These days, probiotics seem to be everywhere – from the toppings at your local frozen yogurt shop to the kimchi in your gourmet sandwich. Unlike some other health trends, there’s substantial research supporting the benefits of probiotics. According to Colin Hill, Ph.D., president of the International Scientific Association for Probiotics and Prebiotics, “We all exist on a spectrum of health. Probiotics can help shift you towards better health or prevent a decline, especially when taken proactively.” In short, this is one health trend worth considering.

Simply put, probiotics are live microorganisms, like certain bacteria, that can provide health benefits when you take enough of them. They can be made and grown in a lab and put into pills, powders, or other products. You can also find them naturally in some fermented foods and drinks. When these probiotics are in your gut, they help keep things running smoothly. Scientists think balancing the bacteria in your gut with probiotics might be a new way to keep people healthy.

Fermented foods like yogurt naturally contain probiotics.

They take temporary residence in your gut. Probiotics don’t settle in permanently — you need to consume them regularly for the best results. According to Daniel J. Merenstein, M.D., an expert in probiotics and associate professor of family medicine at Georgetown University, it takes about five days of consistent intake for probiotics to establish a presence in your system. (Even occasional consumption might offer some benefit.)

They assess the environment. Probiotics are quite intuitive. “Some that aid with diarrhoea can also help with constipation. We believe they enter your system, determine what’s required, and respond accordingly by either decreasing inflammation or enhancing your immune response,” explains Gregor Reid, Ph.D., director of the Canadian Research & Development Centre for Probiotics.

They negotiate with “troublemakers.” Most harmful bacteria aren’t aiming to cause serious injury; they just want to feed and exist. Essentially, probiotics might say, “We’ll let you stay, but you can’t cause harm.” They can then produce substances that prevent the release of toxins, effectively neutralising the harmful bacteria, according to Reid.

They strengthen the gut’s barrier. “Your gut has only one layer of cells separating you from serious illness,” says Reid. This accurately describes the ultra-thin barrier of your GI tract, which allows nutrients to pass while blocking toxins. If this barrier is compromised, pathogens could enter your bloodstream and cause severe illness. Probiotics help by tightening the connections between cells and potentially boosting mucus production, fortifying the barrier and making it harder for harmful bacteria to cause problems.

They clear up the biofilm. “During an infection, bacteria often form a biofilm, similar to the slime on the underside of a boat,” Reid explains. “Certain probiotics produce a substance that acts like soap, breaking down this film.”

They starve harmful bacteria. By competing with harmful bacteria for food, probiotics keep these bad guys in check, making it difficult for them to survive and thrive.

Two key reasons to incorporate probiotics into your diet are to manage gastrointestinal issues and to reduce the likelihood of falling ill. “If you’re traveling, feeling stressed, or not eating or sleeping well, you’ll find that probiotics can make a difference,” says Dr. Merenstein. Emerging research also suggests that probiotics may help prevent or treat other conditions, such as high cholesterol, allergies, and even anxiety. This is because your gut plays a pivotal role in your body’s functions: it has a wealth of nerve endings second only to your brain, and it’s the cornerstone of your immune system.

As you might know, a robust immune system requires exposure to a diverse array of microorganisms, something that modern lifestyles often lack. We also use antimicrobials—present in some soaps and toothpastes—that can kill beneficial bacteria along with harmful ones. Probiotics might help bridge this gap, explains Hill.

Additionally, taking a probiotic supplement can help restore good gut bacteria if you’re on a course of antibiotics.

Probiotics may cause bloating, gas, or changes in your bowel movements. This depends on the type of probiotic and how your body reacts to it.

Most people can take probiotics, but if you have a digestive issue like celiac disease, consult your doctor first. Also, read labels for any food or drug allergies to avoid any adverse reactions.

No single food or supplement can help you lose weight, period. However, the study of probiotics and obesity appears promising, even though the specific link isn’t entirely clear. Diets that lead to long-term weight gain can also affect your gut microbiome. Emerging research areas are examining the relationship between gut bacteria, appetite hormones, and calorie absorption. Although these findings are intriguing, it’s still too early to draw definitive conclusions.

You can get probiotics from fermented foods and drinks like miso, tempeh, sauerkraut, kimchi, and kombucha. They’re also found in dairy products like yogurt, kefir, fermented milk, and some cheeses. For the best benefits, look for products with at least five strains of live and active cultures listed on the ingredients. Avoid highly processed foods that claim to have probiotics, like sugary drinks or candy. Unsweetened Greek yogurt is a good choice because it has a variety of cultures and is high in protein.

You can also find naturally occurring probiotics in kimchi, a Korean fermented vegetable dish.

To maximise the benefits of probiotics while minimizing risks, start with probiotic foods. Remember, the FDA doesn’t regulate dietary supplements, so there’s no assurance you’re getting the probiotics you paid for. Moreover, research reveals that probiotic supplement effects can vary greatly based on your genes and gut bacteria. Essentially, the outcomes are highly personalized.

Before introducing any new supplements, including probiotics, consult your doctor. Probiotic supplements may be particularly beneficial in certain cases, such as when your gut flora has been disrupted by stomach illnesses or antibiotic use.

If you choose to use a probiotic supplement, here’s how to maximize its benefits:

1. Follow instructions precisely. Ensure you store them as recommended; some require refrigeration.
2. Incorporate probiotics into your daily routine. For effectiveness, take them consistently—ideally, at least five days a week.
3. Take it with dairy. Consuming them with dairy products like yogurt, milk, or cheese can help ensure the probiotics survive the journey through your stomach.
4. Focus on quality, not quantity. Having many strains isn’t always better. Look for formulas with strains backed by research.
5. Research brands carefully. Check out products on ConsumerLab.com. Some products might not contain the promised amounts of live bacteria.
6. Be patient. It takes about four to five days for probiotics to build up in your system, and it could take up to three weeks to notice improvements if you’re targeting GI issues.

Foods like lentils, peas, and beans are also excellent sources of prebiotic fiber, which helps probiotics thrive in your digestive system.

Prebiotics, unlike probiotics, aren’t bacteria. They’re naturally occurring soluble fibers such as inulin and oligofructose. These fibers nourish the good bacteria already residing in your gut, helping them flourish. You can find prebiotics in 100% whole grains, various fruits, artichokes, asparagus, onions, shallots, garlic, leeks, legumes, beans, chickpeas, and lentils. Consuming more of these foods may also lower your risk of chronic illnesses such as heart disease, certain cancers, and type II diabetes.

* These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.