In this blog:

Our team breaks down what CFUs are, how they impact you, and why you should be on the lookout for them. 
[3-4 Min Read] 

What Are CFUs? 

Simply put, Colony Forming Units (CFUs) refer to the quantity of living, functional bacteria present in a serving of a probiotic dietary supplement. Usually, these are expressed as CFUs per gram or CFUs per milliliter. The term "colony" refers to a grouping of separate colonies of bacteria, yeast, or mold. Microorganisms include bacteria, yeasts, and viruses. Good "probiotic" bacteriaand occasionally yeastsmake up probiotic supplements in general. The supplement facts label on a probiotic supplement will list a variety of CFUs. Probiotics typically include between 1 and 10 billion CFUs each serving. Some businesses even promote high numbers, such as over 100 billion. 

The quantity of bacterial cells in a probiotic supplement or lab sample is measured using colony forming units, or CFUs. High CFU counts are occasionally taken as a sign of quality, however, this is not necessarily the case. Additional factors are needed to examine the quality and efficacy of a probiotic supplement including the combination of bacterial strains, the distribution method, and clinical research. A lot of probiotics promote how many CFUs they have as if this were the only indicator of quality. Frequently, the price increases with the CFU level. Yet, how are you to tell if that is actually the quality marker? Is it truly all that matters and is it worth it to pay the price for more CFUs? For many people, it has become standard practice to look at the number of CFUs when selecting a probiotic. Oftentimes, businesses focus their marketing on their high CFU count because it is widely believed that a product's CFU count should be as high as possible. Prices thereby rise with a higher CFU count per serving. This should NOT be the case! 

How Many Bacterial Colonies Do You Need in a Probiotic? 

Each serving of a probiotic supplement typically contains 1-10 billion CFUs. As mentioned, a larger CFU count doesn't always indicate a superior product. When selecting a high-quality probiotic, several factors are just as important as the number of bacteria. The purpose of taking a probiotic supplement is to reintroduce healthy bacteria into the gut so that they can enhance gut's environment. Of course, you want to take a high enough quantity of bacteria to ensure that they can make a positive difference in the gut. On the other hand, taking too much of one or a few specific strains of bacteria may have adverse effects. Having higher diversity of good bacteria can be beneficial if that bacteria will have the desired effect on your body. For example, if you need a specific strand of bacteria to help with an intestinal issue, then finding a probiotic with a high CFU count that has research showing its effectiveness may be better than a generic probiotic.  

It may also be beneficial to pick a lower CFU count probiotic over a higher CFU count probiotic. This is usually tied to age, particularly with younger children, because they do not need as many CFUs. Typically, 2-6 billion CFUs is enough for children under 3 and less than 25 billion for under 18. Other than children, adults who are sensitive to supplements may want to try lower CFUs first before committing to probiotics with a high CFU count.  

What are indicators for effective probiotic supplements if not CFU count?  

Combination of bacterial strains:  

This is what you should concentrate on in order to assess the quality of a probiotic. While the quantity of CFUs isnt the most reliable indication of probiotic quality, combining different bacterial strains is. Each of the 400 to 600 different probiotic bacterial strains that reside in your digestive tract have a specific function. As such, the best probiotic supplement to start with is one that has multiple strains of bacteria. In addition, you need to make sure that the supplement has the appropriate probiotic bacterial strains in order to fulfill the requirements of your health. 

Clinical studies and evidence: 

The production of a multi-strain probiotic needs more than merely combining several bacterial strains that have a history of being good to the human body. You need to be aware of which kinds of bacteria work well together rather than bacteria that compete with one another. Researchers conducted a groundbreaking study in which they compared the microbiomes of the guts of identical twins. They arrived at the conclusion that there is an "intense interplay" between our gut flora and our body and that this interplay is vital for the metabolic activities that occur in the body. 

The delivery mechanism: 

Another essential aspect to take into account is the mode of distribution. This refers to the manner in which a product is manufactured and utilized. In order for you to derive the maximum advantage from taking a probiotic, the bacterial species contained within it must be able to survive the journey from the manufacturer, to the store, to your home, and, finally, to your stomach through your intestines and into your large intestine. This could result in a myriad of problems, some of which include being subjected to the acid produced by the stomach as well as fluctuations in temperature and humidity. Sadly, the majority of the beneficial bacteria that are contained in many probiotic supplements die out before you even have the chance to ingest them. Even if the bacteria manage to make it through the acidic environment of the stomach, the probiotics that are found in capsules and chewable forms are likely to have been destroyed by this point. 

When to go for a higher CFU probiotic? 

You are a fully grown adult who does not have a significant gut problem, serious medical difficulties, or a sensitivity to supplements; nonetheless, you would still like to rid yourself of that annoying recurring constipation or improve your overall health. You are most likely prepared for some powerful probiotics, possibly in conjunction with some prebiotic pills to provide a boost and assist them in getting started. Then, by all means, feel free to try the higher 75-100 billion CFU probiotic supplements. 

Naturally, if any transitory die-off symptoms of probioticssuch as gas, bloating, loose stools, or headachesinterfere with your day-to-day activities, you may feel the need to cut the dosage for a period of time. Alternatively, if you begin with a smaller CFUsuch as 25 billionand you don't notice any improvements in your energy or digestion, consider increasing it to see whether a bigger CFU will make a difference. You can try increasing it by doubling it. 

Sources:

Chapman, C. M., Gibson, G. R., & Rowland, I. (2011). Health benefits of probiotics: are mixtures more effective than single strains?. European journal of nutrition, 50(1), 1–17. https://doi.org/10.1007/s00394-010-0166-z  

Chapman, C. M., Gibson, G. R., & Rowland, I. (2012). In vitro evaluation of single- and multi-strain probiotics: Inter-species inhibition between probiotic strains, and inhibition of pathogens. Anaerobe, 18(4), 405–413. https://doi.org/10.1016/j.anaerobe.2012.05.004 

“Colony Forming Units: What Are CFUS and How Many Do You Need?” OMNiBiOTiC, 31 Aug. 2021, https://www.omnibioticlife.com/what-are-colony-forming-units/

Gerritsen, J., Smidt, H., Rijkers, G.T. et al. Intestinal microbiota in human health and disease: the impact of probiotics. Genes Nutr6, 209–240 (2011). https://doi.org/10.1007/s12263-011-0229-7 

Ouwehand, A. C., Isolauri, E., Kirjavainen, P. V., Tölkko, S., & Salminen, S. J. (2000). The mucus binding of Bifidobacterium lactis Bb12 is enhanced in the presence of Lactobacillus GG and Lact. delbrueckii subsp. bulgaricus. Letters in applied microbiology, 30(1), 10–3. https://doi.org/10.1046/j.1472-765x.2000.00590.x 

Timmerman, H. M., Koning, C. J., Mulder, L., Rombouts, F. M., & Beynen, A. C. (2004). Monostrain, multistrain and multispecies probiotics–A comparison of functionality and efficacy. International journal of food microbiology, 96(3), 219–233. https://doi.org/10.1016/j.ijfoodmicro.2004.05.012 

“Why Is CFU Important in a Probiotic Product?” Probi, https://www.probi.com/probiotic-knowledge/product-development/probiotic-potency/