How Long Does It Take For Probiotics To Work?

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By Meghan Stoops, RDN

Reviewed by Juliana Tamayo, MS, RDN - Last Updated

how long does it take for probiotics to work

Gut health is all the rage these days. Walking through the grocery store, you will see a myriad of products that claim to contain probiotics, prebiotics, or “support gut health” in some way, but what does this mean? What exactly are probiotics? And how long does it take for probiotics to work? 

Those are the questions we’re here to answer in this complete guide. Let’s take a look.

What Are Probiotics?

Probiotics are beneficial bacteria that reside in our gut and play a vital role in our health. You can also find probiotics in various foods, specifically those that have been fermented, such as yogurt, kefir, sauerkraut, tempeh, and kimchi. 

probiotic food

The addition of these foods in the diet to help gut health has been a discussion for over a century, but the term “Probiotic” is somewhat new to the game. You may also hear the term ‘prebiotic‘ thrown around. These are often forms of dietary fiber that help to feed these bacteria in our gut so they can flourish.

There are seven different strains of probiotics commonly found in products. These strains include Lactobacillus, Bifidobacterium, Saccharomyces, Streptococcus, Enterococcus, Escherichia, and Bacillus.

According to the American College of Gastroenterology, research suggests that certain probiotics may help with digestion and treating digestive ailments such as diarrhea or irritable bowel syndrome (IBS) symptoms, prevent autoimmune diseases, reduce vaginal infections and urinary tract infections, and even help to improve various skin conditions.

Although the potential functions of probiotics appear to be plentiful, more research is still needed to determine the many roles which they play in the human body. 

Benefits of Probiotics

Along with supporting digestive health, probiotics also provide many other beneficial functions in the body, including the following:

  • Manufacturing vitamins (including vitamin K and B vitamins)
  • Reducing the incidence of childhood and adult obesity
  • Reducing the risk of chronic disease development, such as type 2 diabetes, metabolic syndrome, heart disease, depression, and Alzheimer’s disease.
  • Reduce systemic inflammation
  • Improve blood pressure and cholesterol
  • Reduce depression and anxiety 
  • Improve immune system 
  • Preventing cavities and periodontal disease 
  • Reducing the incidence of Hay fever
  • Improving asthma symptoms
  • Improving atopic dermatitis
  • Reducing allergy symptoms
  • Improving acne
  • Reducing incidences of upper respiratory infections

probiotics supports digestive health

It’s important to note that many studies that support these claims are small or conducted on animal subjects and require further research in human trials. Some conditions also show more benefit with certain strains of probiotics, and other strains may not be as effective for that condition.

How Long Does It Take for Probiotics to Work?

If you are taking a probiotic supplement, for best results, you should be taking it every day around the same time. But how long will it take to see those positive effects? 

If you are consistent with your probiotic intake, the time frame you can expect to notice benefits will vary depending on many factors, including your reason for taking probiotics, the strain of probiotics taken, and how many colony-forming units (CFUs) are in your supplement.

taking probiotic supplement

If you are taking a probiotic supplement for general health, you may not notice a huge difference in how you feel right away. However, if you are taking probiotics due to a digestive ailment, such as diarrhea, you may notice positive effects sooner. 

According to a systematic review of randomized and quasi-randomized controlled trials, probiotics along with rehydration therapy in adults and children with acute infectious diarrhea showed improvement in only 2 days.

Another study conducted in 2011 on sixty-seven IBS patients showed supplementation of Saccharomyces Boulardii experienced a significant improvement in symptoms within a month.

Although Saccharomyces Boulardii was shown to provide improvements in the IBS symptoms, the same results will not likely be shown with those who have upper respiratory infections, because of the strain-specific benefits noted. 

Those who are taking probiotics inconsistently, or those that contain smaller numbers of CFUs, may take longer to notice any improvements in their health, if at all. 

Why Probiotics Take Longer To Work Than Vitamins

Similar to vitamins, probiotics exist to provide further support to your general health and well-being. However, given their roles in promoting good health inside your stomach, probiotics’ stay’ inside your intestines, unlike vitamins who are easily absorbed into the bloodstream.

There are many variables when it comes to how long it takes probiotics to take effect inside the body. If you are using a high quality, potent probiotic supplement, which constitutes billions of microorganisms with a high number of colony-forming units (CFU), and proven to stand the harsh acidic conditions in your gut, chances are you will immediately feel its effects as swiftly as a few hours after intake.

However, there are certain factors as to why probiotics might work slower on some people. Several factors include substance use and/or abuse, lack of proper diet and exercise, the initial state of your microbiota (microbe populations present in your gut), and consuming a low-quality probiotic.

How to Make Probiotics More Effective

Probiotics will work best when combined with a healthy diet and lifestyle. Taking a probiotic supplement and not factoring in these other lifestyle factors will not likely provide a ton of benefit. Just as taking a multivitamin doesn’t make a huge difference if you are not eating balanced meals already. 

You also want to include prebiotics to make sure to support healthy gut flora. If you are going through the trouble of eating probiotic-rich foods or taking supplements, you want to make sure they are thriving in your gut. Good sources of prebiotics include chicory root, dandelion greens, Jerusalem artichoke, garlic, onions, leeks, asparagus, bananas, and apples.

probiotic rich food apple

If you are going to take a probiotic supplement, make sure to choose the right one. Most probiotics are regulated as supplements and not food, which is not regulated by the Food and Drug Administration (FDA). This means they can make certain claims on their products that do not require research to back them up. 

Always choose your supplements from manufacturers that you trust. Look for 3rd party testing on the label. Next, you want to make sure it contains a good number of probiotics without the fillers and extra additives. Probiotics are counted in colony-forming units, or CFUs, which is the total number of live strains expected per serving. This amount will vary from product to product. According to researchers, a good probiotic supplement will contain at least 1,000,000 CFUs per gram (or 106) or more to exert a positive effect.

Lastly, is there a best time to take your probiotic supplement? Experts argue that morning time before a meal, or at night right before bed is likely the best time to take your probiotics as this is when your stomach acid is at its lowest; however, this will depend highly on the strain, and strong research has not confirmed these claims. Although further research is needed to determine the truth to this, it is believed that this will help these beneficial bugs to get into your digestive tract unharmed so they can get to work. 

In the end, what matters most is when you are most likely to take them. Whether you prefer to take them in the morning or evening, it’s most important that you be consistent with your supplementation to ensure the best results. This means taking them at the same time every day. If you are only taking it occasionally, you will not likely see a big benefit.

Choosing A Probiotic

Bacterial diversity is key to a healthy gut. Deciding on what probiotic is best suited for you depends solely on why you are going to use it. Most of the time, people tend to lean on probiotics in terms of the following reasons.

To Relieve Constipation And Irritable Bowel Syndrome (IBS)

Several studies have shown that certain probiotic strains found in supplements can reduce constipation pain for both children and adults. Look for probiotics with B. lactis, B. longum, S. cerevisiae. 

To Supplement Against Diarrhea

Diarrhea is a common health problem associated with loose-to-liquid bowel movements that occurs more frequently than average, with probiotics proven effective against the ailment. These strains include Lactobacillus rhamnosus GG, Lactobacillus acidophilus, and Lactobacillus bulgaricus.

To Help You Lose Weight

There is growing evidence that your probiotics may just have a healthy and profound effect on your body weight! If you are a little conscious of your belly fat, these “good bacteria” seem to be on your side, as some studies show an 8.5% fat loss in that particular area. Just remember to find probiotics such as Lactobacillus gasseri, Lactobacillus rhamnosus, and the combination of Lactobacillus rhamnosus and Bifidobacterium lactis to help you reduce weight.

To Support Heart Health

Aside from addressing your digestive concerns, probiotics may also help reduce the risk of heart disease. Specific bacterial strains that were studied seem to be effective at lowering cholesterol levels, such as Lactobacillus acidophilus, Bifidobacterium longum, and Lactobacillus reuteri.

To Boost Immunity

Probiotics increase your body’s defenses against allergies, infections, and even cancer by shifting the balance of your gut bacteria and reducing inflammation. Some of these probiotics include Lactobacillus GG, Lactobacillus crispatus, Lactobacillus gasseri, Bifidobacterium bifidum, and Bifidobacterium longum.

To Promote General Health

Probiotics do not only target specific diseases or medical conditions, but you may also take probiotics to support health and wellness. In this case, find probiotics with Bifidobacterium bifidum.

On the hunt for ‘true’ probiotics? Keep in mind that your chosen product must contain live and active bacterial cultures, and indicated as much on its packaging.

Best Probiotics On The Market

If you want to start your research on quality-tested products when it comes to probiotics but unsure where to start, never forget to filter brands that complement your needs and current lifestyle. Below are our picks for the best probiotic supplements.

Gundry MD Probiotics

24 Strain Probiotic

Resolute on having a more “gut-friendly” diet? Gundry MD 24 Strain Probiotic might be the one you are looking for!

The supplement pays more attention to your digestive concerns as it provides consumers with one of the most potent probiotic supplements on the market. The brand specially designed a formula combining twenty-four (24) unique probiotic strain, with each capsule containing thirty (30) billion CFUs that will help your “good bugs” thrive. 

Flexible to accommodate even those with the most restrictive diet plans, the product is also vegetarian and is both dairy and caffeine-free. If you are somewhat unsatisfied and somehow still not a fan of this product, the brand is cool on its challenge of giving you a 100% guaranteed money-back for 90 days! 



Seed Daily Synbiotic

seed Daily Synbiotic

What is better than being ‘prebiotic’? It is being both prebiotic and probiotic!

Usually found in many fruits and vegetables, probiotic simply refers to microorganisms that act as fertilizers to help stimulate the growth of healthy bacteria in the gut. 

In essence, it serves as the “food for your good bacteria.” Reaching beyond your gastrointestinal health, Seed Daily Synbiotic also promotes general health and well-being as it proves to be beneficial to your cardiovascular, dermatological, immune system, metabolic, and reproductive health. 

Seed has also pioneered the first synbiotic supplement with strains that increase the production of folate (the natural form of folic acid) within the body.

Apart from being dairy-free, gluten-free, and soy-free, its ingredients are also perfect for those strictly following vegan, vegetarian, and ketogenic diets. 

BONUS: Seed Daily Synbiotics also encourages sustainability. Made from mushrooms and cornstarch, the brand’s packaging also comes with a systematic guide to help you transition into your new regimen. 



Silver Fern’s Ultimate Probiotic

Ultimate Probiotic Supplement

Did you know that “bad bacteria” loves sugar, and it contributes to your induced sugar cravings? The Silver Fern’s Ultimate Probiotic works its magic by replacing it with “good bacteria,” eventually cutting off your unwanted sugar cravings and helping you absorb nutrients faster! 

DNA-verified, meaning you can rest assure that the right strains are freeing your gut from all its issues; it also provides that support to your immune and mental health, as its probiotics work on your Serotonin (your happy neurotransmitter), mostly found on your gastrointestinal tract, effectively improving your mood to reducing anxiety and depression. 

The brand’s unique spore form probiotics are 100% guaranteed to survive the acidity in your stomach, ensuring that all eight (8) billion CFUs will reach your gut to do its work. 

BONUS: Did I mention that they are currently on their limited special price promo?



Bottom Line

There are tons of research studies out there on the benefits of probiotic supplements; however, much research involves specific strains and populations, and further research is needed to determine how to utilize probiotics most effectively for human health. 

If you are interested in taking a probiotic supplement, be sure to choose a supplement from a credible source that contains a high number of CFUs. Make sure you take your probiotic supplement daily, around the same time. The amount of time it will take for you to experience benefits will vary depending on your reason for taking probiotics, the strain you are taking, and how many CFUs per dose. 

If you are considering adding a probiotic supplement into your routine, always speak to your health care provider. Those who are immunocompromised should avoid taking probiotic supplements. 

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Meghan Stoops, RDN

Meghan Stoops is a Registered Dietitian and licensed Nutritionist with a bachelor’s in Dietetics from San Diego State University. Meghan developed an interest in dietetics early on through her own personal struggles with nutrition misinformation. She began doing her own research, which sparked her passion for nutrition and it’s impact on our physical and mental health. Today, she takes take a non-diet, all-foods-fit approach to nutrition, and is devoted to teaching others that eating healthy does not mean restriction or sacrifice.