Can Probiotics Cause Diarrhea? – Introduction
Probiotics are generally thought to be safe, and they can help prevent diarrhea. However, in extremely rare cases, probiotics may trigger diarrhea, especially in people with weak immune systems or other health problems.
It’s important to remember that the type of supplement and dose can also affect how they influence the digestive system. In this article, we will explore whether or not probiotics cause diarrhea. We’ll also look at how probiotics can help with diarrhea and the particular probiotic strains that are beneficial in dealing with this frequent digestive problem.
What are Probiotics?
Probiotics are microorganisms that are good for the human body, particularly the gut. These organisms include yeast and bacteria. These organisms play a vital role in maintaining a healthy microbiome – the community of microorganisms that reside within our bodies.
It is estimated that humans naturally contain about 500 to 1,000 distinct bacterial strains within their bodies. These microbes support a strong immune system and improve the body’s digestive system. Yogurt, kimchi, and sauerkraut are examples of naturally fermented foods that contain probiotics. Supplements also contain them.
Although there are many different types of bacteria that can be categorized as probiotics, there are two particular bacteria types that are widely used as probiotics. These comprise:
Probiotics can also include beneficial yeasts, such as Saccharomyces boulardii.
Probiotics Cause Diarrhea? Myth or Fact?
The answer to this is simply “No.” It is generally accepted that probiotics do not trigger diarrhea in healthy people.
Probiotics have been shown to be safe and have no noticeable negative effects on digestive health in a significant number of studies and clinical trials. In fact, probiotics are commonly used to treat diarrhea because they restore the gut’s natural balance of good bacteria.1
However, in extremely unusual circumstances, certain people might experience short-term gastrointestinal symptoms, such as diarrhea, because of a number of different reasons.
Also, the most common side effect of bacteria-based probiotic supplements is temporary gas and bloating. 2 In most cases, these symptoms are relatively mild and short-lived. Following are the rare conditions when probiotics can potentially cause diarrhea;
If a person consumes an excessive number of probiotics, their digestive system may get overloaded and cause diarrhea. To obtain the ideal level of balance, it is crucial to follow the recommended dosage requirements and talk to certified medical specialists about your probiotic intake.3
Weakened Immune System:
Diarrhea is a possible side effect of probiotic use, especially in people with weakened immune systems due to immunosuppressive therapy or other health conditions.
The immune system’s inability to regulate the effects of probiotics on the intestines could result in loose stools. Therefore, those with compromised immune systems should seek medical advice prior to taking probiotic supplements to ensure safe and effective use. 4
However, a 2017 meta-analysis cautioned against the use of probiotics in people with serious illnesses or compromised immune systems due to a possible increased risk of infection, even though their use poses no significant risk to healthy individuals.5
In another example of how probiotics may pose risks in certain populations, strains of Lactobacillus have also been reported to cause bacteremia in patients with short-bowel syndrome, possibly due to altered gut integrity. 2
Entry of New Strain to a Body:
It may take some time for the digestive system to adjust when beginning treatment with probiotics or when making significant dietary changes. During this period of adjustment, it is possible that the body will experience temporary digestive disturbances, such as diarrhea. This will continue until the body has adapted to the new bacteria or the dietary changes.
It is unclear why some people experience these negative effects, but research has shown that they typically fade away after a few weeks of treatment.2
Allergy or Hypersensitivity:
As is the case with allergic substances, certain probiotic strains may cause sensitivities or allergies in some people. When an individual is exposed to those specific strains, they may experience hypersensitivity reactions that manifest as gastrointestinal symptoms, including diarrhea. For instance, 2
- Avoid Lactobacillus supplements if you are allergic to milk or lactose.
- Avoid S. boulardii if you are allergic to yeast.
- Bifidobacteria have no known side effects
Poor Quality Probiotics:
Probiotic products have the potential to cause digestive problems, including diarrhea if they are accidentally contaminated with harmful bacteria or other pathogens, which happens very infrequently.
Even though such cases aren’t well-documented and there isn’t much evidence to support them, it is best to choose probiotic brands with a good reputation and strict quality control measures to reduce the risk of contamination.
Overall, probiotics are considered safe, well-tolerated, and good for gut health, but reactions can differ from person to person. Probiotics are actually frequently used therapeutically to treat diarrhea and support a healthy gut. However, it is advised to stop using probiotics and seek medical advice if you begin to experience chronic or severe diarrhea or any other unfavorable gastrointestinal symptoms.
Role of Probiotics in Treating Diarrhea
Probiotics have the potential to treat a variety of diarrheal conditions. According to the World Health Organization (WHO) diarrhea is defined as three or more stools that are loose or watery within a 24-hour period. Diarrhea is considered acute if it has lasted less than 14 days and persistent if it has lasted 14 days or more. Some kinds of diarrhea that probiotics may be able to help treat are: 6
Antibiotic-Associated Diarrhea (AAD):
Any diarrhea that occurs after taking an antibiotic is known as Antibiotic-Associated Diarrhea (AAD). Antibiotics are drugs used to treat a wide variety of bacterial infections. Antibiotics disrupt gut microbiota, which can lead to diarrhea.
Antibiotic-associated diarrhea can be prevented or reduced with the use of probiotics. They aid in restoring a healthy bacterial balance in the gut, disrupted due to antibiotic use. The antibiotics which can induce diarrhea are: 7
- Penicillin and penicillin derivatives
A meta-analysis of 42 studies involving 11,305 participants discovered that taking probiotics with antibiotics reduces the risk of antibiotic-associated diarrhea (AAD) in adults by 37%. The study found that high doses of probiotics were more protective than low doses, specifically with certain species, primarily from the lactobacillus and bifidobacteria genera.
These results show that probiotics can help prevent AAD and suggest that higher doses and certain types of probiotics are more effective at lowering the risk. 8
According to the findings of one study, taking a probiotic supplement containing strains of L. acidophilus (LA-5) and B. bacteria (BB-12) can assist in the management Antibiotic-Associated Diarrhea. 9 According to the findings of another study, fermented milk products that contain lactobacilli and bifidobacteria can also help treat diarrhea that is associated by antibiotic use.10
Diarrhea that is caused by an infectious agent, such as bacteria or parasites, is referred to as infectious diarrhea. There are over twenty known types of bacteria, viruses, and parasites that can cause infectious diarrhea, including.
- Viral Species, including rotavirus, astrovirus, and human caliciviruses
- Enteric adenoviruses.
- Escherichia coli.
- Vibrio cholerae.
Another important factor affecting the incidence of infectious diarrhea is the availability of clean water and sanitary facilities locally.
It is believed that contaminated food is the primary cause of the disease’s spread in developed nations, where it affects approximately thirty percent of the population each year. It has the potential to be deadly if it is not properly treated. Probiotics can help reduce infectious diarrhea by avoiding dehydration and reducing the length of time they have diarrhea.11,12
For instance, a review of 63 randomized controlled trials with a total of 8,014 participants (mostly infants and children) discovered that single- and multi-strain probiotics significantly reduced the duration of acute infectious diarrhea by about 25 hours. These supplements also reduced the risk of diarrhea lasting 4 or more days by 59% and resulted in approximately one fewer bowel movement on the second day in patients who received probiotics versus patients who did not.12
Similarly, Lactobacillus rhamnosus GG was found to be most successful in treating infectious diarrhea when administered at a daily dose of at least 1010 CFU, according to an analysis of the results of 11 randomized clinical studies with a total of 2,444 individuals.13, 14 In another study, it was found that Saccharomyces boulardii (most typically 109 to 1010 CFU/day for 5–10 days) reduced both the amount of time spent having diarrhea and the number of times it occurred as a result of 22 randomized clinical trials. 15 Both Lactobacillus rhamnosus GG and Saccharomyces boulardii reduced acute infectious diarrhea by one day.
Traveler’s diarrhea is when a person has three or more loose stools per day and at least one other symptom, such as cramps or abdominal pain, after arriving at their destination. According to estimates, it affects between 40% and 60% of travelers, depending on where they go, and it is the most prevalent condition associated with travel. It is caused by drinking contaminated water or eating foods contaminated with bacteria, viruses, or parasites. Usually, within a few days, it goes away on its own. It is usually caused by the presence of the following viral, fungal, and bacterial strains: 16,17
- Enterotoxigenic Escherichia coli (Represents almost 30% of cases)
- Campylobacter jejuni
- Shigella species
- Salmonella species
- Cryptosporidium and Entamoeba histolytica
- Giardia intestinalis
Based on their meta-analysis of 11 studies, the researchers discovered that probiotics were significantly effective in preventing TD. Probiotic supplementation was associated with a 15% lower risk of TD than no supplementation at all. 17
A further meta-analysis of 12 studies published in 2019 found that only treating with the probiotic Saccharomyces boulardii significantly reduced cases of traveler’s diarrhea by up to 21%.18
A meta-analysis of 34 studies found that taking a median dose of just 6.0 billion CFUs/day of probiotics was able to reduce antibiotic-associated diarrhea by 52%, traveler’s diarrhea by 8%, and acute diarrhea due to diverse causes by 34%. These results were found in a recent publication.19
Inflammatory Bowel Diseases (IBD):
Inflammatory bowel disease (IBD) is characterized by recurring episodes of gastrointestinal inflammation caused by an abnormal immune response to gut microflora. Inflammatory bowel disease (IBD) refers to two conditions: ulcerative colitis and Crohn’s disease. Ulcerative colitis is a disease that specifically attacks the colon. Crohn’s disease is a digestive disorder that may appear anywhere from the mouth to the bottom (anus). Diarrhea is the most common symptom of IBD, appearing in nearly 80% of cases. 20
Lactobacilli, bifidobacteria, or Lactococcus lactis may be useful in the treatment or prevention of colitis, according to the findings of some research conducted on experimental animals.12
The impact of probiotics on patients with IBS has been evaluated in several meta-analyses. Most studies have found that probiotics have a small but positive effect. For example, a meta-analysis of 23 randomized controlled trials with a total of 2,575 patients found that probiotics reduce by 21% the chance that IBS symptoms would stay the same or get worse. 21
Irritable bowel syndrome:
Irritable colon syndrome is a functional disorder of the colon that is characterized by intermittent abdominal pain and an alternating succession of diarrhea and constipation.
There is no apparent biochemical or structural abnormality associated with irritable bowel syndrome. Reports on probiotics’ effects in treating this disorder are still a bit inconsistent.
A randomized, placebo-controlled study of 362 female primary-care patients with IBS found that 108 CFU of the freeze-dried probiotic bacteria B. infantis species improved bowel dysfunction and other symptoms. The results were not significant with other doses. More research is needed to confirm findings in this regard.12
Best Probiotic Strains for Diarrhea
Although there are many different kinds of probiotics, research indicates that supplementing with a few of them is most effective in treating diarrhea. The most effective probiotic strains for treating diarrhea are those listed below:
- Lactobacillus species are widely used against diarrhea worldwide. Among these lactobacillus rhamnosus GG and lactobacillus casei is the most effective probiotic in treating diarrhea in children and adults. However, Lactobacillus casei has been demonstrated to be effective in reducing the length and frequency of diarrhea episodes in young children who have acute diarrhea. 22, 23
- Saccharomyces boulardii is a type of yeast that is good for you and is often used in probiotic supplements. It has been demonstrated to be effective in treating antibiotic-associated and infectious diarrhea. 18, 22
- Bifidobacterium species have also been effective in improving gut health and also treating diarrhea. 9,10, 12
Probiotics are important for a healthy immune system and digestive system. They are also important for keeping the body in balance and regulating bowel movements. But there are some possible side effects of taking probiotics, like short-term diarrhea. Probiotics typically cause mild diarrhea that goes away within a few days. Overall, probiotics are a safe and effective way to prevent diarrhea, but it is best to talk to a doctor before taking any new supplements or making changes to your diet.
- Shi LH, Balakrishnan K, Thiagarajah K, Mohd Ismail NI, Yin OS. Beneficial Properties of Probiotics. Trop Life Sci Res. 2016 Aug;27(2):73-90. doi: 10.21315/tlsr2016.27.2.6. PMID: 27688852; PMCID: PMC5031164. Beneficial Properties of Probiotics – PubMed (nih.gov)
- Williams NT. Probiotics. Am J Health Syst Pharm. 2010 Mar 15;67(6):449-58. doi: 10.2146/ajhp090168. PMID: 20208051 Probiotics – PubMed (nih.gov)
- Matthews, M., & Yan, D. Prebiotics and Probiotics. preprobiotics-pro.pdf (ucdavis.edu)
- Cologne, Germany: Institute for Quality and Efficiency in Health Care (IQWiG); 2006-. Can probiotics help against diarrhea? 2016 May 4 [Updated 2019 Dec 19]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK373095/
- Rondanelli M, Faliva MA, Perna S, Giacosa A, Peroni G, Castellazzi AM. Using probiotics in clinical practice: Where are we now? A review of existing meta-analyses. Gut Microbes. 2017 Nov 2;8(6):521-543. doi: 10.1080/19490976.2017.1345414. Epub 2017 Jul 21. PMID: 28640662; PMCID: PMC5730384. Using probiotics in clinical practice: Where are we now? A review of existing meta-analyses – PubMed (nih.gov)
- Anonymous. Persistent diarrhoea in children in developing countries: memorandum from a WHO meeting. Bulletin of the World Health Organization 1988;66(6):709‐17. Persistent diarrhoea in children in developing countries: Memorandum from a WHO Meeting*
- Varughese, C. A., Vakil, N. H., & Phillips, K. M. (2013). Antibiotic-Associated Diarrhea. Journal of Pharmacy Practice, 26(5), 476–482. doi:10.1177/0897190013499523 Antibiotic-associated diarrhea: a refresher on causes and possible prevention with probiotics–continuing education article – PubMed (nih.gov)
- Goodman C, Keating G, Georgousopoulou E, et al Probiotics for the prevention of antibiotic-associated diarrhoea: a systematic review and meta-analysis BMJ Open 2021;11: e043054. doi: 10.1136/bmjopen-2020-043054 Probiotics for the prevention of antibiotic-associated diarrhoea: a systematic review and meta-analysis – PubMed (nih.gov)
- Chatterjee S, Kar P, Das T, Ray S, Gangulyt S, Rajendiran C, Mitra M. Randomised placebo-controlled double blind multicentric trial on efficacy and safety of Lactobacillus acidophilus LA-5 and Bifidobacterium BB-12 for prevention of antibiotic-associated diarrhoea. J Assoc Physicians India. 2013 Oct;61(10):708-12. PMID: 24772726. Randomised placebo-controlled double blind multicentric trial on efficacy and safety of Lactobacillus acidophilus LA-5 and Bifidobacterium BB-12 for prevention of antibiotic-associated diarrhoea. – Abstract – Europe PMC
- de Vrese M, Kristen H, Rautenberg P, Laue C, Schrezenmeir J. Probiotic lactobacilli and bifidobacteria in a fermented milk product with added fruit preparation reduce antibiotic associated diarrhea and Helicobacter pylori activity. J Dairy Res. 2011 Nov;78(4):396-403. doi: 10.1017/S002202991100063X. Epub 2011 Aug 26. PMID: 21871144. Probiotic lactobacilli and bifidobacteria in a fermented milk product with added fruit preparation reduce antibiotic associated diarrhea and Helicobacter pylori activity – PubMed (nih.gov)
- Allen SJ, Martinez EG, Gregorio GV, Dans LF. Probiotics for treating acute infectious diarrhoea. Cochrane Database Syst Rev 2010:CD003048. Probiotics for treating acute infectious diarrhoea – PubMed (nih.gov)
- Michael de Vrese, Philippe R. Marteau, Probiotics and Prebiotics: Effects on Diarrhea, The Journal of Nutrition, Volume 137, Issue 3, March 2007, Pages 803S–811S, Probiotics and Prebiotics: Effects on Diarrhea1 – ScienceDirect
- Caffarelli C, Cardinale F, Povesi-Dascola C, Dodi I, Mastrorilli V, Ricci G. Use of probiotics in pediatric infectious diseases. Expert Rev Anti Infect Ther 2015;13:1517-35. [PubMed abstract]
- Szajewska H, Skorka A, Ruszczynski M, Gieruszczak-Bialek D. Meta-analysis: Lactobacillus GG for treating acute gastroenteritis in children–updated analysis of randomised controlled trials. Aliment Pharmacol Ther 2013;38:467-76. [PubMed abstract]
- Feizizadeh S, Salehi-Abargouei A, Akbari V. Efficacy and safety of Saccharomyces boulardii for acute diarrhea. Pediatrics 2014;134:e176-91. Efficacy and safety of Saccharomyces boulardii for acute diarrhea – PubMed (nih.gov)
- Dunn N, Okafor CN. Travelers Diarrhea. [Updated 2022 Jul 4]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK459348/
- Bae JM. Prophylactic efficacy of probiotics on travelers’ diarrhea: an adaptive meta-analysis of randomized controlled trials. Epidemiol Health. 2018;40:e2018043. doi: 10.4178/epih.e2018043. Epub 2018 Aug 29. PMID: 30189723; PMCID: PMC6232657. Prophylactic efficacy of probiotics on travelers’ diarrhea: an adaptive meta-analysis of randomized controlled trials – PubMed (nih.gov)
- McFarland LV, Goh S. Are probiotics and prebiotics effective in the prevention of travellers’ diarrhea: A systematic review and meta-analysis. Travel Med Infect Dis. 2019 Jan-Feb;27:11-19. doi: 10.1016/j.tmaid.2018.09.007. Epub 2018 Sep 29. PMID: 30278238. Are probiotics and prebiotics effective in the prevention of travellers’ diarrhea: A systematic review and meta-analysis – PubMed (nih.gov)
- Sazawal S, Hiremath G, Dhingra U, Malik P, Deb S, Black RE. Efficacy of probiotics in prevention of acute diarrhoea: a meta-analysis of masked, randomised, placebo-controlled trials. Lancet Infect Dis. 2006 Jun;6(6):374-82. doi: 10.1016/S1473-3099(06)70495-9. PMID: 16728323. Efficacy of probiotics in prevention of acute diarrhoea: a meta-analysis of masked, randomised, placebo-controlled trials – PubMed (nih.gov)
- Anbazhagan AN, Priyamvada S, Alrefai WA, Dudeja PK. Pathophysiology of IBD associated diarrhea. Tissue Barriers. 2018;6(2):e1463897. doi: 10.1080/21688370.2018.1463897. Epub 2018 May 8. PMID: 29737913; PMCID: PMC6179131. Pathophysiology of IBD associated diarrhea – PubMed (nih.gov)
- Ford AC, Quigley EM, Lacy BE, Lembo AJ, Saito YA, Schiller LR, et al. Efficacy of prebiotics, probiotics, and synbiotics in irritable bowel syndrome and chronic idiopathic constipation: systematic review and meta-analysis. Am J Gastroenterol 2014;109:1547-61; quiz 6, 62 Efficacy of prebiotics, probiotics, and synbiotics in irritable bowel syndrome and chronic idiopathic constipation: systematic review and meta-analysis – PubMed (nih.gov)
- Blaabjerg S, Artzi DM, Aabenhus R. Probiotics for the Prevention of Antibiotic-Associated Diarrhea in Outpatients-A Systematic Review and Meta-Analysis. Antibiotics (Basel). 2017 Oct 12;6(4):21. doi: 10.3390/antibiotics6040021. PMID: 29023420; PMCID: PMC5745464. Probiotics for the Prevention of Antibiotic-Associated Diarrhea in Outpatients-A Systematic Review and Meta-Analysis – PubMed (nih.gov)
- Lai HH, Chiu CH, Kong MS, Chang CJ, Chen CC. Probiotic Lactobacillus casei: Effective for Managing Childhood Diarrhea by Altering Gut Microbiota and Attenuating Fecal Inflammatory Markers. Nutrients. 2019 May 23;11(5):1150. doi: 10.3390/nu11051150. PMID: 31126062; PMCID: PMC6566348. Probiotic Lactobacillus casei: Effective for Managing Childhood Diarrhea by Altering Gut Microbiota and Attenuating Fecal Inflammatory Markers – PubMed (nih.gov)