- What are Probiotics ?
- What Kinds of Microorganisms Are In Probiotics ?
- What do we know about the usefulness of probiotics ?
- What do we know about the safety of probiotics ?
- What Do Probiotics Do
- Benefits of Probiotics
- Probiotics May Help Women Lose Weight
- Probiotics for treating acute infectious diarrhoea
- Probiotics for the Prevention Antibiotic-Associated Diarrhea in Children
- Probiotics to Prevent C. difficile Diarrhea Associated with Antibiotic Use
- Probiotics for persistent diarrhoea in children
- Probiotics for prevention of necrotizing enterocolitis in preterm infants
- Probiotics may Ease Constipation
- Probiotics to Prevent Upper Respiratory Tract Infections (for example, the common cold)
- Probiotics potential treatment for Acne and Rosacea
- Probiotics for Women to Prevent Gestational Diabetes Mellitus
- Probiotics for persistent diarrhoea in children
- Probiotics for the treatment of bacterial vaginosis
- Probiotics for people with hepatic encephalopathy
- Probiotics in infants for prevention of allergic disease and food hypersensitivity
- Probiotics for maintenance of remission in ulcerative colitis
- Probiotics for treatment of active Crohn’s disease and for maintenance of remission in Crohn’s disease
- Safety and Side Effects of Probiotics
- Where Do You Find Probiotics ?
What are Probiotics ?
Probiotics are supplements or foods that contain live microorganisms (in most cases, bacteria) that are similar to beneficial microorganisms found in the human gut 1). Priobiotics are thought to alter the microflora of the host and the live microorganisms are believed to provide health benefits when consumed 2). Products sold as probiotics include foods (such as yogurt), dietary supplements, and products that aren’t used orally, such as such as suppositories and skin creams. Although people often think of them as harmful “germs,” many microorganisms help your bodies to function properly. For example, normal intestinal bacteria digest food, destroy disease-causing microorganisms and produce vitamins. Large numbers of microorganisms live on and in our bodies. In fact, microorganisms in the human body outnumber human cells by 100 to 1. Many of the microorganisms in probiotic products are the same as or similar to the ones in your bodies 3). Although a great deal of research has been done on probiotics, much remains to be learned.
Prebiotics are not the same as probiotics. The term “prebiotics” refers to dietary substances that favor the growth of beneficial bacteria over harmful ones. The term “synbiotics” refers to products that combine probiotics and prebiotics.
The term probiotic —meaning “for life”— is currently used to name ingested live microorganisms associated with benefits for humans and animals. The term came into more common use after 1980. The introduction of the concept is generally attributed to Nobel laureate Élie Metchnikoff, who postulated that yogurt-consuming Bulgarian peasants lived longer lives because of this custom 4). He suggested in 1907 that “the dependence of the intestinal microbes on the food makes it possible to adopt measures to modify the flora in our bodies and to replace the harmful microbes by useful microbes”. Data from the 2012 National Health Interview Survey show that about four million U.S. adults had used probiotics or prebiotics in the past 30 days. Other than vitamins and minerals, probiotics or prebiotics were the third most commonly used dietary supplement. Their use quadrupled between 2007 and 2012. The survey also showed that 300,000 children ages 4 to 17 had used probiotics or prebiotics in the prior 30 days 5).
Although there are numerous claimed benefits of using commercial probiotics, such as reduction of gastrointestinal discomfort or strengthening of the immune system, such claims are not backed by scientific evidence. And it is important to be aware that the U.S. Food and Drug Administration has not approved any health claims for probiotics.
Although a great deal of research has been done on probiotics, much remains to be learned.
You don’t necessarily need probiotics — a type of “good” bacteria — to be healthy. However, these microorganisms may help with digestion and offer protection from harmful bacteria, just as the existing “good” bacteria in your body already do.
Prebiotics are not the same as probiotics. The term “prebiotics” refers to dietary substances that favor the growth of beneficial bacteria over harmful ones. The term “synbiotics” refers to products that combine probiotics and prebiotics.
Prebiotics are nondigestible carbohydrates that act as food for probiotics. When probiotics and prebiotics are combined, they form a synbiotic. Fermented dairy products, such as yogurt and kefir, are considered synbiotic because they contain live bacteria and the fuel they need to thrive.
Probiotics are found in foods such as yogurt, while prebiotics are found in whole grains, bananas, onions, garlic, honey and artichokes. In addition, probiotics and prebiotics are added to some foods and available as dietary supplements.
What Kinds of Microorganisms Are In Probiotics ?
Probiotics may contain a variety of microorganisms. The most common are bacteria that belong to groups called Lactobacillus and Bifidobacterium. Each of these two broad groups includes many types of bacteria. Other bacteria may also be used as probiotics, and so may yeasts such as Saccharomyces boulardii 6).
Although more research is needed, there’s encouraging evidence that probiotics may help:
- Treat diarrhea, especially following treatment with certain antibiotics
- Prevent and treat vaginal yeast infections and urinary tract infections
- Treat irritable bowel syndrome
- Treat inflammatory bowel disease
- Speed treatment of certain intestinal infections
- Prevent or reduce the severity of common colds and flu
- Allergic disorders such as atopic dermatitis (eczema) and allergic rhinitis (hay fever)
- Tooth decay, periodontal disease, and other oral health problems
- Colic in infants
- Liver disease
- Prevention of necrotizing enterocolitis in very low birth weight infants.
What do we know about the usefulness of probiotics ?
Some probiotics may help to prevent diarrhea that’s caused by infections or antibiotics. They may also help with symptoms of irritable bowel syndrome. However, benefits have not been conclusively demonstrated, and not all probiotics have the same effects.
What do we know about the safety of probiotics ?
In healthy people, probiotics usually have only minor side effects, if any. However, in people with underlying health problems (for example, weakened immune systems), serious complications such as infections have occasionally been reported.
Government regulation of probiotics in the United States is complex. Depending on a probiotic product’s intended use, the FDA might regulate it as a dietary supplement, a food ingredient, or a drug. If a probiotic is intended for use as a dietary supplement, it is placed under the umbrella of “foods,” and as such is regulated by FDA’s Center for Food Safety and Applied Nutrition 7).
Many probiotics are sold as dietary supplements, which do not require FDA approval before they are marketed 8). Dietary supplement labels may make claims about how the product affects the structure or function of the body without FDA approval, but they cannot make health claims (claims that the product reduces the risk of a disease) without the FDA’s consent.
If a probiotic is marketed as a drug for specific treatment of a disease or disorder in the future, it will be required to meet more stringent requirements. It must be proven safe and effective for its intended use through clinical trials and be approved by the FDA before it can be sold.
What Do Probiotics Do
Probiotics may have a variety of effects in the body, and different probiotics may act in different ways.
- Help to maintain a desirable community of microorganisms
- Stabilize the digestive tract’s barriers against undesirable microorganisms or produce substances that inhibit their growth
- Help the community of microorganisms in the digestive tract return to normal after being disturbed (for example, by an antibiotic or a disease)
- Outcompete undesirable microorganisms
- Stimulate the immune response.
Under normal or “balanced” conditions, friendly bacteria in the gut outnumber the unfriendly ones. Probiotics can act as gut-beneficial bacteria that create a physical barrier against unfriendly bacteria 9).
Probiotics can also help offset the bacterial imbalance caused by taking antibiotics. Antibiotics kill good bacteria along with the harmful ones, often leading to gas, cramping or diarrhea.
Probiotics may help breakdown protein and fat in the digestive tract — a valuable benefit to help infants, toddlers or patients who need to build strength throughout and after an illness.
Benefits of Probiotics
Probiotics May Help Women Lose Weight
In a double-blind, placebo-controlled, randomised trial 10) involving 125 obese men and women who took either a probiotic supplement, containing a strain of Lactobacillus rhamnosus, or a placebo without probiotic bacteria during a 12-week weight-loss program and a 12-week weight-maintenance period. Each subject consumed two capsules per d of either a placebo or a Lactobacillus rhamnosus formulation (1·6 × 108 colony-forming units of Lactobacillus rhamnosus/capsule with oligofructose and inulin). Each group was submitted to moderate energy restriction for the first 12 weeks followed by 12 weeks of weight maintenance. Body weight and composition were measured at baseline, at week 12 and at week 24.After the first 12 weeks, women taking the supplement had lost an average of 10 pounds, while those on placebo shed 6 pounds. During the weight-maintenance period, the female probiotic users dropped 2 more pounds on average, while the weight of placebo takers reached a plateau. Men did not seem to benefit from the probiotic 11). The mean weight loss was not significantly different between the Lactobacillus rhamnosus and placebo groups when all the subjects were considered. However, a significant treatment × sex interaction was observed. The mean weight loss in women in the Lactobacillus rhamnosus group was significantly higher than that in women in the placebo group after the first 12 weeks, whereas it was similar in men in the two groups. Women in the Lactobacillus rhamnosus group continued to lose body weight and fat mass during the weight-maintenance period, whereas opposite changes were observed in the placebo group. Changes in body weight and fat mass during the weight-maintenance period were similar in men in both the groups.
After the 12-week maintenance period, the weight of the women in the placebo group had remained stable but the probiotic group had continued to lose weight, for a total of 5.2 kg per person. In short, women consuming probiotics lost twice as much weight over the 24-week period of the study. Researchers also noted a drop in the appetite-regulating hormone leptin in this group, as well as a lower overall concentration of the intestinal bacteria related to obesity.
According to Prof. Angelo Tremblay, the head researcher, probiotics may act by altering the permeability of the intestinal wall. By keeping certain proinflammatory molecules from entering the bloodstream, they might help preventing the chain reaction that leads to glucose intolerance, type 2 diabetes, and obesity.
This study focused on only one strain of Lactobacillus rhamnosus, but Professor Tremblay believes that other probiotics found in dairy products could have a similar effect. He stresses, however, that the benefits of these bacteria are more likely to be observed in a favorable nutritional context that promotes low fat and adequate fiber intake.
Probiotics for treating acute infectious diarrhoea
Episodes of acute infectious diarrhoea remain a major disease burden throughout the world, especially in developing countries. They are due to infection by many different organisms. Most episodes are self-limiting and usually investigations are not done to identify the infectious agent. The main risk to health is dehydration and management aims to improve and maintain hydration status. However, rehydration fluids do not reduce the stool volume or shorten the episode of diarrhoea.
Used alongside rehydration therapy, probiotics appear to be safe and have clear beneficial effects in shortening the duration and reducing stool frequency in acute infectious diarrhoea. However, more research is needed to guide the use of particular probiotic regimens in specific patient groups 12).
A review of a number of randomized controlled trials have been done to see whether probiotics are beneficial in acute infectious diarrhoea. The researchers identified 63 trials, which included a total of 8014 people – mainly infants and children. Nearly all studies reported a shortened duration of diarrhoea and reduced stool frequency in people who received probiotics compared to the controls. Overall, probiotics reduced the duration of diarrhoea by around 25 hours, the risk of diarrhoea lasting four or more days by 59% and resulted in about one fewer diarrhoeal stool on day 2 after the intervention. However, there was very marked variability in the study findings and so these estimates are approximate. The researchers concluded that these results were very encouraging but more research is needed to identify exactly which probiotics should be used for which groups of people, and also to assess the cost effectiveness of this treatment.
Probiotics for the Prevention Antibiotic-Associated Diarrhea in Children
Antibiotic-associated diarrhea occurs when antibiotics disturb the natural balance of “good” and “bad” bacteria in the intestinal tract, causing harmful bacteria to multiply beyond their normal numbers. The symptoms of antibiotic-associated diarrhea include frequent watery bowel movements and crampy abdominal pain. Probiotics are found in dietary supplements or yogurts and contain potentially beneficial bacteria or yeast. Probiotics may restore the natural balance of bacteria in the intestinal tract and prevent antibiotic-associated diarrhea.
A team of researchers based in Canada and the United States worked with the Cochrane IBD group to investigate whether probiotics prevent antibiotic-associated diarrhea in children receiving antibiotic therapy and whether probiotics causes any side effects 13). Twenty-three studies were included, with a total of 3,938 children, ranging from 2 weeks to 17 years of age, who were receiving probiotics co-administered with antibiotics to prevent antibiotic-associated diarrhea.
Analyses showed that probiotics may be effective for preventing antibiotic-associated diarrhea in children. The incidence of antibiotic-associated diarrhea in the probiotic group was 8% (163/1992) compared to 19% (364/1906) in the control group. Probiotics were generally well tolerated, and minor side effects occurred infrequently, with no significant difference between probiotic and control groups. Among the various probiotics evaluated, Lactobacillus rhamnosus or Saccharomyces boulardii at a dosage of 5 to 40 billion colony forming units per day may be appropriate for preventing antibiotic-associated diarrhea in children receiving antibiotics 14). Until further research has been conducted, probiotic use should be avoided in pediatric populations at risk for side effects including severely debilitated or immuno-compromised children.
Probiotics to Prevent C. difficile Diarrhea Associated with Antibiotic Use
Antibiotics are among the most prescribed medications worldwide. Antibiotic treatment may disturb the balance of organisms that normally inhabit the gut. This can result in a range of symptoms, most notably, diarrhea. Clostridium difficile is one particularly dangerous organism that may colonize the gut if the normal healthy balance has been disturbed. Clostridium difficile-related disease varies from asymptomatic infection, diarrhea, colitis, and pseudo-membranous colitis to death. The cost of treatment is expensive and the financial burden on the medical system is substantial. The recent increase in incidence and severity of disease caused by hypervirulent strains of C. difficile has prompted some clinicians to prescribe probiotics as drugs in combination with standard antimicrobial drug therapy for these patients.
Based on this systematic review and meta-analysis of 23 randomized controlled trials including 4213 patients, moderate quality evidence suggests that probiotics are both safe and effective for preventing Clostridium difficile-associated diarrhea 15). The study results suggested that when probiotics are given with antibiotics they reduce the risk of developing Clostridium difficile-associated diarrhea by 64%. Side effects were assessed in 26 studies (3964 participants) and the results suggest that probiotics decrease the risk of developing side effects. The most common side effects reported in these studies include abdominal cramping, nausea, fever, soft stools, flatulence, and taste disturbance. The short-term use of probiotics appears to be safe and effective when used along with antibiotics in patients who are not immunocompromised or severely debilitated.
Probiotics for persistent diarrhoea in children
Persistent diarrhoea is defined as a diarrhoeal episode that starts acutely but then lasts for 14 days or more, and it is an important cause of morbidity and mortality in children under five years old in developing countries throughout the world. The cause of persistent diarrhoea is not completely understood but is likely to be complex; this in turn makes management of the condition difficult. Probiotics are bacteria and yeasts that are similar to the normal bacteria found in a healthy gut. These so called friendly bacteria have been used in several studies to treat acute infectious diarrhoea with encouraging results. This review found four trials involving children with persistent diarrhoea. Two studies with a combined total of 324, showed that probiotics shorten the duration of diarrhoea and reduce the stool frequency on day-5. One study (235 children) suggested that probiotics reduce the hospital stay. Three out of four trials reported that no adverse events occurred. However, this review is limited by few trials with small number of participants, and therefore may not represent a reliable estimate of probiotics’ effect 16).
Probiotics for prevention of necrotizing enterocolitis in preterm infants
Necrotizing enterocolitis is a serious disease that affects the bowel of premature infants in the first few weeks of life. Although the cause of necrotizing enterocolitis is not entirely known, milk feeding and bacterial growth play a role. Probiotics (dietary supplements containing potentially beneficial bacteria or yeast) have been used to prevent necrotizing enterocolitis. This review of studies found that the use of probiotics reduces the occurrence of necrotizing enterocolitis and death in premature infants born weighing less than 1500 grams 17). There is insufficient data with regard to the benefits and potential adverse effects in the most at risk infants weighing less than 1000 grams at birth.
Probiotics may Ease Constipation
Researchers at King’s College in London 18) scoured the medical literature and found 14 studies that met their criteria for a well-done study. All were clinical trials that randomly assigned people with constipation to take either probiotics or a placebo (or other control treatment).
By pooling the findings of the trials, the researchers found that on average, probiotics slowed “gut transit time” by 12.4 hours, increased the number of weekly bowel movements by 1.3, and helped soften stools, making them easier to pass 19). Probiotics that contained Bifidobacterium appeared to be the most effective. Adequately powered randomised clinical trials are required to better determine the species or strains, doses, and duration of use of probiotics that are most efficacious.
Probiotics to Prevent Upper Respiratory Tract Infections (for example, the common cold)
With the increasing consumption of probiotics, researchers carried out a review on the effects of probiotics in helping people (without immunodeficiencies) to avoid acute upper respiratory tract infections, for example, the common cold, compared to placebo. Upper respiratory tract infections include the common cold and inflammation of the trachea and larynx, with symptoms including fever, cough, pain and headaches. Most acute upper respiratory tract infections are caused by viral infections and usually resolve after three to seven days. Some probiotics (live micro-organisms) can confer a health benefit to the patient when administered in adequate amounts. Lactic acid bacteria and bifidobacteria are the most common types of probiotics. The quality of the evidence is low or very low mainly due to poorly conducted trials, but study on probiotics vs placebo as treatment for the common cold, probiotics were better than placebo in reducing the number of participants experiencing episodes of acute upper respiratory tract infections by about 47% and the duration of an episode of acute upper respiratory tract infections by about 1.89 days 20).
Probiotics potential treatment for Acne and Rosacea
In an article published by the American Academy of Dermatology 21). Current treatment includes diet with or without medication 22).
Probiotics – ‘good’ bacteria that are usually taken in the form of capsules or drinks – supplement the gut bacteria. They have the potential to change a person’s metabolism and so prevent gestational diabetes mellitus. This review 23) was designed to look at whether there is evidence to show if this is true or not. At the moment there is only one randomised controlled study, which involved 256 women. This study does show a lower rate of gestational diabetes mellitus in women who took probiotics from early pregnancy, with the rate of diagnosis of gestational diabetes mellitus being reduced by two-thirds and their babies on average weighed 127 g less at birth. This study did not find differences in the rates of miscarriage, intrauterine or neonatal death or stillbirth. There was no clear evidence of a change in the proportion of women delivered by caesarean section or in the risk of preterm delivery. The study did not report on how much weight the mothers gained during pregnancy or how many babies were large-for-gestational age or that weighed more than 4000 g at birth or on the body composition of the babies. One study is not enough to draw any definite conclusions at the moment. There are other studies underway.
Probiotics for persistent diarrhoea in children
Persistent diarrhoea is defined as a diarrhoeal episode that starts acutely but then lasts for 14 days or more, and it is an important cause of morbidity and mortality in children under five years old in developing countries throughout the world. The cause of persistent diarrhoea is not completely understood but is likely to be complex; this in turn makes management of the condition difficult. Probiotics are bacteria and yeasts that are similar to the normal bacteria found in a healthy gut. These so called friendly bacteria have been used in several studies to treat acute infectious diarrhoea with encouraging results. This review 24) found four trials involving children with persistent diarrhoea. Two studies with a combined total of 324, showed that probiotics shorten the duration of diarrhoea and reduce the stool frequency on day-5. One study (235 children) suggested that probiotics reduce the hospital stay. Three out of four trials reported that no adverse events occurred. However, this review is limited by few trials with small number of participants, and therefore may not represent a reliable estimate of probiotics’ effect.
Probiotics for the treatment of bacterial vaginosis
Bacterial vaginosis is one of the most common causes of genital discomfort in women of reproductive age. This condition occurs when there is an imbalance in the population of normal vaginal micro-organism with depletion of the dominant lactobacilli and overgrowth of other types of bacteria. Treatment of this condition using recommended antibiotics is often associated with failure and high rates of recurrence. This led to the concept of replacing the depleted lactobacilli using probiotic strains as a treatment approach. This review investigated the evidence for the use of probiotic preparations either alone or in conjunction with antibiotics for the treatment of bacterial vaginosis. The current research 25) does not provide conclusive evidence that probiotics are superior to or enhance the effectiveness of antibiotics in the treatment of bacterial vaginosis. In addition, there is insufficient evidence to recommend the use of probiotics either before, during or after antibiotic treatment as a means of ensuring successful treatment or reduce recurrence.
Probiotics for people with hepatic encephalopathy
Hepatic encephalopathy is a disorder of brain function as a result of liver failure or portosystemic shunt or both. Both hepatic encephalopathy (clinically overt) and minimal hepatic encephalopathy (not clinically overt) significantly impair patient’s quality of life and daily functioning and represent a significant burden on healthcare resources. Of the 21 included trials including 1420 participants, 14 trials compared a probiotic with placebo or no treatment and seven trials compared a probiotic with lactulose. The treatment duration of the trials ranged from 10 days to 180 days.
Compared with placebo or no intervention, probiotics probably improve recovery and may lead to improvements in the development of overt hepatic encephalopathy, quality of life, and plasma ammonia concentrations, but probiotics may lead to little or no difference in mortality. Whether probiotics are better than lactulose for hepatic encephalopathy is uncertain because the quality of the available evidence was very low. High-quality randomised clinical trials with standardised outcome collection and data reporting are needed to further clarify the true efficacy of probiotics 26).
Probiotics in infants for prevention of allergic disease and food hypersensitivity
Reactions to foods and allergies (including asthma, eczema and hay fever) are common and may be increasing in developed countries. Many infants become sensitised to foods, including infant formula, through their gastrointestinal tract, a process that may be affected by the composition of the intestinal bacteria.
There is insufficient evidence to recommend the addition of probiotics to infant feeds for prevention of allergic disease or food reactions 27).
Probiotics for maintenance of remission in ulcerative colitis
Ulcerative colitis is a chronic relapsing inflammatory disorder of the large bowel. Probiotics are living microorganisms that are thought to alter the growth of bacteria in the bowel and reduce inflammation. These reviews 28), 29) investigated the evidence for the use of probiotics for the maintenance of remission in ulcerative colitis. Four studies were identified which tested the effect of probiotics among 587 patients with ulcerative colitis in remission. The studies ranged in length from 3 to 12 months. The studies did not find any benefit for probiotic treatment compared to either placebo (pills not containing probiotics) or conventional treatment using mesalazine (a 5-ASA drug taken by mouth). Furthermore, conventional therapy combined with a probiotic did not improve overall remission rates in patients with mild to moderate ulcerative colitis. Probiotic treatment was generally well tolerated but the number of side effects reported was similar to that reported with mesalazine. Common side effects included diarrhoea, mucous secretion, bloody stools, abdominal pain, flatulence and distension, nausea and vomiting and headache. Whether probiotics are effective in patients with severe and more extensive disease and whether they can be used as an alternative to existing therapies is unknown. Further well designed, larger randomised controlled trials are needed to determine whether probiotics can be used as an alternative to current treatment modalities 30).
Probiotics for treatment of active Crohn’s disease and for maintenance of remission in Crohn’s disease
Crohn’s disease causes chronic inflammation of the intestines, which has periods of inactivity and periods when it flares up. Crohn’s disease can affect any part of the digestive tract, from the mouth to the anus. The most common symptoms of Crohn’s disease are abdominal pain, and diarrhoea. Probiotics are living microorganisms that are thought to benefit health by altering the growth and activity of bacteria in the intestines thereby reducing inflammation.
For Crohn’s disease active treatment, only one study was identified and this did not show that probiotics had any effect in treating active Crohn’s disease 31). However this study was only small (11 patients) and no definite conclusion can be made regarding the effectiveness of probiotics. Probiotics were generally well tolerated and no side effects were reported. There is insufficient evidence to make any conclusions about the effectiveness of probiotics for treatment of active Crohn’s disease.
For Crohn’s disease maintenance treatment, seven small studies of variable quality were reviewed. The studies tested the effect of maintenance treatment with probiotics (e.g. Lactobacilli GG, Escherichia coli strain Nissle 1917, VSL#3, Saccharomyces boulardii) among patients with Crohn’s disease in remission. Remission was induced by medical or surgical treatment. The studies lasted for 6 months to a year. The studies did not demonstrate any benefit for probiotic treatment for the maintenance of remission in Crohn’s disease 32). Therefore, currently, there is no evidence to support the use of probiotics for the maintenance treatment of Crohn’s disease.
Safety and Side Effects of Probiotics
Whether probiotics are likely to be safe for you depends on the state of your health 33). Studies suggest that probiotics usually have few side effects. However, the data on safety, particularly long-term safety, are limited, and the risk of serious side effects may be greater in people who have underlying health conditions.
- In people who are generally healthy, probiotics have a good safety record. Side effects, if they occur at all, usually consist only of mild digestive symptoms such as gas.
- On the other hand, there have been reports linking probiotics to severe side effects, such as dangerous infections, in people with serious underlying medical problems. The people who are most at risk of severe side effects include critically ill patients, those who have had surgery, very sick infants, and people with weakened immune systems.
- Probiotic products may contain different types of probiotic live microorganisms and have different effects in the human body. The effects also may vary from person to person.
Even for healthy people, there are uncertainties about the safety of probiotics. Because many research studies on probiotics haven’t looked closely at safety, there isn’t enough information right now to answer some safety questions. Most of our knowledge about safety comes from studies of Lactobacillus and Bifidobacterium; less is known about other probiotics 34). Information on the long-term safety of probiotics is limited, and safety may differ from one type of probiotic to another. For example, even though a National Center for Complementary and Integrative Health – funded study showed that a particular kind of Lactobacillus appears safe in healthy adults age 65 and older, this does not mean that all probiotics would necessarily be safe for people in this age group.
The National Institutes of Health has established the Human Microbiome Project to study the many microorganisms and their genes (called the “microbiome”) that share our body space. These microbes outnumber our own cells by 10 to 1 and one of the most important things they do for us is to help with digestion. Part of this project is an initiative to study probiotic products, including their health benefits, how they work, and their long-term effects 35).
Don’t replace scientifically proven treatments with unproven products and practices. Don’t use a complementary health product, such as probiotics, as a reason to postpone seeing your health care provider about any health problem.
If you’re considering a probiotic dietary supplement, consult your health care provider first. This is especially important if you have health problems. Anyone with a serious underlying health condition should be monitored closely while taking probiotics.
If you’re pregnant or nursing a child, or if you’re considering giving a child a dietary supplement, such as probiotics, it’s especially important to consult your (or your child’s) health care provider.
Tell all your health care providers about any complementary or integrative health approaches you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care.
Where Do You Find Probiotics ?
Fermented or cultured dairy products are a major source of probiotics 36). Other sources of probiotics include:
- soy beverages
- fermented milk.
The bacteria either occur naturally in these foods or have been added during preparation. Probiotics are also available as dietary supplements in capsule, tablet or powder-form.
Here are the most common strains of probiotics:
- Lactobacillus acidophilus
- Lactobacillus bulgaricus
- Lactobacillus casei
- Lactobacillus gasseri
- Lactobacillus plantarum
- Bifidobacterium bifidum
- Bifidobacterium lactis
- Bifidobacterium longum
- Enterococcus faecium
- Saccharomyces boulardii.
Bifidus regularis, a name created for marketing purposes by Dannon, is also known as Bifidobacterium animalis DN-173 010. This strain of probiotics is used exclusively in Dannon’s popular Activia products, which Dannon claims promote regularity.
Keep in mind that in order for a yogurt to be considered probiotic, it must contain one of the strains listed above. All yogurts are required to be treated with the strains Lactobacillus bulgaricus and Streptococcus thermophilus.
Food marketers have found a new niche with probiotic-containing foods, which include
However, their claims may be based only on preliminary scientific findings.
More research is needed to see whether probiotic bacterias’ beneficial effects are the same when they’re treated or added to food products. Dried probiotics may survive a trip through the intestines if prepared and stored properly. Heat often kills live active cultures.
Although some probiotics have shown promise in research studies, strong scientific evidence to support specific uses of probiotics for most health conditions is still lacking. And the probiotic strains in the supplements may not be specific for the condition you’re looking to treat. The U.S. Food and Drug Administration (FDA) has not approved any probiotics for preventing or treating any health problem. Some experts have cautioned that the rapid growth in marketing and use of probiotics may have outpaced scientific research for many of their proposed uses and benefits. The best we can say right now is taking probiotics as supplement won’t hurt and may help. And remember do not replace scientifically proven treatments with unproven products or practices. For basic information and research news about probiotics you can go to 37).
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|15.||↵||Cochrane Review 31 May 2013. The use of probiotics to prevent C. difficile diarrhea associated with antibiotic use. http://www.cochrane.org/CD006095/IBD_the-use-of-probiotics-to-prevent-c.-difficile-diarrhea-associated-with-antibiotic-use|
|16, 24.||↵||Cochrane Review 20 August 2013. Probiotics for persistent diarrhoea in children. http://www.cochrane.org/CD007401/INFECTN_probiotics-for-persistent-diarrhoea-in-children|
|17.||↵||Cochrane Review 10 April 2014. Probiotics for prevention of necrotizing enterocolitis in preterm infants. http://www.cochrane.org/CD005496/NEONATAL_probiotics-for-prevention-of-necrotizing-enterocolitis-in-preterm-infants|
|18.||↵||The American Journal of Clinical Nutrition August 6, 2014, doi: 10.3945/ajcn.114.089151. The effect of probiotics on functional constipation in adults: a systematic review and meta-analysis of randomized controlled trials. http://ajcn.nutrition.org/content/early/2014/08/06/ajcn.114.089151.abstract|
|19.||↵||The American Journal of Clinical Nutrition August 6, 2014, doi: 10.3945/ajcn.114.089151. The effect of probiotics on functional constipation in adults: a systematic review and meta-analysis of randomized controlled trials. http://ajcn.nutrition.org/content/early/2014/08/06/ajcn.114.089151.abstract|
|20.||↵||Cochrane Review 3 February 2015. Probiotics (live micro-organisms) to prevent upper respiratory tract infections (URTIs) (for example, the common cold). http://www.cochrane.org/CD006895/ARI_probiotics-live-micro-organisms-to-prevent-upper-respiratory-tract-infections-urtis-for-example-the-common-cold|
|21.||↵||American Academy of Dermatology 30 January 2014. Could probiotics be the next big thing in acne and rosacea treatments. https://www.aad.org/media/news-releases/could-probiotics-be-the-next-big-thing-in-acne-and-rosacea-treatments), Dr. Bowe. (a board-certified dermatologist and clinical assistant professor of dermatology at Icahn School of Medicine at Mt. Sinai Medical Center in New York) said, he would recommend that patients with acne or rosacea see their dermatologist to talk about adding foods with live active cultures, such as yogurt, to their diets or taking an oral probiotic supplement daily. Although he doesn’t envision probiotics ever being used as a stand-alone treatment for acne or rosacea, they could be used as an effective combination therapy with prescription medications or over-the-counter topical treatments. Furthermore, he added that more studies are needed to identify the most beneficial aspects of probiotics and determine whether topical or oral probotics yield the best results, and we can expect to see some cutting-edge probiotic products for acne and rosacea in the near future.|
Gestational diabetes mellitus is a condition where the mother has high blood sugar levels during pregnancy. It is associated with a range of adverse pregnancy outcomes for the mother, such as pre-eclampsia (high blood pressure with protein in the urine) and instrumental or operative delivery, as well as for the infants who may be born large-for-gestational age, as a result, be injured at birth, or cause injury to their mothers during birth. Additionally, there can be long-term health problems for women and their babies, including an increased risk of cardiovascular disease or type 2 diabetes. The number of women being diagnosed with GDM is increasing around the world, so finding simple and cost-effective ways to prevent women developing gestational diabetes mellitus is important ((Cochrane Review 3 January 2017. Dietary advice during pregnancy to prevent gestational diabetes. http://www.cochrane.org/CD006674/PREG_dietary-advice-during-pregnancy-prevent-gestational-diabetes
|22, 23.||↵||Cochrane Review 27 February 2014. Probiotics to prevent gestational diabetes mellitus. http://www.cochrane.org/CD009951/PREG_probiotics-to-prevent-gestational-diabetes-mellitus|
|25.||↵||Cochrane Review 7 October 2009. Probiotics for the treatment of bacterial vaginosis. http://www.cochrane.org/CD006289/STI_probiotics-for-the-treatment-of-bacterial-vaginosis|
|26.||↵||Cochrane Review 23 February 2017. Probiotics for people with hepatic encephalopathy. http://www.cochrane.org/CD008716/LIVER_probiotics-people-hepatic-encephalopathy|
|27.||↵||Cochrane Review 17 October 2007. Probiotics in infants for prevention of allergic disease and food hypersensitivity. http://www.cochrane.org/CD006475/NEONATAL_probiotics-in-infants-for-prevention-of-allergic-disease-and-food-hypersensitivity|
|28.||↵||Cochrane Review 7 December 2011. Probiotics for maintenance of remission in ulcerative colitis. http://www.cochrane.org/CD007443/IBD_probiotics-for-maintenance-of-remission-in-ulcerative-colitis|
|29, 30.||↵||Cochrane Review 17 October 2007. Probiotics for the treatment of active ulcerative colitis. http://www.cochrane.org/CD005573/IBD_probiotics-for-the-treatment-of-active-ulcerative-colitis|
|31.||↵||Cochrane Review 16 July 2008. Probiotics for treatment of active Crohn’s disease. http://www.cochrane.org/CD006634/IBD_probiotics-for-treatment-of-active-crohns-disease|
|32.||↵||Cochrane Review 18 October 2006. Probiotics for maintenance of remission in Crohn’s disease. http://www.cochrane.org/CD004826/IBD_probiotics-for-maintenance-of-remission-in-crohns-disease|
|33, 34, 35.||↵||The National Institutes of Health, Medline Plus. What the Science Says About the Safety and Side Effects of Probiotics. https://medlineplus.gov/magazine/issues/winter16/articles/winter16pg23.html|
|36.||↵||Harvard University. Harvard Health Publication. The Benefits of Probiotics Bacteria. http://www.health.harvard.edu/staying-healthy/the-benefits-of-probiotics|