The Power of Probiotics: A review of the Evidence

A. Thomas et al., 2010: This comprehensive review published in Pediatrics looked at the role of probiotics in various pediatric conditions including: acute viral gastroenteritis, prevention of antibiotic-associated diarrhea, prevention of necrotizing enterocolitis, treatment of Helicobacter pylori gastritis, irritable bowel syndrome, chronic ulcerative colitis, infantile colic, prevention of childhood atopy, prevention of atopic eczema, prevention of common infections. Summary of results for AGE:

1. Several RCTs reviewed indicate that probiotics decrease the number of  diarrheal stools and duration of diarrhea by approximately 1 day. The benefit was strain dependent with Lactobacillus rhamnosus (LGG) being the most effective.  Probiotics were shown to be more effective when given early in the course of diarrhea. 

B. Depoorter et al., (2021):  This systematic review published in Nutrients look at the role of probiotics in the treatment of infectious gastroenteritis, prevention of antibiotic-associated, Clostridioides difficile-associated, and nosocomial diarrhea. Summary of results:

1. There is some evidence that probiotics can decrease the duration of diarrhea in AGE however this review did not find sufficient evidence to recommend it routinely.

C. Szajewska et al.(2022): This position paper by the ESPGHAN (European Society for Paediatric Gastroenterology Hepatology and Nutrition) Working Group provides recommendations for the use of probiotics for the treatment of AGE in previously healthy infants and children. This is based on a systematic review of previously completed systematic reviews and of randomized controlled trials (RCTs) published subsequently to these reviews. Initial review was in 2016, updated in 2022.  Summary of 2022 recommendations:

1. HCPs may recommend Saccharomyces (S) boulardii* (at a dose of 250–750 mg/day, for 5–7 days) for the management of acute gastroenteritis in children, since there is evidence of reduced duration of diarrhea (certainty of evidence: low; grade of recommendation: weak).
2. HCPs may recommend Limosilactobacillus reuteri (L reuteri) DSM 17938 (at daily doses 1 × 108 to 4 × 108 CFU, for 5 days) for the management of acute gastroenteritis in children, since there is evidence of reduced duration of diarrhea (certainty of evidence: very low; grade of recommendation: weak).
3. HCPs may recommend the combination of L rhamnosus 19070-2 and L reuteri DSM 12246 (at a dose of 2 × 1010 CFU for each strain, for 5 days) for the management of acute gastroenteritis in children, since there is evidence of reduced duration of diarrhea (certainty of evidence: very low; grade of recommendation: weak).
4. HCPs should not recommend the combination of Lactobacillus helveticus R0052 and L rhamnosus R0011 for the management of acute gastroenteritis due to the lack of efficacy (certainty of evidence: moderate; grade of recommendation: strong).                                             

D. Schnadower et al., (2020): This RCT published in the New England Journal of Medicine conducted a prospective, randomized, double-blind trial involving children 3 months to 4 years of age with acute gastroenteritis who presented to one of 10 U.S. pediatric emergency departments. Participants received a 5-day course of Lactobacillus rhamnosus GG at a dose of 1×1010 colony-forming units twice daily or matching placebo and were followed up at 5 days, 14 days, and 30 days after enrollment to determine if it decreased moderate to severe AGE, and to see if there was an effect on duration and frequency of diarrhea and vomiting, the duration of day-care absenteeism, and the rate of household transmission.  Summary of results:

1. This RCT involved 971 preschool children with acute gastroenteritis. Those who received a 5-day course of L. rhamnosus GG did not have better outcomes than those who received placebo.
2. Treatment with L. rhamnosus GG did not result in a smaller proportion of participants having moderate-to-severe gastroenteritis and failed to show benefit with respect to the duration or frequency of vomiting or diarrhea, the rate of household transmission, or the duration of day-care or work absenteeism.

E. Jones et al., (2023): This systematic review aims to identify the effectiveness of probiotics in treating AGE in children globally. It looked at 29 quantitative studies published between 2014 and 2023.  Summary of results:

1. The results of this review concluded there was strong evidence to support the use of probiotics to improve AGE in children.  Probiotics reduce the severity of AGE, improved recovery time, and reduced hospitalization rates. 

Probiotics for AGE Conclusions 

Numerous studies have explored the potential benefits of probiotics for AGE; however, significant variability in the strains and doses administered, the demographics of the patient populations, and the overall study designs have resulted in heterogeneous outcomes. While there certainly is research that suggests a potential positive effect, the inconsistency among findings indicates that the evidence is insufficient to recommend the routine use of probiotics for this purpose. Notably, European guidelines do advocate for their use in managing AGE, reflecting a divergence in clinical practice and research interpretation. This discrepancy underscores the need for further investigation to establish clearer recommendations. 

A. Depoorter et al., (2021):  This systematic review published in Nutrients look at the role of probiotics in the treatment of infectious gastroenteritis, prevention of antibiotic-associated, Clostridioides difficile-associated, and nosocomial diarrhea. Summary of results:

1. This review concluded that there is sufficient evidence to recommend LGG or S. boulardii for antibiotic-associated diarrhea prevention.
2. With regard to C. difficile diarrhea, the routine administration of these probiotics can also be considered.

B. Thomas et al., 2010: This comprehensive review published in Pediatrics looked at the role of probiotics in various pediatric conditions including: acute viral gastroenteritis, prevention of antibiotic-associated diarrhea, prevention of necrotizing enterocolitis, treatment of Helicobacter pylori gastritis, irritable bowel syndrome, chronic ulcerative colitis, infantile colic, prevention of childhood atopy, prevention of atopic eczema, prevention of common infections. Summary of results:

1. A meta-analysis of published results of RCTs of probiotic use in the prevention of antibiotic associated diarrhea indicates a beneficial effect with LGG and s. Boulardii. Studies reviewed indicate a reduction in the incidence of antibiotic-associated diarrhea. 
2. Treatment of antibiotic-associated diarrhea could not be determined as at the time of publishing, there were no RCTs done on this topic. 

C. Guo et al.., (2019): This Cochrane review set out to assess the efficacy and safety of probiotics (any specified strain or dose) used for the prevention of AAD in children. Thirty‐three studies (6352 participants) were included. Probiotics assessed included Bacillus spp., Bifidobacterium spp., Clostridium butyricum , Lactobacilli spp. , Lactococcus spp., Leuconostoc cremoris , Saccharomyces spp., orStreptococcus spp., alone or in combination. Summary of results:

1. The overall evidence suggests a moderate protective effect of probiotics for preventing AAD. Probiotics reduced antibiotic-associated diarrhea incidence from 19% to 8%.
2. The overall certainty of the evidence for the primary endpoint, incidence of AAD, based on high dose probiotics was moderate due to the minor issues with risk of bias and inconsistency related to a diversity of probiotic agents used. 
3. Evidence also suggests that probiotics may moderately reduce the duration of diarrhea, a reduction by almost one day. 
4. The benefit of high dose probiotics (e.g. Lactobacillus rhamnosus orSaccharomyces boulardii) needs to be confirmed by a large well‐designed multi‐centered randomized trial. 

D. Szajewska et al., (2016):  This article provides recommendations, developed by the Working Group (WG) on Probiotics of the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition, for the use of probiotics for the prevention of antibiotic-associated diarrhea (AAD) in children based on a systematic review of previously completed systematic reviews and of randomized controlled trials published subsequently to these reviews.  Summary of results:

1. If the use of probiotics for preventing AAD is considered because of the existence of risk factors such as class of antibiotic(s), duration of antibiotic treatment, age, need for hospitalization, comorbidities, or previous episodes of AAD diarrhea, the WG recommends using Lactobacillus rhamnosus GG (moderate evidence, strong recommendation) or Saccharomyces boulardii (moderate evidence, strong recommendation). 
2. If the use of probiotics for preventing Clostridium difficile-associated diarrhea is considered, the WG suggests using S boulardii (low evidence, conditional recommendation). Other strains or combinations of strains have been tested, but sufficient evidence is still lacking.

E. Lukasik et al., (2022):   This randomized, quadruple-blind, placebo-controlled trial, published in JAMA Pediatrics,  was conducted from February 2018 to May 2021 in a multicenter, mixed setting (inpatients and outpatients). It set out to determine the efficacy of a multispecies probiotic in the prevention of antibiotic-associated diarrhea in children. A multispecies probiotic was given consisting of Bifidobacterium bifidum W23, Bifidobacterium lactis W51, Lactobacillus acidophilus W37, L acidophilus W55, Lacticaseibacillus paracasei W20, Lactiplantibacillus plantarum W62, Lacticaseibacillus rhamnosus W71, and Ligilactobacillus salivarius W24, for a total dose of 10 billion colony-forming units daily, for the duration of antibiotic treatment and for 7 days after. Summary of results:

1. AAD incidence was comparable between the probiotic and placebo groups. The frequency of AAD according to the alternative definitions (mild, severe) was also similar between both study groups. The patients in the probiotic group had a significantly lower risk of developing diarrhea than those in the placebo group when analyzed regardless of its etiology; they were also less likely to require intravenous rehydration owing to diarrhea.

F. Yang et al., (2023): This systematic review overviewed the Systematic Reviews (SRs) of probiotics in preventing and treating AAD in children. It also assessed the reporting, methodological, and evidence quality of the included SRs to provide evidence for their clinical practice.  Summary of results:

1. The results of the Meta-analysis showed that high doses (5–40 billion CFUs per day) of probiotics had a significant effect in the prevention of AAD, but it is too early to conclude the effectiveness and safety of other probiotic drugs for AAD in children, except for Lacticaseibacillus rhamnosus and Saccharomyces boulardii. 

Conclusions for Probiotics and Prevention of ADD
Probiotics, particularly Lactobacillus rhamnosus GG and Saccharomyces boulardii, are effective in preventing antibiotic-associated diarrhea in children, especially when administered in high doses (5 million CFUs or greater). They are generally safe with minimal adverse effects, however, caution is advised in immunocompromised children. Further research is needed to confirm the efficacy of other probiotic strains and to standardize outcome measures in clinical trials.

A. Hua-Ian Xu et al., (2021):  This systematic review and meta-analysis included 9 RCTs looking at the efficacy of probiotics for children with IBS.  Summary of results:

1. This study overall  found that compared with placebo, probiotics could significantly reduce abdominal pain, the subject’s global assessment of relief, and the frequency of abdominal pain.  There was not a statistically significant effect on bloating.
2. Probiotics are effective at treating abdominal pain caused by IBS in children; however, there was not a significant correlation between abdominal pain and the amount of probiotics ingested.

B. Giannetti et al., (2017): This RCT looked at a mixture of 3 bifidobacteria  strains to determine their effect on abdominal pain and quality of life in children with IBS and functional dyspepsia.  Summary of results: 

1. This probiotic mixture improved abdominal pain and quality of life in children with IBS, but not functional dyspepsia. 

C. Dale et al., (2019): This systematic review looked at 11 studies to determine if probiotic supplementation improved IBS when used over a long period of time.  Summary of results:

1. 63.6% of studies found that probiotics significantly improved IBS symptoms compared to placebo, with an intervention of 8 weeks or more.  The effects were more distinct in the trials using multi-strain probiotics, suggesting that multi-strain probiotics can improve IBS symptoms. 

D. Sudha et al., (2018): This RCT published in Beneficial Microbes looked at the use of probiotic Bacillus Coagulans Unique IS2 in the treatment of pediatric IBS.  Summary of results: 

1. B. coagulans Unique IS2 significantly reduced IBS pain intensity, abdominal discomfort, bloating, staining, urgency, incomplete evaluation and passage of gas in children.

E. Guandalini et al., (2010): This RCT published in the Journal of Pediatric Gastroenterology and Nutrition looked a probiotic combination called VSL #3 to determine if it improves IBS symptoms in children.  VSL #3 is a multistrain probiotic.  Summary of results:

1. VSL #3 was significantly superior to placebo in improving patient’s subjective assessment of relief of symptoms as well as improving abdominal pain/discomfort, bloating/gassiness, and family assessment of life disruption.  No difference was found with regard to stool pattern.

F. Thomas et al., 2010:: This comprehensive review published in Pediatrics looked at the role of probiotics in various pediatric conditions including: acute viral gastroenteritis, prevention of antibiotic-associated diarrhea, prevention of necrotizing enterocolitis, treatment of Helicobacter pylori gastritis, irritable bowel syndrome, chronic ulcerative colitis, infantile colic, prevention of childhood atopy, prevention of atopic eczema, prevention of common infections. Summary of results:

1. One RCT was evaluated in children with IBS. LGG reduced abdominal distension and discomfort in a group of 50 pediatric patients over a 6-week study period. It was concluded that probiotics may benefit kids with IBS but more confirmatory studies needed. 
2.  This review concluded that at the present time (2010), the sustained or long-term benefit of using probiotics for treating disorders such as Crohn disease, IBS, constipation, atopic disorders and extraintestinal infections requires further RCTs and cannot be recommended in children.

IBS conclusions

There is evidence that probiotics may be effective in reducing abdominal pain and improving the quality of life in children with IBS. Multi-strain probiotics tend to be more beneficial, especially for children with diarrhea-predominant or post-infectious IBS. While more high-quality studies are needed to standardize treatment protocols, current evidence supports the use of probiotics in managing IBS symptoms in children.

A. Wang et al., (2021): This comprehensive review published in Molecules looks at the influence of probiotics on the gut microbiota and human immunity, and the relationship between immunity, probiotics, gut microbiota, and life quality. Summary of results:

1. Probiotics can improve host immunity by maintaining the epithelial barrier, inhibiting pathogens from adhering to the intestinal surface, and modulating and properly maturing the immune system. Moreover, probiotics can also improve host immunity by affecting intestinal flora to treat certain diseases. 

B. Mazziotta et al., (2023): This comprehensive review published in Cells aims to collect and describe the main scientific results published to date and their implications on how immune cells and probiotics interact to enhance the immune function. Summary of results:

1. Broad evidence indicates that intestinal immune cells interact with consumed probiotics, and this interaction can improve host immune homeostasis and immune function by various mechanisms. 
2. Consumed probiotics specifically mediate the activation/modulation of both innate and adaptive immune responses in the intestine by stimulating the production of various cytokines and chemokines from DCs, lymphocytes, macrophages, mast cells, granulocytes, and intestinal epithelial cells, and IgA-producing cells and consequent IgA secretion. Probiotics can therefore improve the host immune system and induce important beneficial effects, allowing the prevention and/or management of immune/inflammatory-related diseases, including IBD, IBS, inflammation, diarrhea, pathogenic infections, infant colic, and certain cancer types.
3. 1.  

C. Hong Zhang et al.,(2018): This study, published in Synthetic and Systems Biotechnology, aimed to investigate the effects of a probiotic supplementation on volunteers who have contracted the common cold four or more times in the past year and to evaluate their immune response.  Summary of results:

1. Findings indicate that the combination of probiotics (Lactobacillus paracasei, Lactobacillus casei 431® and Lactobacillus fermentum PCC®) could reduce the incidence of the upper respiratory infection, which is possible by increasing the level of IFN-γ in the blood and sIgA in the gut. 
2. The probiotics combination did not show any statistically significant effect on changing the level of IL-4 and IL-10 indicating that Th2 helper cells were not activated during the probiotics intervention. (Th2 cells produce IL-4, which facilitates B cell isotype switching.) Nor did the probiotics combination have any impact on the level of IgA, IgG and IgM, which must be explained as the combination of probiotics in this study have little or no activation of Th2 cells.

Conclusion on Probiotics Effect on Enhancing Immunity

The collective evidence from multiple studies indicates that probiotics can enhance immunity through various mechanisms, including the regulation of gut microbiota, interaction with immune cells, and strain-specific modulation of immune responses. Probiotics have shown potential in improving immune function in healthy individuals as well as in individuals with specific health conditions. While the exact mechanisms and effectiveness can vary depending on the probiotic strain and the host, the overall consensus supports the beneficial role of probiotics in enhancing immune function.

A. Garaiová et al (2021): In this RCT, published in Beneficial Microbes, children were given a probiotic based supplement for 6 months with L. acidophilus, B. bifidum, B. lactis and 50mg of vitamin C to assess the impact on incidence and duration of URTI symptoms. Summary of results:

1. Daily intake of this probiotic supplement resulted in a significant reduction in the incidence of coughs, absenteeism, and antibiotic usage. 
2. Children taking the intervention had a 69% lower risk of experiencing all 5 URTI symptoms including cough, sore throat, sneezing, nasal discharge, and nasal congestion.
3. This study observed a significant 27% reduction in the incidence of antibiotic usage alongside a significantly reduced incidence rate of pediatric physician visits.

B. Garaiová et al (2014): This RCT was published in the European Journal of Clinical Nutrition and was a randomized controlled pilot study evaluating Probiotics and Vitamin C supplementation’s effect for preventing URIs in preschool children.  These children received L. acidophilus (2 species), B. bifidum, and B. lactis plus 50mg of Vitamin C daily for 6 months. Summary of results:

1. Significant reduction in the incidence of URTIs, the number of days with URTI symptoms, and a reduction in the incidence rate of absence from preschool. 
2. This was the pilot study for the study listed above. 

C. Gutiérrez-Castrellón et al.,(2018):This systematic review and network- meta analysis looked at 31 RCTs and 20 studies to determine the role of Probiotics to prevent and reduce the duration of URTIs in ambulatory children. Summary of results:

1. L. reuteri and L. acidophillus were superior to placebo to reduce URIs. L. rhamnosus also reduced URIs but to a lesser extent. 
2. L. reuteri showed preventative equivalence when compared to L. rhamnosus GG, L. casei, and BB12. 
3. Lactobacillus reuteri, Lactobacillus rhamnosus GG and Bifidobacterium BB12 are evidence-based alternatives to be considered to prevent URIs in children.

D. Amaral et al., (2017): This systematic review published in Pediatric Pulmonology looked at 21 trials to assess the effect of probiotics on URTI prevention in children.  Summary of results:

1. Pairwise meta-analysis suggested that L. rhamnosus was the only effective probiotic to reduce the rate of URTIs compared to placebo however showed no better effect compared to other probiotic strains by indirect analysis. 
2. Overall, this systematic review found a lack of evidence to support the effect of probiotics on the incidence rate of respiratory infections in children and adolescents.

E. Ouwehand et al., (2008): This RCT published in Pediatrics looked at children ages 3-5 who were assigned to one of three groups: Placebo, L. acidophilus for 6 months, or L, acidophilus plus B. lactis for 6 months. Summary of results:

1. The groups assigned to daily consumption of L. acidophillus or B. lactis plus L acidophillus showed significant reduction in the incidence and duration of URTI. The combination product performed better overall. 
2. Probiotics reduced fever by 63%, runny nose by 44%, and antibiotic use by 80% in the combined probiotic group. 
3. Children in the placebo group had an average of 6.5 days of symptoms whereas children in the combined probiotic group had 3.4 days with symptoms. 

F. Cochrane Database of Systematic Reviews(2022): This systematic review assessed the safety and efficacy of Probiotics, compared with placebo or no treatment in the prevention of acute URTIs in all ages. This included 23 individual RCTS and one cluster-RCT. Summary of results:

1. Probiotics may reduce the number of people diagnosed with at least one URTI by about 24%; likely reduce the number of people diagnosed with at least three URTIs by about 41%; may reduce the incidence rate of acute URTIs by about 18%; may reduce the mean duration of an episode of acute URTIs by about 1.22 days; likely reduce the number of people who used antibiotics for URTIs by about 42%
2. Evidence showing a decrease in the number of people absent from childcare centre, school, or work due to acute URTIs with probiotics is very uncertain.

Reduced Incidence of URTI Conclusions

There is some evidence that probiotics may reduce the incidence and severity of upper respiratory tract infections in children. They also may contribute to lower school absenteeism and reduced antibiotic use, likely through immune modulation. Probiotics are generally safe and well-tolerated in pediatric populations.  Both lactobacillus and bifidobacterium strains have been studied and show promising results.

A. King et al., (2018): This meta-analysis published in the European Journal of Public Health analyzed 17 RCTs and set out to determine if Probiotics reduce antibiotic utilization for common infections. Included studies used 13 probiotic formulations, all comprising single or combination Lactobacillus and Bifidobacterium delivered in a range of food or supplement products. Summary of results:

1. Infants and children who received probiotics to prevent acute illnesses had a lower risk of being prescribed antibiotics, relative to those who received placebo
2. Probiotics, provided to reduce the risk for common acute infections, may be associated with reduced antibiotic use in infants and children. Additional well-designed studies are needed to substantiate these findings in children and explore similar findings in other population groups.

B. Korpela et al., (2016): This RCT analyzed the influence of long-term Lactobacillus rhamnosus (LGG) intake on preschool children’s antibiotic use, and antibiotic-associated gastrointestinal complaints in a double blind, randomized placebo-controlled trial with 231 children aged 2–7. It also looked at the composition of the microbiota with LGG supplementation. Summary of results:

1. LGG supplementation appears to have a beneficial influence on the microbiota composition, to prevent penicillin-associated changes in the microbiota, and to confer long-term protection against certain infections.
2. The use of macrolide and sulphonamide-trimethoprim antibiotics was significantly and persistently reduced after the intervention for up to 3 years.

C. Garaiová et al (2021): In this RCT published in Beneficial Microbes, children were given a probiotic based supplement for 6 months with L. acidophilus, B. bifidum, B. lactis and 50mg of vitamin C to assess the impact on incidence and duration of URTI symptoms. Summary of results:

1. Daily intake of this probiotic supplement resulted in a significant reduction in the incidence of coughs, absenteeism, and antibiotic usage. 
2. The incidence rate of total antibiotic use in the active group was 27% lower than in the control group.

 D. Cochrane Database of Systematic Reviews(2022): This systematic review assessed the safety and efficacy of Probiotics, compared with placebo or no treatment in the prevention of acute URTIs in all ages. This included 23 individual RCTS and one cluster-RCT. Summary of results:

1. Probiotics may reduce the number of people diagnosed with at least one URTI by about 24%; likely reduce the number of people diagnosed with at least three URTIs by about 41%; may reduce the incidence rate of acute URTIs by about 18%; may reduce the mean duration of an episode of acute URTIs by about 1.22 days; likely reduce the number of people who used antibiotics for URTIs by about 42%.
2. Evidence showing a decrease in the number of people absent from childcare centers, school, or work due to acute URTIs with probiotics is very uncertain.

Conclusions on Probiotics decreasing Antibiotic Usage

Emerging evidence suggests that regular consumption of probiotics may lower the incidence of common infections, such as upper respiratory infections (URIs), which could, in turn, reduce the need for antibiotic prescriptions by decreasing secondary infections. This has important public health implications, as lowering antibiotic use can help curb the growing threat of antibiotic resistance. However, research in this area has often employed varying strains and doses of probiotics, leading to inconsistent results. To fully realize the potential of probiotics in infection prevention and antibiotic reduction, further studies are needed to determine the most effective formulations and clarify the underlying mechanisms of their protective effects. More rigorous research will be critical in establishing best practices for probiotic use in clinical settings.

A. Thomas et al., 2010:: This comprehensive review published in Pediatrics looked at the role of probiotics in various pediatric conditions including: acute viral gastroenteritis, prevention of antibiotic-associated diarrhea, prevention of necrotizing enterocolitis, treatment of Helicobacter pylori gastritis, irritable bowel syndrome, chronic ulcerative colitis, infantile colic, prevention of childhood atopy, prevention of atopic eczema, prevention of common infections. Summary of results:

1. Several RCTs reviewed indicate that probiotics decrease the number of diarrheal stools and duration of diarrhea by approximately 1 day.  The benefit was strain dependent with Lactobacillus rhamnosus (LGG) being the most effective.  Probiotics were shown to be more effective when given early in the course of diarrhea. 
2. A meta-analysis of published results of RCTs of probiotic use in the prevention of antibiotic associated diarrhea indicates a beneficial effect with LGG and s. Boulardii. Studies reviewed indicate a reduction in the incidence of antibiotic-associated diarrhea. 
3. Treatment of antibiotic-associated diarrhea could not be determined as at the time of publishing, there were no RCTs done on this topic. 
4. This review did not show any effect of probiotics on constipation in the pediatric population.
5. One RCT was evaluated in children with IBS. LGG reduced abdominal distension and discomfort in a group of 50 pediatric patients over a 6-week study period. It was concluded that probiotics may benefit kids with IBS but more confirmatory studies needed. 
6.  This review concluded that at the present time (2010), the sustained or long-term benefit of using probiotics for treating disorders such as Crohn disease, IBS, constipation, atopic disorders and extraintestinal infections requires further RCTs and cannot be recommended in children.

B. Depoorter et al., (2021): This systematic review published in Nutrients look at the  role of probiotics in the treatment of infectious gastroenteritis, prevention of antibiotic-associated, Clostridioides difficile-associated, and nosocomial diarrhea. Summary of results:

1. This review concluded that there is sufficient evidence to recommend LGG or S. boulardii for antibiotic-associated diarrhea prevention.  
2. There is some evidence that probiotics can decrease the duration of diarrhea in AGE.  The European guidelines recommend LLG, L. reuteri, or S. boulardii in the treatment of AGE. 
3. The use of S.boulardii or L. rhamnosusGG could be considered to prevent antibiotic-associated diarrhea. In patients at risk for developing C. difficile diarrhea, the routine administration of these probiotics can also be considered.
4. The use of L. reuteri has been shown to reduce infant colic in breastfed infants. 
5. Prelim evidence suggests that probiotics can reduce persistent symptoms of IBS.
6. Insufficient evidence for the use of probiotics to prevent or treat asthma or allergic rhinitis.