Saccharomyces boulardii in the prevention of antibiotic-associated diarrhoea in children: a randomized double-blind placebo-controlled trial

Meta-analysis of probiotics for the prevention of antibiotic associated diarrhea and the treatment of Clostridium difficile disease

CONTEXT

Antibiotic-associated diarrhea (AAD) is a common complication of most antibiotics and Clostridium difficile disease (CDD), which also is incited by antibiotics, is a leading cause of nosocomial outbreaks of diarrhea and colitis. The use of probiotics for these two related diseases remains controversial.

OBJECTIVE

To compare the efficacy of probiotics for the prevention of AAD and the treatment of CDD based on the published randomized, controlled clinical trials.

DATA SOURCES

PubMed, Medline, Google Scholar, NIH registry of clinical trials, metaRegister, and Cochrane Central Register of Controlled Trials were searched from 1977 to 2005, unrestricted by language. Secondary searches of reference lists, authors, reviews, commentaries, associated diseases, books, and meeting abstracts.

STUDY SELECTION

Trials were included in which specific probiotics given to either prevent or treat the diseases of interest. Trials were required to be randomized, controlled, blinded efficacy trials in humans published in peer-reviewed journals. Trials that were excluded were pre-clinical, safety, Phase 1 studies in volunteers, reviews, duplicate reports, trials of unspecified probiotics, trials of prebiotics, not the disease being studied, or inconsistent outcome measures. Thirty-one of 180 screened studies (totally 3,164 subjects) met the inclusion and exclusion criteria.

DATA EXTRACTION

One reviewer identified studies and abstracted data on sample size, population characteristics, treatments, and outcomes.

DATA SYNTHESIS

From 25 randomized controlled trials (RCTs), probiotics significantly reduced the relative risk of AAD (RR = 0.43, 95% CI 0.31, 0.58, p < 0.001). From six randomized trials, probiotics had significant efficacy for CDD (RR = 0.59, 95% CI 0.41, 0.85, p = 0.005).

CONCLUSION

A variety of different types of probiotics show promise as effective therapies for these two diseases. Using meta-analyses, three types of probiotics (Saccharomyces boulardii, Lactobacillus rhamnosus GG, and probiotic mixtures) significantly reduced the development of antibiotic-associated diarrhea. Only S. boulardii was effective for CDD.

Probiotics for the prevention of antibiotic-associated diarrhea and Clostridium difficile diarrhea

Antibiotic-associated diarrhea is a common clinical problem occurring in up to 25% of patients, with diarrhea owing to Clostridium difficile accounting for up to a quarter of cases. The clinical and economic costs of antibiotic-associated diarrhea are significant and better treatments are needed. Probiotics may offer potential effective therapy for antibiotic-associated diarrhea by restoring intestinal microbial balance. A number of different probiotics have been evaluated in the prevention and treatment of antibiotic-associated diarrhea in adults and children, including the nonpathogenic yeast Saccharomyces boulardii and multiple lactic-acid fermenting bacteria such as Lactobacillus rhamnosus GG (LGG). A careful review of the literature supports the efficacy of S. boulardii in the prevention of antibiotic-associated diarrhea recurrent C. difficile infection in adults, whereas LGG is useful in the treatment of antibiotic-associated diarrhea in children. Not enough data exist to currently support the use of other probiotic preparations in these conditions. Although generally safe and well tolerated, both S. boulardii and LGG should be used cautiously in immunocompromised patients. Further study of probiotics, including large, well-designed, randomized controlled dose-ranging trials, comparative trials, and cost-benefit analyses are necessary.

Probiotics for children: use in diarrhea

The use of probiotics in diarrheal diseases of children is increasing. Probiotics, mostly lactic acid bacteria such as Lactobacilli and Bifidobacteria, but also the yeast Saccharomyces boulardii, have been tried in many double-blinded, randomized, placebo-controlled studies, and several well-conducted meta-analyses are now available. There is some evidence of efficacy in the prevention of community-acquired and nosocomial diarrhea. More solid evidence of efficacy is found in the treatment of sporadic, infectious diarrhea, where several probiotics, and especially Lactobacillus GG, have been found capable of reducing by approximately 1 day the duration of diarrhea, shorten the initial phase of watery stools, and reducing hospital stay in developed countries. The effect is best documented in viral diarrheas. Although there are valid conceptual premises for probiotics to be helpful in inflammatory bowel diseases, only 1 trial has been published in children, showing Lactobacillus GG not to be superior to placebo in maintaining remission of Crohn disease. All considered, more research is needed for a better understanding of the role of probiotics in gastrointestinal diseases of children, addressing issues such as pharmacokinetics, mechanism of action, and role of specific probiotics, alone or in combination, in different disorders.

Effects of probiotics on the gastrointestinal tract

PURPOSE OF REVIEW

This review summarizes recent developments in our understanding of what gastrointestinal disorders probiotics can be of benefit for, focussing on conditions associated with infection or disruption of the normal gut flora. New insights into the effects administered strains can have in the gut, their safety, and potential for future development, will also be discussed.

RECENT FINDINGS

Recent clinical studies have shown that probiotics can protect young children from diarrhoeal illness, including antibiotic-associated diarrhoea. They may also protect neonates from necrotizing enterocolitis. In adults, they can help prevent or reduce the severity of diarrhoeal illness, and ameliorate side-effects for those undergoing antibiotic therapy for infection. Researchers are looking at combining probiotics with prebiotics to enhance anti-inflammatory effects and restore colonization resistance of the commensal flora. New technologies are elucidating complex effects on gene expression in the gut, the probiotic, and bacterial pathogens. Recombinant strains capable of binding bacterial toxins are being developed as novel therapeutics against gastrointestinal infection.

SUMMARY

Considering the clinical trial evidence of therapeutic benefit, probiotics are an underused treatment modality for prevention and amelioration of diarrhoeal illness. Better understanding of strain-specific effects, dosing regimens and any contraindications should help resolve this.

Meta-analysis: non-pathogenic yeast Saccharomyces boulardii in the prevention of antibiotic-associated diarrhoea

BACKGROUND

Antibiotic-associated diarrhoea occurs in up to 30% of patients who receive antibiotics but can be prevented with probiotics.

AIM

To systematically evaluate the effectiveness of Saccharomyces boulardii in preventing antibiotic-associated diarrhoea in children and adults.

METHODS

Using medical subject headings and free-language terms, the following electronic databases were searched for studies relevant to antibiotic-associated diarrhoea and S. boulardii: MEDLINE, EMBASE, CINAHL and The Cochrane Library. Additional sources were obtained from references in reviewed articles. Only randomized-controlled trials were considered for study inclusion.

RESULTS

Of 16 potentially relevant clinical trials identified, five randomized-controlled trials (1076 participants) met the inclusion criteria for this systematic review. Treatment with S. boulardii compared with placebo reduced the risk of antibiotic-associated diarrhoea from 17.2% to 6.7% (RR: 0.43; 95% CI: 0.23-0.78; random effect model). The number needed to treat to prevent one case of antibiotic-associated diarrhoea was 10 (95% CI: 7-16). No side-effects were reported.

CONCLUSIONS

A meta-analysis of data from five randomized-controlled trials showed that S. boulardii is moderately effective in preventing antibiotic-associated diarrhoea in children and adults treated with antibiotics for any reason (mainly respiratory tract infections). For every 10 patients receiving daily S. boulardii with antibiotics, one fewer will develop antibiotic-associated diarrhoea.

Inducible nitric oxide synthase involvement in the mechanism of action of Saccharomyces boulardii in castor oil-induced diarrhoea in rats

The biotherapeutic agent Saccharomyces boulardii has been shown to inhibit castor oil-induced diarrhoea in rats in a dose-response fashion, and one of the suggested mechanisms of action included involvement of the nitric oxide pathway. The present study was designed to address this mechanism of action by firstly measuring the effects of S. boulardii on the inducible nitric oxide synthase (iNOS) isoform activity in vitro. Second, the effects of S. boulardii on the increase in colonic citrulline level associated with castor oil treatment were examined. In vitro, S. boulardii showed a dose-dependent inhibition of iNOS activity with an IC50 of 0.89 mg/ml. In the rat diarrhoea model, the antidiarrhoeal effect of S. boulardii was confirmed using a single oral dose of 12 x 10(10) CFU/kg (viable cells). In this model, castor oil significantly elevated citrulline level from 2526+/-164 to 3501+/-193 nmol/g in the colon. When the rats were treated with the same antidiarrhoeal single dose of S. boulardii, no increase in citrulline level was observed. Moreover, the iNOS inhibitor 1400 W at 10 mg/kg and the inhibitor of iNOS expression dexamethasone at 1 mg/kg, administered subcutaneously, blocked the citrulline production induced by the laxative. Taken together, these findings confirm the involvement of inhibition of the inducible isoform of nitric oxide synthase in the mechanism of action of S. boulardii in diarrhoea.