It’s been a whirlwind the last few months. I’m teaching my last lecture in Endocrine tomorrow.. I’m excited it’s on functional medicine approach to pre-diabetes and obesity! The best part about teaching part-time is getting to teach what I’m passionate about. After this, I just have lots of grading and course coordination items. But the course ends next week then I’m off to Seattle, WA to speak on diabetes cardiovascular outcomes trials. It’s the same presentation from December in Anaheim showcased at a different meeting. It’s nice when you spend a lot of time on something, to be able to do it twice! For this blog post, I had a lot of help from two students working on this probiotic series, so thank you to Vineeta Rao and Ruth Gunti for your hard work. Soon they will be my colleagues! Enjoy!
Welcome to probiotics 101, a guide to all your FAQs!
What are probiotics?
‘Probiotics are defined as live microorganisms, which when administered in adequate amounts, confer a health benefit on the host.’ 1 The microorganisms are bacteria of different strains that process our food into nutrients that benefit our health. Probiotics come from the Latin preposition pro (“for”) and the Greek adjective (biōtikos) meaning “fit for life, lively.” Put together this means that probiotics are for life.
Why use probiotics?
Using probiotics enhances the gut microbiota to better do its job. The gut microbiota/microbiome is the conglomerate of bacteria that live in your gut and work together to bolster the immune system, to fight against potential infections, and to make nutrients such as vitamins, fats and other molecules that are needed by the body to function. 1 Furthermore facets of our modern day western lifestyle, such as diet, stress, geography, as well as sleep and travel patterns can negatively affect our gut microbiome meaning we don’t have a healthy gut to begin with. 2 In addition to the poor lifestyle factors, the increasingly prevalent use proton pump inhibitors is correlated with and probably contributes to “decreased bacterial richness” of gut microbiome, an increased amount of oral bacteria that is potentially pathogenic present in the gut, and an overall greater “microbial alterations” in the gut than those on antibiotics. 3
How do probiotics work?
While probiotics are most commonly associated with replacing flora or colonizing the gut, modifications made to the gut microbiota are not likely permanent and reflect only one of many actions that probiotics have in the body. Among these actions are immune modulation, anti-inflammatory activity, pathogen antagonism, production of short chain fatty acids, repairing and strengthening of the intestinal barrier, metabolism of gut cholesterol, and enhanced antibody secretion.4 While not all probiotics encompass all of these features, depending on the strain, a given probiotic may provide one or several of these protective benefits.5
What is genus, species, and strain?
Bacteria are usually classified to the public by three names much like people who have first, middle and last names. Therefore the first name is a broad name termed genus, followed by a more specific name called a species finally followed by a strain number that is further specifies the exact kind of bacteria. A labeled example is below!
What is the evidence for probiotic use?
Numerous review studies indicate that probiotics are beneficial overall, especially for gut health.6 However, evidence for treating or preventing specific conditions through probiotics is best established through clinical trials that demonstrate how probiotics produce a specific effect. While the number of controlled trials demonstrating specific effects in humans is still growing, probiotics have also been evaluated in animal experiments and or other in vitro studies that demonstrate efficacy and safety in terms of their use. 1 Fermented foods with probiotics in them have been consumed for centuries for health benefits. Additionally, the modern diet lacks prebiotic fiber that contributes to a diverse gut microbiome.7
What is the difference between Bifidobacterium and Lactobacillus genus of bacteria?
Lactobacillus bacteria is a type of bacteria that produces lactic acid as an end-product of its metabolism. Bifidobacterium bacteria on the other hand produce lactic acid and acetic acid; both these substances are important for the maintenance of the gut microbiome. 8,9
Here are some of the bacteria in each genus considered to be probiotics.8
considered as probiotics
|Lactobacillus species||Bifidobacterium species|
|L. acidophilus |
|B. adolescentis |
How to know you are getting a good product?
There are many overarching reviews that conclude that probiotics as a whole class are effective, suggesting that many strains share the similar levels of effectiveness. Additionally, there are number of factors that contribute to how probiotics act in our bodies such as genetics, diet and host microbiome that makes it difficult to isolate the effects of one strain over another. However, it is important that the product contains the live bacteria in large doses that will survive the harsh environments of the stomach.6
How much does the specific strain matter when ensuring that you have a good product? As more studies for probiotic use emerge, there is an ongoing controversy about the importance of the strain. On one side of the debate, larger studies that examine multiple clinical trials suggest that probiotics have benefit even when grouping similar strains together in one class. The theory behind this position is that similar strains of probiotics will have actions causing similar effects in the body.6 One the other side of the debate, some clinicians compare strain selection to choosing a particular antibiotic to attack a specific disease-causing microbe.4 Advocates of this position point to the fact that Lactobacillus plantarum DSM 9843 reduces irritable bowel syndrome while Lactobacillus plantarum MF 1298 aggravates the condition and thus conclude that when supporting a specific condition, one should only use a strain that has demonstrated efficacy for that specific condition.10-12
In summary, data for use of probiotics is exploding on a daily basis. Probiotics are useful to promote healthy gut transit and repair and for a myriad of immune benefits. In addition, data suggests significant changes to the gut microbiome is most easily stimulated by ingestion of prebiotics, which are non-digestible foods that promote and stimulate the growth of bacteria in the gut.13 Prebiotics are often combined with probiotic supplements. Sometimes they may not be well tolerated by certain individuals especially those that have an imbalance in bacteria. Certain non-gas producing prebiotics may be helpful for some patients. We will talk more about these situations in my next post!
If you are looking for quality probiotics, check out our favorite adult probiotics and favorite children’s probiotics. You can also take our “How healthy is Your Gut Quiz?” to see if probiotics and potentially a gut healing protocol might be needed for you!
- Fijan S. Microorganisms with claimed probiotic properties: an overview of recent literature. Int J Environ Res Public Health. 2014;11(5):4745-67.
- Conlon MA, Bird AR. The impact of diet and lifestyle on gut microbiota and human health. Nutrients. 2014;7(1):17-44.
- Imhann F, Bonder MJ, Vich vila A, et al. Proton pump inhibitors affect the gut microbiome. Gut. 2016;65(5):740-8.
- Probiotic Advisor. The Importance of Strain. https://www.probioticadvisor.com/probiotic-essentials-1/the-importance-of-strain/#.XC-EEPZFxPZ. Accessed January 21, 2019.
- Hill, C., et al., Expert consensus document: The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic. Nat Rev Gastroenterol Hepatol, 2014. 11(8): p. 506-514.
- California Dairy Research Foundation. Is it time to consider generic probiotic effects? http://cdrf.org/2013/03/01/is-it-time-to-consider-generic-probiotic-effects/. Updated March 1, 2013. Accessed August 20, 2018.
- Holscher HD. Dietary fiber and prebiotics and the gastrointestinal microbiota. Gut Microbes. 2017;8(2):172-184.
- Kechagia M, Basoulis D, Konstantopoulou S, et al. Health benefits of probiotics: a review. ISRN Nutr. 2013;2013:481651.
- Bifidobacteria Institute. Difference between bifidobacteria and lactobacillus. http://bb536.jp/english/basic/basic03.html. Accessed August 20, 2018.
- Ducrotte, P., P. Sawant, and V. Jayanthi, Clinical trial: Lactobacillus plantarum 299v (DSM 9843) improves symptoms of irritable bowel syndrome. World J Gastroenterol, 2012. 18(30): p. 4012-8.
- Niedzielin, K., H. Kordecki, and B. Birkenfeld, A controlled, double-blind, randomized study on the efficacy of Lactobacillus plantarum 299V in patients with irritable bowel syndrome. Eur J Gastroenterol Hepatol, 2001. 13: p. 1143-1147.
- Ligaarden, S.C., et al., A candidate probiotic with unfavourable effects in subjects with irritable bowel syndrome: a randomised controlled trial. BMC Gastroenterol, 2010. 10: p. 16.
- Cashman K. Prebiotics and calcium bioavailability. Curr Issues Intest
Microbiol. 2003 Mar;4(1):21-32. Review.