What Happens When You Take Probiotics Every Day

If you have trouble with your digestive system, you’re not alone. According to statistics, 60 to 70 million Americans have a digestive disease. Since maintaining a healthy gastrointestinal tract is important for overall health and well-being, many people take probiotic supplements every day.

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

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 can probiotic supplements really promote digestive health? And can they help promote other areas of your health, too? Read on to learn what the research shows about the health benefits of taking probiotics, what to look for in a probiotic supplement and how to get probiotics from food.

Why We Love Probiotics

May Improve 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. 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 (IBS).

A recent study reports that people with IBS symptoms as part of inflammatory bowel disease and Crohn’s disease who took a four-strain probiotic that included Lactobacillus strains and a strain of Enterococcus for three months had a significant reduction in symptoms.

However, more high-quality research is needed to confirm these benefits. Many research reviews are inconclusive because of the wide variations in strains studied and the mixed results of the studies.

May Lower Stress Levels

You may have heard of the gut-brain connection. One small study 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, in this case, for older adults.

May Support Cardiovascular Health

There is evidence that probiotics may help lower cardiovascular risk factors. For example, a narrative review concluded that probiotics may offer a beneficial, non-pharmacological option to support conventional CAD therapies, specifically by targeting key modifiable risk factors, like blood lipids, blood pressure, blood sugar and inflammatory markers. 

Another systematic review 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.

May Reduce Upper Respiratory Tract Infections

One review study 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.

May Support Dental Health

Periodontal disease results from infection or inflammation of the gums. One review found that probiotics may be beneficial for treating oral Candida—a yeast infection in the mouth.

And another review suggests that probiotics may help prevent halitosis (bad breath), maintain a healthy balance of the oral bacterial flora, and prevent the growth of dangerous bacteria that cause tooth decay and gum disease. As with all the other studies on probiotics, researchers note that more research is necessary.

Probiotic Deficiency

A deficiency of probiotics isn’t a deficiency in the traditional sense of the word. The goal is to improve the ratio of potentially harmful bacteria to beneficial bacteria in your gut. When the ratio favors the potentially harmful bacteria, inflammation and health issues may ensue. You can have your microbiome tested with a stool sample, so ask a health care provider about having a test done.

How Much You Need

There is no RDA for probiotics, but the World Gastroenterology Organisation Practice Guidelines acknowledge that most probiotic supplements on the market contain between 1 billion and 10 billion CFUs per dose. CFUs stands for colony-forming units (CFUs), the number of living bacteria in the product. Still, therapeutic benefits may be seen at doses outside of this range depending on the strain and the health concern. For this reason, it’s best to speak with a health care provider, like a registered dietitian, to help you choose a dose that’s best for you.

Food Sources of Probiotics

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

Probiotics are found in fermented foods, including:

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

It’s also important to provide the beneficial bacteria with food. This is referred to as prebiotics, and just about anything with fiber qualifies, including fruits, vegetables, whole grains, nuts, seeds and legumes.

Are Probiotics Safe for Everyone?

Probiotics are generally safe for most healthy people. With that said, certain populations should be cautious or avoid probiotic supplements. This includes people with severe illnesses and compromised immune systems, as probiotics may cause severe infections. Premature infants should not receive probiotics, as cases of severe and fatal infections have been reported.

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.

Probiotics supplements can be sold as capsules, powders and drinks. Many probiotic supplements are shelf-stable, but some require refrigeration, so read and follow the manufacturer’s storage instructions (chances are, if you bought it from the refrigerated section, it requires refrigeration).

As far as what strain to choose, there are many different strains of probiotics, with species of Bifidobacterium and Lactobacillus being the most common. These two strains are also considered to be quite safe.

“There are many different strains of healthy bacteria, and these different strains have different impacts on gut health,” says Hilbert. “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.”

Since dietary supplements are not heavily regulated, the listed doses or ingredients may be inaccurate. For that reason, it is important to find a supplement that is independently verified to ensure the label is accurate and the product has been tested for safety.

Our Expert Take

Probiotic supplements may have some health benefits, but more research is necessary to confidently provide recommendations on the strains, dosage and length of time they should be taken to see these benefits. While probiotic supplements have generally been shown to be safe, speak with a health care provider before adding a new supplement to your routine. If possible, try to get your probiotics through fermented foods, like yogurt, kefir, kimchi and sauerkraut.