Arguably, probiotics are the most important category of nutraceuticals for gut health. A quick search of PubMed reveals over 3,300 human clinical studies on probiotics—a testament to the scientific recognition that these products possess.
Consumer demand for probiotics is poised for substantial growth. The global value of the probiotic supplement market is projected to reach $213.1 billion by 2032, with an anticipated compound annual growth rate (CAGR) of 12.4% from 2023 to 2032.[i]
With such popularity, you may wonder how many types of probiotics are there. Get ready to have your mind blown: the gut microbiome (i.e., bacterial make-up) is exceptionally diverse, with estimates of 100 trillion probiotic strains from upwards of 1,000 different species.[ii]
Additionally, ponder the comprehensive advantages various strains of probiotics contribute to human health and well-being. These include modulation of the gut microbiota, improvement of the intestinal mucosal barrier, gut immunomodulation and general immune health, neurotransmitter synthesis, support for cardiovascular health, and a broad range of other health considerations[iii].
What are Probiotics?
The Food and Agriculture Organization of the United Nations and the World Health Organization define probiotics as “Live microorganisms which when administered in adequate amounts confer a health benefit on the host”[iv] (a.k.a., friendly bacteria).
Ancient physicians in the Near and Middle East prescribed soured milk containing lactic acid bacteria (probiotics) to manage gastrointestinal health issues.[v] Élie Metchnikoff, a Russian zoologist, immunologist, and Nobel laureate, can be partially credited with contemporary interest in probiotics due to his theory that the growth of toxin-producing putrefactive organisms in the gastrointestinal tract could be controlled by the implantation of beneficial cultures in the gut.[vi] Concurrently the French pediatrician, Henry Tissier, suggested that “bifid” bacteria could be administered to patients with diarrhea to help restore a healthy gut flora.[vii] From these humble beginnings, the popularity of probiotic products has grown significantly, as previously cited.
Probiotics may have various effects on the body, and different probiotics may act differently.[viii] This includes:
- Helping your body maintain a healthy community of microorganisms or help your body’s community of microorganisms return to a healthy condition after being disturbed.
- Producing substances that have desirable health effects.
- Influencing your body’s immune response.
- Positively impacting digestive health.
- Supporting mental health.
- Promoting skin health.
- Emerging areas of probiotic research also include cognitive function and metabolic health.
Understanding Probiotic Classification and Nomenclature
There are different kinds of probiotics, and when talking about them you often hear the terms “genus”, “species” and “strains” used. Let’s take a moment to explain these terms in context of probiotics classification:
- Genus refers to a general classification of the above species. Often, probiotics in the same genus may have similar properties. The first letter of the genus is always capitalized, and the entire word is italicized. For example, in the probiotic Bifidobacterium lactis BI-07, Bifidobacterium is the genus.
- Species refers to a specific classification under genus. The first letter of the species is generally lower case. For example, in the probiotic Bifidobacterium lactis BI-07, lactis is the species.
- Strain refers to a variation within a species with unique properties. The strain designation may be a few letters, numbers, or a combination of both. For example, in the probiotic Bifidobacterium lactis BI-07, BI-07 is the strain. It should be noted that some people refer to the strain as “strand”, but this is incorrect.
A good way to help remember this classification system is to compare it to a person’s name, for example John Smith Jr., (or Smith, John Jr., to keep the order the same).
In this example “Smith” would be equivalent to the genus, “John” would be equivalent to the species, and “Jr.” would be equivalent to the strain. Here is an infographic to better illustrate the nomenclature of this system of classification for probiotics:
Popular Probiotic Categories Used in Supplements
Virtually all probiotics offer support for some aspect of immune health. Likewise, most (except for the S. salivarius strains) also promote gut/digestive health.
In addition, some species and strains offer other benefits such as support for weight management, cholesterol metabolism, vaginal health, sleep, and so much more. Among the most popular probiotics (i.e., genus), here is a list of probiotic strains and benefits commonly used in supplements:
- Lactobacillus – Lactobacillus refers to a group of lactic acid-producing, friendly bacteria[ix] [x] that make up many of the 400 normal probiotic species in the human body.[xi] [xii] [xiii] [xiv] [xv] Lactobacilli provide many benefits, including the following:
- Inducing growth factors and increasing the bioavailability of minerals.[xvi]
- Stabilizing the mucosal barrier and decreasing intestinal permeability.[xvii] [xviii]
- Maintaining a balance of healthy bacteria vs. undesirable bacteria by producing lactic acid and hydrogen peroxide.[xix] [xx] [xxi]
- Immunomodulating effects[xxii] [xxiii] [xxiv] such as promoting healthy immune function.[xxv]
- Promoting healthy levels of Candida albicans.[xxvi]
- Denaturing food allergens such as lactose and gluten.
Some of the more popular Lactobacillus strains include L. acidophilus DDS-1 and L. rhamnosus GG.
- Bifidobacterium – Bifidobacteria normally colonize in the human colon[xxvii] [xxviii] and, like Lactobacillus species, also produce lactic acid. These probiotics are important microorganisms in the intestine because they help create a microbial barrier to undesirable substances.[xxix] [xxx] In fact, some species of Bifidobacteria bind to the intestinal mucosa and interfere with the attachment of undesirable substances.[xxxi] [xxxii] Since Bifidobacteria disappear from the feces within 2 weeks after discontinuing supplementation, this suggests that there is no long-term colonization[xxxiii] [xxxiv], so Bifidobacteria must be used regularly to achieve a continued benefit.
Some of the more popular Bifidobacteria strains include Bifidobacterium lactis BI-07 and Bifidobacterium animalis subsp. lactis CECT 8145 BPL1
- Bacillus – Probiotics in the Bacillus genus are spore-forming. The spore is a naturally occurring protective encasement that acts like a cocoon, allowing the probiotic within to survive transit through harsh stomach acid and bacteria-killing bile. [xxxv] Different Bacillus species offer different benefits:
- Maintaining healthy cholesterol levels already in a normal range.[xxxvi] [xxxvii]
- Maintaining healthy glucose levels already in a normal range. [xxxviii]
- Promoting cardiovascular health.[xxxix]
- Reducing intestinal gas after a meal.[xl]
- Assisting in the breakdown of gluten.[xli]
Some of the more popular Bacillus strains include Bacillus subtilis DE111 and Bacillus coagulans MTCC5856.
- Streptococcus – Some of the probiotics in this genus reside in the oral cavity (i.e., the mouth) and have benefits for dental and throat health[xlii] [xliii] [xliv] [xlv]. The most important of these include Streptococcus salivarius K12 and Streptococcus salivarius M18.
Factors to Consider While Choosing a Probiotic Strain
When choosing which probiotic strain(s) to use in your product, there are a few criteria to consider.
First and foremost, what is the purpose of the product? Is it meant to be a general gut/immune probiotic formula—in which case there are dozens of possible strain choices—or is there a more specific purpose such as weight management? Depending on the purpose, you’ll want to choose those probiotic strains with research supporting the intended use.
Another consideration is colony-forming units or CFUs. CFUs are the units of measurement for expressing the potency of probiotics. In most cases, doses are in the billions of CFUs (e.g., 1, 5 or 10 CFUs, or more) although there are a few using doses in the millions of CFUs. In any case, dose determination should be a function of the published research. Namely, the product should provide the same number of CFUs as the probiotic(s) used in the study.
Yet another consideration is the presence of other nutraceuticals, as well as the delivery form. Many probiotic strains don’t play well with others, meaning that if some nutraceuticals with a slightly higher moisture content are present, they may ultimately inactivate probiotic activity. Consequently, those probiotic strains are best provided in a product that only contains other probiotics or prebiotics.
Capsules and powders are traditionally the best delivery formats for probiotics, but tablets also work – especially chewables and quick-melts. For the reasons previously discussed, liquids are not the best choice for probiotics. Likewise, gummies are not the best delivery format because of their high moisture content.
Even the most stable probiotics will lose potency over time, especially if not delicately handled during manufacturing. Under FDA regulations, the number of CFUs declared on a Supplement Facts label must represent the potency on the last day of shelf life. However, some products illegally claim CFUs “at the time of manufacture”. Some probiotics can lose 90% of their activity in two years, so confirm your probiotic supplement manufacturer is incorporating sufficient overages to fully meet the label claim on the expiration date.
Given the wide range of benefits, probiotics can be used in almost any demographic. This includes children, although you’ll want to ensure the strain and dosage are consistent with what has previously been demonstrated to be safe and effective in research.
Multi-Strain Probiotics in Supplement Formulations
Some supplements provide multiple strains of probiotics. While this approach certainly has marketing appeal, does this mean that the product will necessarily be more effective? The answer is that it depends upon the doses used.
Let’s say that a supplement provides 10 probiotic strains, but only one is present at a clinically relevant dose shown in research to be effective. That means the only claims you can make about the product (other than it contains 10 strains) will be limited to the single probiotic strain. Furthermore, without research specific to the 10-strain combination, there is no indication that the much lower doses of the other strains will offer any meaningful benefits. On the other hand, some combinations of probiotics have been studied and have published research to support claims based on the combination. Whatever you decide, only utilize claims based on clinically relevant doses of the probiotic strains in question.
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Concluding Thoughts
Probiotics are a rapidly growing category in the dietary supplements industry and promote numerous health benefits. Various strains like L. acidophillus DDS-1, L. rhamnosus GG, Bifidobacterium lactis BI-07, Bifidobacterium animalis subsp. lactis CECT 8145 BPL1, Bacillus subtilis DE111, Bacillus coagulans MTCC5856, Streptococcus salivarius K12 and Streptococcus salivarius M18 and others contribute to this. To stand out in the market, you need a unique probiotic product. With over 45 years of dietary supplement contract manufacturing experience and more than 100 probiotic strains available, Vitaquest can help you create a superior probiotic supplement product for your business.
Frequently Asked Questions
Q: Do strains matter in probiotics?
They absolutely matter! Different strains can offer distinctly different benefits. Sometimes they also offer different levels of stability. Choosing the right strain can make all the difference in the world for product efficacy.
Q: How many strains should a good probiotic have?
The dose of each strain is more important than how many strains the product contains. If the product has 10 strains, but only one is present at a clinically relevant dose, then the other strains are essentially window-dressing.
Q: Are more strains in probiotics better?
Not necessarily. See the response to the previous question.
Q: Which is better Bifidobacterium or Lactobacillus?
These two genera of probiotics do very different things. Both are important and neither is more important than the other.
References
[i] Acumen Research and Consulting. Probiotics Market is forecasted to Reach USD 213.1 Billion by 2032, growing at a 12.4% CAGR from 2023 to 2032. GlobeNewswire. October 5, 2023. https://www.globenewswire.com/news-release/2023/10/06/2755864/0/en/Probiotics-Market-is-forecasted-to-Reach-USD-213-1-Billion-by-2032-growing-at-a-12-4-CAGR-from-2023-to-2032.html
[ii] Probiotics, Prebiotics, and the Microbiome. GI Society: Canadian Society of Intestinal Research. Accessed from https://badgut.org/information-centre/a-z-digestive-topics/prebiotics-probiotics/#:~:text=The%20gut%20microbiome%20is%20exceptionally,there%20is%20a%20fine%20balance.
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[v] FAO/WHO. Health and Nutritional Properties of Probiotics in Food including Powder Milk with Live Lactic Acid Bacteria. Report of a Joint FAO/WHO Expert Consultation on Evaluation of Health and Nutritional Properties of Probiotics in Food Including Powder Milk with Live Lactic Acid Bacteria; 2001. Retrieved https://www.who.int/foodsafety/publications/fs_management/probiotics/en/index.html.
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[viii] Probiotics: What You Need To Know. National Institutes of Health: National Center for Complementary and Integrative Medicine. Last updated August 2019. https://www.nccih.nih.gov/health/probiotics-what-you-need-to-know
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[xxxv] Ngo TH. Characterization of Bacillus Species Used for Oral Bacteriotherapy and Bacterial Prophylaxis of Gastrointestinal Disorders. Appl Environ Microbiol. 2000 Dec;66(12):5241-7.
[xxxvi] Mazruei Arani N, Emam-Djomeh Z, Tavakolipour H, Sharafati-Chaleshtori R, Soleimani A, Asemi Z. The Effects of Probiotic Honey Consumption on Metabolic Status in Patients with Diabetic Nephropathy: a Randomized, Double-Blind, Controlled Trial. Probiotics Antimicrob Proteins. 2019;11(4):1195-1201.
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