"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," Eran Elinav said in a statement. "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."

What's more, people who have serious heart issues commonly have S. mutans in their heart valves—this is an undesirable type of bacteria that’s actually more often found in the mouth. If your oral microbiome is in balance, S. mutans are normally kept in control by more beneficial species, but if things get out of balance, they can reproduce and make their way into your bloodstream via openings in your gums, compromising your cardiovascular function.3
Selecting a multi-strain probiotic is also consistent with the theory that filling your gut with enough good bacteria outcompetes any bad bacteria for the same space and resources. In your gut, the more diversified the good bacteria, the harder it is for the baddies to gain a foothold. With all this in mind, we only looked at supplements containing multiple strains of bacteria. 

After further analyzing the data, the researchers found that they could predict whether the probiotics would take hold in people's guts by examining their microbiome and gene expression in the gut taken at the start of the study. However, this prediction method needs to be confirmed in future studies. The researchers called for further research to better understand why some people resist colonization by probiotics, as that future research may enable researchers to counteract the resistance.
A popular dish in Japan consisting of fermented soybeans, natto contains the extremely powerful probiotic bacillus subtilis, which has been proven to bolster your immune system, support cardiovascular health and enhance digestion of vitamin K2. Natto can also contain vitamin B12, which is usually lacking in vegan diets. It’s also one of the highest plant-based proteins.
The best probiotic manufacturers will list their potency (in CFUs) at the time of expiration, ensuring you get the dosage you’re paying for. Dr. David Perlmutter, board-certified neurologist, American College of Nutrition Fellow, and author of The New York Times bestsellers "Brain Maker" and "Grain Brain" puts it this way: “Avoid products that indicate a specific number of bacteria ‘at the time of manufacture,’ and instead look for products that, like other supplements, have a shelf life.” Each of our top picks clearly shows a specific “best by” or “expires on” date on its bottle.

Uncontrolled changes in blood sugar levels or a decreased ability to regulate insulin can have serious effects on your overall health, and since far more men than women are at risk for these changes, these issues are well worth paying attention to.5 Research indicates that regularly taking probiotic supplements containing Lactobacillus and Bifidobacterium can help your body maintain blood sugar levels already within a normal range, whether you're simply at risk for insulin-related challenges or you're already experiencing them.
The best probiotic manufacturers will list their potency (in CFUs) at the time of expiration, ensuring you get the dosage you’re paying for. Dr. David Perlmutter, board-certified neurologist, American College of Nutrition Fellow, and author of The New York Times bestsellers "Brain Maker" and "Grain Brain" puts it this way: “Avoid products that indicate a specific number of bacteria ‘at the time of manufacture,’ and instead look for products that, like other supplements, have a shelf life.” Each of our top picks clearly shows a specific “best by” or “expires on” date on its bottle.
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.

Yes, they may help. Lebwohl says there are reputable studies that show a link between the use of probiotics and the reduction in IBS symptoms, citing this meta-analysis. It's estimated that 11 percent of the world population complains of symptoms like abdominal cramps, diarrhea, constipation, excessive gas and/or mucus in their stools. While for some the condition can be attributed to certain dietary triggers, others appear to be stress-related, which brings us to the heart of where many claims about the effectiveness of probiotics lie—in the gut-brain axis.
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.
Next the researchers measured what happens to the microbiome of people who take probiotics in the hope of restoring their microbiome after antibiotics. Twenty-one volunteers took an identical course of antibiotics and were then assigned to one of three groups. The microbiome of the first group was allowed to recover by itself, whereas the second group was given probiotics. The third group was treated with a dose of their own original pre-antibiotic microbiome by a faecal microbiota transplant (FMT).
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.
When I polled friends and family about their personal experiences with probiotics, I got a real mixed bag of responses. Some called them a lifesaver and others felt no effects whatsoever. I put the anecdotes aside and talked to Ben Lebwohl, gastroenterologist and director of clinical research at Columbia University’s Celiac Disease Center, to get the straight poop on whether probiotics are miracle or myth.
"Although all of our probiotic-consuming volunteers showed probiotics in their stool, only some of them showed them in their gut, which is where they need to be," co-senior author Eran Segal, a computational biologist at the Weizmann Institute, said in the statement. "If some people resist and only some people permit them, the benefits of the standard probiotics we all take can't be as universal as we once thought."
Other foods without substantial research: miso (fermented soybean paste); tempeh; sauerkraut; aged soft cheese; sourdough bread; sour pickles; gundruk (nonsalted, fermented, and acidic vegetable product); sinki (indigenous fermented radish tap root food); khalpi (fermented cucumber); inziangsang (traditional fermented leafy vegetable product prepared from mustard leaves); soidonis (widespread fermented product prepared from the tip of mature bamboo shoots)
For example, yogurt is made with two “starter” bacterial cultures — Streptococcus thermophilus and Lactobacillus bulgaricus — but these bacteria are often destroyed by your stomach acid and provide no beneficial effect, Dr. Cresci explains. Some companies, though, add extra bacteria into the product, so check the labeling and choose products with bacteria added to the starter cultures, she advises.

One thing that is often overlooked is gut health and the benefits of probiotics for weight loss. Gut microbiota can affect food intake choices, appetite, and body weight and composition. Dysbiosis, an imbalance in the gut microbiota with a shift favoring pathogens and opportunists, is common in overweight people. The pathogens and opportunists create an inflammatory situation that affects insulin and other hormones, resulting in the inability to lose weight.


Kefir: This could be the most ideal probiotic dairy product because it contains both bacteria and yeast working together to provide the numerous health benefits. In a recent eight-week study, people with diabetes were given kefir milk containing Lactobacillus casei, Lactobacillus acidophilus, and bifidobacteria vs. conventional fermented milk. The hemoglobin A1C levels were significantly lower in the group consuming the kefir.

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.


“Highly recommend –There are quite a few probiotics manufactured specifically for women. Some are decent while others are not so good. For me, I require one on a daily basis to maintain my feminine health. When I try a new probiotic that is made specifically for women, it makes me a bit nervous because I will end up with yeast or bladder infection if it is not effective. With AZO, I am happy to report it is a great probiotic and highly recommend it to all women! It works great.” – Vicki
Because poor gut health is related to autoimmune responses like those found in rheumatoid arthritis (RA), probiotics have been a proposed treatment option for the condition. Only a few studies have been conducted in humans, and only one testing L. casei 01, a particular probiotic strain, was able to find a decrease in RA inflammation and progression of the disease.
We found the most evidence linking strains to antibiotic recovery, immune health, and IBS/IBD relief. We made checklists of the most researched strains that treat those issues (10 strains known to boost general health, six for immune health, seven for antibiotic recovery, and seven for IBS/IBD relief) and dug into ingredient lists to find the supplements containing the highest number of effective strains for each use case.

"When certain types of probiotics are placed in contact with skin cells, they calm the parts of the cells that may want to react to the presence of bad bacteria that they see as a threat. These healthy signals produced by the probiotics stop the skin cells from sending 'attack' messages to the immune system that result in flares of acne or rosacea."
If you’ve ever clicked on the 6:00 news or scrolled through the latest headlines on your smartphone, you probably know that supplements and vitamins are not typically backed by governmental entities like the FDA or the World Health Organization. This fact can leave supplement newbies a bit wary, which is exactly why we love the Garden of Life Dr. Formulated Once Daily Women’s Probiotic so much.
Research suggests probiotics work better as a team. Even pairs are more effective than individuals. Take the strains Lactobacillus Acidophilus and Bifidobacterium Bifidum BB-12, for example. When combined, this duo-force has been shown to help treat GI-specific ailments. In fact, one survey found 75 percent of studies that compared the effect of a strain mixture with a single-strain supplement showed a mixture was more effective at improving irritable bowel symptoms, immune function, and digestive health.
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.
×