommended dosage may vary based on individual health concerns, he notes it’s always wise to check with your doctor.
  • Check for prebiotics: For probiotic bacteria to grow, they also need prebiotics, and high-quality prebiotic supplements will have prebiotics and other ingredients to support digestion and immunity, Kellman says. Some of these ingredients might include flaxseed, chia seed, astragalus, ashwagandha, hemp seed, pumpkin seed, milk thistle, peas, ginger, mung bean and turmeric.
  • Read the label: If a supplement says “live and active cultures,” that’s better than those “made with “active cultures,” which Kellman says may be heat-treated after fermentation to extend shelf life, thus killing the good and bad bacteria.

Take the probiotic supplements for at least 30 days (longer if you’ve been on antibiotics or had symptoms for which you might need to go six to eight weeks), Kellman says. After that, you could take one a few times a week or take a break for one to two months before restarting. He also recommends doing a 30-day course of probiotics after traveling, especially internationally, or after a holiday season of overeating and drinking too much.

Bottom Line: Probiotics have a wealth of health benefits including weight loss.

Taking probiotics can help improve gut health and boost immunity, absorb more energy from your food and even promote natural weight loss. So should you take one or try to get more fiber in the whole foods you eat including a plant-rich diet.

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