What Happens to Your Body When You Take Probiotics Every Day

They're usually safe, but we need more research to understand who could benefit.

According to the National Institutes of Health, 60 to 70 million Americans have a digestive disease. Even if you don't have a diagnosed digestive illness, you may have heard that your digestive system's role in breaking down food can impact your mental and immune health. Since maintaining a healthy gastrointestinal tract is so important for overall health and well-being, you may be curious whether you should incorporate probiotics into your wellness routine.

Probiotics are living microorganisms often touted for their digestive health benefits. They are found in fermented foods and beverages and sold as dietary supplements. But do they really promote digestive health? And can they help promote other areas of your health, too? In this article, you'll learn what the research shows about the health benefits of taking probiotics and what to look for in a probiotic supplement.

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What Are Probiotics?

Your intestinal tract is lined with bacteria that form your gut microbiome. Despite bacteria often having a negative connotation, plenty of good bacteria help you fight illness and promote health. Having a diverse microbiome helps promote not just digestive health, but many other aspects of health.

Probiotics are living microorganisms that are thought to boost your microbiome's diversity by introducing bacteria that can help promote healthy digestion, support immunity and more.

Megan Hilbert, M.S., RDN, a registered dietitian specializing in gut health nutrition for Top Nutrition Coaching, says, "Probiotics have been shown to increase the amounts of healthy bacteria into our digestive system, which has a positive effect on many areas of our health like our skin health, immunity, metabolism and mental well-being."

What Happens When You Take Probiotics Every Day

While probiotics may have some health benefits, more research is necessary to confidently provide recommendations on the strains, dosage and length of time probiotics should be taken to see these benefits. In much of the existing research, researchers have struggled to confidently make conclusions on the health benefits of probiotics because of the wide range of strains studied, mixed results and the lack of information on necessary length of treatment to see an effect.

You May Have Better Gut Health

Gut health is probably the first thing you think of when thinking about probiotics. And for a good reason! Studies have shown that probiotics are promising for preventing or treating various digestive illnesses or concerns. According to the NIH, probiotics may prevent the following:

  • Antibiotic-associated diarrhea
  • Constipation
  • Clostridium difficile infection

They may also help induce or maintain remission from ulcerative colitis and moderately reduce symptoms of irritable bowel syndrome, according to the National Center for Complementary and Integrative Health.

Additionally, a 2019 study published in the European Journal of Applied Physiology found that marathon runners taking probiotics containing Lactobacillus and Bifidobacterium during four weeks prior to a marathon race had less gastrointestinal symptoms and lower severity of symptoms than those who took a placebo.

However, more high-quality research is needed to confirm these benefits. In fact, the American Gastroenterology Association does not recommend probiotics for treating IBS because of insufficient evidence. Many research reviews are inconclusive because of the wide variations in strains studied and mixed results of the studies.

You May Have Lower Stress Levels

At this point, you may have heard of the gut-brain connection. Research, such as this 2019 article published in Nature Microbiology, has found a connection between your gut microbiome and your quality of life. But can probiotics help?

A small 2021 study published in The Journals of Gerontology found that 12-week supplementation in healthy adults over 65 years of age with probiotics containing Bifidobacterium resulted in:

  • A significant reduction in inflammation-causing gut bacteria
  • Greater improvement in a mental flexibility test than the placebo group
  • Greater improvement in stress score than the placebo group

While more research is necessary to confirm these findings, this shows that probiotics may play a role in promoting mental health and preventing mental challenges, specifically for older adults.

You May Support Your Cardiovascular Health

A 2020 systematic research review published in Nutrients found that supplementation with vitamin D and probiotics—mainly Lactobacillus, Bifidobacterium and Streptococcus—improved various heart-health metrics, including lipid levels, inflammation and insulin sensitivity. This pairing of supplements improved health more than vitamin D supplementation alone or placebo.

Another systematic review published in 2020 in Advances in Nutrition found that consumption of fermented dairy—a probiotic source—resulted in reduced cardiovascular risk. Researchers concluded that probiotic supplementation paired with fermented dairy consumption could reduce lipid concentrations—a marker of cardiovascular health. However, they noted that there was a wide variety of probiotic strains used in the studies, so the results should be received with caution.

You May Experience Fewer and Shorter Upper Respiratory Tract Infections

An updated 2022 Cochrane review found that probiotic supplementation played a role in preventing upper respiratory tract infections and reducing the length of infection. There was a mix of low- to moderate-certainty evidence supporting these findings. The researchers concluded that probiotic supplementation was better than no supplementation or placebo in preventing upper respiratory tract infections.

You May Have Better Dental Health

Periodontal disease results from infection or inflammation of the gums, per the Centers for Disease Control and Prevention. A 2020 systematic review published in Probiotics and Antimicrobial Proteins found that probiotics could help treat and prevent infectious diseases in the oral cavity, including periodontitis and dental caries. It also reduced the levels of disease-causing pathogens.

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Food Sources of Probiotics

One way to get in probiotics is through food sources. Probiotics are found in fermented foods, including:

  • Yogurt
  • Kefir
  • Sauerkraut
  • Miso
  • Kimchi
  • Kombucha
  • Tempeh

Hilbert says, "I prefer to recommend my clients get their probiotic sources from foods like yogurt, kefir, kimchi, kombucha, etc. While probiotic supplements can be very useful in some cases, they should be targeted for specific symptoms."

Eating a well-rounded diet helps promote overall health, including gut health. So, in addition to consuming probiotic-rich foods, be sure to incorporate whole grains, lean proteins, unsaturated fats and fiber.

What to Look For in a Probiotic Supplement

Before adding any supplement to your wellness routine, speak with a trusted health care provider to ensure it is safe and doesn't interact with any medications you are taking.

Check the Storage Instructions

Probiotics supplements can be sold as capsules, powders and liquids. Be sure to read and follow the manufacturer's storage instructions. Some products must be refrigerated to preserve the probiotics, since they are living microorganisms.

Check the Strain

There are many different strains of probiotics, with species of Bifidobacterium and Lactobacillus being the most common. According to the NIH, these two strains are also considered to be quite safe.

Hilbert says, "There are many different strains of healthy bacteria, and these different strains have different impacts on gut health. Some have been proven to help with IBS symptoms, others help balance vaginal microbiota and help urogenital health, and others support the immune system. Talking with a gastroenterologist or GI dietitian can help you determine what probiotic strains may be helpful for you to take to target specific symptoms."

Check the Dose

Probiotics are measured in colony forming units (CFUs), the number of living bacteria in the product. The World Gastroenterology Organisation Practice Guidelines acknowledge that most probiotics on the market contain between 1 billion and 10 billion CFUs per dose. Still, therapeutic benefits may be seen at doses outside of this range depending on the strain and the health concern.

Some testing has revealed variations in the actual CFUs of a probiotic-containing food or supplement compared to what the label claims. Probiotics can also die off over time, causing the CFUs to vary with age.

Ultimately, it's best to speak with your doctor or registered dietitian about the strain and dose of probiotics that might work best for your health concerns.

Verify It's Third-Party Tested

Dietary supplements are not heavily regulated, so the listed doses or ingredients may be inaccurate. For that reason, it is important to find a supplement that is third-party tested to ensure the label is accurate.

Frequently Asked Questions

1. What are probiotic supplements good for?

Probiotic supplements may help promote gastrointestinal, mental, immune, cardiovascular and dental health. However, more research is needed to confirm some of these links and understand the specific probiotic strains and dosages that help with each health concern.

2. Which probiotic supplement is the most effective?

Generally, species of Lactobacillus and Bifidobacterium are the most commonly studied and are generally safe. Therefore, the risk of adverse effects from these species is pretty low.

The World Gastroenterology Organisation has guidelines for probiotics that address strains and dosages for different health concerns. We recommend finding a third-party tested supplement to ensure the label is accurate and speaking with your health care provider for individualized recommendations.

3. What are the signs that you need a probiotic?

Hilbert says, "If you deal with chronic gas, constipation or even acid reflux, probiotics can help. Certain strains have also been shown to help with non-GI issues like recurrent urinary tract infections (UTIs) or upper respiratory tract infections." However, she notes that most everyone would benefit from probiotic-rich foods.

4. Is it OK to take probiotics every day?

Regularly taking probiotics has generally been shown to be safe, according to the NIH, especially Lactobacillus and Bifidobacterium. The most common side effect is gas.

Some cases of infections have resulted in severe illness in immunocompromised or severely ill patients after taking probiotics. Regardless, speak with a trusted health care provider before taking a new supplement.

5. Who should avoid taking a probiotic supplement?

Those who are immunocompromised or have a severe underlying illness should avoid taking a probiotic supplement. If you are curious whether a probiotic supplement may be helpful for you, speak with a trusted health care provider.

The Bottom Line

Probiotics can play a role in promoting a diverse microbiome. While probiotic supplements show a lot of promise for gut, immune, mental and cardiovascular health, more research is necessary to confirm their benefits, along with the ideal strains and dosages for various health concerns. They are generally shown to be safe but speak with your health care provider before adding a new supplement to your routine.

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