Digestive Health Stomach Flu Health Benefits of Probiotics Can a daily supplement treat IBS, diarrhea, and yeast infections? By Kristina Duda, RN facebook twitter linkedin Kristina Duda, BSN, RN, CPN, has been working in healthcare since 2002. She specializes in pediatrics and disease and infection prevention. Learn about our editorial process Kristina Duda, RN Medically reviewed by Medically reviewed by Robert Burakoff, MD, MPH on September 17, 2020 linkedin Robert Burakoff, MD, MPH, is board-certified in gastroentrology. He is the vice chair for ambulatory services for the department of medicine at Weill Cornell Medical College in New York, where he is also a professor. He was the founding editor and co-editor in chief of Inflammatory Bowel Diseases. Learn about our Medical Review Board Robert Burakoff, MD, MPH Updated on October 15, 2020 Print Table of Contents View All Health Benefits Possible Side Effects Dosage and Preparation What to Look For Other Questions Probiotics are live bacteria and yeast that are good for you, especially your digestive tract. These naturally occurring microorganisms are considered "good" in that they keep "bad" bacteria and fungus in check. They can even promote vaginal health by preventing the overgrowth of microbes that cause yeast infections and bacterial vaginosis. Probiotics are found in yogurt and fermented foods but can also be purchased as dietary supplements, skin care products, and vaginal suppositories. The most common types of probiotics sold in the United States are Lactobacillus and Bifidobacterium. The increasing popularity of these products has led to misconceptions about what they can and cannot do and whether they can deliver the promised results. Verywell / Alexandra Gordon Health Benefits A lot of research has been devoted to evaluating the benefits of probiotics, most especially in the area of digestive health. While some of the results have been positive, other long-held health claims have been unsupported by research. The American Gastroenterology Association (AGA) released clinical practice guidelines specifically addressing the use of probiotics in managing digestive health disorders. The guidelines were developed based on a review of available research and are intended to provide doctors with guidance about the appropriate use of specific probiotics across different patients in the context of specific gastrointestinal diseases. Here are some of the key findings from recent research: Irritable Bowel Syndrome The role of gut microflora in the development of irritable bowel syndrome (IBS) is well established. As such, the body of research into the potential for probiotics in helping alleviate symptoms of IBS continues to grow. Several studies have found that probiotics can have a positive effect on the severity of common IBS symptoms - including abdominal pain and diarrhea. Although clinical research has been encouraging, it hasn't been enough to garner an official endorsement from most gastroenterologists. The AGA guidelines do not recommend the use of probiotics in children and adults with IBS except in the context of a clinical trial. Antibiotic-Associated Diarrhea Other studies have focused on whether probiotics can play a role in preventing diarrhea caused by antibiotic use. Since antibiotics can kill both "good" and "bad" bacteria, the hope has been that probiotic supplements could help restore the digestive flora back to its normal state. A 2018 review of studies from China concluded that probiotics can reduce the risk of diarrhea by 50 to 60 percent if taken with antibiotics, particularly the probiotics Saccharomyces boulardii and Lactobacillus rhamnosus GG. The AGA guidelines recommend certain probiotic strains for adults and children on antibiotic treatment or other probiotics for prevention of C difficile infection. Of note, the AGA tempers this recommendation by saying patients with severe illnesses, an aversion to the cost or a low concern for C difficile development can reasonably choose to not take antibiotics at all. The specific strains the AGA recommends for adults and children taking antibiotics include S boulardii; or the 2-strain combination of L acidophilus CL1285 and L casei LBC80R; or the 3-strain combination of L acidophilus, L delbrueckii subsp bulgaricus, and B bifidum; or the 4-strain combination of L acidophilus, L delbrueckii subsp bulgaricus, B bifidum, and S salivarius subsp thermophilus. Vaginal Infections The use of probiotics in treating common vaginal infections, like bacterial vaginosis and vaginal candidiasis (yeast infection), remains controversial with some studies showing benefits and others not. A 2014 review in the Journal of Lower Genitourinary Tract Disease would only go so far as to say that oral probiotics taken daily may prevent the recurrence of bacterial vaginosis but would unlikely offer much in the way of treatment. Of the oral supplements reviewed, Lactobacillus acidophilus, Lactobacillus rhamnosus GR-1, and Lactobacillus fermentum RC-14 were considered the most beneficial. By contrast, the oral or vaginal use of probiotics has not yielded positive results in treating yeast infections, according to a 2006 review in the Journal of Antimicrobial Chemotherapy. Inflammatory Bowel Disease Inflammatory bowel disease (IBD), which consists of ulcerative colitis and Crohn's disease, is characterized by persistent gastrointestinal symptoms, including abdominal pain, bloating, blood in stool, flatulence, diarrhea, nausea, and vomiting. Interestingly, while much of the current evidence suggests that probiotics that may prevent recurrence of ulcerative colitis, the same was not seen with Crohn's disease. Moreover, the benefits were attributed to specific probiotic strains or combinations of strains. In 2011, VSL#3 (a high-potency combination probiotic) and the probiotic Escherichia coli Nissle 1017 were both given an A rating at the 3rd Yale Workshop on Probiotics based on strong evidence that they sustained remission of ulcerative colitis. By contrast, a 2009 Cochrane review, which evaluated 23 different randomized controlled studies, found that probiotics were no more effective in preventing or treating Crohn's disease than a placebo. Possible Side Effects Probiotic supplements are considered safe and well-tolerated if taken as directed. Side effects may include bloating and gas. Taking a yeast-based probiotic can sometimes cause constipation or increased thirst. Most of these side effects are mild and tend to improve once your body adapts to treatment. Probiotics may contain allergens that can affect people with an egg or soy allergy. People with a yeast allergy would need to avoid yeast-based probiotics. There are no documented drug interactions associated with probiotic supplements. With that said, speak with your doctor before taking a probiotic if you are on antibiotics or antifungal medications. Taking these together can negatively alter your digestive or vaginal flora. Dosage and Preparation Because there are many different probiotic strains and formulations, there is no set dosage. Factors like age, weight, and general health may influence how much or little you need. As a general rule, a probiotic should provide at least 1 billion colony forming units (CFU) per day, with dosages ranging from 1 billion to 10 billion for adults. If used in children, less than 1 billion CFU would be prescribed. Probiotic supplements are generally taken on a daily basis, ideally before a meal. Probiotic suppositories tend to have higher CFUs as they are meant for short-term use only. Generally speaking, suppositories should be used for no more than seven consecutive days. 7 Best Probiotics Reviewed What to Look For In the United States, probiotics are classified as dietary supplements. Under this classification, the products are not strictly regulated and are allowed to be sold without the burden of clinical research. With that being said, the U.S. Food and Drug Administration (FDA) forbids manufacturers making any claims that the products can cure, treat, or prevent any disease or health condition. To ensure quality and safety, only buy supplements that have tested and certified by an independent certifying body like the U.S. Pharmacopeia, ConsumerLab, or NSF International. When used as a food ingredient, probiotics fall under the FDA umbrella category "GRAS," meaning they are "generally regarded as safe." Other Questions Which foods are highest in probiotics? Generally speaking, it is always best to get your daily nutrients for food. Even though probiotic supplements are unlikely to cause you any harm, you should consider trying the following if you've been advised to increase your probiotic intake: Kefir: 27.7 billion CFU per 1-cup servingKimchi: 2.6 billion CFU per 1/2-cup servingYogurt: 3.6 billion CFU per 1-cup servingMiso: 54.1 thousand CFU per tablespoonSauerkraut: 195.2 million CFU per 1/2-cup servingKombucha: 23.1 million CFU per 1-cup serving How to Choose the Right Probiotic Was this page helpful? Thanks for your feedback! Gas pain? Stool issues? Sign up for the best tips to take care of your stomach. Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit Article Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. National Center for Complementary and Integrative Health. Probiotics: What you need to know. Updated August 2019. Su G, Ko C, Bercik, P, ET al. AGA clinical practice guidelines on the role of probiotics in the management of gastrointestinal disorders. Gastroenterology. June 9 2020. doi:10.1053/j.gastro.2020.05.059 Didari T, Mozaffari S, Nikfar S, Abdollahi M. Effectiveness of probiotics in irritable bowel syndrome: Updated systematic review with meta-analysis. World J Gastroenterol. 2015;21(10):3072-3084. doi:10.3748/wjg.v21.i10.3072 Homayouni A, Bastani P, Somayeh Z, et al. Effects of probiotics on the recurrence of bacterial vaginosis: A review. Low Genit Tract Dis. 2014 Jan;18(1):79-86. doi:10.1097/LGT.0b013e31829156ec Falagas ME, Betsi GI, Athanasiou S. Probiotics for prevention of recurrent vulvovaginal candidiasis: a review. J Antimicrob Chemother. 2006;58(2):266-72. doi:10.1093/jac/dkl246 Floch MH, Walker WA, Madsen K, et al. Recommendations for probiotic use-2011 update. J Clin Gastroenterol. 2011;45 Suppl:S168-71. doi:10.1097/MCG.0b013e318230928b Doherty G, Bennett G, Patil S, Cheifetz A, Moss AC. Interventions for prevention of post-operative recurrence of Crohn's disease. Cochrane Database Syst Rev. 2009;(4):CD006873.doi:10.1002/14651858.CD006873.pub2 National Institutes of Health Office of Dietary Supplements. Probiotics. Updated une 26, 2019. Additional Reading Cai, J.; Zhao, C.; Du, Y. et al. Comparative efficacy and tolerability of probiotics for antibiotic-associated diarrhea: Systematic review with network meta-analysis. United European Gastroenterol J. 2018 Mar; 6(2): 169-80. DOI: 10.1177/2050640617736987.