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Last Update: July 3, 2023.

Continuing Education Activity

Probiotics are used in managing and treating a variety of disease states. They are live microorganisms that are known to help improve gut health. This activity reviews the current indications for the use of probiotics, also highlighting the few contraindications. This activity will also explain the mechanism of action and critical factors that are important for the interprofessional team in terms of treatment and management of patients with various gut disorders.


  • Identify the mechanism of action of probiotics.
  • Describe the possible adverse effects associated with probiotics.
  • Summarize the use of probiotics and the need for further research on the topic.
  • Review interprofessional team strategies for improving care coordination and communication to advance the proper usage of probiotics and improve outcomes.
Access free multiple choice questions on this topic.


There is a range of diseases that are associated with the intestinal tract, causing alterations in bowel habits. Usually, due to a particular inciting event, patients get changes in the microbes found in the gut, leading to significantly distressing various gut disorders ranging from antibiotic-associated diarrhea to chronic irritable bowel syndrome.[1] Yet, these are just some examples of the many intestinal health disorder that may benefit from different forms of alternative treatment. Various treatment options have undergone analysis, one being the use of probiotics to suppress unwanted symptoms.[2] Probiotics are living microorganisms that are considered non-pharmacological methods to promote gut health.[3] They can be indicated for the treatment of a variety of disease states. Determining which strains of probiotics are beneficial for specific disease outcomes has been proven to be most helpful.[4] With probiotics being both strain and disease-specific, it is crucial to identify the strains that produce the best outcome for different ailments to achieve the most optimal results.

A systematic review was conducted by McFarland and his colleagues to provide the most up-to-date information on the strain specificity of probiotics.[2] Antibiotic-associated diarrhea (AAD) showed a robust preventative correlation with three strains: Saccharomyces boulardii I-745, three lactobacillus strains (L. acidophilus CL1285 + L. casei Lbc80r + L. rhamnosus CLR2), and Lactobacillus casei.3. The treatment of Helicobacter pylori infections includes many side effects. Strong evidence linked the use of two probiotics, S. boulardii I-745 and the mixture of L. helveticus R52 + L. rhamnosus R11, in offsetting many of the unwanted side effects. The prevention of post-surgical complications occurred with one synbiotic: Pediococcus pentosaceus 5–33:3, Leuconostoc mesenteroides 77:1, L. paracasei ssp. paracasei F19, L. plantarum 2362. One probiotic, S. boulardii CNCM I-745, prevented traveler's diarrhea. Pediatric diarrhea had the most definite link with probiotics, displaying seven different strains found to be preventative.[2] However, prevention Clostridium difficile, nosocomial infections, respiratory tract infections, urinary tract infections, and constipation had no definite evidence linked to probiotics. [2] The FDA has indicated that certain probiotics added to a variety of foods are categorized as Generally Recognized as Safe (GRAS). [5] However, research also indicates that there has been insufficient evidence recorded on the overall safety and side effects. More research is necessary on the different strains of probiotics and which disease states would benefit the most to provide the best care for patients. Establishing a set of standard guidelines would prove beneficial both for the physician and the patient, as it will make prescribing easier.[2]

Mechanism of Action

Although the complete mechanism of action probiotics have on the body is not fully understood, there have been certain notable findings in the past. Research has found probiotics to enhance the immune system, playing a role in both innate and adaptive immunity and increasing the overall efficiency. Furthermore, research shows that probiotics carry many anti-inflammatory effects. They act as a regulatory substance for the immune system, helping to sustain homeostasis when it comes to inflammatory and anti-inflammatory responses.[6] Probiotics have also been implicated in impacting both the enteric and central nervous systems, thereby decreasing notions of pain through the activation of opioid and endocannabinoid receptors.[7]


Probiotics come in a variety of different forms. They are available in fermented foods, capsules, liquids, and powders.[7] They are easily accessible and located in most grocery stores, pharmacies, and through online purchases.[7] With the easy accessibility of probiotics, sellers must be informed about the benefits of supplementation to provide better information to consumers.

Adverse Effects

There has been insufficient evidence on whether probiotics are safe or not. There have been rare occurrences where patients who took probiotics were subject to fungemia, bacteremia, and endocarditis. Research has revealed the most documented probiotics to cause fungemia to be Saccharomyces cerevisiae and Saccharomyces boulardii. Studies also show that bacteremia and sepsis resulted from various Lactobacillus strains, S. boulardii, S. cerevisiae, Bacillus subtilis, and Bifidobacterium breve. Endocarditis caused by probiotics is on record to be caused by Lactobacillus and Streptococcus.[5]


Generally, since most research indicates that probiotics are safe, there are no real contraindications. Instead, following the rare occurrences, specific individuals should proceed with caution. Those with short gut syndrome, the immunocompromised, and the elderly patients should consider potential side effects before initiation.[8] Furthermore, when placing central venous catheters, a proper protocol should be enforced to prevent the introduction of pathogens. 

Enhancing Healthcare Team Outcomes

A variety of probiotic strains have implications for use in various ailments. Identifying the strains that produce the most beneficial results is crucial to create a proper treatment regimen for potential patients. Probiotics can alleviate several different problems, which are only effective when adequately implemented.[9] 

Not only should clinicians be aware of the possible beneficial outcomes, but other health care professionals, such as nurses and pharmacists, should also be involved, working together as an interprofessional team. Although clinicians are the most influential in this matter, as they are usually the ones to advise patients on what to do next regarding specific disease processes, nurses are also crucial to this team. They can explain the use of this treatment regime while also monitoring the patient's vitals and potential side effects. Furthermore, pharmacists should be knowledgeable in regards to the patient's history and use of probiotics to ensure proper usage and provide efficient guidance. Now that probiotics are readily available in stores and online, the general public (as in the sellers and consumers) must also be aware of the uses and potential side effects. Therefore, to ensure the best possible outcomes for patients, the interprofessional group should be assembled to create a strategic plan for each person. When working as a group to assure excellent patient care and outcome, more patients will be able to attain the adequate care they require. [Level 5]

Studies indicate that most health care providers only have a medium level of expertise on probiotics, displaying the need for increased awareness and education. Since probiotics can treat a wide variety of diseases, it is crucial to better understand the topic to provide the best care to future patients.[10] As of now, there are no standard guidelines for prescribing probiotics, displaying the need for more significant research on this topic since it proves to have many potential health benefits.

Review Questions


Saha L. Irritable bowel syndrome: pathogenesis, diagnosis, treatment, and evidence-based medicine. World J Gastroenterol. 2014 Jun 14;20(22):6759-73. [PMC free article: PMC4051916] [PubMed: 24944467]
McFarland LV, Evans CT, Goldstein EJC. Strain-Specificity and Disease-Specificity of Probiotic Efficacy: A Systematic Review and Meta-Analysis. Front Med (Lausanne). 2018;5:124. [PMC free article: PMC5949321] [PubMed: 29868585]
Zawistowska-Rojek A, Tyski S. Are Probiotic Really Safe for Humans? Pol J Microbiol. 2018;67(3):251-258. [PMC free article: PMC7256845] [PubMed: 30451441]
Sniffen JC, McFarland LV, Evans CT, Goldstein EJC. Choosing an appropriate probiotic product for your patient: An evidence-based practical guide. PLoS One. 2018;13(12):e0209205. [PMC free article: PMC6306248] [PubMed: 30586435]
Doron S, Snydman DR. Risk and safety of probiotics. Clin Infect Dis. 2015 May 15;60 Suppl 2(Suppl 2):S129-34. [PMC free article: PMC4490230] [PubMed: 25922398]
Kang HJ, Im SH. Probiotics as an Immune Modulator. J Nutr Sci Vitaminol (Tokyo). 2015;61 Suppl:S103-5. [PubMed: 26598815]
Liu Y, Tran DQ, Rhoads JM. Probiotics in Disease Prevention and Treatment. J Clin Pharmacol. 2018 Oct;58 Suppl 10(Suppl 10):S164-S179. [PMC free article: PMC6656559] [PubMed: 30248200]
Snydman DR. The safety of probiotics. Clin Infect Dis. 2008 Feb 01;46 Suppl 2:S104-11; discussion S144-51. [PubMed: 18181712]
Yadav M, Shukla P. Recent systems biology approaches for probiotics use in health aspects: a review. 3 Biotech. 2019 Dec;9(12):448. [PMC free article: PMC6848287] [PubMed: 31763126]
Fijan S, Frauwallner A, Varga L, Langerholc T, Rogelj I, Lorber M, Lewis P, Povalej Bržan P. Health Professionals' Knowledge of Probiotics: An International Survey. Int J Environ Res Public Health. 2019 Aug 28;16(17) [PMC free article: PMC6747149] [PubMed: 31466273]

Disclosure: Mahsa Shahrokhi declares no relevant financial relationships with ineligible companies.

Disclosure: Shivaraj Nagalli declares no relevant financial relationships with ineligible companies.

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Bookshelf ID: NBK553134PMID: 31985927


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