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Home arrow Health arrow Gut Health arrow What Is CFU in Probiotics? Definition and Role in Supplements

What Is CFU in Probiotics? Definition and Role in Supplements

Written by Edibel Quintero, RD
Fact checked by Rosmy Barrios, MD
Last update: July 25, 2023
3 min read 1165 Views 0 Comments
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CFU is a word commonly found on probiotic supplements, but what does it mean? We explain the meaning of CFU in terms of gut bacteria and how much you need to take when gaining several health benefits.

What is CFU in probiotics

People take probiotic supplements to replenish their gut. These types of supplements can balance the bacteria in your digestive tract to prevent common problems like constipation, diarrhea, and bloating. 

If you consume probiotics, you may have already noticed the word CFU on the label. It is a measurable term that companies use when designing probiotic formulas. But what does it mean, and how does it contribute to gut health?

Keep reading to discover what CFU stands for, the recommended dosage, and when you should opt for stronger probiotics.

What Is CFU in Probiotics?

CFU stands for colony-forming units. This refers to the number of live bacteria and microorganisms that exist in each probiotic supplement. Companies use this measurement to help people understand more about what they’re consuming.

Colony-forming units represent bacterial cells that grow together as a cluster. They work to eliminate diarrhea, bloating, excess gas, and constipation symptoms. The more CFUs a probiotic supplement has, the stronger it will be at reducing bad gut bacteria. 

It’s important to remember that colony-forming units multiply to improve your digestive system. Low doses mean there might not be enough bacteria to flourish, so always choose high-quality strains. 

Bifidobacterium longum and lactobacillus acidophilus are some of the best probiotic strains since they can have up to 60 billion CFUs. Not all probiotics have these strains, but that doesn’t mean the supplement is ineffective or weak. 

You can support the growth of CFUs in your gut by eating more probiotic foods like kefir, sauerkraut, kombucha, soft cheeses, pickles, and tempeh. Strengthening your gut’s ecosystem can help CFUs thrive and multiply at a quicker pace.

How Many CFUs Do I Need?

People in relatively good health can take 10–20 billion CFUs daily. This should be enough to support the immune and digestive systems. However, this dosage can change depending on your symptoms and the type of strains in the probiotic. 

The general requirement is no more than 20 billion CFUs for healthy individuals, but that doesn’t mean you can’t take more. Some people need stronger probiotics to keep certain health conditions like irritable bowel syndrome (IBS) in check.

For example, someone who gets constipated more than once a week may take up to 30 billion CFUs a day. The same goes for those who get bloating from regular urinary tract infections

In terms of children, the recommended dose is 5–10 billion CFUs daily. They typically need a lower dosage because of their developing digestive tract. Before giving probiotics to your child, speak to a registered clinician. 

You should consult with a doctor about finding the right dosage. A medical professional can evaluate your symptoms and determine whether a higher CFU count is necessary. 

When to Go for Higher CFU Probiotics?

If the average dose of 10–20 billion CFUs isn’t calming your symptoms, it might be time to find probiotics with a high CFU count. You could try 25–70 billion CFUs to see whether those supplements make a difference in your digestive health. 

A study found that taking 25–70 billion CFUs helps reduce gastrointestinal symptoms over four weeks. These symptoms might be fatigue, constipation, bloating, or stomach cramps that affect your daily life. 

On the other hand, people with leaky gut syndrome and other serious conditions like gastroesophageal reflux disease can take a stronger probiotic strain. 50–70 billion CFUs a day might be suitable for replenishing a damaged gut microbiome. Take a look at the best probiotics for leaky gut.

Those who want a higher dosage should always speak to a doctor beforehand. You could trigger potential side effects from quickly switching doses. Some side effects might be temporary constipation, flatulence, diarrhea, and headaches. 

How to Know if Your Probiotic CFU Is Too High?

A sudden onset of diarrhea, bloating, migraines, and cramps can suggest that your CFU dose is too high. This is common for people who take 70 billion CFUs or who have health conditions that affect their digestive and immune systems.

Side effects that last longer than seven days are another sign that you should try other supplements. Certain probiotic bacteria could be overthrowing the natural balance in your gut, which leads to stomach discomfort and poor gut health. 

You need to stop taking that many CFUs and let your gut adjust again. Give the body time to regulate immune function and replenish beneficial bacteria. After that, find some probiotic products with fewer CFUs and try them for a few days. 

There are medical professionals who can point you toward the best supplements for bloating or general gut health. Seek professional help if your symptoms worsen or don’t go away after 1–2 weeks of stopping probiotic supplementation. 

A Word From a Nutritionist

Probiotics with a high CFU count usually contain multiple strains. These strains feed the good bacteria in your gut and promote regular bowel movements. Not everyone needs them, but it’s worth taking some to prevent constipation and age-related problems.

Always look at the CFUs before buying a probiotic supplement. You don’t want to take too many when improving your overall health. Some companies clearly state the number of colony-forming units on the back of the packaging or in the ingredients list.

For those who don’t like taking probiotics, try some effective gut health hacks. Drink more water and exercise regularly to keep the gut functioning properly. You can even consume fermented beverages like kombucha for bloating and constipation.

Just remember to speak to a doctor before buying a new supplement that has a higher CFU dosage.


Colony-forming units (CFU) just represent the number of cultured bacteria and microorganisms you’ll be ingesting from a supplement. People like to check this measurement to determine whether they’re getting enough active strains in the daily supplement. 

Written by Edibel Quintero, RD
Edibel Quintero is a medical doctor who graduated in 2013 from the University of Zulia and has been working in her profession since then. She specializes in obesity and nutrition, physical rehabilitation, sports massage and post-operative rehabilitation. Edibel’s goal is to help people live healthier lives by educating them about food, exercise, mental wellness and other lifestyle choices that can improve their quality of life.
The article was fact checked by Rosmy Barrios, MD
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Written by Edibel Quintero, RD
Fact checked by Rosmy Barrios, MD
Last update: July 25, 2023
3 min read 1165 Views 0 Comments

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