What's nice about supplement company Care/of is that it allows you to design personalized daily vitamin and supplement packs containing everything you need, including probiotics. Its vegan, gluten-free probiotic formula has one billion lactobacillus acidophilus and four billion bifidobacterium lactis per dose, popular strains thought to help promote digestive and immune health.
In addition to its powerful probiotic strands, the Vitamin Bounty Women’s Pro-Daily Probiotic also features a proprietary women’s health formula. This blend includes many of the minerals and plant extracts that have been found to be the most beneficial to women’s health, making it ideal for any women that have experienced feminine health problems. Specifically, this Vitamin Bounty formula includes Ashwagandha Root Powder, Cranberry Fruit Powder and Black Cohosh Root Powder.
With Prebiotin, you can easily add prebiotic fiber to your diet without worrying about eating huge amounts of troublesome foods or hunting down hard-to-find ingredients. You also won’t have to worry about loading up on high-calorie foods that can negatively affect any effort to lose weight. Combining Prebiotin prebiotic fiber with a diet enriched with probiotic foods can only help your effort to positively influence the bacterial balance in your lower gut.

“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.”
The benefit of taking a probiotic supplement is that a supplement contains very specific bacteria known to have a beneficial effect on human health, and a positive impact on our gut microbiome. Taking a probiotic supplement has the added benefit of providing a specific and concentrated dosage of healthy bacteria, so you know you are getting a therapeutic, research-proven dosage every time.
If you decide to use a probiotic supplement and get clearance from your doctor for doing so, be sure to read the label carefully. You want to be sure that the supplement contains live strains of the bacteria or yeast, and that the life of these strains is guaranteed at the time of use, and not at the time of manufacture. Other points of comparison are the number of bacteria strains and the number of colony-forming units, although this does not necessarily guarantee results.
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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.
Probiotics One Daily Support is easily one of our favorite probiotics right now and currently sits at #2 in our ranking of the best probiotics supplements.  There’s a number of reasons why I like it so much, but the main one is I just felt SO much better while taking it!  My stomach (which sometimes gives me issues due to IBS) felt great and I had a bit more energy than usual.  I was also able to digest all my meals without any problems, a major plus!  Further, Daily Support is very allergy-friendly, doesn’t require refrigeration and comes with a 60-day guarantee.  So all-in-all, we gave Probiotics One 5 out of 5 stars and truly think it’s a REALLY great probiotic.  Read the full review here… or click here to go buy it now!
Many Lactobacillus and Bifidobacterium species are naturals at protecting and improving gut health. Additionally, research in animals and humans has shown that probiotics decrease scores on depression assessments, thereby alleviating depression. As a matter of fact, there is a new term, psychobiotics, for these microbes that influence mental health conditions like depression.
If you've tried a probiotic after following these steps and it doesn't seem to be working for you (or you just want some extra guidance in choosing one), head to your doctor (or a dietitian) to get a recommendation. "Have a thorough discussion with your doctor to make sure you are taking the appropriate bacterial strain for the appropriate reason," advises Dr. Ivanina. "Then, follow up after taking the probiotic to make sure it is having the intended effect."

If your child has a history of stomach problems that medicine doesn’t seem to help, adding a probiotic to his or her diet can help. We love the OLLY Kids Happy Tummy Gummy Supplements because they offer complete probiotic support in a kid-friendly gummy form. Each gummy has a blend of prebiotic, probiotic, and peppermint to help soothe upset stomachs. They contain 500 million CFU of Bacillus coagulans. This container comes with 30 gummies (to be taken once a day) and is recommended for children 2 years and older.
Some companies have been around for years, and you may know their names. Those that have made probiotics for a while likely have tested and studied them over and over. It's smarter to choose a product from them over one from a maker you don't know. Check a third-party certifier (like ConsumerLab or the USP) to see if they have tested the product and found that it’s safe and reliable. If you're in doubt, ask your doctor.
This is one of the newer areas of probiotic research. Described as the “gut-brain axis,” researchers believe that the communication between the gut and the brain affects not just physical but also mental health and behavior. For example, a recent study found that probiotics can reduce anxiety, relieve stress and improve mental outlook. Another study found that the probiotics L. helveticus and Bifidobacterium longum reduced depression, anger, hostility and self-blame and improved problem-solving ability. Another study showed a difference in brain activity between women consuming yogurt and those consuming a placebo. More research needs to be done to confirm the effect of probiotics on mental and emotional health.
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.
She totally did, but you may have noticed that you don't see those yogurt commercials anymore. That’s because in 2010, the Federal Trade Commission in conjunction with 39 states' attorney generals banned those ads, finding that the Dannon Company had no scientific evidence to back up their claims,. Dannon had to pay $21 million to resolve the associated investigations.
It is well known that people with lactose intolerance can often consume yogurt with few symptoms. This is because the probiotics in yogurt help digest the lactose in the small intestine, before it reaches the colon. In addition, the yogurt starter cultures L. bulgaricus and Streptococcus thermophilus help to break down the lactose. Because of its probiotics, yogurt is a good way for people with lactose intolerance to consume the recommended servings of dairy without experiencing uncomfortable symptoms they may get from other dairy products.
​​​​​​AZO Complete Feminine BalanceTM is a daily probiotic supplement designed for the unique needs of women. Many everyday things can throw off your balance (stress, sex, pregnancy, aging, even medications! This product supports your feminine health and maintain a healthy pH so that you can own your day! It contains INTELLIFLORATM: a probiotic blend of four lactobacilli that are associated with vaginal health* (Lactobacillus crispatus LBV 88, Lactobacillus rhamnosus LBV 96, Lactobacillus jensenii LBV 116, and Lactobacillus gasseri LBV 150.)  The INTELLIFLORATM blend has been shown in clinical studies to help restore and maintain the healthy balance of the vaginal microbiota.*

B. Bifidum has also been shown to prevent intestinal pathogens or digestive disrupters from flourishing in the gut, essential in restoring the bacterial balance and optimizing digestion. Clinical research found it supports a significant reduction in IBS symptoms, an improvement in quality of life and even helps relieve occurrences of ulcerative colitis – a chronic inflammatory bowel disease. [1].

Immunity and colds/flu.There’s a close connection between the bacteria in your colon and the immune system. Several studies, including one in 2012 in the British Journal of Nutrition, have found that certain probiotic strains boost measures of immune response—but whether this translates into any clinical benefits is uncertain. Studies have been inconsistent, for example, as to whether probiotics will actually curb colds and other upper respiratory infections. In 2014 a review in the British Journal of Nutrition, which looked at 20 clinical trials, linked probiotics to shorter duration of colds, but not necessarily reduced incidence or severity. Similarly, a 2015 Cochrane review of 12 clinical trials concluded that certain probiotics may help prevent or shorten such infections, though the quality of the studies was poor.
There’s preliminary evidence that some probiotics are helpful in preventing diarrhea caused by infections and antibiotics and in improving symptoms of irritable bowel syndrome, but more needs to be learned. We still don’t know which probiotics are helpful and which are not. We also don’t know how much of the probiotic people would have to take or who would most likely benefit from taking probiotics. Even for the conditions that have been studied the most, researchers are still working toward finding the answers to these questions.

Evidence from clinical trials is mixed and often of low quality, but findings from meta-analyses suggest that probiotics can provide benefits in the treatment of some conditions, such as infectious and antibiotic-associated diarrhoea. As such, taking probiotics after antibiotic treatment is an increasingly common practice. However, two studies recently reported in Cell question whether taking highly concentrated supplements of so-called good bacteria aids the recovery of normal gut flora.


They probably are. Lebwohl says probiotics may decrease the risk of getting diarrhea during the course of taking antibiotics, and may also play a role in specifically preventing the development of the dreaded antibiotic-related super diarrhea called C. difficile or C. diff. Antibiotics can wipe out the good bacteria that keep you from getting sick if you’re exposed to C. diff, or if you already have it in your system. C. diff symptoms can range from a moderate watery diarrhea several times a day to severe infections, which can be accompanied by fever, bloody stools, rapid heart rate, and can even lead to kidney failure. 500,000 Americans were infected with C. diff in 2015 and 15,000 died from it.
Walk into any grocery store, and you will likely find more than a few “probiotic” products brimming with so-called beneficial bacteria that are supposed to treat everything from constipation to obesity to depression. In addition to foods traditionally prepared with live bacterial cultures (such as yogurt and other fermented dairy products), consumers can now purchase probiotic capsules and pills, fruit juices, cereals, sausages, cookies, candy, granola bars and pet food. Indeed, the popularity of probiotics has grown so much in recent years that manufacturers have even added the microorganisms to cosmetics and mattresses.
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.

Probiotics can also help offset the bacterial imbalance caused by taking antibiotics. Antibiotics kill good bacteria along with the harmful ones, often leading to gas, cramping or diarrhea. Potential benefits of probiotics have been seen in the treatment or prevention of many conditions such as diarrhea, irritable bowel syndrome, ulcerative colitis, and Crohn's disease.
An imbalance between good bacteria and pathogenic bacteria, yeasts or fungi, or a change in the bacteria species that colonize the digestive tract is called dysbiosis. It can have short and long-term effects on our body functions. These disruptions can reduce the immune system’s effectiveness, create unpleasant digestive symptoms (diarrhea, constipation, gas, etc.), be a contributor to certain chronic illnesses like obesity, and participate in producing pro-inflammatory metabolites.
Undaunted, researchers looked into whether probiotics might be beneficial in a host of disorders, even when the connection to gut health and the microbiome was tenuous. Reviews show that there is insufficient evidence to recommend their use to treat or prevent eczema, preterm labor, gestational diabetes, bacterial vaginosis, allergic diseases or urinary tract infections.
DNA Shift is a once-daily, powerful probiotic delivering 50 billion CFUs and 11 probiotic strains. It’s perfect for both men and women who want to improve their gut and brain health. With long-term use, you may even see improved mood and energy levels. This probiotic can help relieve the following: symptoms of gas and bloating, constipation indigestion, irregularity, leaky gut, and diarrhea induced by antibiotics.

If that’s the case, I recommend steering clear. They either don’t want you to know that they’re using a poorly-researched strain of probiotics or they’re simply ignorant to the fact that the strain of probiotic really matters and determines the benefit that you’ll receive as the consumer. I usually want to give these companies the benefit of the doubt, but honestly, if you’re making a probiotic supplement you should know this stuff is important.


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.
If you've tried a probiotic after following these steps and it doesn't seem to be working for you (or you just want some extra guidance in choosing one), head to your doctor (or a dietitian) to get a recommendation. "Have a thorough discussion with your doctor to make sure you are taking the appropriate bacterial strain for the appropriate reason," advises Dr. Ivanina. "Then, follow up after taking the probiotic to make sure it is having the intended effect."
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.
Let’s start at the very beginning: probiotics are bacteria. We know what you’re thinking, bacteria cause infections and are just generally kind of gross. Well, in some aspects, you’re absolutely right. But when it comes to your digestive and feminine health, some bacteria are teeny tiny miracle workers that can make all the difference in the way you feel!
Probiotic supplements and foods can play a major positive role in brain fog. Lactobacillus, in particular, can produce neurotransmitters used for brain neuron-to-neuron transmission to facilitate thinking. Probiotics can interact with the vagus nerve to the brain, with the enteric nervous system that can communicate with the brain, and with the brain via chemical messengers.
Jo A. Panyko is a Master Nutrition Therapist and author of two books about probiotics. She is a professional member of the National Association of Nutrition Professionals (NANP) and works as a functional medicine nutrition therapist (nutritionist) at her company, Chrysalis Nutrition and Health. She writes about how to be healthy with probiotics on her website, powerofprobiotics.com.
Gut flora makes up 70 to 80 percent of the human immune system. Too much bad bacteria can inflame and destroy intestinal walls, enter the bloodstream, and trigger a multitude of health issues — constipation, depression, skin problems, autoimmune disease, and even bad breath. Adding good bacteria protects the digestive tract from the harmful bacteria in sugars, pesticides, and saturated fats.

Pinning down the exact causes of IBS is difficult because each person has his or her own combination of causes. One cause that is receiving much attention is that of a disrupted microbiome, as there is a strong association between having a gastrointestinal (GI) infection, like food poisoning, and the onset of IBS. Also, the FODMAP diet, and nonabsorbable antibiotics to kill gut microbiota, have provided relief in many patients, further supporting the suspicion of a disrupted microbiome as contributing to IBS.

As the best-selling author of Happy Gut and a medical doctor who specializes in gut health and once suffered from IBS (irritable bowel syndrome), I have experienced for myself, as well as see on a daily basis, how a disrupted gut flora opens the door for unfriendly microbes to step in and take over, creating all sorts of pandemonium that causes patients to gain weight, feel sick and tired, and become more disease-prone.


The other way that probiotics help is the impact that they have on our immune system. Some believe that this role is the most important. Our immune system is our protection against germs. When it doesn't function properly, we can suffer from allergic reactions, autoimmune disorders (for example, ulcerative colitis, Crohn's disease, and rheumatoid arthritis), and infections (for example, infectious diarrhea, H. pylori, skin infections, and vaginal infections). By maintaining the correct balance from birth, the hope would be to prevent these ailments. Our immune system can benefit anytime that balanced is restored, so it's never too late.
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.
Probiotics are live microorganisms that are thought to have health benefits, as the National Institutes of Health (NIH) reports. These bacteria and yeast are believed to help populate our guts with beneficial microbes, according to Mayo Clinic, and can be found in fermented or unpasteurized foods including yogurt, kefir, sauerkraut, and kimchi, as well as, yes, supplements.
In the second study, the researchers questioned whether patients should be taking probiotics to counter the effects of antibiotics, as they are often told to do in order to repopulate the gut microbiota after it's cleared by antibiotic treatment. To look at this, 21 volunteers were given a course of antibiotics and then randomly assigned to one of three groups. The first was a "watch-and-wait" group that let their microbiome recover on its own. The second group was administered the same generic probiotics used in the first study. The third group was treated with an autologous fecal microbiome transplant (aFMT) made up of their own bacteria that had been collected before giving them the antibiotic.
Prebiotic fibers are the non-digestible parts of food that are typically found in fruits, vegetables, and legumes. These fibers act as food for the healthy bacteria in your gut, and are an essential part of the digestive process. That’s why the Vitamin Bounty Women’s Pro-Daily Probiotic contains prebiotics and probiotics for a truly complete formula that helps ease digestive issues while also maintaining proper feminine health.
Prebiotics and supplementary ingredients — For probiotic bacteria to grow, they also need prebiotics. High-quality probiotic supplements have both prebiotics and other ingredients designed to support digestion and immunity. Examples of these ingredients are (preferably fermented) flaxseed, chia seed, cañihua seed, astragalus, ashwagandha, hemp seed, pumpkin seed, milk thistle, peas, ginger, mung bean and turmeric.

A woman’s anatomy is different than a man’s, and so are our nutritional needs! That’s why Garden of Life designed a specially formulated mixture of digestive, immune, and feminine health probiotics exclusively for women. If you’re curious about the specific probiotic strains that are included in the Garden of Life Dr. Formulated Once Daily Women’s Probiotic, check out our complete list below:
Jotham Suez, Niv Zmora, Gili Zilberman-Schapira, Uria Mor, Mally Dori-Bachash, Stavros Bashiardes, Maya Zur, Dana Regev-Lehavi, Rotem Ben-Zeev Brik, Sara Federici, Max Horn, Yotam Cohen, Andreas E. Moor, David Zeevi, Tal Korem, Eran Kotler, Alon Harmelin, Shalev Itzkovitz, Nitsan Maharshak, Oren Shibolet, Meirav Pevsner-Fischer, Hagit Shapiro, Itai Sharon, Zamir Halpern, Eran Segal, Eran Elinav. Post-Antibiotic Gut Mucosal Microbiome Reconstitution Is Impaired by Probiotics and Improved by Autologous FMT. Cell, 2018; 174 (6): 1406 DOI: 10.1016/j.cell.2018.08.047
As far as effectiveness, keep in mind that unlike medications, dietary supplements do NOT need to be approved by the FDA. This means that manufacturers can sell supplements simply with "claims" of safety and effectiveness. Currently, researchers are undecided if probiotic supplements are effective. Some say probiotics are effective; others believe they offer no benefit whatsoever. It also remains unclear which probiotics (or combination of probiotics) work to treat certain diseases. Despite these issues, some studies have shown positive results. Still, more research is needed to confirm that probiotics are safe and effective.
Look for the probiotic yeast Saccharomyces boulardii (S. Boulardii)—you can take it as a separate supplement or find it in multi-strain probotics. Studies show that it is effective at preventing antibiotic-induced diarrhea and Clostridium diffcicile (C. difficile) infection, which a course of antibiotics can cause. Saccharomyces boulardii increases your secretory IgA—in other words, it strengthens the immune system in the gut. (Some people say that Saccharomyces boulardii is also the panacea for Candida—it’s a yeast that fights yeast—but while it’s helpful for some, other people do not tolerate it well, so I recommend trying it as an individual supplement first to see how you respond.)

To boost the immune system, B. Lactis is a promising choice. One study had participants taking either a probiotic or a placebo for 6 weeks. At the end of the period, researchers measured antibody levels and found greater increases in antibodies of the B. Lactis group than in placebo participants, concluding that this probiotic may help improve immune function [1]. In addition, a 2009 study found that supplementation of the strain B. Lactis DN-173 led to self-reported improvements in digestive comfort [2].
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.

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.


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.
Women’s health expert Dr. Amy Myers is a goop-trusted authority on subjects from autoimmunity and Candida to thyroid dysfunction; and she’ll be speaking IRL at our first wellness summit on June 10. Here, Myers helps us evaluate the increasing buzz around probiotics, and outlines the ins and outs of selecting a particular supplement (whether hers or other brands). Plus, we’ve rounded up our probiotic essentials, from inner beauty powders to favorite fermentation recipes, in one guide:
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.
In October 2013, the International Scientific Association for Probiotics and Prebiotics (ISAPP) organized a meeting of clinical and scientific experts on probiotics (with specialties in gastroenterology, pediatrics, family medicine, gut microbiota, microbiology of probiotic bacteria, microbial genetics, immunology, and food science) to reexamine the concept of probiotics. They define probiotics as "live microorganisms that, when administered in adequate amounts, confer a health benefit on the host." They also differentiated between products containing probiotics and those containing live or active cultures and established the following criteria:
Dr. Tobias responded with Deep Immune Support, a shelf-stable capsule that does not require refrigeration and employs four acid-resistant probiotic strains. One such strain: DE111, a highly effective spore-forming probiotic, which complements and balances the non-spore strains most commonly found today, and also supports the proliferation of beneficial bacteria. The patented, delayed-release capsules are made in the USA and are both kosher and vegetarian.
We have to give a nod to the most famous probiotic food: yogurt. Whether you love Greek or regular, low-fat or full-fat, look for the phrase "live active cultures" on the label. And although choosing a plain yogurt has less added sugar than the flavored kinds, Tallmadge gives you the okay to choose a fruit-infused flavor if that's the only way you'll eat it. Just be sure to aim for fewer than 15 grams of the sweet stuff per serving; sugar can feed the bad bugs in your gut.
As far as effectiveness, keep in mind that unlike medications, dietary supplements do NOT need to be approved by the FDA. This means that manufacturers can sell supplements simply with "claims" of safety and effectiveness. Currently, researchers are undecided if probiotic supplements are effective. Some say probiotics are effective; others believe they offer no benefit whatsoever. It also remains unclear which probiotics (or combination of probiotics) work to treat certain diseases. Despite these issues, some studies have shown positive results. Still, more research is needed to confirm that probiotics are safe and effective.
Large bodies of evidence suggest that probiotics are effective against several forms of diarrhea, including antibiotic-associated diarrhea, acute diarrhea, traveler’s diarrhea, infectious diarrhea and other associated diarrhea symptoms. They also help with constipation relief. Probiotics have also been found in meta-analyses to reduce the pain and severity of irritable bowel syndrome (IBS) symptoms, aid in the eradication of H. pylori and treat pouchitis, a condition that occurs after the surgical removal of the large intestine and rectum.
There are both probiotics and prebiotics in fermented foods. I differ from a lot of doctors in that I recommend that patients with infections like Candida and SIBO don’t eat prebiotics until they’ve cleared up the infection—because the prebiotics can feed those infections, too. I find that it’s better to get rid of those infections first, and then add in prebiotics to your diet after. [See here for more from Dr. Myers on treating yeast infections.]
Today, most of the Japanese population begins the day with a warm bowl of miso soup, believed to stimulate the digestive system and energize the body. Made from fermented soybeans, rice or barley, adding a tablespoon of miso to some hot water makes an excellent, quick, probiotic-rich soup. The fermentation process can take anywhere from a few days to a couple of years to complete, and the end result is a red, white or dark brown paste with a buttery texture.

Probiotic bacteria readily colonised the gut of everyone in the second group after antibiotics had cleared the way. However, the researchers were surprised to find that this prevented the return of the person’s normal microbiome for up to six months. “The probiotics very potently and persistently prevented the original microbiome returning to its original situation,” says Elinav. “This was very surprising and alarming to us. This adverse effect has not been described to date.”
Probiotic supplements and foods can play a major positive role in brain fog. Lactobacillus, in particular, can produce neurotransmitters used for brain neuron-to-neuron transmission to facilitate thinking. Probiotics can interact with the vagus nerve to the brain, with the enteric nervous system that can communicate with the brain, and with the brain via chemical messengers.
Jotham Suez, Niv Zmora, Gili Zilberman-Schapira, Uria Mor, Mally Dori-Bachash, Stavros Bashiardes, Maya Zur, Dana Regev-Lehavi, Rotem Ben-Zeev Brik, Sara Federici, Max Horn, Yotam Cohen, Andreas E. Moor, David Zeevi, Tal Korem, Eran Kotler, Alon Harmelin, Shalev Itzkovitz, Nitsan Maharshak, Oren Shibolet, Meirav Pevsner-Fischer, Hagit Shapiro, Itai Sharon, Zamir Halpern, Eran Segal, Eran Elinav. Post-Antibiotic Gut Mucosal Microbiome Reconstitution Is Impaired by Probiotics and Improved by Autologous FMT. Cell, 2018; 174 (6): 1406 DOI: 10.1016/j.cell.2018.08.047
Most recently, two back-to-back papers were published simultaneously on September 6 in the journal Cell showing that many people can’t successfully colonize standard probiotic microbiome in their gut. The scientists also found that consuming generic probiotic strains after taking antibiotics often delayed gut bacteria and gene expression from returning to their natural "naïve" state.
The best case for probiotic therapy has been in the treatment of diarrhea. Controlled trials have shown that Lactobacillus GG can shorten the course of infectious diarrhea in infants and children (but not adults). Although studies are limited and data are inconsistent, two large reviews, taken together, suggest that probiotics reduce antibiotic-associated diarrhea by 60%, when compared with a placebo.
Lactobacillus predominantly live in your small bowel (the portion of your gut that follows the stomach). Probiotics containing Lactobacillus sp. help to repopulate the small intestine with friendly organisms that aid in supporting digestion and immune function. The most beneficial are L. acidophilus, L. plantarum, and L. paracasei. One study found Lactobacillus acidophilus could reduce gut inflammation. L. rhamnosus helps increase GABA expression (an inhibitory neurotransmitter that helps you feel relaxed) in the brain, resulting in lower anxiety and depression-related behavior. Another found that a combination of Lactobacillus and Bifidobacteria (which we'll talk about next) improved symptoms of bloating in patients with functional bowel disorders, and yet another found that when people took the Lactobacillus rhamnosus GG strain, it significantly reduced the risk for antibiotic-associated diarrhea.
Even if some of the bacteria in a probiotic managed to survive and propagate in the intestine, there would likely be far too few of them to dramatically alter the overall composition of one's internal ecosystem. Whereas the human gut contains tens of trillions of bacteria, there are only between 100 million and a few hundred billion bacteria in a typical serving of yogurt or a microbe-filled pill. Last year a team of scientists at the University of Copenhagen published a review of seven randomized, placebo-controlled trials (the most scientifically rigorous types of studies researchers know how to conduct) investigating whether probiotic supplements—including biscuits, milk-based drinks and capsules—change the diversity of bacteria in fecal samples. Only one study—of 34 healthy volunteers—found a statistically significant change, and there was no indication that it provided a clinical benefit. “A probiotic is still just a drop in a bucket,” says Shira Doron, an infectious disease expert at Tufts Medical Center. “The gut always has orders of magnitude more microbes.”
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