Probiotics

DEFINITION: Helpful, “friendly” bacteria that offer specific health benefits.

PRINCIPAL PROPOSED USES: Various forms of diarrhea, including travelers’ diarrhea, diarrhea caused by antibiotics, and viral diarrhea (in children); gastrointestinal side effects of cancer therapy; irritable bowel syndrome; ulcers (as an adjunct to standard therapy)

OTHER PROPOSED USES: Allergic rhinitis, Behçet’s syndrome, canker sores, colds (prevention), colon cancer prevention, chronic constipation, diverticular disease, dyspepsia, eczema, high cholesterol, immune support, inflammatory bowel disease (ulcerative colitis and Crohn’s disease), insomnia, milk allergies, probiotics, rheumatoid arthritis, ulcers, vaginal infection, yeast hypersensitivity syndrome

Overview

Lactobacillus acidophilus is a friendly strain of bacteria used to make yogurt and cheese. Although humans are born without it, acidophilus soon establishes itself in the intestines and helps prevent intestinal infections. Acidophilus also flourishes in the vagina, where it provides protection from yeast infections.

Acidophilus is one of several microbes known collectively as probiotics (meaning “pro-life”), indicating that they are bacteria and yeasts that help rather than harm. Other helpful microbes include the yeast Saccharomyces boulardii and the bacteria L. bulgaricus, L. reuteri, L. plantarum, L. casei, B. bifidum, Streptococcus salivarius, and S. thermophilus.

The digestive tract contains billions of bacteria and yeasts. Some of these internal inhabitants are more helpful to the body than others. Acidophilus and related probiotics not only help the digestive tract function but also reduce the presence of less healthful organisms by competing with them for the limited space available. For this reason, the use of probiotics can help prevent infectious diarrhea.

Antibiotics can disturb the balance of the digestive tract by killing friendly bacteria. When this happens, harmful bacteria and yeasts can move in and flourish. This can lead to vaginal yeast infections (Candida albicans). Conversely, the regular use of probiotics may help prevent vaginal infections and generally improve the health of the gastrointestinal system. Persons taking antibiotics may also benefit from probiotics during and after antibiotic treatment.

Sources

Although probiotic bacteria are helpful for human health, no daily requirement exists. Probiotics are living creatures, not chemicals, so they can sustain themselves in the body unless something damages them, such as antibiotics.

Cultured dairy products such as yogurt and kefir are good probiotic bacteria, Lactobacillus acidophilus, sources. Other natural sources of probiotics include sauerkraut, kimchi, kombucha, miso, and tempeh. Supplements are widely available in powder, liquid, capsule, or tablet form. Grocery stores and natural food stores sell milk that contains live acidophilus. In addition to probiotics, related substances known as prebiotics may enhance the colonization of healthy bacteria in the intestinal tract. Sources of prebiotics include bananas, asparagus, onion, garlic, dandelions, apples, and chicory.

Therapeutic Dosages

Dosages of acidophilus are expressed not in grams or milligrams (mg) but in billions of organisms. A typical daily dose should supply about three to five billion live organisms. Other probiotic bacteria are used similarly. The typical dose of S. boulardii yeast is 500 mg twice daily (standardized to provide 3 x 10¹⁰ colony-forming units per gram), to be taken while traveling or at the start of using antibiotics and to be continued for a few days after antibiotics are stopped.

Because probiotics are not drugs but rather living organisms that a person is trying to transplant to the digestive tract, it is necessary to take the treatment regularly. Each time this is done, beneficial bacterial colonies in the body are reinforced so that they can gradually push out harmful bacteria and yeasts.

Probiotics, as living organisms, may die on the store shelf. A study reported in 1990 found that most acidophilus capsules on the market contained no living acidophilus. The situation has improved in subsequent evaluations, but some products remain substandard. The container label should guarantee living organisms at the time of purchase, not just at the time of manufacture. Another approach is to eat acidophilus-rich foods such as yogurt, in which the bacteria are most likely still alive.

Finally, in addition to increasing one’s intake of probiotics, taking fructo-oligosaccharide supplements can promote thriving colonies of helpful bacteria in the digestive tract. From the words fructo, which means “fruit,” oligo, which means “few,” and saccharide, which means “sugar,” fructo-oligosaccharides are carbohydrates found in fruit. Taking this supplement fosters a healthy environment for the bacteria. The typical daily dose of fructo-oligosaccharides is between 2 and 10 grams.

Therapeutic Uses

Evidence from many double-blind, placebo-controlled trials suggests that probiotics may be helpful for many types of diarrhea and for irritable bowel syndrome. Additionally, probiotics have shown some promise for preventing or treating eczema.

Probiotics may be helpful for controlling symptoms and maintaining remission in ulcerative colitis. However, probiotics may be less useful for inducing remission. For example, when probiotics were added to standard medications used for induction of remission, no additional benefits were seen in a study of people with mild-to-moderate ulcerative colitis. Some preliminary double-blind trials suggest that probiotics may improve cholesterol profile.

Probiotics might help prevent colds, possibly by improving immunity. On a related note, one small double-blind study found evidence that the use of the probiotic bacterium L. fermentum improved the effectiveness of the influenza vaccine. The probiotic supplement was taken in two doses. One was taken two weeks before the vaccine, and the other was taken two weeks after.

Although probiotics are widely used to prevent or treat vaginal yeast infections, evidence regarding potential benefits remains incomplete and inconsistent. A small trial of fifty-five women with vulvovaginal candidiasis did demonstrate that daily L. rhamnosus and L. reuteri supplementation for four weeks, combined with single-dose fluconazole (an antifungal medication), decreased symptoms compared with fluconazole alone. Another large and well-designed trial, however, failed to find a Lactobacillus preparation helpful for preventing yeast infections caused by antibiotics. One study did find that probiotics might reduce levels of C. albicans in the mouth.

The bacterium Gardnerella vaginalis can cause a different type of vaginal infection. As with vaginal yeast infections, probiotics have shown some promise for this condition, but evidence remains inconclusive. A trial of sixty-four women taking a single dose of tinidazole for bacterial vaginosis suggests that women who also took daily probiotics capsules had better cure rates at four weeks. A larger trial involving 120 women with a history of bacterial vaginosis found that taking one capsule daily of the probiotics L. rhamnosus, acidophilus, and S. thermophilus reduced recurrence.

The bacterium Helicobacter pylori is the main cause of ulcers in the stomach and duodenum. Antibiotics can kill H. pylori, but more than one type of antibiotic must be used at the same time. Even in this case, the bacteria are not necessarily eradicated. Probiotics may be helpful for this. Evidence suggests that various probiotics can inhibit the growth of H. pylori. While this effect does not appear to be strong enough for probiotic treatment to eradicate H. pylori on its own, preliminary evidence, including several small double-blind trials, suggests that various probiotics may help standard antibiotic therapy work better, reducing side effects and possibly increasing the rate of eradication.

Various probiotics might be helpful for allergic rhinitis (hay fever). Research indicates that individuals with allergic rhinitis (hay fever) may experience an increased quality of life and fewer symptoms after incorporating a probiotic into their diet. However, the type of probiotic, the time of day and time of year it is taken, and an individual’s other health conditions impact the effectiveness of probiotics for treating hay fever. While Lactobacillus and Bifidobacterium have shown positive impacts on hay fever symptoms, a standardized guideline for dosing and strain recommendation is lacking in the literature.

Milk fermented by probiotics may slightly improve blood pressure levels. While there is some evidence that probiotics can help reduce symptoms of milk allergies, one study found that adding probiotics to cow’s milk formula for infants was not helpful. One study found that the use of probiotics during pregnancy and breastfeeding may decrease the likelihood that a highly allergic nursing mother will pass her allergic tendencies to her breastfed infant.

One double-blind, placebo-controlled study of seventy people with chronic constipation found some evidence of benefit with L. casei Shirota. Another study found that L. rhamnosus was helpful for chronic constipation in children. A small trial also found benefits in children, this time with a mixture of bifidobacteria and lactobacilli. In another study, a combination of B. lactis and B. longus showed promise for improving bowel regularity in residents of nursing homes. Finally, in a six-week, double-blind, placebo-controlled trial of 274 people with constipation-predominant irritable bowel syndrome, the use of a probiotic formula containing B. animalis significantly improved stool frequency.

A preliminary double-blind, placebo-controlled study found evidence that Lactobacillus GG might potentially be helpful for treating antibiotic-resistant bacteria. This small study followed twenty-three people with severe kidney disease who tested positive for vancomycin-resistant bacteria in the stool. (Vancomycin is one of the main final-option antibiotics for the treatment of resistant bacteria.) The use of a yogurt product containing L. rhamnosus appeared to be more effective at ridding the gastrointestinal tract of these bacteria than the placebo. However, the study had a number of flaws, especially its small size. Note also that participants in this study did not have active infection with antibiotic-resistant bacteria; they were carriers for it. One should not attempt to use probiotics as the sole treatment for active infection with resistant bacteria. The preventive use of probiotics does not appear to help prevent the development of resistant bacterial strains that may arise during antibiotic treatment.

Probiotic treatment has also been proposed as a treatment for canker sores and as a preventive measure against colon cancer, but there is no solid evidence that it is effective. One study found that giving probiotics to certain critically ill people could help prevent multiple organ failure.

Probiotics have shown some promise in preventing cavities by antagonizing cavity-causing bacteria and healing mouth sores caused by Behçet’s syndrome. One small, placebo-controlled study found that the use of L. helveticus might improve sleep quality in older adults. Further research found that L. helveticus also improves sleep quality in all stressed adults by affecting GABAergic or serotonergic neurons. L. helveticus produces bioactive peptides and tripeptides that inhibit angiotensin-I-converting enzymes, which may cause the observed improved sleep quality, but further research is needed.

Probiotics have shown some promise in the treatment of infections with the yeast C. albicans. Probiotics are also proposed for the treatment of a theoretically related, but markedly controversial, condition known as candida hypersensitivity syndrome (also known as chronic candidiasis, chronic candida, systemic candidiasis, yeast hypersensitivity syndrome, and candida). As described by some alternative medicine practitioners, yeast hypersensitivity syndrome is a common problem that consists of a population explosion of the normally benign candida yeast that lives in the vagina and elsewhere in the body, coupled with a type of allergic sensitivity to it. Probiotic supplements are widely recommended for this condition because they establish large, healthy populations of friendly bacteria that compete with the candida. However, there is no evidence that yeast hypersensitivity is a common problem and virtually no evidence that it exists at all.

In one small, twelve-week study, Lactobacillus GG failed to prove more effective than placebo for the treatment of rheumatoid arthritis. Another study failed to find Lactobacillus GG helpful for dyspepsia (generic stomach pain of unknown origin) in children.

A one-year-long open trial of 150 women failed to find Lactobacillus probiotics effective for preventing urinary tract infections, compared with cranberry juice or no treatment. Other studies, however, including a large (453-participant), three-month, double-blind, placebo-controlled study of a special healthful Escherichia coli probiotic did find benefits.

A substantial study failed to find a mixture of L. casei, L. bulgaricus, and S. thermophilus in yogurt and milk helpful for asthma in children. However, another study found that the combination of a probiotic (B. breve) and a prebiotic (galacto- and fructo-oligosaccharide) may help reduce wheezing in infants with eczema.

Scientific Evidence

Travelers’ diarrhea. According to several studies, it appears that the regular use of acidophilus and other probiotics can help prevent travelers’ diarrhea, an illness caused by eating contaminated food, usually in developing countries. One double-blind, placebo-controlled study followed 820 people traveling to southern Turkey and found that the use of Lactobacillus GG significantly protected against intestinal infection.

Other studies using S. boulardii, including a double-blind, placebo-controlled trial enrolling three thousand Austrian travelers, found similar benefits. The greatest benefits were seen in travelers who visited North Africa and Turkey. The researchers noted that the benefit depended on consistent use of the product, and that a dosage of 1,000 mg daily was more effective than 250 mg daily.

Infectious diarrhea. Probiotics may also help prevent or treat acute infectious diarrhea in children and adults. A review of the literature published in 2001 found thirteen double-blind, placebo-controlled trials on the use of probiotics for acute infectious diarrhea in infants and children; ten of these trials involved treatment, and three involved prevention. Overall, the evidence suggests that probiotics can significantly reduce the duration of diarrhea and perhaps help prevent it. The evidence is strongest for the probiotic Lactobacillus GG and for infection with a particular virus, rotavirus, which causes severe diarrhea in children.

One double-blind, placebo-controlled trial of 269 children (aged one month to three years) with acute diarrhea found that those treated with Lactobacillus GG recovered more quickly than those given placebo. The best results were seen among children with rotavirus infection. Similar results with Lactobacillus GG were seen in a double-blind study of seventy-one children. However, 224 young Chinese children with severe, acute diarrhea found no benefit from lactose-free formula supplemented with bifidobacteria and S. thermophilus, suggesting that probiotics may not be as useful for cases of severe, dehydrating diarrhea. Also, L. rhamnosus GG is not always associated with improvement. When given for ten days to 229 infants from rural India who were hospitalized with acute diarrhea, the probiotic did not reduce the severity of the diarrhea during that time period.

In addition, a double-blind study evaluated the possible benefits of the probiotic L. reuteri in sixty-six children with rotavirus diarrhea. The study found that treatment shortened the duration of symptoms and that the higher the dose, the better the effect. Similar benefits were seen in a placebo-controlled trial of 151 infants and children given the probiotic E. coli Nissle 1917 (a safe strain of E. coli) for twenty-one days for nonspecific (presumably viral) cases of mild to moderate diarrhea.

A double-blind, placebo-controlled study of eighty-one hospitalized children found that treatment with Lactobacillus GG reduced the risk of developing diarrhea, particularly rotavirus infection. A double-blind, placebo-controlled study found that Lactobacillus GG helped prevent diarrhea in 204 undernourished children.

Other studies generally (though not consistently) indicate that the probiotics B. bifidum, S. thermophilus, L. casei, Lactobacillus LB, and S. boulardii (individually and combined with L. reuteri and L. rhamnosus) may also help prevent or treat diarrhea in infants and children. One study found that bacteria in the B. bifidum family can kill numerous bacteria that cause diarrhea.

A randomized study published in 2012 found evidence that adding Lactobacillus fermentum and other probiotics to infant formula given to healthy infants helped reduce the incidence of gastrointestinal infections and upper respiratory infections compared to infants who were given formula with probiotics but without L. fermentum. A systematic literature review published in 2012 examined twenty randomized trials with more than 3,400 patients (including three trials with 605 children) and found that prophylactic use of probiotics was effective at preventing Clostridium difficile-induced diarrhea, and that the most effective probiotics for such use were S. boulardii and L. acidophilus combined with L. casei.

A large (211-participant), double-blind, placebo-controlled study found that adults with diarrhea also can benefit from probiotic treatment. Another study found that the regular use of probiotics could help prevent gastrointestinal infections in adults.

Antibiotic-related diarrhea. The results of many double-blind and open trials suggest that probiotics, especially S. boulardii and Lactobacillus GG, may help prevent or treat antibiotic-related diarrhea. For example, one study evaluated 180 people, who received either placebo or 1,000 mg of Saccharomyces daily with their antibiotic treatment, and found that the treated group developed diarrhea significantly less often. A similar study of 193 people also found benefit. Three more studies involving adults found that various species of Lactobacillus, taken either alone or in combination, were beneficial, even in cases of C. difficile infection, the most serious type of antibiotic-induced diarrhea. Systematic literature reviews published in 2011 and 2012 further added to this evidence.

However, a study of 302 people found no benefit with Lactobacillus GG. A review of four probiotic studies found insufficient evidence for their effectiveness in the treatment of C. difficile. According to a 2013 study, prophylactic use of Lactobacillus acidophilus LA-5 plus Bifidobacterium BB-12 (in combination with antibiotic treatment) was not associated with reduced incidence of diarrhea when compared to placebo. However, the probiotic reduced the duration of diarrhea. Finally, although taking probiotic organisms in the proper concentration may be beneficial for antibiotic-induced diarrhea, one study found that consuming fresh yogurt during antibiotic treatments had no significant effect on the incidence of diarrhea.

Other forms of diarrhea. Two double-blind, placebo-controlled studies enrolling almost seven hundred people undergoing radiation therapy for cancer found that the use of probiotics significantly improved radiation-induced diarrhea. Similar evidence supports the use of L. rhamnosus and a special, nonpathogenic form of E. coli. However, of eighty-five women receiving pelvic radiation for cervical or uterine cancer, those who consumed a liquid yogurt preparation enriched with L. casei had no less diarrhea than those who took a placebo drink. Small double-blind studies suggest that S. boulardii might be helpful for treating chronic diarrhea in people with human immunodeficiency virus infection, in persons hospitalized and being fed through a tube, and in people with Crohn’s disease.

Premature infants weighing less than 2,500 grams (5.5 pounds) are at risk for a life-threatening intestinal condition called necrotizing enterocolitis (NEC). In a study that pooled the results of nine randomized, placebo-controlled trials involving 1,425 infants, probiotic supplementation significantly reduced the occurrence of NEC and death associated with it. A subsequent study found similar benefits in very low-birth-weight infants weighing less than 1,500 grams (3.3 pounds). For one probiotic strain, L. reuteri, there may be additional benefits. In another study (published 2011) involving 249 premature infants, those treated with L. reuteri experienced fewer gastrointestinal symptoms, received fewer antibiotics, and were hospitalized less frequently than those treated with L. rhamnosus or no probiotic. Three further reviews of randomized trials, published in 2014, supported these findings.

Inflammatory bowel disease. The conditions Crohn’s disease and ulcerative colitis are in the family of conditions known as inflammatory bowel disease. Chronic diarrhea is a common feature of these conditions.

A double-blind trial of 116 people with ulcerative colitis compared probiotic treatment with a relatively low dose of the standard drug mesalazine. The results suggest that probiotic treatment might be just as effective as low-dose mesalazine for controlling symptoms and maintaining remission. Evidence of benefit was also seen in other trials.

One preliminary study found S. boulardii helpful for mild diarrhea in stable Crohn’s disease. However, two studies failed to find benefit with Lactobacillus probiotics, and in an analysis of eight randomized, placebo-controlled studies, probiotics were ineffective at maintaining remission in persons with Crohn’s disease.

Probiotics might be useful for people with ulcerative colitis who have had part or all of their colon removed. Such people frequently develop a complication called pouchitis—the inflammation of part of the remaining intestine. A nine-month, double-blind trial of forty people found that a combination of three probiotic bacteria could significantly reduce the risk of a pouchitis flare-up in people with chronic pouchitis. Participants were given either placebo or a mixture of probiotics, including four strains of lactobacilli, three strains of bifidobacteria, and one strain of S. salivarius. The results showed that treated people were far less likely to have relapses of pouchitis.

Another study found that probiotics used right after surgery can help prevent pouchitis from developing. One study, however, failed to find benefit with L. johnsonii in people with Crohn’s disease who had undergone a similar operation. Finally, some evidence hints that probiotics might reduce the joint pain that commonly occurs in people with either kind of inflammatory bowel disease.

Irritable bowel syndrome. People with irritable bowel syndrome (IBS) experience crampy digestive pain and alternating diarrhea and constipation and other symptoms. Although the cause of IBS is not known, one possibility is a disturbance in healthy intestinal bacteria. Based on this theory, probiotics have been tried as a treatment for IBS, with some success.

In a six-week, double-blind, placebo-controlled trial of 274 people with constipation-predominant IBS, the use of a probiotic formula containing B. animalis significantly reduced discomfort and increased stool frequency. Also, 266 women with constipation who consumed yogurt containing B. animalis and the prebiotic fructo-oligosaccharides twice daily for two weeks experienced significant improvement compared with women consuming regular yogurt as a placebo. Finally, in another trial of 298 persons with IBS, eight weeks of treatment with beneficial E. coli reduced typical symptoms compared with placebo.

Benefits were seen in eight other small, double-blind trials too, using L. plantarum, L. acidophilus, L. rhamnosus, L. salivarius, and Bifidobacterium, and using proprietary probiotic combinations of various strains. Benefits have also been seen with combination prebiotic and probiotic formulas and prebiotics alone. Other studies have failed to find probiotics more effective than placebo.

Two studies that pooled previous randomized trials on the use of probiotics for IBS came to similar conclusions: Probiotics appear to offer some benefit, most notably for global symptoms and abdominal discomfort. However, these two studies were unable to determine what probiotic species were most effective.

Eczema. The use of probiotics during pregnancy and after childbirth may reduce the risk of childhood eczema. In a large, long-term, double-blind study, 1,223 pregnant women were given either placebo or a probiotic mixture (containing lactobacilli and bifidobacteria) beginning two to four weeks before delivery. Their newborn children then received either probiotics or placebo for six months. The results showed that the probiotics mixture markedly reduced the incidence of eczema (though not of other allergic diseases). However, in a follow-up to this study, researchers found that the probiotic supplementation was not associated with reduced eczema in children followed through the age of five years. The probiotics also had no effect on allergic rhinitis or asthma.

Another study also yielded marginal results, and a third study involving only Lactobacillus found no benefit for the prevention of eczema. This latter study actually demonstrated a modestly increased risk of wheezing bronchitis in infants who took the probiotic. However, some probiotics combined with prebiotics may help to reduce wheezing in infants with eczema. For example, B. breve and a galacto- and fructo-oligosaccharide mixture showed benefit in one randomized study involving ninety infants.

B. longum and L. rhamnosus supplementation did not reduce the incidence of eczema atopic dermatitis or allergic sensitization at twelve months among Asian infants at risk of allergic diseases. Researchers in another study concluded that not all probiotics are created equal. In this placebo-controlled study, L. rhamnosus reduced the incidence of eczema in the children, but a strain of B. animalis did not. A randomized trial (published 2012) of 118 children found that L. plantarum was effective in reducing the severity of eczema symptoms.

According to some studies, infants who already have eczema may benefit from probiotics. However, a careful review of twelve studies involving 781 children found no convincing evidence that probiotics can effectively treat eczema in this age group.

If probiotics are beneficial for childhood eczema, they are likely more effective at preventing the condition than treating it. A carefully conducted review of numerous studies cautiously concluded that probiotics may help reduce the risk of eczema in infants and children, particularly those at high risk. Also, two subsequent reviews found that probiotics were more effective at preventing childhood eczema, particularly when given before birth to the pregnant woman and the fetus.

Immunity. A number of studies suggest that various probiotics can enhance immune function. One twelve-week, double-blind, placebo-controlled trial evaluated twenty-five healthy older adults, half given milk containing a particular strain of B. lactis and the other half given milk alone. The results showed various changes in immune parameters, which the researchers took as possibly indicating improved immune function. Another double-blind, placebo-controlled study of fifty people using B. lactis found similar results.

A seven-month, double-blind, placebo-controlled study of 571 children in daycare centers in Finland found that milk fortified with Lactobacillus GG reduced the number and severity of respiratory infections. In another controlled trial, probiotics (L. rhamnosus GG and B. lactis Bb-12) given daily to infants in their formula significantly reduced the risk of acute otitis media and of recurrent respiratory infections during the first year of life, compared with placebo.

Benefits were seen in three other large studies, in which probiotics combined with multivitamins and multiminerals helped prevent colds (or helped reduce their duration and severity) in adults. However, a smaller and shorter study failed to find any effect on respiratory infections. Similarly, L. fermentum given to twenty healthy, elite distance runners for four months during winter training was significantly more effective at reducing the number and severity of respiratory symptoms compared with placebo. One study found that Lactobacillus GG or L. acidophilus may improve the immune response to vaccinations.

A 2015 review of thirteen randomized trials with 3,780 children, adults, and older adults found that probiotic use was associated with reducing the risk and length of colds. The trials studied several probiotics, including Actimel with L. paracasei (L. casei), Streptococcus thermophilus, and Lactobacillus bulgaricus; L. plantarum HEAL 9 plus L. paracasei 8700:2; Lactobacillus rahamnosus strain GG; L. rhamnosus plus Bifidobacterium lactis Bb-12; Lactobacillus acidophilus plus Bifidobacterium bifidum; and L. acidophilus plus L. casei.

Cholesterol. An eight-week, double-blind, placebo-controlled trial of seventy overweight people found that a probiotic treatment containing S. thermophilus and Enterococcus faecium could reduce LDL (bad) cholesterol by about 8 percent. Similarly positive results were seen in other short-term trials of various probiotics. However, a six-month, double-blind, placebo-controlled trial found no long-term benefit. Researchers speculate that participants stopped using the product regularly in the later parts of the study.

Safety Issues

Probiotics may cause a temporary increase in digestive gas, but they do not present any known significant risks for most people. In one trial of 140 healthy infants, formula supplemented with long-chain polyunsaturated fatty acids and probiotics appeared as safe as standard formula and did not affect infant growth by the end of the seven-month trial. However, immunosuppressed persons could be at risk for developing a dangerous infection with the probiotic organism itself; at least one person taking immunosuppressive medications has died in this manner.

In a detailed review of four studies, researchers concluded that probiotics did not benefit persons with severe acute pancreatitis. According to another study, using probiotics led to an increased risk of mortality in persons with severe acute pancreatitis and should, therefore, be avoided under these circumstances. It may be beneficial for persons taking antibiotics to take probiotic supplements simultaneously and to continue the probiotics for a couple of weeks after finishing the drug treatment. Doing so will help restore the balance of natural bacteria in the digestive tract.

Beginning in the early 2020s, researchers noted that studies touting the benefits of probiotics were common, but possible negative effects remained underreported. The International Scientific Association for Probiotics and Prebiotics recognized the research gap in probiotic efficacy and adverse reaction reporting. Particularly, experts highlighted the need to create evidence-based recommendations for physicians and the public regarding product quality, guidelines for selecting the correct probiotic strain and species option based on individual needs, and identifying risks for vulnerable populations. These considerations were vital in light of the rise in antibiotic resistance.

Bibliography

Do, V. T., B. G. Baird, and D. R. Kockler. “Probiotics for Maintaining Remission of Ulcerative Colitis in Adults.” Annals of Pharmacotherapy 44 (2010): 565–71.

Gao, X. W., et al. “Dose-Response Efficacy of a Proprietary Probiotic Formula of Lactobacillus acidophilus CL1285 and Lactobacillus casei LBC80R for Antibiotic-Associated Diarrhea and Clostridium difficile-Associated Diarrhea Prophylaxis in Adult Patients.” American Journal of Gastroenterology 105 (2010): 1636–41.

Gibson, R. A., et al. “Safety of Supplementing Infant Formula with Long-Chain Polyunsaturated Fatty Acids and Bifidobacterium lactis in Term Infants.” British Journal of Nutrition 101 (2009): 1706–13.

Liu, P., et al. “Research Advances in the Treatment of Allergic Rhinitis by Probiotics.” Journal of Asthma and Allergy, vol. 15, 2022, pp. 1413–28. doi.org/10.2147/JAA.S382978.

McFarland, L. V., and S. Dublin. “Meta-analysis of Probiotics for the Treatment of Irritable Bowel Syndrome.” World Journal of Gastroenterology 14 (2008): 2650–61.

Merenstein, Daniel, et al. “Emerging Issues in Probiotic Safety: 2023 Perspectives.” Gut Microbes, vol. 15, no. 1, 2023, doi:10.1080/19490976.2023.2185034.

Misra, S., T. K. Sabui, and N. K. Pal. “A Randomized Controlled Trial to Evaluate the Efficacy of Lactobacillus GG in Infantile Diarrhea.” Journal of Pediatrics 155 (2009): 129–32.

Park, S. K., et al. “The Effect of Probiotics on Helicobacter pylori Eradication.” Hepatogastroenterology 54 (2007): 2032–36.

Pillai, A., et al. “Probiotics for Treatment of Clostridium difficile-Associated Colitis in Adults.” Cochrane Database of Systematic Reviews (2008): CD004611. EBSCO DynaMed Systematic Literature Surveillance.

Rautava, S., S. Salminen, and E. Isolauri. “Specific Probiotics in Reducing the Risk of Acute Infections in Infancy.” British Journal of Nutrition 101 (2009): 1722–26.

Reid, Gregor, et al. “Probiotics: Reiterating What They Are and What They Are Not.” Frontiers in Microbiology, 12 Mar. 2019, p. 424, doi:10.3389/fmicb.2019.00424.

Sanders, Mary Ellen. “Beyond Rx: OTC Corner. Probiotics In Clinical Practice.” Clinical Advisor, 2015, www.clinicaladvisor.com/features/probiotics-in-clinical-practice. Accessed 20 Sept. 2024.

Sulaimany, S., K. Farahmandi, and A. Mafakheri. "Computational Prediction of New Therapeutic Effects of Probiotics." Scientific Reports, vol. 14, no. 11932, 2024, doi.org/10.1038/s41598-024-62796-4.

Sun, Minghui, et al. “Can Mixed Strains of Lactobacillus and Bifidobacterium Reduce Eczema in Infants under Three Years of Age? A Meta-Analysis.” Nutrients, vol. 13, no. 5, Apr. 2021, p. 1461. doi:10.3390/nu13051461.

Underwood, M. A., et al. “A Randomized Placebo-Controlled Comparison of Two Prebiotic/Probiotic Combinations in Preterm Infants: Impact on Weight Gain, Intestinal Microbiota, and Fecal Short-Chain Fatty Acids.” Journal of Pediatric Gastroenterology and Nutrition 48 (2009): 216–25.

Wang, Yuxuan, et al. “Probiotic Supplements: Hope or Hype?” Frontiers in Microbiology, 28 Feb. 2020, doi.org/10.3389/fmicb.2020.00160.

Woo, S. I., et al. “Effect of Lactobacillus sakei Supplementation in Children with Atopic Eczema-Dermatitis Syndrome.” Annals of Allergy, Asthma, and Immunology 104 (2010): 343–48.

Ya, W., C. Reifer, and L. E. Miller. “Efficacy of Vaginal Probiotic Capsules for Recurrent Bacterial Vaginosis.” American Journal of Obstetrics and Gynecology 203 (2010): 120.