There have been multiple additional studies which link stress to changes in gut bacteria, so there does appear to be some sort of link. But Lebwohl says it’s not enough to recommend widespread use in clinical practice. He referred to these as “hypothesis-generating studies,” which should lead to concrete clinical trials in which the probiotics are tested against a placebo. “These are important studies,” he says. “But it’s premature to call them practice-changing studies.”
Kimchi: This fermented vegetable is made from Chinese cabbage (beachu), radish, green onion, red pepper powder, garlic, ginger, and fermented seafood (jeotgal). Many bacteria have been found to be present and can include any of the following: Leuconostoc mesenteroides and Lactobacillus plantarum, L. mesenteroides, L. citreum, L. gasicomitatum, L. brevis, L. curvatus, L. plantarum, L. sakei, L. lactis, Pediococcus pentosaceus, Weissella confusa, and W. koreensis. A recent review linked the health benefits of kimchi to anticancer, antiobesity, anticonstipation, colon health promotion, cholesterol reduction, antioxidative and antiaging properties, brain health promotion, immune promotion, and skin health promotion.

This mildly sour, chewy bread is made with a lactic acid starter that contains strains of lactobacillus, a friendly type of bacteria that adds good microbes into the bakery staple. Sourdough may be the healthiest bread choice if diabetes is a concern for you: one 2008 study found that people with pre-diabetes who ate sourdough bread had less of a blood sugar spike compared to when they ate bread made with baker's yeast. (Experts also say fiber-rich whole grain bread can also reduce a post-meal blood sugar spike.) The researchers credit the lactic acid for the favorable effect.
The bad news about constipation is that there can be many causes, from simple causes like dehydration and lack of fiber to complicated structural causes or disease. While constipation may seem to be only a nuisance that causes uncomfortable symptoms such as abdominal bloating or pain, the truth is that constipation increases the risks of several diseases.
"People have thrown a lot of support to probiotics, even though the literature underlying our understanding of them is very controversial; we wanted to determine whether probiotics such as the ones you buy in the supermarket do colonize the gastrointestinal tract like they're supposed to, and then whether these probiotics are having any impact on the human host," says senior author Eran Elinav, an immunologist at the Weizmann Institute of Science in Israel. "Surprisingly, we saw that many healthy volunteers were actually resistant in that the probiotics couldn't colonize their GI tracts. This suggests that probiotics should not be universally given as a 'one-size-fits-all' supplement. Instead, they could be tailored to the needs of each individual."
The bottom line: Stick to trusted whole food sources of probiotics if you don’t know a probiotic supplement brand you trust. “Kimchi, pickled beets, Greek yogurt and sauerkraut are great sources of probiotics. If you don’t like them, throw them into a food you do like, like a smoothie, and add your favorite fruit to help mask the flavor,” Taub-Dix says. 

Bacteria in your digestive tract can be good or bad, according to the website Best Probiotic. It quotes the Royal Academy of Medicine England as blaming an imbalance between good and bad bacteria for causing 80 percent of all degenerative diseases. Probiotic supplements with "good" bacteria have become increasingly popular. They can aid the immune system, digestion and vitamin absorption, as well as prevent diarrhea and irritable bowel syndrome. The website Women to Women recommends probiotics that combine saccharomyces, lactobacillus acidophilus and bifidobacteria in the billions. MayoClinic.com also recommends lactobacillus and advises looking for products that contain live, active cultures. You should always check with your doctor before adding any supplements to your diet.


We also found strains linked to five other health benefits like weight loss and lowering cholesterol. We feature options for those cases below, but they aren’t top picks because those use cases aren’t as heavily researched as immune health or IBS relief. Still, chances are any probiotic supplement is going to make some improvement to your digestive health, so don’t be afraid to experiment.
“I’d probably stay away from store brands and pay a little extra for the name brand that’s been studied,” Dr. Cresci adds. “Ideally, look for a product that’s been tested for whatever you’re looking to address. It might say it helps with IBS, but you wouldn’t take that same product if you were taking antibiotics. You would want a product that helps with immunity. That’s where a lot of people get confused.”
This Korean staple relies on lactic acid fermentation (also called lacto-fermentation) to turn cabbage or other vegetables into a spicy, pungent side dish that's packed with vitamin C. Order it at Korean restaurants or buy it in the refrigerated section of your grocery store (King's Kimchi is widely available at Walmart). For some guidance on making your own, turn to The Art of Fermentation ($23; amazon.com). Then, use it to spike veggie-laden rice bowls, top on soup, or serve alongside meat.

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.

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.


We also found strains linked to five other health benefits like weight loss and lowering cholesterol. We feature options for those cases below, but they aren’t top picks because those use cases aren’t as heavily researched as immune health or IBS relief. Still, chances are any probiotic supplement is going to make some improvement to your digestive health, so don’t be afraid to experiment.
Probiotics have become buzzy in recent years: Celebrities including Lauren Conrad and Anna Paquin have been spotted carrying bottles of kombucha, a probiotic-containing fermented tea, and the probiotics market has been growing rapidly as more people pursue better health by taking probiotic supplements. Prebiotics are attracting notice too, but you may still be unsure of what exactly prebiotics and probiotics are. Here's what you need to know about them to decide whether taking supplements is right for you.
However, these quality of life improvements are varied, and some improvements are quite mild. Sample group, types of allergies, symptoms, and results are across a broad spectrum. For example, numerous studies have shown that allergic rhinitis responses to the household dust mite decrease significantly in adults and children when probiotics were used. However, people allergic to birch pollen saw neither a decrease in general allergic responses to birch pollen or to apple food.
Probiotics are live microorganisms (bacteria or yeast) that have been shown to have a health benefit for humans. They are available in supplement form or in probiotic foods and drinks. Probiotics are thought to be akin to (and to increase the level of) the "good" bacteria found in your intestines. These "good" bacteria are thought to enhance our health through their support of our immune systems.
Third-party testing: Lastly, it's important to remember that probiotics are an unregulated supplement. "Find out whether there is third-party data verifying the potency, purity, and effectiveness of the product," suggests Dena Norton, a registered dietitian and holistic nutrition coach. "Remember that dietary supplements aren't regulated, so you can't necessarily just trust the claims on the label." Check out AEProbio, a site that has compiled research on specific brands of probiotics available in the U.S., recommends Scarlata, and an NSF seal is always a good marker to look for.
Among their numerous health benefits, research shows these friendly microorganisms help prevent bowel diseases, improve your immune system, reduce traveler’s diarrhea, help you maintain a healthy weight, heal various skin conditions, improve bloating and other uncomfortable GI symptoms, and even boost your mood, helping to reduce the effects of anxiety and depression.
Probiotics may also be of use in maintaining urogenital health. Like the intestinal tract, the vagina is a finely balanced ecosystem. The dominant Lactobacilli strains normally make it too acidic for harmful microorganisms to survive. But the system can be thrown out of balance by a number of factors, including antibiotics, spermicides, and birth control pills. Probiotic treatment that restores the balance of microflora may be helpful for such common female urogenital problems as bacterial vaginosis, yeast infection, and urinary tract infection.
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.
The scientists discovered that the probiotics successfully colonized the GI tracts of some people, called the "persisters," while the gut microbiomes of "resisters" expelled them. Moreover, the persister and resister patterns would determine whether probiotics, in a given person, would impact their indigenous microbiome and human gene expression. The researchers could predict whether a person would be a persister or resister just by examining their baseline microbiome and gut gene expression profile.
Yes! Beneficial yeast is a probiotic, defined as a microorganism that supports human wellness. (Probiotic means “for life.”) Saccharomyces boulardii is a remarkable yeast that can significantly support your whole internal ecosystem. It helps reduce problematic yeasts, such as Candida, and replenishes healthy gut flora.* While many probiotic supplements only deliver friendly bacteria without yeast, Probiotic All-Flora contains 5 billion CFU of beneficial yeast for complete support.

A closer look at the science underlying microbe-based treatments, however, shows that most of the health claims for probiotics are pure hype. The majority of studies to date have failed to reveal any benefits in individuals who are already healthy. The bacteria seem to help only those people suffering from a few specific intestinal disorders. “There is no evidence to suggest that people with normal gastrointestinal tracts can benefit from taking probiotics,” says Matthew Ciorba, a gastroenterologist at Washington University in St. Louis. “If you're not in any distress, I would not recommend them.” Emma Allen-Vercoe, a microbiologist at the University of Guelph in Ontario, agrees. For the most part, she says, “the claims that are made are enormously inflated.”
Probiotics' side effects, if they occur, tend to be mild and digestive (such as gas or bloating). More serious effects have been seen in some people. Probiotics might theoretically cause infections that need to be treated with antibiotics, especially in people with underlying health conditions. They could also cause unhealthy metabolic activities, too much stimulation of the immune system, or gene transfer (insertion of genetic material into a cell).
Following a healthy and active lifestyle and eating a balanced diet are the best ways to foster a bountiful gut flora. Taking care of your gut flora can help with things like irritable bowel syndrome and chronic constipation, among other things. Even if you’re not sold on pursuing probiotics for your allergies, they’re good to consider if you’re experiencing any gastrointestinal issues.

You experience that afternoon slump and reach for a candy bar or a sugar-laden coffee. Or maybe you go through your day, starting with a breakfast of doughnuts or sugary cereal, and then proceed to sodas for drinks, cookies to snack on, dessert after dinner, and finally to a nighttime snack of ice cream. You know that feeling; it’s that I-have-to-have-something-sweet-and- I-have-to-have-it-NOW feeling.
The two main species you want to look for are: Lactobacillus and Bifidobacterium. Within these two species, there are a lot of different strains. The strains we chose for our probiotic—Lactobacillus acidophilus, Lactobacillus plantarum, and Bifidobacterium longum—have been shown to help modulate the immune system, help with autoimmunity conditions (which affect most of my patients), and counter infections in the gut.

Overall, Enzymatic Therapy Acidophilus Pearls are a great daily probiotic supplement. They give you a ton of flexibility and is convenient since it doesn’t need to be refrigerated and can be taken with or without food! This probiotic makes on-the-go belly support a breeze. All in all, Enzymatic Therapy Acidophilus Pearls finally make it easy to travel with probiotics, are simple to take, and can give you the piece of mind that the money you’re spending on probiotics isn’t being wasted at the first sign of stomach acid.  Read the full review here… or click here to go buy it now!


Probiotics stick around for a while, though for how long isn’t precisely clear. You have to keep taking them to continue to reap the benefits. Further, getting a wide variety of strains into your system is beneficial. “Periodically mixing up your probiotic supplement is also a good way to ensure that you get different health-building strains in your health regime,” says Dr. Cook. 

The research also showed that while probiotics colonised the gastrointestinal tract of some people, the gut microbiome of others just expelled them. There was no way of telling from their stool sample which category people fell into. “Some people accept probiotics in their gut, while others just pass them from one end to the other,” says Elinav. They found that the probiotic colonisation patterns were highly dependent on the individual. That tells us that the concept that everyone can benefit from a universal probiotic bought from the supermarket is empirically wrong, he says. 

The takeaway: Certain strains were found useful in preventing diarrhea among children being prescribed antibiotics. A 2013 review showed that after antibiotic use, probiotics help prevent Clostridium difficile-associated diarrhea. A review focused on acute infectious diarrhea found a benefit, again for certain strains of bacteria at controlled doses. There’s also evidence that they may help prevent necrotizing enterocolitis (a serious gastrointestinal condition) and death in preterm infants. 

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.
The root of the word probiotic comes from the Greek word pro, meaning "promoting," and biotic, meaning "life." The discovery of probiotics came about in the early 20th century, when Elie Metchnikoff, known as the "father of probiotics," had observed that rural dwellers in Bulgaria lived to very old ages despite extreme poverty and harsh climate. He theorized that health could be enhanced and senility delayed by manipulating the intestinal microbiome with host-friendly bacteria found in sour milk. Since then, research has continued to support his findings along with suggesting even more benefits.
Candida yeast species, on the other hand, can cause numerous infections in and on you. Although they are usually present in controlled amounts, Candida overcomes your usual defenses and establishes itself when conditions are favorable, such as when you take antibiotics and many beneficial bacteria, which normally would control Candida, are killed. Unlike the Saccharomyces yeasts, which are not invasive, Candida species form hyphae, finger-like projections that penetrate tissues, causing deep infections that are difficult to eliminate. Candida is also able to weaken your immune defenses.
Probiotics produce enzymes that help break down chemicals the average human gut has a hard time with, like the oligosaccharides in legumes. That results in less gastrointestinal distress and better absorption of nutrients. Probiotics also elicit an immune response that helps your body deal with harmful pathogens and other GI problems. The hard research, especially on recommended CFU dosages, is minimal, but it’s expanding as interest in the product does.
Given that you can get probiotics from the food you eat, you don't necessarily need to take a supplement, and Keatley says she prefers food sources of probiotics to supplements. However, she adds that "There are times when you really need a boost." One example might be during or after a course of antibiotics, as long as you have your doctor's OK, since antibiotics kill both good and bad bacteria: "Seeding your gut with good bacteria can lay the groundwork for a faster recovery and less constipation and diarrhea," Keatley points out. Angelone echoes Keatley's emphasis on food sources of probiotics, but also says that supplements can also play a useful role in "maintaining a healthy gut bacteria colony."
You experience that afternoon slump and reach for a candy bar or a sugar-laden coffee. Or maybe you go through your day, starting with a breakfast of doughnuts or sugary cereal, and then proceed to sodas for drinks, cookies to snack on, dessert after dinner, and finally to a nighttime snack of ice cream. You know that feeling; it’s that I-have-to-have-something-sweet-and- I-have-to-have-it-NOW feeling.

Most people with diverticulosis have few if any symptoms at all. When people do experience signs and symptoms of diverticulosis (diverticular disease) they may include abdominal pain, abdominal cramps, diarrhea, constipation, and bloating. Diverticulitis is a condition in which diverticuli in the colon rupture. The rupture results in infection in the tissues that surround the colon. Treatment methods for diverticulitis includes prescription medications, and in some cases, diverticulitis surgery.

Probiotics may seem new to the food and supplement industry, but they have been with us from our first breath. During a delivery through the birth canal, a newborn picks up the bacteria Bacteroides, Bifidobacterium, Lactobacillus, and Escherichia coli from his/her mother. These good bacteria are not transmitted when a Cesarean section is performed and have been shown to be the reason why some infants born by C-section have allergies, less than optimal immune systems, and lower levels of gut microflora.
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.
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.
This mildly sour, chewy bread is made with a lactic acid starter that contains strains of lactobacillus, a friendly type of bacteria that adds good microbes into the bakery staple. Sourdough may be the healthiest bread choice if diabetes is a concern for you: one 2008 study found that people with pre-diabetes who ate sourdough bread had less of a blood sugar spike compared to when they ate bread made with baker's yeast. (Experts also say fiber-rich whole grain bread can also reduce a post-meal blood sugar spike.) The researchers credit the lactic acid for the favorable effect.
Previous studies have been contradictory, with some yielding more positive results about the benefits of probiotics, but most of them looked at probiotics in stool samples, not directly in the gut itself. In the new research, the scientists used more invasive methods to take samples of gut bacteria directly from different areas of the digestive system.
The research also showed that while probiotics colonised the gastrointestinal tract of some people, the gut microbiome of others just expelled them. There was no way of telling from their stool sample which category people fell into. “Some people accept probiotics in their gut, while others just pass them from one end to the other,” says Elinav. They found that the probiotic colonisation patterns were highly dependent on the individual. That tells us that the concept that everyone can benefit from a universal probiotic bought from the supermarket is empirically wrong, he says.
Because chronic inflammation is at the root of many diseases and health conditions, the fact that probiotics exert this effect in the gut, where 80 percent of the immune system lies, is crucial. The immune-boosting benefits of probiotics seem to be particularly helpful for the quality of life of seniors. Currently, research is underway to test whether probiotics can “reduce inflammation and improve gut immune health in HIV-positive individuals” who haven’t yet undergone treatment.
D-Mannose can be naturally found in citric fruits like cranberries and has been found to be extremely beneficial in the prevention and relief of urinary tract infections. However, unless you are growing your own cranberries or spending hours in the kitchen measuring out portions, it can be extremely difficult (if not impossible!) to know how much D-Mannose you are ingesting by eating alone. That’s why HyperBiotics cut out the middle man and includes the D-Mannose compound directly in its probiotic blend.
Unless you have a perfect gut and are already eating lots of fermented foods—which is rare, although you can work up to this point—it’s difficult to get all the probiotics you need from diet alone. Most of us don’t have perfect guts—everything from antibiotics to high-carbohydrate diets to being born via a C-section can compromise the balance of bacteria in our microbiome. Supplementing with a probiotic can help to restore imbalances, and it’s also just a great preventative health measure, helping to keep your microbiome in balance and your immune system healthy to ward off illnesses.
Because there's a huge variety of probiotic products available on the market, many people struggle to find the right one for them. "There are many different strains of bacteria in different combinations within different probiotic supplements," explains Brooke Scheller, a clinical and functional nutritionist. "For example, a probiotic may contain a single strain of bacteria or many. It may also contain other vitamins, minerals, or other ingredients that may tout health benefits," she says. There are many different dosages, delivery systems (powder, tablets, capsules), and formulations (refrigerated vs. shelf-stable), and some probiotics also contain prebiotics, which basically act as fertilizer for the probiotics. (Related: Why Your Probiotic Needs a Prebiotic Partner)

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.
Probiotic therapy may also help people with Crohn's disease and irritable bowel syndrome. Clinical trial results are mixed, but several small studies suggest that certain probiotics may help maintain remission of ulcerative colitis and prevent relapse of Crohn's disease and the recurrence of pouchitis (a complication of surgery to treat ulcerative colitis). Because these disorders are so frustrating to treat, many people are giving probiotics a try before all the evidence is in for the particular strains they're using. More research is needed to find out which strains work best for what conditions.
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