Probiotics are found in everything from chocolate and pickles to hand lotion and baby formula, and millions of people buy probiotic supplements to boost digestive health. But new research suggests they might not be as effective as we think. Through a series of experiments looking inside the human gut, researchers show that many people's digestive tracts prevent standard probiotics from successfully colonizing them. Furthermore, taking probiotics to counterbalance antibiotics could delay the return of normal gut bacteria and gut gene expression to their naïve state. The research publishes as two back-to-back papers on September 6 in the journal Cell.


If this happens, it's time to consider switching to a new probiotic. Other reasons a probiotic may not be the right fit: SIBO or Candida. If you have either of these conditions, the strain of the probiotic could potentially make your symptoms worse. Remember, if you think a probiotic is not helping, seek the advice of a functional medicine provider to help you navigate the choices out there.
But what if investigators could design probiotics to treat specific individuals? Many researchers think personalized probiotics are the most promising path forward for patients with compromised gut microbiomes. Last year Jens Walter of the University of Alberta and his colleagues published a study that gives a glimpse of this potential future. The researchers decided to see what it would take to get the bacteria in a probiotic to successfully colonize the intestines of 23 volunteers. They chose a particular strain of Bifidobacterium longum that earlier studies had indicated could survive in the human intestine. In the study, the volunteers consumed either a drink containing 10 billion live B. longum bacteria or a placebo in the form of a glucose-based food additive (maltodextrin) each day for two weeks. Periodic fecal samples revealed higher than typical levels of B. longum in participants who did not consume the placebo.
Flora offers a high potency blend of eight super strain probiotics for general gut health and immune system support including multiple varieties of Lactobacillus and Bifidobacterium, among others. Containing up to 42 billion CFUs per capsule, this powerful health-boosting blend uses only strains found naturally in the human body, which increases its effectiveness.

Called probiotics, these good bacteria help break down food, synthesize vitamins, prevent bacteria that cause illness from getting a foothold, and bolster immunity. Some studies suggest that as we get older, the number and variety of good bacteria in our bodies decline. So taking probiotic supplements to replenish them might seem like a no-brainer.
That said, supplements with higher numbers of CFUs are sometimes used to treat conditions such as irritable bowel syndrome (IBS), allergies, and respiratory illness. While probiotics have generally been found to be safe for most people with normal immune systems, too much can cause gas and upset stomach. We narrowed our search to supplements with dosages between 1 billion and 100 billion CFUs.
Unlike MegaFood, the Renew Life label’s cold-storage recommendation is printed so small we nearly missed it (and it didn’t ship with a cold pack). If a probiotic requires refrigeration, be vigilant when buying it — the retailer that stores it or the company that ships it should keep it refrigerated until it gets to you. Otherwise, some of its potency might diminish in storage or transit.
Eating more foods that are naturally rich in probiotics, like yogurt, kimchi and kefir, can help restore balance in your gut and create more “good” bacteria to fight off inflammation from “bad” bacteria. But what about food products that have probiotics infused into them? Indeed, manufacturers are banking on a new crop of gut-friendly products. From chocolates and granola bars to juices and tonics, nut butters, bottled water and even air sprays, you can’t escape the probiotic movement.

The science on what probiotics do is still emerging. There is some hard evidence that suggests eating probiotic foods and supplements can have a beneficial effect on health. Other evidence suggests probiotics benefits are limited to those individuals in good health and should be avoided by those who suffer from certain serious health conditions. There is no research that demonstrates the risks or the benefits of probiotic supplements on children.


Though capsules are ideal for quick, convenient consumption, powdered products are a great choice for anyone who wants to mix their probiotics with shakes or smoothies. The Hyperbiotics Organic Prebiotic Powder is a totally taste-free prebiotic powder that has inulin, FOS, resistant starch, and dietary fiber to help keep your gut health in line. Unlike probiotics, prebiotics works to nourish and grow the bacteria that is already in your body. This supplement also has acacia fiber, which is said to help suppress appetite and reduce gas and bloating. You can take between one and three scoops of powder a day, depending on how much microbial support you’re looking for. Each container comes with 375 grams or roughly 54 servings, and it doesn’t need to be refrigerated.

On my recent trip to Japan, one thing I noticed was the inclusion of pickled vegetables in almost every traditional Japanese meal. Unfortunately, many Americans don’t consume enough of these probiotic-rich foods and drinks. Even when they do, restoring equilibrium oftentimes requires therapeutic doses of these microorganisms, because most everyone has been on several rounds of antimicrobials. That’s where a probiotic supplement comes in.
This story has played out before, most notably with vitamin supplements, which decades of research have revealed to be completely unnecessary for most adults and, in some cases, dangerous, correlating with higher rates of lung, breast and prostate cancers. But that has not stopped marketers from pushing another nutritional craze. According to a National Institutes of Health survey, the number of adults in the U.S. taking probiotics or their cousins, prebiotics (typically nondigestible fibers that favor the development of gut bacteria), more than quadrupled between 2007 and 2012, from 865,000 people to nearly four million. San Francisco–based business consulting firm Grand View Research estimates that the global probiotics market exceeded $35 billion in 2015 and predicts that it will reach $66 billion by 2024.

If you go with a supplement, know that the FDA regulates these products but treats them like foods and not medications. Unlike drug manufacturers, supplement makers don’t have to show their products are safe or effective to sell them. That means that these firms are in charge of checking the safety and labeling of their products before they sell them to make sure they meet FDA rules.

Make sure dosages are listed in CFU, colony forming units. (Most brands list CFU in billions now: so 30 billion CFU, 100 billion CFU, and so on.) For one, this means that the bacteria strains are living, which is essential. When you’re looking at the cost of products, be sure to look at the cost per unit. I spoke to a woman the other day who had bought probiotics that had 2 billion CFU per capsule. In comparison, to get the 30 billion CFU I recommend, she’d have to take essentially half of her bottle to get the same dosage as one of our capsules.
Most bacteria are included through the fermentation process. Fermentation helps extend the shelf life of perishable foods. It is a slow decomposition process of organic substances induced by microorganisms or enzymes that essentially convert carbohydrates to alcohols or organic acids. The lactic acid supplies the bacteria that then add the health benefits to the food. You can purchase foods that are fermented or ferment them yourself.
The National Center for Complementary and Integrative Health (NCCIH) calls probiotics “live microorganisms (in most cases, bacteria) that are similar to beneficial microorganisms found in the human gut.” The NCCIH makes the point that we often think of bacteria as harmful “germs” — however, probiotic bacteria actually helps the body function properly.
While raw probiotics tend to be the freshest (and most effective!) cultures on the market, it is important to ensure that you will store these properly in between each use. Cultures can die unrefrigerated in as little as a few hours, rendering them completely ineffective and, if you’re especially unlucky, even harmful to your body’s natural flora. Think about it, when has stale or moldy bread made your tummy feel better? The same thing goes for stale probiotic cultures!
Our gut is home to over 500 bacterial species. These “visitors” form a bioreactor, which facilitates digestion, provides nutrients, and helps form the immune system. Some important nutrients made by this bioreactor include several B vitamins, vitamin K, folate, and some short-chain fatty acids. Up to 10% of an individual’s daily energy needs can be derived from the byproducts of the good bacteria in your gut.
Probiotics are clearly incredibly supportive, but they can't do their work alone. To make sure that you're getting the most out of your microbes, it's important that you give them the support they need to work. You've got lots of options for supporting your gut health, from dietary changes to probiotic supplementation, but make sure you're at least covering the following bases.
Although people often think of bacteria and other microorganisms as harmful “germs,” many microorganisms help our bodies function properly. For example, bacteria that are normally present in our intestines help digest food, destroy disease-causing microorganisms, and produce vitamins. Large numbers of microorganisms live on and in our bodies. Many of the microorganisms in probiotic products are the same as or similar to microorganisms that naturally live in our bodies.
Most probiotics are like what is already in a person's digestive system. Some probiotics have been used for a very long time throughout history, such as in fermented foods and cultured milk products. These don't appear to cause illness. But more study is needed on the safety of probiotics in young children, the elderly, and people who have weak immune systems.
We love that RAW offers proprietary blends for various needs, including specialty formulas for women and men. Both support the standard systems (immune, digestive, etc.), and the women’s probiotic tacks on extras, including L. reuteri and L. rhamnosus, to support vaginal health. The men’s blend adds L .fermentum, to boost immunity during exercise and other physical exertion.
Some foods are made by adding bacteria — yogurt, pickles, cottage cheese, kombucha, and sauerkraut are good examples. Those foods work to provide the same probiotic benefits as supplements. However, most foods are so processed and pasteurized that it’s unlikely you’ll see the same benefits, let alone the right strains, as you would with a supplement. Regardless, it can’t hurt to get extra probiotics through your diet.
The idea that consuming probiotics can boost the ability of already well-functioning native bacteria to promote general health is dubious for a couple of reasons. Manufacturers of probiotics often select specific bacterial strains for their products because they know how to grow them in large numbers, not because they are adapted to the human gut or known to improve health. The particular strains of Bifidobacterium or Lactobacillus that are typically found in many yogurts and pills may not be the same kind that can survive the highly acidic environment of the human stomach and from there colonize the gut.
Importantly, patients with gastrointestinal conditions are not the only ones taking probiotics. 3·9 million people in the USA alone regularly take probiotic supplements, with promised benefits ranging from improved digestion and immune function to improved mental health and prevention of heart disease. However, evidence for these benefits is lacking, and because probiotics are often sold as supplements, manufacturers in many countries are not required to provide evidence of their safety and efficacy to regulatory bodies. The ubiquity of probiotic products would suggest that, at worst, they are harmless. Nevertheless, some safety concerns have been raised, including the risk of contamination, possibility of fungaemia or bacteraemia (particularly in immune-compromised, elderly, or critically ill individuals), small intestinal bacterial overgrowth, and antibiotic resistance. Adding to concerns, clinical trials of probiotics have not consistently reported safety outcomes. 

Keep in mind that when supplements contain a specific number of organisms, this number may not be what is actually within each capsule at the time of purchase. Probiotics are living organisms and can die out easily. Especially if that supplement sits on your drugstore or warehouse shelf for months or longer, the number of organisms you get may be far less than what the bottle claims. Hardier strains have a longer shelf life. Capsule strength decays faster if the probiotic has been sitting around at elevated temperatures during transport to the store. Companies actually have to produce probiotics with a much higher CFU (colony-forming units; see below) count in each capsule in order to guarantee the label potency by the expiration date.
Add in a naturally derived prebiotic, which feeds probiotics to boost both potency and effectiveness, and you have a slow-release capsule that delivers beneficial bacteria exactly where it’s needed. What’s more, Hyperbiotics Pro-15 has a long shelf life (18 months from the date of manufacture) and requires no refrigeration, which makes it as portable as it is tiny. This product is made in the USA, an NSF- and GMP-certified facility.
Garden of Life RAW Probiotics are some of the most popular out there – and for good reason. Let’s start with the basics: You’ll get 85 billion CFUs and 31 to 33 probiotic strains out of your daily, whole-food, gluten-free, soy-free probiotic, which helps support the immune system, a healthy thyroid, nutrient absorption, digestive function, and a healthy microbial balance.

Until recently, testing of probiotics by ConsumerLab.com found that some products had far lower amounts of live organisms than claimed on the labels. But in 2018, it found that 17 out of 18 products tested contained the amounts listed; none exceeded limits for heavy metal contaminants. In contrast, in 2016, a study in Pediatric Research found that only one out of 16 Bifidobacterium longum supplements tested contained the species named on the label.


Most probiotics are like what is already in a person's digestive system. Some probiotics have been used for a very long time throughout history, such as in fermented foods and cultured milk products. These don't appear to cause illness. But more study is needed on the safety of probiotics in young children, the elderly, and people who have weak immune systems.
Coming in at a close second, our runner-up as the best probiotic for women is the Culturelle Women’s Healthy Balance Probiotic. As the #1 recommended brand by pharmacists, it is easy to see why so many women are turning to Culturelle for their digestive health. Featuring the LGG culture and a laundry list of other healthy bacteria, this probiotic offers a wonderful balance between digestive and feminine health. The Culturelle Women’s Healthy Balance Probiotic is also taken in an easy, chewable tablet and can even be taken during pregnancy, making it one of the most versatile formulas we reviewed!
Additionally, it's a good idea to take note of the number of colony-forming units (CFUs) that are in the supplement you're considering, Angelone says. CFU count tells you the number of viable, active bacteria present in a tablet, she explains, and one billion (yes, seriously) is a typical dose. However, if you're struggling with a specific health condition, you may need more than that, Warren says. Your doctor can help you decide whether that's the case and may be able to steer you toward a good supplement to get you started. Here are a few to consider if you decide that probiotics are right for you.
Minerals And Extracts – Many probiotics, especially those marketed for women, also contain blends of vitamins, minerals, and plant extracts for optimal results. In some cases, these blends can be so inclusive that they actually replace your traditional multi-vitamin, and can be an excellent source of nutrition for women that don’t receive enough vitamins or nutrients in their basic diets.

How is it that probiotics are such a ubiquitous trend in the wellness scene but subject to tons of misinformation all the same? Consider the myth, for example, that the only appeal of replenishing your good bacteria is smoother digestion. On the contrary, the benefits of probiotics abound: from a boosted mood and better skin to a healthier immune system.

B. Longum is one of the first types of bacteria to colonize our bodies at birth. These important microorganisms ferment sugars into lactic acid, helping to stabilize the acidity of the GI tract and inhibit growth of harmful bacteria. For a group of adults prone to constipation, taking a mix of B. Longum BB536 with milk or yogurt for 2 weeks increased bowel movements [1].
Probiotics are “friendly” bacteria that inhabit your body. Sound strange? These microscopic roommates can be your best buds if you show them a little love. One surefire way to do that is with probiotic supplements. Probiotics support the right ratio of good to bad bacteria in your gut. For bonus points, call on digestive enzymes. These unique blends offer specific nutritional support to assist digestion and nutrient absorption. Your healthy body will quickly appreciate these lifelong friends.
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