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Studies have shown some benefits linked to Lactobacillus and treating and/or preventing yeast infections, bacterial vaginosis, urinary tract infection, irritable bowel syndrome, antibiotic-related diarrhea, traveler's diarrhea, diarrhea resulting from Clostridium difficile, treating lactose intolerance, skin disorders (fever blisters, eczema, acne, and canker sores), and prevention of respiratory infections.
Probiotics have also been researched for how they support the immune system. Studies suggest that probiotics can improve how the immune system functions such as by decreasing upper respiratory tract infections in adults and reducing the need for antibiotics. Studies in children show that a regular diet including probiotics reduces colds and flu-like symptoms and improves attendance in preschool and day care settings.
The label should also specify that the living microbes are viable through end of shelf life or best by date rather than at time of manufacture to ensure the bacteria are still live when you take them and able to reach your colon. Quality trumps everything- supplements that are a bargain are typically not of quality. A good probiotic (depending on strands) can cost anywhere from $25-$60.
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!
You may have heard some questions over whether SBOs are safe: The NIH has a presumed case report, which hasn’t been 100 percent verified, of someone with Lymphoma getting septicemia from taking a SBO (the organism B. subtilis). Some say that if you have leaky gut, you should heal it before supplementing with SBOs. If you are immunocompromised or have cancer, you can consult with a physician first to be safe.
As of now, the most comprehensive meta-study (a study of different studies) has not been able to decisively identify any particular strain of bacteria that is specifically useful to treat seasonal allergies. Some studies contradict each other on which bacteria can treat grass pollen, and other studies will find that those strains the first two studies examined weren’t nearly as effective in their own trials.
The other thing to remember is that these microorganisms are not all created equally. In fact, the genus, strain, and species all need to be the same for the results that found in the study to be the results that one hopes to achieve when taking it. For example, with the strain Lactobacillus rhamnosus GG, the genus is Lactobacillus, the species is rhamnosus, and the strain is GG. If any one of those is different in your supplement, you may not attain the same results.
We started our search with the most popular products from major supplement retailers like Amazon, Drugstore.com, GNC, and Whole Foods. That gave us over 200 supplements. With so many options, we then narrowed our search to 70 probiotics whose purity, potency, and projected efficacy have been vetted by an independent lab like ConsumerLab, Labdoor or the National Science Foundation (NSF). Those labs test — among other things — supplements’ actual composition against labels, verifying ingredient lists are truthful and that contaminants aren’t present. Because supplement claims aren’t regulated by the Food and Drug Administration (FDA), we wanted to make sure someone was testing whether they worked as described.
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.
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.
When reading a probiotic label, it should reveal the genus, species and strain of the probiotic. The product (usually in capsules or probiotics pills) should also give you the colony forming units (CFUs) at the time of manufacturing. Also, the majority of probiotics can die under heat, so knowing the company had proper storing and cooling of the facility is also important.
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.
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.
"The skin and the gut go hand in hand," explains Shapiro. "Since probiotics help improve the gut microbiome and aid in reducing inflammation, skin conditions will also improve. When eating a healthy, whole food diet as well, skin conditions get better over time. When the gut is not intact, other parts of the body also start to break down and become toxic. With probiotics, your gut becomes healthier and therefore, your skin problems start to disappear. "
While the logic behind probiotics might seem sound, it is clear that we have a long way to go before understanding the complexity of the microbiota and the effects—both good and bad—that probiotics might have. All individuals have a unique gut microbiome, and the effects of different bacteria on different people are likely to be highly variable; as such, probiotic use might even need to be personalised for optimal benefits. Commercially available products might not contain the correct strains or quantities of bacteria to provide benefits, and most probiotic supplements contain only single strains, vastly oversimplifying the complexity of the microbiota. While taking a supplement for improved health is certainly an attractive prospect, those looking to aid their gut microbiota might be better served by consuming a healthy, varied diet. In the meantime, rigorous clinical trials are needed to substantiate potential health benefits and to confirm whether probiotics are elixirs or just empty promises.
While one 2009 study did show some evidence for reducing cold and flu symptoms in children ages three to five and a 2015 analysis showed probiotics to be better than placebo in preventing acute upper respiratory infections, neither were enough to convince the National Institutes of Health of the efficacy of probiotics for colds and flu. The NIH confirms, “the evidence is weak and the results have limitations.”
If you want to supercharge your probiotic friends, you may want to feed them with prebiotics. That’s P-R-E-biotics. They nourish the good bacteria in your gut in order to keep them healthy against the bad bacteria. They should go hand-in-hand with probiotics. Prebiotics are found in many foods, including bananas, whole grains, honey, garlic and onions. Try to get two to four servings of these prebiotic-rich foods a day.
Inside your body bacterial and other microbial cells live in close contact with your own cells, and in healthy conditions the thing that separates them from you is a layer of mucus. Between that layer of mucus and the inside of you is a layer of skin-like cells one-cell thick. One thing you have to understand about your gastrointestinal (GI) tract is that although it resides within you, it is really connected to the outside world, from your lips to your anus, and the things that protect you from the outside world are the mucus; the skin-like layer of cells with immune, nervous, and endocrine cells below it; and the beneficial microbes. At least 70 percent of your immune system is in your GI tract! This is why taking probiotics benefits the immune system greatly.
While probiotics have been around as long as bacteria have, they were first officially identified for their health benefits in the early 20th century by Russian-born biologist Élie Metchnikoff. Metchnikoff believed that “good bacteria” like the microbes that produce lactic acid could prolong life and stave off senility, and actually recommended drinking sour milk daily for overall health. While Metchnikoff’s theories were pooh-poohed by many of his contemporaries, the first commercial probiotic, Yakult, hit the market in 1935 and is still on the shelves today.
The Bifidobacteria (Bifidus) predominantly live in your colon or large intestine. They produce the very important short-chain fatty acid butyrate, which supplies energy to your colon cells to keep them functioning optimally. But butyrate also gets absorbed by the body, regulating a variety of metabolic processes, including your sensitivity to the hormone insulin (which regulates blood sugar) and even memory formation in the brain. The most beneficial of these are B. lactis and B. longum. Research shows the benefits for Bifidobacteria include reducing inflammatory bowel disease and several cancers, especially colon cancer. Another study showed that a specific strain of Bifidobacterium lactis helped control body fat mass and reduced waist circumference and food intake.
If this ratio gets out of balance, the condition is known as dysbiosis, which means there’s an imbalance of too much of a certain type of fungus, yeast or bacteria that affects the body in a negative way. By consuming certain types of probiotics foods and dietary supplements (often in capsule form), you can help bring these ratios back into balance.
In the 2016 paper, Dr. Ghannoum and is research partners looked at parameters of microbiome makeup in Crohn’s Disease patients and healthy members of the same families in an area in Belgium. The researchers said they “identified positive interkingdom correlations between C. tropicalis (a fungus), E. coli, and S. marcescens (both microbial species) in CD patients and validated these correlations using in vitro biofilms. These results provide insight into the roles of bacteria and fungi in CD.”
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.
Unfortunately, many commercial brands don’t measure up. They are unstable in stomach acid. Quality control measures aren’t intact, including ensuring supplements have been handled correctly and maintain their freshness. Moisture slipping into probiotic supplements can reduce their efficacy. Companies that use bioshield capsules produce higher quality probiotic supplements that are able to endure the stomach acid, releasing their contents within the small intestine, where a more alkaline environment ensures the survival of the bacteria.
We are clearly getting to the strain level by going beyond “Saccharomyces boulardii” and to “Saccharomyces boulardii CNCM I-745”. They did a great job by actually putting it on the label so you don’t even have to contact the company to see exactly what strain you’re getting. (P.S. this is a well-researched strain that I highly recommend, especially for preventing antibiotic-associated diarrhea.)
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.
The second type of probiotics are soil-based organisms (SBO), which tend to be more resistant to acid in the gut. Here’s the thinking behind soil-based probiotics: Many people (particularly in the paleo community) believe that widespread gut and health issues today are the result of life in a too-clean society. In the past, when more people worked in the dirt, played in the dirt, there was less obsessing over cleanliness and antibacterial products, we got more natural exposure to probiotics. The benefit of soil-based probiotics is that they come from the earth, and the bacteria (which are still living) have their own natural, protective capsule surrounding them. I recommend soil-based probiotics to patients with autoimmunity, in addition to the classic form. They are particularly helpful for people with SIBO (small intestinal bacterial overgrowth)—with SIBO, you also have an overgrowth of good bacteria; and in this case, the classic form of probiotic is not what you need to fight the infection.
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.
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.