Probiotics – Probiotic Foods, Supplements, Pills, Benefits & Side Effects

Probiotics foods, probiotics for weight loss and probiotic supplements could help IBS discomfort.
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Emerging research suggests probiotics can reduce IBS symptoms by 37%

What are Probiotics

Curious about the benefits of probiotics or possible probiotic side effects? With growing interest around probiotics, science has begun to uncover some big benefits from these tiny organisms. In this article we’ll answer what are probiotics, what do probiotics do, compare the benefits of probiotics for men vs. probiotics for women and explain how probiotics supplements work to keep you healthy and performing at optimal levels.

Probiotics Definition

What is a probiotic? – The most frequently used probiotic definition is a living microorganism that when consumed in high doses, can provide health benefits to the individual beyond basic nutrition.1,2 While we often think of microorganisms, or bacteria as bad things, we need bacteria to stay healthy. It’s estimated that 100 trillion microorganisms can be found in a healthy bowel.3

Types of Probiotics

There are over 500 different species of microorganisms that may be active in normal bowels, including probiotics. But not all probiotics are equal.3 Three types of probiotics that have been most frequently researched are L. acidophilus (commonly known as acidophilus probiotic), Bifidobacterium sp. and Saccharomyces boulardii, a species of yeast.1

While scientists have begun to isolate the most beneficial kinds for human health, different strains of probiotics can be found in probiotic foods, probiotic supplements or probiotic pills.

What Do Probiotics Do?

What does a probiotic do? – Probiotics work to maintain the delicate microflora balance in our gastrointestinal (GI) tract. By reducing intestinal pH levels, preventing the colonization of pathogenic (disease-causing) organisms, helping to absorb nutrients and supporting the immune system, probiotics add good bacteria to our gut.4,5 When thrown off balance, harmful microorganisms may grow and develop into problems within the GI tract.3

How Do Probiotics Work?

Taking probiotics boosts the amount of good, or ‘friendly’ bacteria in the GI tract to achieve a microbial balance.5 Without this bacteria, our immune system would not function properly and can lead to negative health outcomes.

A number of studies have been conducted on the use of probiotics for preventing or reducing the symptoms of diarrhea. In the U.S., an estimated 48 million foodborne diarrheal illnesses take place each year, resulting in 120,000 hospitalizations.8 While there are several forms of diarrhea, probiotics have been extensively researched as a treatment for antibiotic-associated diarrhea (AAD) and Acute Infectious Diarrhea.1

Probiotics have been the most clinically effective in the treatment of acute diarrhea.5 In a meta-analysis of 23 studies, researchers evaluated several strains of probiotics on variations of acute infectious diarrhea (traveler’s diarrhea and viral diarrhea). They concluded that probiotics significantly decreased the risk of diarrhea and reduced the mean duration of the diarrhea by 30 hours.1

AAD is caused by a change in intestinal flora and is a common side effect of hospitalized patients taking a general antibiotic.7 A meta-analysis of 19 studies indicated that probiotics reduced the risk of developing ADD by 52% and were most effective if taken in the first 72 hours of antibiotic treatment.1

- Article Continues Below-

Probiotic Foods

With growing interest in the health benefits provided by probiotics, an increasing amount of food products have begun to add probiotics to provide additional health benefits to customers.12

Foods that contain probiotics include: cheese, milk or probiotic yogurt.10 In recent years, orange juice, pizza and chewing gum products have also advertised the use of probiotics.12

Probiotic Yogurt

Yogurt is the most common food product associated with probiotics. By nature, plain yogurt carries two strains of bacteria, which are required to create its form. However, both of these strains are destroyed by the acid in your stomach and never reach the gastrointestinal tract.11 Yogurt probiotics may be additionally added to increase the probiotic count and health benefits.14
However, not all yogurt with probiotics provide equal health benefits. The strain and dosage play an important role in receiving positive outcomes. To add confusion, captions such as “live or active cultures” are often displayed on food products but are not synonymous with probiotics, and do not carry the same health benefits.13

While many products claim favorable properties, it’s important to read the label and make sure the strain and amount is identified. Most food products have not conducted the necessary clinical trials to back these claims up with science. In North America, governments do not require scientific evidence for companies to use the term.12

Probiotic Supplements

Probiotic supplements are an easy way to add healthy bacteria into your diet and promote a functional digestive tract. n particular, athletes should not overlook the importance of pro biotics, as even mild GI conditions can have an impact on performance.15

Supplements offer customers the ability to properly identify which strain of probiotics they’re consuming and control the dose. Probiotics are measured in colony-forming units or CFUs and effective doses are different for each strain.13,14

Probiotic Pills

If you’re looking to improve overall health, and don’t have a current gastrointestinal condition, health experts recommend taking a probiotic capsule that contains several strains to maximize the number of good bacteria entering your system.16 While there is no daily recommended probiotic dose, supplements can contain anywhere from 2-6 billion active bacteria per tablet.13,16 While some pills, such as Bio-K+ may contain 12.5 billion active cells per capsule.14
To ensure you receive all the benefits of probiotics, look for slow-release capsules. This will protect the supplement from being absorbed too quickly in your stomach.14

In clinical trials, positive results have been documented when patients take the probiotic supplement every day. To see similar benefits, daily consumption is recommended to maintain good intestinal flora.13

Natural Probiotics

As a type of microorganism, probiotics are a form of naturally occurring, good bacteria. Even in supplement form, the probiotics are natural, but may be isolated to be concentrated at higher doses. If you’re looking to purchase all-natural probiotic supplements, shop for brands that identify this directly on the label.

Probiotic Drinks

Probiotic drinks provide customers with an easy and transportable form of probiotic supplement. As of 2006, over 25 liquid probiotics were available instore and online, proving challenging for supplement users to choose the right one.18According to Glenn Gibson, professor of food microbiology at the University of Reading, when it comes to choosing a probiotic drink,

As a rule of thumb, you can trust the big manufacturers. Their quality control is very good.’18

Big manufacturers have the resources to perform rigorous, quality control checks. These big names have to adhere to strict operations and international manufacturing protocols as their products are shipped to thousands of people around the world. It would be disastrous for these big manufactures to have unidentified organisms in their products.18

At minimum, products should contain a count of 10 million lactobacilli or bifidobacterium, which can be confirmed on the label.18

Kefir Probiotics

As a type of fermented milk, kefir is quickly gaining worldwide recognition for its probiotic and additional health benefits. Kefir has been produced for over 2,000 years and is different from other milk products due to the complex interaction between bacteria and yeast.19 Kefir is characterized by its unique, almost sour taste and yogurt-like consistency. Kefir probiotics trump those found in natural yogurts, with 47 strains commonly found in kefir compared to the two strains in plain yogurt.20

Several clinical studies have shown that kefir may be a useful preventative tool for stopping food borne pathogens (bad bacteria like salmonella), activating the immune system, potentially inhibiting carcinogenic compounds, improving lactose intolerance and acting as an anti-inflammatory.19

Refrigerated Probiotics

It has been shown that microbes survive for longer when stored at low temperatures. Emerging studies have concluded that the number of bacteria may drop the longer supplements are on the shelf, although some manufacturers have developed technologies for keeping probiotics alive at room temperatures.13

When purchasing supplements, always make sure to store them as directed. And for extended storage, keep probiotics refrigerated to preserve the beneficial bacteria.14

Probiotic Gummies

Who says probiotics have to come in a pill? Chewable, probiotic gummies offer an easy way to balance intestinal flora and promote good digestion. Gummies come in a variety of tasty flavors for children or adults. Many brands are free from artificial colors or flavors and include up to 2 billion CFU per serving.21

Live Probiotics

By definition, probiotics should be alive when consumed. If they’re not, they’re considered dead bacteria. There are limited studies conducted on the effect of bacteria when it’s dead. It’s thought to be unlikely that dead bacteria could produce the same effects as live probiotics.13

Organic Probiotics

With an increasing demand for less processed foods and health supplements, many brands are launching completely organic supplements to compliment a wide range of customer preferences. Organic probiotics are available in pill, powder or gummy form. When shopping for organic supplements, look for certification that the product has been verified organic.22

Probiotics for Women

Taking probiotics can provide additional benefits for women and promoting vaginal health. Similar to the digestive tract, the vagina is a self-sustaining ecosystem. But common interventions such as birth control pills, antibiotics or spermicides can alter the bacteria balance.3

Using probiotics may work to restore microflora, or good bacteria in the vagina. Consuming probiotics may be an effective natural treatment for common urogenital issues such as urinary tract infections, yeast infections and bacterial vaginosis.3

In a 2015 randomized, double blind, and placebo-controlled clinical trial, women with reoccurring bacterial vaginosis (excessive bacteria growth) or aerobic vaginitis (abnormal vaginal infections) were prescribed an oral probiotic supplement to alleviate symptoms. Bacterial vaginosis is the most common vaginal infection amongst women of reproductive age. With current treatments, success rates hover at a mere 50% and the potential for reoccurrence within the year also at 50%.23

Do probiotics work? Probiotics for women effective for treating bacterial vaginosis and aerobic vaginitis.
Probiotics found to delay the relapse of reoccurring bacterial vaginosis up to 76%, compared to a placebo group.

Data suggests that the use of a probiotic supplement, in addition with the standard antibiotic treatment that accompanies these conditions, significantly delayed the relapse of symptoms. In some cases, the re-appearance of bacterial vaginosis symptoms was prolonged by 76%.23

Probiotics for Men

A lack of friendly bacteria, or pro biotics in the digestive tract may have larger impacts on GI function, inflammation and oxidative stress. These factors can inhibit optimal performance during exercising or sports.24

Athletes such as runners or triathletes often encounter disrupting GI pain or conditions. In these performance sports, blood flow patterns are changed and pull blood away from the intestines and to the heart or skeletal muscle. This can result in damage to the intestinal mucous which may evolve into symptoms such as inflammation, intestinal cramps, vomiting, nausea or diarrhea. Prolonged breakdown of intestinal walls can leave the GI track open to infect or the development of autoimmune diseases.24

In a 14-week study, athletic men (runners, cyclists, triathletes) aged 30-45 were administered a multi-species probiotic supplement to improve intestinal health. To measure the success, researchers observed levels of zonulin, a ‘gatekeeper’ protein that opens up a small amount of space between cells. This allows nutrients to enter the intestines, but inhibits toxins or harmful bacteria.24,25 High levels of zonulin can create too much space, letting harmful bacteria pass through and has been associated with inflammation, a weak intestinal barrier and intolerances like Celiac disease.25

Probiotic for adults decreased the risk of inflammation for athletic men.
Taking a probiotic supplement significantly reduced high levels of zonulin, a marker of a weakened gut lining, in active men.

Researchers concluded that taking a probiotic supplement decreased levels of zonulin and maintained them within a normal range, improved the protective, intestinal barrier and reduced the risk of inflammation in physically active men.24

Further, researchers observed a trend between protein oxidation and supplementing with probiotics. Protein oxidation can result in comprised protein function, structure and a loss of enzymes. At the end of the study, participants who took the probiotics had lower concentrations of protein oxidation, indicating a possible link between probiotics, healthy intestines and reduced oxidative stress.24

Probiotics for Kids

For several years, probiotics for children have been used to treat numerous conditions. An extensive body of scientific research has been conducted to evaluate the effectiveness of taking a probiotic for kids with acute infectious diarrhea, irritable bowel syndrome (IBS), preventing infections, reducing the risk of antibiotic-assisted diarrhea (ADD), preventing allergies and possibly atopic dermatitis.26

Several, well-conducted clinical trials have examined the efficacy of probiotics for toddlers and young children with acute infectious diarrhea. In 2005, a double-blind, randomized, placebo-controlled study was conducted to determine whether probiotics, specifically L. rhamnous strains, could decrease the duration of acute infectious diarrhea. 87 children ranging from 2 months to 6 years old with various forms of acute infectious diarrhea were treated with a probiotic dose of 1.2 × 1010 CFU.28

Can probiotics cause diarrhea? In a recent study, the opposite was found. Pro biotic strains of L. rhamnous effective for reducing duration of diarrhea in young children with rotavirus.
Mean number of watery stools reduced significantly over 5-day period, in children with rotaviral diarrhea.

The data suggests that the probiotic supplement was a particularly useful tool in reducing the duration of diarrhea for a subgroup of children with rotaviral diarrhea. Rotavirus was identified in 45% of the participating children and is a contagious virus that most often effects infants and young children.28,29 Left untreated it can lead to serious dehydration or death.29

Researchers also noted that if the kids’ probiotic was administered within 72 hours of diarrhea, duration of symptoms were significantly lowered. Notably, the symptoms were substantially reduced in children 12 months or younger.28

Probiotics for Infants

Intestinal microflora may play an important role in the development of colic pathogens. Lower levels of lactobacilli have been observed in colicky infants. Colic is a common, unexplained phenomenon that occurs in infants that leads to crying fits for at least three hours.30

Infant probiotics may help reduce duration or severity of colic in infants. While research is still ongoing, in a 2010 clinical trial, 46 colicky infants were given the probiotic L reuteri for 21 days. At the end of the trial, the probiotic group had a daily crying time of 35 minutes compared to 90 minutes in the placebo group.31,32 Researchers reported the probiotic was safe and well tolerated, with no changes in stool, increase in constipation, regurgitation or adverse effects between groups.32

Supplement Analyst recommends to always consult with your health care provider before starting any probiotic treatment with infants.

Probiotics for Children

In general, probiotics for kids are considered safe to use. Special populations of children, such as patients with indwelling central venous catheters, have reported bacteremia (bacteria in the blood) or fungemia (yeast or fungus in the blood).26,27

Baby Probiotics

When born, babies’ guts are sterile but bacteria colonization begins to immediately occur. Mode of delivery, diet and gestational age are important factors on which microorganisms develop in the intestinal track, and at what speed. After infancy, the microflora profile becomes less diet dependent and will not drastically change in adulthood. Therefore, diet and immune function play a pivotal role on overall baby health.33

The idea is that by providing probiotics for babies, it will introduce good bacteria into the intestinal environment and prevent the development of harmful bacteria.33

In a double blind, random controlled trial, LGG (strain of probiotic) was given to women with infants at a high risk for an atopic disease. Probiotic treatment started in the last 4 weeks of pregnancy until the child was 6 months old. Out of 132 infants, 46 (35%) were diagnosed with atopic eczema by the age of 2. Of the probiotic group, 15 out of 64 children (23%) were diagnosed; compared to 31 out of 68 (46%) in the placebo group.33

Probiotics Weight Loss

Are probiotics and weight loss connected? – In a recent study, a Japanese research team studied 210 overweight individuals. Participants were given a fermented milk drink, with two smaller groups given the milk plus a strain of lactobacillus.43

By the end of the study, all groups lost 1-3% of belly fat, and the probiotic groups has roughly lost 8-9% of unhealthy, visceral fat.43

While the exact strain isn’t commercially available in the United States, emerging research is investigating how other strains may promote similar results.

If you’re looking to shed more than a few pounds, find out why a weight loss supplement may be right for you.

Benefits of Probiotics

What are probiotics good for? – Probiotic benefits are commonly associated with individuals experiencing gastrointestinal (GI) tract issues. Probiotics may reduce the risk of antibiotic related diarrhea, severity of infectious diarrhea, bloating and pain in patients with irritable bowel syndrome (IBS).1

Additional studies have identified that probiotics can be beneficial in reducing symptoms of lactose intolerance, stimulating the immune system, decreasing inflammation in patients with inflammatory bowel disease (IBD), treating chronic ulcerative colitis (CUC) and preventing certain forms of diarrhea. Preliminary research indicates probiotics may be potentially beneficial for regulating blood cholesterol levels and could contribute to cancer prevention.34

GI issues can also be provoked by radiation therapy. In a clinical trial of nearly 500 patients with abdominal or pelvic cancer, researchers examined the efficacy of a high-dose probiotic preparation (VSL#3) in preventing radiation side effects.35

Results indicated decreased rates of diarrhea in the probiotic group, compared to the placebo group (31.6% vs. 51.8%). Not only did patients in the placebo group experience diarrhea more often, but 55.4% of these patients experienced severe grade 3-4 diarrhea, compared to 1.4% in the probiotic group. Probiotics that induce lactic acid production, may be an effective and easy way to reduce the risk of radiation-associated diarrhea and improve the quality of life.35

Do Probiotics Work?

As of 2011, over 700 randomized controlled studies involving probiotics have been conducted on human participants.6 Studies have ranged from preventing diarrhea, improving symptoms of irritable bowel syndrome (IBS), treatment of Crohn’s disease, reducing the risk of allergies in children and even maintaining a healthy weight.1,3

Are Probiotics Good for You?

Thinking of buying a probiotic? Read our latest Buying Guide first.

It’s thought that many digestive and non-digestive diseases can be attributed to a dysfunctional, or out of balance micro bacterial environment, as a large portion of our immune system is located within the GI track.36

Diseases that may develop from an inadequate intestinal defense barrier may be autoimmune (chronic inflammatory bowel disease (IBD), multiple sclerosis or type 1 diabetes) or atopic (asthma, allergic rhinitis or eczema).36

Probiotics benefits can vary from strain to strain and depend on the amount consumed. There is no recommended dose of probiotics. As each strain may be most effective at different levels, ranging from 50 million colony-forming units (CFUs) to more than 1 trillion CFUs.36 While optimal effectiveness and benefits may range, it’s important to keep supplementation consistent.37

Probiotics for IBS

Should I take probiotics if I have a history of GI issues, such as IBS? – For users with irritable bowel syndrome (IBS), probiotics may offer a natural form of relief. In 2007, the FDA discontinued one of the major prescription treatments for IBS constipation. In the same year, a research trial investigated the effects of taking a multispecies probiotic supplement in IBS patients over the course of five months.9

Probiotics for IBS. Pro biotic supplement reduces symptoms in IBS patients by 37%.
Taking probiotics reduces symptoms in IBS patients by 37%, according to clinical study.

Patients who received the probiotics for IBS saw a mean decrease of 37% on total IBS score, which includes symptoms such as distension, abdominal pain, gas and stomach rumbling. Individuals also reported a decrease in symptom intensity. Internally, the probiotic supplement helped stabilize intestinal microbiota which is closely associated with inflammation.9

Probiotics Side Effects

The side effects of probiotics are very minimal for most populations.11 While many consumers may have concerns such as “do probiotics make you poop” or “can probiotics cause constipation?”

Probiotics for adults and children have very small side effects, if any. Small increases in flatulence, stomach rumbles or changes in bowel movements may be possible.3

Are probiotics safe? – Probiotics have been consumed for generations and are considered relatively safe and well-tolerated for the vast majority of people.11 There have been no reported cases of toxicity caused by pro biotic consumption. Even consuming too much probiotics would likely not affect normal populations.2
Special populations with severely depressed immune systems or premature babies may develop minor side effects.11

Can Probiotics Cause Diarrhea?

Probiotics diarrhea is not commonly observed, in fact, the opposite. Extensive research indicates that specific strains of probiotics are effective in preventing certain forms of diarrhea.42

Probiotics and antibiotics both play an important role in balancing the bacteria in our intestinal track. Antibiotic-associated diarrhea (ADD) is a common ailment which occurs in 5-25% of adults and 11-40% of children after being prescribed a broad-based antibiotic. While a number of probiotic strains can be taken to counteract ADD, in clinical trials Lactobacillus GG and the yeast Saccharomyces boulardii reduced the duration and severity. Additionally, the probiotic acidophilus decreased the duration of diarrhea by at least a day.41

When to Take Probiotics

According to a 2012 National Health Interview Survey (NHIS), 4 million U.S. adults had used probiotics or prebiotics (the food for probiotics) in the past month.38 With growing popularity and number of brands available – each with specific instructions – it appears that confusion on how to take probiotics is growing as well. Labels may instruct users to take before, after or even during meals for optimal effects.39

Shockingly, little research exists on the timing of taking a probiotic. In 2011, researchers sought to fill this gap in scientific evidence and provide answers for consumers. In the study, researchers built a fake model of the upper human digestive track to accurately record the time-sensitive impacts of probiotic supplementation.39

Using real saliva and enzyme solutions, a multi-strain probiotic (Lactobacillus helveticus R0052, Lactobacillus rhamnosus R0011, Bifidobacterium longum R0175 and Saccharomyces cerevisiae boulardi) was administered into the model with an on oatmeal-milk mix (gruel), 1% milk, apple juice or spring water to mimic possible options consumers may use while taking a supplement.39

Best time to take probiotics? With a meal, or 30 minutes prior is when to take probiotics.
Survival of probiotics in the stomach (left) and duodenal (right) were most successful when combined with a meal or 30 minutes before.

Results indicated that the best time to take probiotics is with a meal or 30 minutes prior to a meal. This timing allowed for the highest survival rate amongst the 4 strains of probiotics. Overall probiotic survival was significantly improved when combined with the milk or gruel, indicating increased effectiveness when taken with a meal containing fat.39

GNC Probiotics – and Other Retailers

Effective and affordable probiotic supplements are readily available in pharmacies, supermarkets or supplement stores like GNC.

GNC probiotics are available for men, women, children and adults looking to promote digestive health, and immunity support.

For beginner supplement users, Walgreens probiotics, Costco probiotics, CVS probiotics or probiotics Walmart offer affordable, good probiotics brands that can conveniently be purchased while grocery shopping. And for individuals with dietary requirements, Whole Foods probiotics may be a good choice for organic and specialty products.

Probiotics Reviews

Read our Official Supplement Analyst probiotic reviews here.

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