Your Simple Guide to Probiotics … Plus the 1 BIG thing Your Doc Isn’t Telling You
8 Simple Tips for Buying Probiotics
Probiotics continue to be a hot topic. Depending on what you read or listen to, probiotics can cure anything and everything, or they’re good for nothing at all. They are evidence-based to support a number of conditions, or they’re largely ineffective. So, what’s the deal?
Probiotics absolutely can be an effective way to support gut health and the symptoms of certain acute and chronic conditions. There are plenty of substantial, well-conducted research studies for specific probiotics strains and specific conditions. They are not a cure-all and there are definitely some things to be aware of and keep in mind when choosing a supplement. Further, when random, unspecified probiotics are used in a broad-spectrum manner, that’s when the efficacy can be questionable.
I’m a food-first practitioner, but there are times when supplements can be helpful. At those times, it’s helpful to know what to look for when choosing a probiotic supplement. I’ll do a similar guide for prebiotics in the future.
Before we get into probiotics, it’ll be helpful to review the microbiome at a high level.
A quick primer on the gut microbiome (in case you missed it in last week’s article)
Your body has trillions of microbes in it, and there’s more than one microbiome. These collections of bacteria are found in our large intestine, small intestine, mouth, vagina (for those of us that have them), and skin.
There’s billions of these bacteria in the gut microbiome, which primarily refers to the large intestine but also includes the small intestine. There are a HUGE number of families and species of bacteria; some are beneficial and are commonly called “good” and some are harmful or pathogenic, these are considered “bad.” Your gut bacteria is fed by the food you eat, the beverages you drink, the medications you take, etc.. These bacteria don’t just simply consume what you consume, they also create waste products, called metabolites. These metabolites can be neurotransmitters and hormones, endotoxins like lipopolysaccharides and TMAO, and other things – what they all have in common, though, is that they tell your body to function in a certain way.
Imbalance or dysbiosis occurs when:
There are reduced beneficial bacteria
An overabundance of harmful bacteria
A lack of diversity of different families and species
There’s no such thing as a perfect or ideal microbiome. There are so many families and species of bacteria that we don’t yet clearly understand what each species does for the body; added to that, no person has the exact same bacterial makeup – your specific combination of types and number of bacteria are as unique to you as your fingerprints … except this would be like fingerprints that are constantly changing. The closest I can come to describing an ideal gut microbiome is: A highly diverse microbiome with more beneficial than harmful bacteria.
There are some families and species of bacteria that probably are familiar to you: Lactobacillus acidophilus (commonly found in yogurt), Lactobacillus rhamnosus GG (one of the most well-studied strains, Streptococcus (there are both harmful and beneficial species in this family), and Akkermansia (this has gotten a LOT of attention in the past 2 years; it’s technically an archaea not a bacteria).
Probiotics, Prebiotics, Postbiotics, Synbiotics … What’s the Difference?
Probiotics
Probiotics are defined as live organisms that when consumed in adequate amounts benefit the host (aka, you!). Often these organisms are bacteria, but they also can be yeasts and archaea. Probiotics can be found in foods where they occur naturally through the process of fermentation, like in the case of yogurt, sauerkraut, kimchi, kombucha, and natto. Most often, though, you’ll see them offered as supplements or added to foods. Strains may be added to yogurts, soda, and even collagen peptides and protein shakes.
Probiotics are sensitive to heat; often, manufacturers will include billions more of live cultures/bacteria to their supplements along with heat-resistant coatings simply to ensure the amount of bacteria they promise per serving survive long enough in your gastrointestinal tract to make it to you large intestine – where the vast majority of your microbiome exists. However, even dead probiotics, sometimes called ghostbiotics, heat-inactivated probiotics, or postbiotics may have health benefits, just in a different way than probiotics, more on that below.
Different strains of probiotics do different things, also more on that below.
Prebiotics
Prebiotics are essentially the food that probiotics feed on. According to the International Scientific Association of Probiotics and Prebiotics (ISAPP), prebiotics technically are “selectively fermented ingredient[s] that result in specific changes in the composition and/or activity of the gastrointestinal microbiota.”
They tend to be specific types of complex starches (oligosaccharides) that are not fully digestible and are degraded by the bacteria in the gut; the end-product they’re degraded into are primarily short-chain fatty acids that also can be circulated in the blood stream and shuttled to various organs.
Prebiotics naturally occur in foods in smaller quantities; they can be found in Jerusalem artichokes, chicory (inulin), onions, garlic, dandelion greens, asparagus, etc. Prebiotic-rich foods and fiber are not necessarily the same thing. Fiber-rich foods have prebiotic-like qualities, which is why they’re so beneficial to the gut flora, but most sources of fiber are not actually prebiotics.
Prebiotics work to feed beneficial gut bacteria while starving harmful gut bacteria, which encourage the harmful bacteria to die off. Similar to probiotics, prebiotics do different things and some are more suitable for an individual than others. A few of the major prebiotics include fructooligosaccharides (FOS), galactooligosaccharides (GOS), xylooligosaccharides (XOS), modified citrus pectin, inulin (a source of FOS), and lactulose (not available for commercial purchase in the U.S.). For FOS and GOS, therapeutic levels are about 7-9 g; for modified citrus pectin, 5 g.
Be aware that if you’re trying a prebiotic for the first time, it may cause bloating, gas and discomfort. I often have clients work up to 7 g over the course of a couple weeks to avoid unwanted side effects. I also have them take it at night, so any bloating and flatulence happens overnight. Note: Prebiotics (and fiber supplements) should not be taken with medications; they can absorb the medication and block it from being absorbed by the body.
My go-to prebiotics are partially hydrolyzed guar gum (which technically is prebiotic-like) and modified citrus pectin. I like these for ME, because they help address specific things I’m trying to achieve or address.
Be wary of prebiotic sodas
Poppi “prebiotic” soda is bullshit. Yeah, I’m being that blunt about it. There’s 2g of inulin (which is a FOS) per can. To have a therapeutic amount – meaning an amount shown to be clinically effective – you’d have to have 4 cans, which at 5 g of sugar per can, you’re looking at 40 g of extra sugar, which is about the same amount of sugar as a can of Coke. Yes, there’s some benefit if you’re using it to cut down on traditional soda (4 cans of Poppi is preferable to 4 can of Coke), but it should not be viewed as a good source of prebiotics. There’s actually a class-action lawsuit in progress against Poppi for this exact reason. If you absolutely have to have a prebiotic soda, opt for OlliPop, which has 7 g of inulin per can.
Be careful of how many you have, though, as you may end up with some uncomfortable bloating and gas if your body isn’t used to that much prebiotics.
Synbiotics
Synbiotics are supplements that combine a probiotic and prebiotic together. I don’t love these and hardly ever recommend them. Yes, they sound good, in theory … who wouldn’t want to get a 2-fer?! BUT, they usually don’t contain enough of the prebiotic to be clinically effective. Remember, it takes 5-9 g of prebiotics (depending on which one) to be clinically effective; for reference, 1 tsp of salt is about 6 g and 1 tsp of granulated sugar is about 4 g … far more than what can fit in a capsule.
Postbiotics
The last, and newest, addition to the “biotics” are postbiotics. These are what ISAPP defines most broadly as the inanimate (or not alive) microorganisms and/or their components that confer a health benefit to the host; they may or may not include the metabolites or byproducts of the bacteria. Often, postbiotics refer to the more specific soluble byproducts from live bacteria. As mentioned above, these can come from inactivated probiotics, but not all dead probiotics have beneficial effects, sometimes they’re just dead and ineffective.
For postbiotics that contain metabolites (enzymes, peptides, polysaccharides, cell-surface proteins, etc.), the thinking here is to bypass the breakdown and conversion that needs to happen with probiotics (and prebiotics) and simply get the byproducts that may benefit the body.
Postbiotics are still being validated for their efficacy. They occur naturally in the same foods as probiotics and consuming prebiotic foods may also benefit postbiotics. While some studies have shown a tremendous amount of promise for postbiotics (being gentler than probiotic and prebiotic supplements), more human studies are needed to determine the benefits they confer compared to their live probiotic counterparts. For instance, if a probiotic (live microorganism) eases IBS symptoms, it is not a safe assumption that its postbiotic (inactive form or metabolites) would do the same.
How do I know what MY gut microbiome needs?
There’s only one real way to understand the microbial mix of gut flora in your gut and that’s through a gut microbiome mapping stool test. These are not typically available for purchase without working with a licensed healthcare provider. Some labs do exist that offer direct-to-consumer versions, but many of those companies lack the clinical level of quality of the testing, assessment and reporting.
These tests all involve a stool sample, and high-quality labs will actually culture your sample in the lab. Results can take 6 weeks (or longer) to get back because of this; direct-to-consumer products that promises faster results are ones I would be warry of. These tests tend to run anywhere from $280 to over $1,000, depending on what is being tested. The large variation in costs can be attributed to the extent and thoroughness of the specific test, the type of analysis, how many times a sample is analyzed, and additional biomarkers that are being assessed – for instance, it is not uncommon for fecal calprotectin (an indicator of inflammation) or zonulin (a marker generally associated with gut permeability) to be added on by a practitioner. Most standard tests do not land at the high end of the range.
These stool tests will tell you the exact makeup of your gut – or at least what was present in the stool sample you provided. This can help identify harmful, pathogenic bacteria that may be overabundant and beneficial bacteria that may be insufficient. These tests help practitioners recommend very specific care plans to help you rebuild and rebalance your gut without having to simply guess.
Now, that you’ve had a primer on the basics, let’s get down to some probiotic supplement specifics.
Probiotics: The 1 BIG thing doctors probably aren’t telling you
Strain specificity matters.
It’s important to know that there are families (genus), species, and strains of bacteria. Here are some examples from the same family, but all very different for what they do and what they can help with:
Lactobacillus rhamnosus GG
Genus (or what I’ve been referring to as the family): Lactobacillus (the genus was recently renamed to Lacticaseibacillus)
Species: rhamnosus
Strain GG
L. rhamnosus HN001
Genus: Lactobacillus
Species: rhamnosus
Strain HN001
Lactobacillus johnsonii LJ1
Genus: Lactobacillus
Species: johnsonii
Strain: LJ1
Lacticaseibacillus casei Shirota
Genus: Lacticaseibacillus
Species: casei
Strain: Shirota
Why does this matter? Strain specificity matters because the strain is what dictates its effectiveness for being able to help with a specific condition. All three of the above are part of the same family and you’ll note that there are two L. rhamnosus strains, but be assured that GG (which is great for IBS symptoms) is different from HN001 (which has been studied for maternal depression and anxiety during the postpartum period).
I had a friend whose doctor told them to get a probiotic to help with some digestive distress, specifically constipation. As most people do these days, she went to Amazon and bought one. She told me that it was useless and did nothing to improve her symptoms. Therefore, she felt all probiotics are bullshit. I asked her to send me a photo of the label: NONE of the strains included were helpful for GI symptoms, they were all beneficial for the immune support. So, of course she wouldn’t experience improvement in her GI symptoms.
She was like: Why didn’t my doctor tell me that the strain matters?
Simple: Because they don’t know. Most docs aren’t properly educated on probiotics.
Where can I go to get information on specific strains?
So, if strain specificity matters, you might wonder what a good resource is for getting this info. Well, I’m sad to say there’s no easy, free resource – there’s easy and there’s free, but not both.
Free. Look up studies on Pubmed. Not all studies that come up will be available for free but probiotics have been studied for long enough that chances are, if there are studies that have been done on what you’re looking for, you’ll find one or more that’s open text. That said, this presumes you want to read a research study and can spot poorly designed studies. Not all results reported can be taken at face value. Further, it’s not uncommon for strains that are studied to ONLY exist within the lab and not be commercially available. I’ve spent a TON of time hunting down different strains only to realize they are not commercially available.
Low cost, but easy. One of my professors from way back in my Master’s program, Dr. Jason Hawrelak, one of the foremost experts on probiotics, created the Probiotic Advisor. It’s the only repository of its kind that I’ve found. Probiotic Advisor, lets you search by condition/disease or by strain; it shows you the clinical efficacy of the probiotic for the condition it was trying to address, with the a star-rating for the quality of the research study, and also lists which commercially available products have those strains in them. It’s about $40 to access the database for a year. This is a resource I use when making recommendations to clients.
Here’s 8 Simple Tips for Buying Probiotics
Know the strain you need. If you’re buying a probiotic to do something specific, do your research (or ask me!)
No strain = No purchase. If a probiotic only lists the family/genus and species and doesn’t include the strains on the label, don’t buy it. You have no idea what you’re getting.
Skip the super-insane, evidence-lacking multi multi-strain products. Most of the multi-strain probiotics are potentially useless; there are some products that have 50 different strains – and they love to tout that fact. Except, they probably don’t have research that backs up the function and efficacy of every strain, so they’re including them without knowing if they will actually be beneficial to your gut. If a product has a few strains, fine; if they have 10 or more, be wary. I chose 10 arbitrarily; if they have evidence that backs all 10+, great! There are some out there, certainly, but most probably don’t.
More is not necessarily better. You only need 1 billion colony forming units (CFU) to be clinically effective. So, if you’re buying something with 80 billion CFU and you don't have a GI mapping lab to know YOUR microbiome, you may be feeding the wrong ones for you.
Skip the probiotic+prebiotic combo (technically called a synbiotic). They will almost definitely not have enough of the prebiotic to be effective. Plus, you won’t know if it’s the prebiotic your body needs. Best to consume prebiotic foods and/or take a specific powdered prebiotic supplement.
Protective coating. Check to make sure the brand you choose as a coating on the capsule that allows the probiotic to actually make it to the large intestine.
Shelf-stable vs refrigeration. Make sure you know if you’re buying a shelf-stable probiotic or if it requires refrigeration. If it requires refrigeration and you don’t refrigerate it, the bacteria may die before getting to your colon.
If you’re not trying to do something specific, skip the probiotic supplement completely. For the most part, probiotics really only work when you take them, but eating probiotic-rich foods regularly will encourage both the growth of beneficial bacteria and will limit the growth of harmful bacteria (this is where prebiotics and fiber really come in handy).
References
Lacticaseibacillus rhamnosus: A Suitable Candidate for the Construction of Novel Bioengineered Probiotic Strains for Targeted Pathogen Control
https://pmc.ncbi.nlm.nih.gov/articles/PMC8947445/
Prebiotics: Definition, Types, Sources, Mechanisms, and Clinical Applications
https://pmc.ncbi.nlm.nih.gov/articles/PMC6463098/
The Concept of Postbiotics
https://pmc.ncbi.nlm.nih.gov/articles/PMC9027423/
Postbiotics: Functional Food Materials and Therapeutic Agents for Cancer, Diabetes, and Inflammatory Diseases
https://pmc.ncbi.nlm.nih.gov/articles/PMC10778838/
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