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Probiotics. So many choices.
We know taking them can be very beneficial, but which products are best for you?
What is a probiotic, anyway?
Most people think of probiotics as something they get from eating certain fermented foods like yogurt, kefir, sauerkraut and kimchi, or from supplements containing beneficial bacteria like Lactobacillus acidophilus.
A probiotic is defined as a product or preparation that contains one or more microorganisms that when consumed, maintains or restores beneficial bacteria to the digestive tract. I would expand on this definition; we should probably include any bacteria, yeast, parasites (yes, there are parasites with beneficial effects on the immune system) or even viruses that when consumed or applied topically or via inhalation, maintains, restores, or improves the microbiome, the community of microorganisms that live in a specific location in or on the body, to a healthy state. In fact, “probiotic” is often used as an adjective to describe the effect that a product has on the body, that is pro (good) + biotic (Ancient Greek, biotikos, “of life”; of, pertaining to, or produced by life or living organisms).
Did you know that we have as many or more microbial cells living in and on our bodies than human cells? These microbes make up what’s known as our ‘microbiome.’ Beneficial microbes live in symbiosis with us, with many important (even vital) benefits.
Probiotics improve gut integrity and nutrient
Probiotics work through multiple mechanisms to achieve their beneficial effects. One primary mode of action is to create an environment favoring a healthy-functioning gut with minimal inflammation. If you have a damaged or ‘leaky’ gut, probiotic supplements can help restore a healthy gut barrier. Healthy gut bacteria help to increase production of helpful nutrients, including Vitamin K, folate, and other important B vitamins. Good bacteria are responsible for producing 70% of the energy used by intestinal epithelial cells. They do this by fermenting dietary fiber and making SCFAs (short-chain fatty acids), particularly n-butyrate. Probiotics also tend to promote a healthier balance of microorganisms, reducing the number of pro-inflammatory bacteria like E. Coli and Klebsiella pneumoniae.
Probiotics reduce disease risk
The list of reported benefits of probiotics is continually being expanded upon. Current known or potential benefits include reducing LDL cholesterol, improving markers of the metabolic syndrome (diabetes, hypertension, fatty liver, heart disease), reducing tooth decay, prevention and treatment of diarrhea caused by traveler’s diarrhea or a life-threatening inflammation of the colon caused by C. difficile, preventing allergic conditions such as eczema, reducing the incidence of urinary tract and upper respiratory tract infections, reducing symptoms of irritable bowel syndrome or the more serious intestinal inflammatory conditions Crohn’s disease and Ulcerative colitis, as well as inflammatory forms of arthritis such as Rheumatoid arthritis. Certainly there is ample supportive evidence for use of probiotics for many conditions, and likely for other conditions not yet researched.
Should I choose a single strain or multi-strain probiotic?
So, we’ve established that probiotics are living microorganisms that we ingest, or incorporate into our bodies in other ways, for our benefit. How do we know which strains to use for which circumstances? The simple and honest answer is that we don’t know enough to make that type of specific recommendation in most cases. Sure, there are individual studies on specific strains used for specific purposes, such as using L. casei 01 in rheumatoid arthritis. But most clinicians would not use a single strain of probiotic since we know that using multiple strains achieves synergistic effects, as seen in this review of multi-strain probiotic therapy for treatment of the ulcer causing H. pylori bacteria, by stimulating different cellular actions or biochemical pathways.
Is more better?
How about the claim that using higher concentrations of probiotic bacteria (measured in CFUs = colony forming units) is of greater benefit? This makes sense: there is probably a certain concentration requirement that a probiotic supplement must achieve in order to be effective. Remember, though that by using probiotics, we are still only adding a small fraction of microbes compared to the 10 to 100 trillion that are estimated to reside in our intestines. Medical experts in gastroenterology don’t offer much guidance concerning dosing and type of probiotics, in fact advising patients to wait until there is more evidence to support their use, fearing safety issues, which are not entirely unfounded. However, when reliable products are used in people with relatively healthy immune systems, the benefits most likely outweigh any risks. Concerning CFU concentrations, various sources recommend using a probiotic with either 1-10 billion or 10-20 billion CFU for everyday use, which seems reasonable. However, if treating a condition like ulcerative colitis, studies support to aiming much higher for (>1011 =100 billion CFUs). Pediatric doses are usually in the 5-10 billion range. There is probably little risk to using higher doses, although some people can develop upset stomach or diarrhea if they aren’t used to taking probiotics. Hopefully we will know more about probiotic dosing requirements in the future, as more clinical studies are performed.
Do I have to buy a refrigerated probiotic?
How about the claim that refrigerated or “shelf-stable” probiotics are more effective than those kept at room temperature? The answer is probably “yes.” However, it is clear that probiotic bacteria can be effective in some ways even if they are killed or inactivated. In fact, there is a name for these probiotic products: paraprobiotics or “ghost” probiotics. In other words, if your probiotic product does not survive the manufacturing, transportation, and storage process, or does not accomplish the delivery of live bacteria past your stomach acids into your large intestine, all is not lost.
How is it possible that dead or inactivated bacteria could have some of the beneficial effects that live bacteria offer? The answer to this question is that probiotics do not always act in the way that we think they do. Most of the time, bacteria in probiotics do not actually take up residence in the intestine, they slowly pass through, exerting their effects in a time-limited way. This is probably why we need to take probiotics on a regular basis to maintain the health benefits. That being said, there is some evidence that if the person ingesting the probiotic has a deficiency of a specific bacterial strain, a probiotic can actually re-populate the gut microbiome.
So, if the probiotic bacteria are mainly passing through without becoming part of the intestinal microbiome family, how is it that they deliver health benefits? The scientific thinking is that cell wall or DNA material from the (live or dead) bacteria acts as a signal to the immune cells of the , exerting an anti-inflammatory response or an anti-cancer effect. Inactivated bacterial content is also thought to influence the quantity and variety of the more permanent bacteria. This is an important concept, as it may be possible to achieve some of the beneficial effects using “ghost” probiotics instead of live probiotics.
In most people, using a good quality product that delivers live bacteria to the intestine is the best way to derive the full benefits of using probiotics. Using “ghost” probiotics only confers some of the benefits of their live counterparts—it is unlikely, for example, that an inactivated probiotic would lead to production of the essential nutrient folate as occurred in this study showing that administration of live Bifidobacterium led to the production of folate in test subjects. When might we consider “ghost” probiotics? Using inactivated “ghost” bacteria could possibly be useful in reducing the risk that live bacteria could end up in the blood stream and cause severe illness for a person with a suppressed immune system or an extremely weakened gut barrier. More scientific exploration is needed for this important topic.
What brand should I choose?
Now to answer the original question which was asked: “which probiotics are best?” There really is not one correct answer to this question. Some truly healthy people, who are eating a super-healthy, extremely varied diet, may not benefit as much from taking probiotics. But is there really anyone who has a completely healthy intestinal microbiome? There are not many people who have never taken antibiotics or never had food poisoning or gastroenteritis, all of which disrupt the intestinal microbiome incredibly. So, most of us benefit from a reasonably dosed probiotic product (1-10 billion CFU) consisting of a mixture of well-studied probiotic strains.
These include the following:
- Lactobacillus rhamnosus GG (available as the brand )
- Lactobacillus acidophilus
- Lactobacillus bulgaricus LB-51
- Lactobacillus gasseri
- Lactobacillus plantarum
- Lactobacillus reuteri
- Lactobacillus rhamnosus
- Bifidobacterium lactis BB12
- Bifidobacterium bifidum Malyoth strain
- Bifidobacterium breve
- Bifidobacterium infantis
- Streptococcus salivarius
- Bifidobacterium longum
- Lactobacillus acidophilus DDS1
- Saccharomyces boulardii
Probiotic products that I routinely recommend for general health include the professional grade probiotics Ther-Biotic Complete (Klaire Labs), Ortho Biotic (Ortho Molecular), UltraFlora Balance (Metagenics), Probiotic Synergy (Designs for Health), and ProbioMax Daily DF (Xymogen). Good quality, consumer grade, broad spectrum products are also available. These have been tested and found to contain at least 1 Billion CFU organisms, according to consumerlab.com. They include Garden of Life Primal Defense Ultra, Dr. Mercola Complete Probiotics, and Nature’s Bounty Ultra Strength Probiotic 10. VSL #3 is also a good (but more expensive) choice for those looking for a very high CFU product (>225 billion), which is especially useful for patients who have ulcerative colitis.
What about so-called ‘soil-based’ probiotics?
Another trend in probiotics that you may have heard about are soil based, or spore based probiotics. These consist mainly of spores of beneficial Bacillus species. Bacterial spores are dormant and can persist in a dehydrated state indefinitely. When taken as a probiotic, they germinate and briefly colonize the intestine. Data is accumulating for using Bacillus based probiotics for various health conditions as detailed in this excellent recent review . Examples of these spore based probiotics include Prescript Assist, MegaSporebiotic, and ProbioMax IG26DF (Xymogen, immune globulins + Bacillus coagulans MTCC5856). I tend to use the more standard probiotics first, but if they are either not well tolerated or sufficient improvement has not been achieved, I will certainly consider using these spore-based probiotics.
How can I evaluate the overall health of my gut microbiome?
Stool testing can certainly be done to determine which of several ‘good’ (commensal) bacteria are present in the gut. We like the Genova GI Effects test for this, which determines the relative concentration of 24 different species by PCR (genetic identification) method. uBiome Smart Gut test is very similar to the Genova test, although it does not include other key markers of digestion or intestinal inflammation. The findings on these tests rarely cause me to alter my recommendations for which probiotic should be used, although they are helpful for identifying and addressing pathogenic, or ‘dysbiotic’ bacteria, as well as digestive sufficiency and inflammation.
What if I feel worse after taking a probiotic?
If after starting a probiotic, you experience uncomfortable GI symptoms (or even more systemic symptoms such as headaches), it could be that SIBO (small intestinal bacterial overgrowth) is present. In this case, the addition of more bacteria (especially Lactobacillus sp.) can lead to excessive bacterial production of D-lactate, which can cause fatigue and headaches. For people experiencing these symptoms I would certainly consider ordering a lactulose breath test for SIBO. I would also think about using a probiotic that does not contain D-lactate producing bacteria, like this one. If SIBO or D-lactate is not the problem, simply starting with a lower CFU product and working up to a higher concentration may be the answer. This may also be a reason to consider using a product with fewer strains or a spore-based probiotic.
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