When it comes to probiotic supplements, determining the right amount of colony forming units (CFU) to take can be confusing. CFU is the measure of how many viable bacteria cells are in a probiotic. While higher CFU counts seem better, more doesn’t necessarily mean better results. The ideal dosage depends on your specific needs and the strains you’re taking.
What are CFUs?
CFU stands for colony forming units and it refers to the number of viable bacteria cells in a probiotic supplement. Manufacturers calculate CFU by growing the bacteria in a medium and literally counting the number of colonies (groups of bacteria) that form. This gives a measure of how many living organisms are in a supplement.
So if a probiotic has 1 billion CFU, it means there are estimated to be 1 billion viable bacteria cells in each dose. The higher the CFU number, the more bacteria cells you’re getting.
Do higher CFUs mean a better probiotic?
Not necessarily. When comparing probiotic supplements, many people assume that a higher CFU count means it’s a more potent and effective product. However, this isn’t always true for a few reasons:
- CFU is just a measure of quantity, not quality. The number doesn’t tell you anything about the strains, effectiveness, manufacturing quality, or survivability of the organisms.
- More cells doesn’t mean better results. Studies show that probiotic benefits depend more on the strains you take rather than sheer quantity. 1-10 billion CFU is typically enough for most general benefits.
- High CFU numbers may actually be counterproductive. Too many cells can overcrowd your intestines and trigger side effects like gas, bloating, and diarrhea.
The key is finding a probiotic supplement with proven strains, a reasonable CFU count, and proper manufacturing standards. So don’t just go by the biggest number – make sure the product matches your needs.
What is the ideal CFU dosage for probiotics?
There isn’t a single ideal CFU dosage that applies to all probiotics and all situations. The optimal amount depends on:
- The probiotic strains: Different strains have different effective dosages. Some require less while others may need more based on the research.
- The goal: Dosage recommendations can vary based on what you’re taking probiotics for. For example, higher CFUs may be used for antibiotic-associated diarrhea.
- The individual: Factors like age, health status, and existing gut bacteria affect how you respond to probiotics.
That being said, there are some general dosage guidelines for different uses of probiotics:
| Use | CFU Range |
|---|---|
| General gut health | 1-10 billion CFUs per day |
| Constipation | 10-20 billion CFUs per day |
| Diarrhea | 8-20 billion CFUs per day |
| IBS | 10-50 billion CFUs per day |
| Immune health | 1-10 billion CFUs per day |
For general gut health and immune support, most healthy adults will benefit from taking a daily probiotic supplement with 1-10 billion CFU. But you may need up to 50 billion CFU for certain gastrointestinal conditions like IBS.
Should I take a probiotic with 20, 50, or 100 billion CFU?
Probiotic supplements with CFU counts in the billions may sound impressive, but more doesn’t mean better. Here’s a quick rundown of these high potency options:
20 billion CFU
Taking a probiotic with 20 billion CFU can be beneficial for digestive issues like constipation, diarrhea, gas, and bloating. 20 billion CFU is on the higher end for general gut health, so make sure to follow dosage instructions.
50 billion CFU
Supplements with 50 billion organisms are typically used for more specific GI conditions like irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). This high CFU dosage helps replenish bacteria and reduce symptoms.
100 billion CFU
Probiotics with 100 billion CFU are marketed as “maximum strength.” However, this exceptionally high number is usually excessive, especially for daily maintenance. Such a high dose can lead to side effects without providing much added benefit.
Very few people need a 100 billion probiotic. Doses over 50 billion CFU should be recommended by a doctor for a specific condition.
When should you take higher or lower CFU probiotics?
As a general rule, healthy adults can start with a daily probiotic in the 1-10 billion CFU range. But you may want to adjust the dosage up or down in certain situations:
Increase CFU dosage:
- Digestive complaints like diarrhea, constipation, gas, bloating
- Yeast infections and UTIs
- May be helpful during or after antibiotic treatment
- Higher dosages shown to be effective for your probiotic strains
Decrease or moderate CFU dosage:
- Sensitive stomach that’s prone to side effects
- Taking multiple probiotic supplements
- Switching between significantly different CFU dosages
- Maintaining gut bacteria after a round of higher dose probiotics
People with underlying health conditions should consult their doctor before significantly increasing their probiotic dosage. And if you experience any side effects like excess gas or bloating, reduce your dosage or switch strains.
Tips for choosing the right CFU count
Choosing a probiotic supplement with the right CFU count involves some trial and error. Here are some tips:
- Start low and go slow – Begin with 1-5 billion CFU and gradually increase over 2-4 weeks if needed.
- Take the lowest effective dosage – Increase CFU only if you need added benefits and have no side effects.
- Read the label carefully – Make sure the CFU count listed is per serving, not the whole bottle.
- Go by function, not number – Choose proven strains for your needs rather than just the highest CFU products.
- Combine multiple products – You can combine a general probiotic with a targeted one instead of mega-dosing a single product.
Pay attention to how you feel on a probiotic rather than just the CFU number. And consult your doctor if you’re considering dosages over 10 billion CFU per day.
Do children and babies need different CFU dosages?
Yes, children and infants require much lower CFU dosages compared to adults:
- Newborns: up to 1 billion CFU
- Infants: 1-10 billion CFU
- Children aged 1-4: 3-5 billion CFU
- Children aged 4-12: 5-10 billion CFU
These dosages are general guidelines only. Probiotic needs can vary greatly among babies and children depending on weight, health conditions, and the advice of their pediatrician.
Things to watch out for in kids and probiotics:
- Make sure the supplement contains strains safe for pediatric use.
- Use powder or liquid forms that are easier for kids to take.
- Start low and gradually increase every few days while monitoring for side effects.
- Give with or right after a meal to reduce stomach upset.
- Look for child-friendly flavors like orange or strawberry.
Children, especially infants, are more sensitive to probiotics. Consult your pediatrician before giving any new supplement to a child.
How long does it take for probiotics to work at different CFU levels?
In general, it takes about 1-2 weeks of consistent probiotic use to notice benefits. But the time it takes to work can vary based on:
- CFU dosage – Higher CFUs may work faster, but effects are often dosage-dependent up to a certain threshold (10-20 billion).
- Probiotic strains – Some strains act faster than others, so check research on your chosen probiotic’s effects.
- Health status – Those with disrupted gut flora (like after antibiotics) may respond faster than healthy adults.
- Digestive symptoms – Probiotics may act more quickly to relieve diarrhea compared to chronic constipation.
Be patient when starting probiotics – it takes time for the bacteria to populate your gut. Give it at least a couple weeks before increasing your dosage or trying different strains.
Typical timeframes at different CFU levels:
- 1-5 billion CFU: 2-4 weeks
- 10 billion CFU: 1-2 weeks
- 20-50 billion CFU: 1-2 weeks
- 50+ billion CFU: 1 week
These timeframes assume daily use. You’ll need to take your probiotic consistently for gut bacteria levels to increase and benefits to fully develop.
Do I need to stagger or cycle high CFU probiotic doses?
Probiotic cycling involves taking a supplement for a period of time, then switching to a different one before cycling back to the first. Some people stagger or switch high-CFU probiotics (like 20 billion or more) to avoid side effects or get a broader spectrum of strains.
Potential benefits of cycling high-CFU probiotics:
- Prevents probiotic tolerance or decreased effectiveness over time
- Increases microbial diversity by exposing you to different strains
- Allows you to target specific strains for certain benefits
- May reduce risk of side effects from prolonged mega-dosing
There are no set guidelines on how long to take one probiotic before cycling or the optimal cycle length. Some basic guidelines include:
- Take each probiotic for 2-4 weeks before switching
- Rotate between 2-3 different probiotic supplements
- Return back to your first probiotic after 1-3 months
Listen to your body and adjust your cycling schedule accordingly. Stop cycling if you have trouble tolerating the switch between probiotics.
Should you take probiotics with food or on an empty stomach?
Probiotics are best taken with food. Eating helps buffer stomach acid, protecting the bacteria as they pass through your upper GI tract. Food also slows digestion, giving probiotics more time to reach your intestines intact.
Aim to take your probiotic supplement either with a meal or right after eating. Some tips:
- Swallow your probiotic capsule along with a bite of your breakfast or dinner
- Take your probiotic in the middle of a larger meal
- Consume probiotic powders stirred into food or drink like smoothies
- Pair supplements with something small like yogurt, cottage cheese, applesauce, etc.
If you forget to take your probiotic with food, wait until your next meal. Avoid taking on an empty stomach, especially first thing in the morning before breakfast.
Should you take probiotics WITH or AFTER a meal?
You can take your probiotic supplement either along with OR after eating a meal. Some basic guidelines:
- With meal: Swallow capsule amidst a few bites of food for protection
- After meal: Take immediately following meal or within 30 mins while stomach is less acidic
Taking probiotics either during or right after eating are both effective strategies. Do whatever is most convenient and comfortable for your schedule.
What foods are high in probiotics (CFU)?
Many fermented foods and dairy products contain live probiotic bacteria. Some top food sources of probiotics include:
| Food | CFU per Serving |
|---|---|
| Yogurt | 100 million – 1 billion CFU |
| Kefir | Up to 50 billion CFU |
| Sauerkraut | 10 million – 100 million CFU |
| Kimchi | 1 billion – 1 trillion CFU |
| Miso | 160 million – 200 million CFU |
| Kombucha | 100 million CFU |
The CFU amounts can vary widely by brand and type of fermented food. Check labels for concrete CFU numbers. Consuming probiotic foods helps increase your daily intake from multiple sources.
Can you take too many probiotic CFUs or overdose?
It’s very rare, but possible to overdose on certain probiotic strains, especially at extremely high CFU doses. Potential risks of taking too many probiotic CFUs include:
- Digestive symptoms like gas, bloating, diarrhea
- Allergic reaction in sensitive individuals
- Overstimulation of the immune system
- Bacterial overpopulation disrupting gut microbiome
Healthy adults are unlikely to experience complications at doses under 50 billion CFU. But immune-compromised patients and critically ill individuals should use lower doses and consult a doctor first.
Signs you may be taking too high of a probiotic dosage:
- Increased stomach discomfort, cramping, diarrhea
- Skin reactions like itching, rash, hives
- Headache, fatigue, flu-like symptoms
Reduce your probiotic dosage and see a doctor if you experience any concerning symptoms or side effects while taking probiotics.
The bottom line
When it comes to probiotic CFU, focus on finding clinically-studied strains in the right dosages for your needs. Start low and go slow, increasing CFU gradually only if needed. While CFU count is important, it’s just one piece of finding the right probiotic. Focus on strain potency, manufacturing quality, survivability, and other factors for the best results.
