Prevention of further recurrences of Clostridium difficile colitis with Saccharomyces boulardii

Health-promoting properties of Saccharomyces cerevisiae var. boulardii as a probiotic; characteristics, isolation, and applications in dairy products

Saccharomyces cerevisiae var. boulardii (S. boulardii) has been isolated from lychee (Litchi chinensis), mangosteen fruit, kombucha, and dairy products like kefir. Dairy products containing S. boulardii have been revealed to possess potential probiotic activities owing to their ability to produce organic acids, essential enzymes, vitamins, and other important metabolites such as vanillic acid, phenyl ethyl alcohol, and erythromycin. S. boulardii has a wide spectrum of anti-carcinogenic, antibacterial antiviral, and antioxidant activity, and is known to reduce serum cholesterol levels. However, this yeast has mainly been prescribed for prophylaxis treatment of gastrointestinal infectious diseases, and stimulating the immune system in a number of commercially available products. The present comprehensive review article reviews the properties of S. boulardii related to their use in fermented dairy foods as a probiotic microorganism or starter culture. Technical aspects regarding the integration of this yeast into the dairy foods matrix its health advantages, therapeutic functions, microencapsulation, and viability in harsh conditions, and safety aspects are highlighted.

Effectiveness of probiotics in reducing the incidence of Clostridium difficile-associated diarrhea in elderly patients: a systematic review

BACKGROUND

Clostridium difficile bacteria are a leading cause of infectious diarrhea. This is an anaerobic, gram-positive and spore-forming rod responsible for significant morbidity and mortality, especially among elderly hospitalized patients. Standard management of C. difficile-associated diarrhea (CDAD) consists of discontinuing a causative antibiotic, correcting fluid-electrolytes imbalance and initiating an antibiotic treatment for CDAD. Alternative approaches for prevention of CDAD include probiotics. This systematic review will provide a comprehensive, unbiased summary of the available research on the effectiveness of probiotics in decreasing the incidence of infectious diarrhea in elderly hospitalized patients.

OBJECTIVES

To conduct a systematic review to determine the best available evidence related to the effectiveness of probiotics in the prevention of CDAD in elderly hospitalized patients. The review question was: are probiotics effective in decreasing the incidence of CDAD in elderly hospitalized patients?

INCLUSION CRITERIA TYPES OF PARTICIPANTS

The current review included studies of participants who were aged 60 years and more and who were residents of acute- and post-acute care facilities undergoing or planning to undergo antibiotic treatment for the management of any infectious conditions, except CDAD.

TYPES OF INTERVENTION(S)

The current review included studies that evaluated the effectiveness of probiotics for prevention of CDAD in elderly hospitalized patients in acute- and post-acute care settings compared to usual care.

OUTCOMES

The current review included studies examining the following outcome measures: incidence or relapse of CDAD. Cases of CDAD were defined by presence of diarrhea and verified by positive results for stool enzyme immunoassay for toxins A and B.

TYPES OF STUDIES

The current review included only experimental study designs including randomized controlled trials.

SEARCH STRATEGY

The search strategy included studies published in English between 1978, when the first case of CDAD was reported, and 2015.

ASSESSMENT OF METHODOLOGICAL QUALITY

Papers selected for retrieval were assessed by two independent reviewers for methodological quality prior to inclusion in the review using standardized critical appraisal instruments from the Joanna Briggs Institute (JBI).

DATA EXTRACTION

Data were extracted from papers included in the review using the standardized data extraction tool from the JBI Meta-Analysis of Statistics Assessment and Review Instrument. The data extracted included specific details about the interventions, populations, study methods and outcomes of significance to the review question and specific objectives.

DATA SYNTHESIS

Quantitative data were pooled using statistical meta-analysis. Effect sizes were expressed as odds ratios, and their 95% confidence intervals were calculated to determine if probiotic treatment was superior to placebo in reducing CDAD incidence. Heterogeneity was assessed using the standard I statistic.

RESULTS

Five studies were included in the review. The individual study results were conflicting, including non-significant results for four studies and statistically significant results in one that demonstrated fewer cases of CDAD among patients receiving probiotics compared to placebo. The meta-analysis finding indicated that there was no statistically significant difference in CDAD incidence in elderly hospitalized patients taking probiotics when compared to a placebo.

CONCLUSION

Probiotics were not found to be more effective than placebo for reducing CDAD incidence in elderly hospitalized patients. However, studies that demonstrate improved outcomes must be examined to determine future needs for research. Studies varied with regard to the dose, frequency, method of administration (probiotic drinks versus capsule), length of administration and the number of strains of bacteria administered. Further studies are needed to evaluate the effectiveness of probiotics for CDAD prevention in this population. Clinical trials with evidence-based administration methods and meta-analyses that pool the results of studies with congruent methodologies are needed to enable conclusions to be drawn on the effectiveness of probiotic administration for CDAD prevention.

Probiotics for the treatment of Clostridium difficile associated disease

The purpose of this review paper is to update the current and potential future role of probiotics for Clostridium difficile-associated disease (CDAD). Included in this review, is an update on the testing of newer probiotics (e.g., Bacillus coagulans GBI-30, 6086) in animal models of CDAD. There is a focus on the modulation of signal transduction pathways (i.e., transcription factors like cAMP response element-binding, activator protein 1, and nuclear factor kappa B), as well as the inhibition of certain kinases (e.g., p38 mitogen activated protein kinases) by probiotics. Inhibition of signal transduction by probiotics, such as Saccharomyces boulardii, result in multiple effects on intestinal fluid secretion, neutrophil influx into the colon, inflammation, and colonocyte apoptosis that may positively impact CDAD. Recent clinical approaches with probiotics, for the prevention of primary and recurrent CDAD, are also summarized in this review paper. Future directions for the treatment of CDAD by probiotics are also mentioned in this review. In particular, the use of multi-strain probiotic formulations such as Ecologic^® AAD and VSL #3^® may represent a rationale pharmacological approach, particularly as adjunctive therapies for CDAD. Understanding the mechanistic basis of CDAD, and how probiotics interfere at ceratin steps in the pathogenic process, may also present the opportunity to design other multi-strain probiotics that could have a future impact on CDAD.

Bacillus coagulans GBI-30, 6086 limits the recurrence of Clostridium difficile-Induced colitis following vancomycin withdrawal in mice

Background

Recently, we found that the probiotic strain Bacillus coagulans GBI-30, 6086 (GanedenBC³⁰) improved indices of Clostridium difficile (C. difficile)-induced colitis in mice (Fitzpatrick et al., Gut Pathogens, 2011). Our goal was to determine if BC30 could also prevent the recurrence of C. difficile-induced colitis in mice, following initial treatment with vancomycin. During study days 0 through 5, mice were treated with antibiotics. On day 6, the C. difficile strain VPI 10463 was given by oro-gastric gavage at ≈ 5x10⁴ CFU to induce colitis. Mice were treated on study days 6 to 10 with vancomycin (50 mg/kg) (vanco) or vehicle (saline) by gavage. On days 10 to16, mice were dosed by gavage with saline vehicle or BC30 (2 x 10⁹ CFU per day). Mice were monitored for mortality, weight loss and diarrhea. On study days 14, 16 and 17, stools and colons were collected for analyzing other parameters of colitis.

Results

The mean stool consistency score in Vehicle/C.difficile/Vanco mice increased from 0.4 (day 10) to a range of 1.1 to 1.4 (days 14 to 17), indicating the recurrence of colitis. On days 13 through 17, the stool consistency scores for the vancomycin/BC30 mice were significantly lower (p< 0.05) than for the vancomycin/vehicle cohort of animals. On day 17, 88.9% of mice treated with BC30 had normal stools, while this value was 0% with vehicle treatment (p value = 0.0004). Colonic myeloperoxidase (Units/2 cm colon) was significantly (p < 0.05) reduced from 4.3 ± 0.7 (Vehicle/C.difficile/Vanco) to 2.6 ± 0.2 (BC30/C. Difficle/Vanco). The colonic histology score and Keratinocyte derived-chemokine level in the colon were also lower in BC30 treated mice.

Summary

In BC30-treated mice, there was evidence of better stool consistency, as well as improved biochemical and histological indices of colitis, following initial treatment of animals with vancomycin.

Conclusion

BC30 limited the recurrence of CD-induced colitis following vancomycin withdrawal in mice.

Bacillus Coagulans GBI-30 (BC30) improves indices of Clostridium difficile-Induced colitis in mice

Background

Probiotics have beneficial effects in rodent models of Clostridium difficile (C. diffiicle)-induced colitis. The spore forming probiotic strain Bacillus Coagulans GBI-30, 6086 (BC30) has demonstrated anti-inflammatory and immune-modulating effects in vitro. Our goal was to determine if BC30 improved C. difficile-induced colitis in mice. Starting on study day 0, female C57BL/6 mice were dosed by oro-gastric gavage for 15 days with vehicle (saline) or BC30 (2 × 10⁹ CFU per day). Mice in the C. difficile groups received an antibiotic mixture (study days 5 to 8 in the drinking water), and clindamycin (10 mg/kg, i.p., on study day 10). The C. difficile strain VPI 10463 was given by gavage at 10⁴ CFU to induce colitis on day 11. On day 16, stools and colons were collected for further analyses.

Results

All mice treated with BC30 survived on study day 13, while two mice treated with vehicle did not survive. On day 12, a significant difference (p = 0.0002) in the percentage of mice with normal stools (66.7%) was found in the BC30/C. difficile group, as compared to the vehicle/C. diffcile group (13.0%). On study day 16, 23.8% of mice treated with BC30 had normal stools, while this value was 0% with vehicle treatment (p value = 0.0187). On this day, the stool consistency score for the BC30/C. difficile group (1.1 ± 0.2) was significantly lower (p < 0.05) than for the vehicle/C. difficile cohort (1.9 ± 0.2). BC30 modestly attenuated the colonic pathology (crypt damage, edema, leukocyte influx) that was present following C. difficile infection. Colonic MIP-2 chemokine contents (pg/2 cm colon) were: 10.2 ± 0.5 (vehicle/no C. difficile), 24.6 ± 9.5 (vehicle/C. difficile) and 16.3 ± 4.3 (BC30/C. difficle).

Conclusion

The probiotic BC30 improved some parameters of C. difficile-induced colitis in mice. BC30 prolonged the survival of C. diffiicle infected mice. Particularly, this probiotic improved the stool consistency of mice, in this infectious colitis model.

Clostridium difficile and the disease it causes

Clostridium difficile is a spore-forming, toxin-producing, anaerobic bacterium abundant in soils and water. Frequent and early colonization of the human intestinal flora is common and often asymptomatic. Antimicrobials given commonly disrupt the intestinal microflora and through proliferation in colon and production of toxin A and B it precipitates C. difficile infection (CDI). The enterocytic detachment and bowel inflammation provoke C. difficile-associated diarrhoea (CDAD) sometimes developing into severe pseudomembranous colitis (PMC) and paralytic ileus. Infection is acquired from an endogenous source or from spores in the environment, most easily facilitated during hospital stay. In the elderly, comorbidity, hospitalization and antimicrobial treatment present as major risk factors and the slow recolonization of the normal flora likely responsible for single or multiple recurrences of CDI (25-50%) post therapy. The key procedure for diagnosis is toxin detection from stool specimens and sometimes in combination with culture to increase sensitivity. In mild cases stopping the offending antimicrobial will lead to resolution (25%) but standard therapy still consist of either oral metronidazole or vancomycin. Alternative agents are presently being developed and fidaxomicin, as well as nitrothiazolide are promising. Furthermore, host factors like low antitoxin A levels in serum relates to increased risk of recurrence and small numbers of patients have received immunoglobulin with good results. An immunogenic toxoid vaccine has been developed and human colostrum rich in specific secretory Ig A also support the future use of immunotherapy. Today we experience a tenfold increase of CDI incidence in the western world and both epidemics and therapeutic failure of metronidazole is contributing to morbidity and mortality. The current epidemic of the C. difficile strain NAP1/027 emerging in 2002 in Canada and the USA has now spread to most parts of Europe and virulence factors like high toxin production and sporulation challenge the therapeutic situation and cause great concern among infection control workers. Excessive use of modern fluoroquinolones is thought to play an important role in facilitating this epidemic since NAP1/027 was shown to have acquired moxifloxacin resistance compared to historical strains of the same genotype. Both the current epidemic like this and other local outbreaks from resistant or virulent strains warrant culture to be routinely performed enabling susceptibility testing and typing of the pathogen. Genotyping is most commonly done today by pulse-field gel electrophoresis (PFGE) or PCR ribotyping but multilocus variable-number tandem-repeat analysis (MLVA) seems promising. Epidemiological surveillance using all these tools will help us to better understand the global spread of C. difficile.

Probiotics and Gastrointestinal Disease: Clinical Evidence and Basic Science

Our intestinal microbiota serve many roles vital to the normal daily function of the human gastrointestinal tract. Many probiotics are derived from our intestinal bacteria, and have been shown to provide clinical benefit in a variety of gastrointestinal conditions. Current evidence indicates that probiotic effects are strain-specific, they do not act through the same mechanisms, and nor are all probiotics indicated for the same health conditions. However, they do share several common features in that they exert anti-inflammatory effects, they employ different strategies to antagonize competing microorganisms, and they induce cytoprotective changes in the host either through enhancement of barrier function, or through the upregulation of cytoprotective host proteins. In this review we focus on a few selected probiotics - a bacterial mixture (VSL#3), a Gram-negative probiotic (E. coli Nissle 1917), two Gram-positive probiotic bacteria (LGG, L. reuteri), and a yeast probiotic (S. boulardii) - for which sound clinical and mechanistic data is available. Safety of probiotic formulations is also discussed.

Treatment of Clostridium difficile-associated disease

Clostridium difficile infection is an increasing burden to the health care system, totaling more than $1 billion/year in the United States. Treatment of patients with C difficile infection with metronidazole or vancomycin reduces morbidity and mortality, although the number of patients that do not respond to metronidazole is increasing. Despite initial response rates of greater than 90%, 15%-30% of patients have a relapse in symptoms after successful initial therapy, usually in the first few weeks after treatment is discontinued. Failure to develop specific antibody response has recently been identified as a critical factor in recurrence. The review discusses the different management strategies for initial and recurrent symptomatic C difficile infections.

The use of probiotics in the prevention and treatment of antibiotic-associated diarrhea with special interest in Clostridium difficile-associated diarrhea

Antimicrobials are effective agents used to combat virulent bacterial, yeast, and fungal infections that may otherwise cause rampant disease leading to skyrocketing social/economic costs and possible epidemic morbidity and mortality rates. Antibiotics are designed to attack specific bacterial pathogens but, in the process, indiscreetly reduce the number of beneficial human microbiota that is part of the gut-associated lymphatic tissue. Broad-spectrum antibiotics can upset this uniquely balanced gut ratio, allowing pathogens to propagate in a largely unrestrained environment, which may result in antibiotic-induced diarrhea. Critical illness, age, immunosuppression, exposure to nosocomial microorganisms, and the length of hospitalization are additional factors that contribute to the overgrowth of opportunistic pathogens. In mild to moderate cases of diarrhea, absorptive impairment may occur, thereby reducing micro/macronutrient assimilation, resulting in malnutrition and growth issues in children. In severe cases, infectious diarrhea can have devastating complications. Of particular interest is the bacterium Clostridium difficile, which has the potential to cause a host of symptoms ranging from mild diarrhea to severe life-threatening conditions. C. difficile infection can increase mortality rates by 10%-30%. Probiotic supplementation may prevent and treat antibiotic-associated diarrhea. Specific probiotics may modulate the intestinal mucosa by antagonizing pathogens through the production of antimicrobial compounds and chemicals, thereby reducing the rate of nosocomial infection and recurrence of C. difficile.

Is there a future for probiotics in preventing Clostridium difficile-associated disease and treatment of recurrent episodes?

Due to morbidity, mortality, and high costs associated with eradicating Clostridium difficile once this organism causes colitis, this bacterium has been termed one of the most ecologically relevant microorganisms of the present day. Symptoms associated with C. difficile diarrhea often first present during or shortly after a course of antibiotic therapy. During the past 5 years, the virulence of this organism has increased. C. difficile-associated disease (CDAD) has reached epidemic proportions in some hospital settings, prompting Medicare to propose adding CDAD to the list of hospital-acquired conditions for which reimbursements may be cut. Thus, it is imperative that effective preventive strategies be implemented in hospitals to decrease CDAD infections. It is plausible that probiotic supplements may offer a safe and effective means of preventing both initial CDAD episodes as well as CDAD recurrences. This review critically examines the current literature in which probiotic supplements have been studied for efficacy in CDAD prevention. This analysis will guide practitioners in applying available probiotic data to CDAD clinical scenarios and will assist researchers in the appropriate design of future studies as examination continues into the role that probiotics may have in CDAD prevention.

Clostridium difficile infection in solid organ transplant recipients

PURPOSE OF REVIEW

To provide a general understanding of Clostridium difficile infection with a focus on recent publications that evaluate the disease in solid organ transplant recipients.

RECENT FINDINGS

The incidence of C. difficile infection is increasing worldwide. Epidemics due to a hypervirulent C. difficile strain are associated with an escalating severity of disease. New evidence further supports basing initial treatment choice on disease severity.

SUMMARY

C. difficile is a significant pathogen in solid organ transplant recipients. Multiple risk factors are found in this population that may result in more severe disease. A high index of suspicion is necessary for the early diagnosis and treatment of C. difficile infection in transplant recipients. Metronidazole and vancomycin show equivalent efficacy in the treatment for mild-to-moderate disease, but vancomycin has demonstrated superiority in the treatment of severe disease. Surgical intervention is also an important consideration in the treatment of solid organ transplant recipients with severe colitis. Rigorous infection control practices are essential for preventing the spread of C. difficile within the hospital environment.

Probiotics for prevention of antibiotic-associated diarrhea

Antibiotic-associated diarrhea (AAD) occurs in approximately 25% of patients receiving antibiotics. Hospitalized patients with AAD are at increased risk for nosocomial infections and have a higher mortality. Probiotics are living microorganisms used to restore gut health by changing the intestinal microbiota. Several have been studied for the prevention of AAD. Five meta-analyses of trials of probiotics for the prevention of AAD have been performed. The results showed an overall reduction in the risk of AAD when probiotics were coadministered with antibiotics. McFarland conducted the largest meta-analysis to date analyzing 25 randomized controlled trials of probiotics for the prevention of AAD including 2810 subjects. More than half of the trials demonstrated efficacy of the probiotic. In particular, Lactobacillus GG, Saccharomyces boulardii, and the probiotic mixtures were effective. The Cochrane Database of Systematic Reviews published a review of the literature on the use of probiotics for the prevention of pediatric AAD, including 10 randomized trials testing 1986 children. The per protocol pooled analysis, but not the intent-to-treat analysis, showed that probiotics are effective for preventing AAD with the number needed to treat to prevent 1 case of diarrhea being 10. Lactobacillus GG, Bacillus coagulans, and S. boulardii appeared to be most effective. Probiotics are generally safe, however, they should be used with caution in patients who have compromise of either the immune system or the integrity of the intestinal mucosa, and in the presence of a central venous catheter.

Role of probiotics in antibiotic-associated diarrhea, Clostridium difficile-associated diarrhea, and recurrent Clostridium difficile-associated diarrhea

The role of probiotics in the prevention and treatment of antibiotic-associated diarrhea, Clostridium difficile diarrhea, and recurrent C. difficile diarrhea is reviewed. Various probiotics have variable efficacy. More studies are needed to define further their efficacies, roles, and indications.

Saccharomyces boulardii ameliorates Citrobacter rodentium-induced colitis through actions on bacterial virulence factors

Saccharomyces boulardii has received increasing attention as a probiotic effective in the prevention and treatment of infectious and inflammatory bowel diseases. The aim of this study was to examine the ameliorating effects of S. boulardii on Citrobacter rodentium colitis in vivo and identify potential mechanisms of action. C57BL/6 mice received 2.5 x 10(8) C. rodentium by gavage on day 0, followed by S. boulardii (25 mg; 5 x 10(8) live cells) gavaged twice daily from day 2 to day 9. Animal weights were monitored until death on day 10. Colons were removed and assessed for epithelial barrier function, histology, and myeloperoxidase activity. Bacterial epithelial attachment and type III secreted proteins translocated intimin receptor Tir (the receptor for bacterial intimin) and EspB (a translocation apparatus protein) required for bacterial virulence were assayed. In infected mice, S. boulardii treatment significantly attenuated weight loss, ameliorated crypt hyperplasia (234.7 +/- 7.2 vs. 297.8 +/- 17.6 microm) and histological damage score (0.67 +/- 0.67 vs. 4.75 +/- 0.75), reduced myeloperoxidase activity (2.1 +/- 0.4 vs. 4.7 +/- 0.9 U/mg), and attenuated increased mannitol flux (17.2 +/- 5.0 vs. 31.2 +/- 8.2 nm.cm(-2).h(-1)). The ameliorating effects of S. boulardii were associated with significantly reduced numbers of mucosal adherent C. rodentium, a marked reduction in Tir protein secretion and translocation into mouse colonocytes, and a striking reduction in EspB expression and secretion. We conclude that S. boulardii maintained colonic epithelial barrier integrity and ameliorated inflammatory sequelae associated with C. rodentium infection by attenuating C. rodentium adherence to host epithelial cells through putative actions on the type III secretion system.

Probiotics for Clostridium difficile-associated diarrhea: focus on Lactobacillus rhamnosus GG and Saccharomyces boulardii

OBJECTIVE

To review the literature on the use of probiotics to treat or prevent recurrences of Clostridium difficile-associated diarrhea (CDAD) by replacing normal gastric flora.

DATA SOURCES

PubMed (1970-March 2007) was searched using the terms probiotics, Clostridium difficile, colitis, diarrhea, prevention, and treatment.

STUDY SELECTION AND DATA EXTRACTION

Case reports, case series, and clinical trials describing the use of probiotics in the treatment or prevention of recurrences of CDAD as primary outcome were included.

DATA SYNTHESIS

A variety of controlled trials, case series, and case reports have evaluated probiotics to treat first or recurrent episodes of CDAD. In addition, a meta-analysis has been conducted to try to determine the role of probiotics in CDAD. In general, most case series and case reports have shown favorable results with Lactobacillus rhamnosus GG or Saccharomyces boulardii. However, other reports have shown lack of benefit. The meta-analysis showed that these probiotics may be useful in treating or preventing recurrences of CDAD. Nonetheless, the heterogeneity of the studies makes definite conclusions difficult. In addition, several cases of bacteremia or fungemia associated with probiotic use have been reported, particularly in the last decade. Patients most commonly affected by these complications are immunosuppressed. Unfortunately, these are also the patients more likely to have severe CDAD or are at risk for recurrences.

CONCLUSIONS

Additional experience with and study of probiotics are warranted due to numerous unanswered questions. Given the potential for complications in debilitated and immunosuppressed patients, the risks may outweigh benefits, and rational antibiotic use may be a better option to prevent a first episode or recurrence of CDAD.

Probiotics in paediatric gastrointestinal diseases

Probiotics have become increasingly popular and are now promoted as having a wide range of benefits. Probiotics are generally very well tolerated and safe but many of the purported uses are not yet well supported with adequate scientific evidence. Two well-established roles for probiotics in children are acute diarrhoeal illness and antibiotic-associated diarrhoea. This review summarises the evidence supporting probiotics for various gastrointestinal disorders with particular reference to their role in the management of acute diarrhoea and antibiotic-associated diarrhoea in children.

Prevalence of Clostridium Difficile Colonization at Admission to Rehabilitation

OBJECTIVES

To assess the prevalence of intestinal colonization with Clostridium difficile (C. difficile) at admission to acute rehabilitation and to identify risk factors associated with colonization.

DESIGN

Case-control study.

PARTICIPANTS

Consecutive admissions to 2 rehabilitation units (spinal cord injury, brain injury and stroke).

SETTING

Free-standing acute rehabilitation facility.

INTERVENTIONS

Rectal swabs for culture for C. difficile were obtained at admission and cytotoxin assay performed on all culture positive specimens. Rates of colonization with cytotoxic C. difficile were calculated. Charts were reviewed for medical and demographic factors that may have predisposed patients to colonization, and for possible symptoms at the time of admission.

MAIN OUTCOME MEASURES

Percentage of patients with culture and cytotoxin assay positive for C. difficile. Frequency of specific patient characteristics that could predispose to C. difficile colonization.

RESULTS

Of admission stool samples, 16.4% tested positive for C. difficile; none of these patients had been identified as colonized before admission. No patients were discordant for C. difficile positivity on culture and presence of a toxigenic strain. No medical or demographic factors were associated with increased risk of colonization, including age (t(52)=-.748, P=.458, not significant [NS]), diarrhea within 24 hours of admission (chi(1)(2) test=.001, P=.973 [NS]), or use of oral or intravenous antibiotics at admission (chi(1)(2) test=.044, P=.834 [NS]).

CONCLUSIONS

Patients admitted to acute rehabilitation may have an elevated rate of intestinal colonization with C. difficile without having clinical symptoms. No medical or demographic characteristics were found to be predictive of colonization, however, most of the patients admitted had more than 1 factor that may have increased their susceptibility to infection with this organism. Inadvertent transfer of this organism within the rehabilitation setting may occur because asymptomatic colonization is not recognized.

Efficacy of Saccharomyces boulardii for treatment of horses with acute enterocolitis

OBJECTIVE

To evaluate the viability of Saccharomyces boulardii after PO administration in clinically normal horses and its efficacy as a treatment for horses with acute enterocolitis.

DESIGN

Prospective study.

ANIMALS

5 clinically normal horses and 14 horses with acute enterocolitis.

PROCEDURE

Feces were collected from 5 clinically normal horses and submitted for microbial culture for 2 days prior to administration of a lyophilized form of S. boulardii (25 or 50 g, PO, q 12 h) for 10 days. Feces were collected for microbial culture 5 and 10 days after treament initiation and 10 days after treatment was discontinued. Fourteen horses with acute enterocolitis were randomly allocated to receive a placebo or S. boulardii (25 g), PO, every 12 hours for 14 days.

RESULTS

S. boulardii was not detected in feces of clinically normal horses. After administration, yeast survived within the gastroinestinal tract but did not permanently colonize it. In horses with acute enterocolitis, the severity and duration of gastrointestinal tract disease during hospitalization were significantly decreased in horses receiving S. boulardii, compared with horses receiving the placebo.

CONCLUSIONS AND CLINICAL RELEVANCE

Administration of S. boulardii may help decrease the severity and duration of clinical signs in horses with acute enterocolitis.

Screening of yeasts as probiotic based on capacities to colonize the gastrointestinal tract and to protect against enteropathogen challenge in mice

Probiotics are defined as viable microorganisms that exhibit a beneficial effect on the host's health when they are ingested. Two important criteria are used for selection of probiotic microorganisms: they must be able to survive in the gastrointestinal environment and to present at least one beneficial function (colonization resistance, immunomodulation or nutritional contribution). Generally, in vitro assays demonstrating these properties were used to select probiotics but it is unclear if the data can be extrapolated to in vivo conditions. In the present work, twelve Saccharomyces cerevisiae strains isolated from different environments (insect association, tropical fruit, cheese and "aguardente" production) and pre-selected for in vitro resistance to simulated gastrointestinal conditions were inoculated in germ-free mice to evaluate their real capacity to colonize the mammal digestive tract. Using these data, one of the yeasts (S. cerevisiae 905) was selected and tested in gnotobiotic (GN) and conventional (CV) mice for its capacity to protect against oral challenge with two enteropathogenic bacteria (Salmonella Typhimurium and Clostridium difficile). The yeast reached populational levels potentially functional in the gastrointestinal portions where the enteropathogens tested act. No antagonism against either pathogenic bacterium by the yeast was observed in the digestive tract of GN mice but, after challenge with S. Typhimurium, mortality was lower and liver tissue was better preserved in CV animals treated with the yeast when compared with a control group (p<0.05). Histopathological results of intestines showed that the yeast also presented a good protective effect against oral challenge with C. difficile in GN mice (p<0.05). In conclusion, among the 12 S. cerevisiae tested, strain 905 showed the best characteristics to be used as a probiotic as demonstrated by survival capacity in the gastrointestinal tract and protective effect of animals during experimental infections.

Failure of dietary oligofructose to prevent antibiotic-associated diarrhoea

BACKGROUND

Oligofructose is metabolized by bifidobacteria, increasing their numbers in the colon. High bifidobacteria concentrations are important in providing 'colonization resistance' against pathogenic bacteria.

AIM

To reduce the incidence of antibiotic-associated diarrhoea in elderly patients.

METHODS

Patients over the age of 65 taking broad-spectrum antibiotics received either oligofructose or placebo. A baseline stool sample was cultured for Clostridium difficile and tested for C. difficile toxin. A further stool sample was analysed for C. difficile if diarrhoea developed.

RESULTS

No difference was seen in the baseline characteristics, incidence of diarrhoea, C. difficile infection or hospital stay between the two groups (n = 435). Oligofructose increased bifidobacterial concentrations (P < 0.001, 95% CI: 0.69-1.72). A total of 116 (27%) patients developed diarrhoea of which 49 (11%) were C. difficile-positive and were more likely to be taking a cephalosporin (P = 0.006), be female (P < 0.001), to have lost more weight (P < 0.001, 95% CI: 0.99-2.00) and stayed longer in hospital (P < 0.001, 95% CI: 0.10-1.40). Amoxicillin (amoxycillin) and clavulanic acid increased diarrhoea not caused by C. difficile (P = 0.006).

CONCLUSION

Oligofructose does not protect elderly patients receiving broad-spectrum antibiotics from antibiotic-associated diarrhoea whether caused by C. difficile or not. Oligofructose was well-tolerated and increased faecal bifidobacterial concentrations.

Treatment of clostridium difficile infection

With the introduction of broad-spectrum antibiotics into clinical practice, Clostridium difficile infection has become the most common cause of infectious diarrhea in hospitalized patients. Although mild cases may resolve by discontinuing antibiotics, thus allowing re-establishment of colonic microflora, oral metronidazole or vancomycin is indicated if the process is more severe. Metronidazole may be given intravenously, with intracolonic therapeutic levels achieved by excretion of drug into bile and exudation across inflamed tissue. Vancomycin is preferred treatment of severe cases. Bacitracin given orally is a therapeutic alternative and cholestyramine is a useful adjunct. Most patients with diarrhea or colitis caused by C. difficile respond to initial therapy; however, up to 20% experience relapse when treatment is discontinued. Repeating initial therapy for 10 to 14 days is indicated for first relapse. Multiple relapses require prolonged treatment with vancomycin, which may be supplemented with cholestyramine. Saccharomyces boulardii alone or in combination with vancomycin has been reported to be an effective therapeutic alternative for recurrent infection. Intravenous immunoglobulin can be effective in patients with severe recurrent Clostridium difficile colitis and immune deficiency or low pretreatment levels of serum antitoxin. Surgery is indicated only if recurrent infections are severe and associated with serious complications.

Probiotics and inflammatory bowel disease

Inflammatory bowel disease (IBD) is characterised by a chronic dysregulation of the inflammatory response in the gastrointestinal tract. While the pathogenesis is unclear, studies have demonstrated that the gastrointestinal tracts of patients with IBD are populated with increased levels of adherent and pathogenic bacteria. This evidence, combined with growing data accumulated from genetic studies as well as animal models of IBD, indicates that an aberrant response to altered enteric flora plays a significant role in the disease process. Current therapies for IBD have been directed towards the development of anti-inflammatory agents and immunomodulators to attenuate the inflammatory response in the gastrointestinal tract. Antibiotics are also partially effective in the treatment of IBD, presumably by altering the bowel flora. However, it is clear from clinical trials that immunomodulators and antibiotics are not effective in a large proportion of patients with IBD and other therapeutic alternatives need to be pursued. Probiotics are microbial supplements capable of recolonising the bowel with non-pathogenic strains of bacteria or yeast. Probiotics have long been shown to be beneficial in both infectious and non-infectious digestive disorders. Growing evidence indicates that probiotics may be effective in the treatment of specific clinical IBD conditions. This article addresses the current evidence for the role of enteric flora in the pathogenesis of IBD and the clinical evidence supporting the use of probiotics in specific clinical IBD conditions.

A pilot trial of Saccharomyces boulardii in ulcerative colitis

OBJECTIVES

Probiotics can be useful in the treatment of inflammatory bowel disease. In a previous report, the non-pathogenic yeast Saccharomyces boulardii was found to be beneficial in the maintenance treatment of Crohn's disease. The aim of this study was to assess the efficacy of S. boulardii in ulcerative colitis patients.

METHODS

A group of 25 patients with a mild to moderate clinical flare-up of ulcerative colitis received additional treatment with S. boulardii 250 mg three times a day for 4 weeks during maintenance treatment with mesalazine. These patients were unsuitable for steroid therapy. Before and after treatment, Rachmilewitz's clinical activity index was calculated. The probiotic treatment was considered a therapeutic success only when the final score was lower than 6.

RESULTS

Of the 24 patients who completed the study, 17 attained clinical remission; this was confirmed endoscopically.

CONCLUSIONS

Our preliminary results suggest that S. boulardii can be effective in the treatment of ulcerative colitis. Controlled studies with this probiotic agent are warranted.

Clustering of Saccharomyces boulardii strains within the species S. cerevisiae using molecular typing techniques

AIMS

This study was undertaken to characterize and differentiate therapeutically relevant Saccharomyces yeasts. Among the isolates were so-called Saccharomyces boulardii strains, which are considered as probiotic agents, but whose taxonomic assignment is controversial. Moreover, the discriminative power of the applied molecular typing techniques should be evaluated.

METHODS AND RESULTS

Genotyping was performed using species-specific polymerase chain reaction (PCR), randomly amplified polymorphic DNA-PCR, restriction fragment length polymorphism analysis of rDNA spacer regions and pulsed-field gel electrophoresis. Species-specific PCR assigned all of the product isolates to the species S. cerevisiae. By combining the other techniques, all isolates could be discriminated. Moreover, it could be demonstrated that probiotic S. boulardii strains form a separate cluster located within the species.

CONCLUSIONS

With the exception of species-specific PCR, all of the applied methodologies were suitable for subspecies typing and indicated a close relationship between the probiotic strains.

SIGNIFICANCE AND IMPACT OF THE STUDY

The methods applied in this study are considered powerful tools for quality control of therapeutically relevant yeasts. It is of crucial importance, especially regarding S. boulardii yeasts, to verify the identity of the correct strain, since the beneficial properties are considered to be strain-specific.

Saccharomyces Boulardii in the Prevention of Pseudomembranous Colitis

Objective

To evaluate the efficacy of the yeast Saccharomyces boulardii in the prevention of pseudomembranous colitis (PMC).

Data Sources

A MEDLINE search (January 1966–April 2000, updated July 2001) of English-language medical literature was conducted. Key search terms included Saccharomyces boulardii, pseudomembranous colitis, antibiotic-associated diarrhea, and Clostridium difficile. Additional information was obtained from pathophysiology and medical textbooks.

Data Synthesis

S. boulardii is a nonpathogenic yeast used to treat and prevent antibiotic-associated diarrhea, including PMC, a serious, sometimes refractory complication of antibacterial drug therapy. A literature search was conducted to determine its efficacy in preventing PMC.

Conclusions

When administered in combination with standard treatments, S. boulardii does not appear to prevent the first relapse but does appear to reduce subsequent recurrences of probable PMC in patients experiencing antibiotic-associated diarrhea. It has also shown promise as monotherapy in preventing the development of antibiotic-associated diarrhea in patients not experiencing diarrhea. Further well-designed, controlled studies are needed.

Epidemiology of Clostridium difficile infection in a large population of hospitalized US military veterans

The Patient Treatment File (PTF) of the Department of Veterans Affairs (VA) comprises the computerized records of all inpatients treated at all VA hospitals throughout the United States. The database was utilized to study the clinical epidemiology and impact of C. difficile colitis on health care among hospitalized US military veterans. The computerized medical records of 15,091 cases with C. difficile colitis and 61,931 controls without the diagnosis were extracted from the annual files between 1993 and 1998. Of all patients admitted to the hospital, 1% were diagnosed with C. difficile colitis, in 16% of whom it was listed as the primary discharge diagnosis. C. difficile colitis was more likely to occur in elderly white patients with multiple comorbid conditions. Compared with a control population of hospitalized patients without C. difficile colitis, the case population was subjected to more medical and surgical procedures and experienced longer hospital stays. The diagnosis of C. difficile colitis was associated with more frequent admissions to the intensive care unit and higher hospital-related and subsequent mortality. Eleven percent of the cases were admitted to hospital a second time after a mean of 202 days, 2.5% were readmitted a third time after an additional 182 days, and 0.8% were readmitted a fourth time after an additional 194 days. In conclusion, as old age, multiple comorbid conditions, a high number of medical and surgical intervention, and long hospitalization constitute the main risk factors for the development of C. difficile colitis, efforts at prevention should be directed primarily towards patients who present with these characteristics.

Saccharomyces boulardii stimulates intestinal immunoglobulin A immune response to Clostridium difficile toxin A in mice

Saccharomyces boulardii is a nonpathogenic yeast that protects against antibiotic-associated diarrhea and recurrent Clostridium difficile colitis. The administration of C. difficile toxoid A by gavage to S. boulardii-fed BALB/c mice caused a 1.8-fold increase in total small intestinal immunoglobulin A levels (P = 0.003) and a 4.4-fold increase in specific intestinal anti-toxin A levels (P < 0.001). Enhancing host intestinal immune responses may be an important mechanism for S. boulardii-mediated protection against diarrheal illnesses.

Protection from gastrointestinal diseases with the use of probiotics

Probiotics are nonpathogenic microorganisms that, when ingested, exert a positive influence on the health or physiology of the host. They can influence intestinal physiology either directly or indirectly through modulation of the endogenous ecosystem or immune system. The results that have been shown with a sufficient level of proof to enable probiotics to be used as treatments for gastrointestinal disturbances are 1) the good tolerance of yogurt compared with milk in subjects with primary or secondary lactose maldigestion, 2) the use of Saccharomyces boulardii and Enterococcus faecium SF 68 to prevent or shorten the duration of antibiotic-associated diarrhea, 3) the use of S. boulardii to prevent further recurrence of Clostridium difficile-associated diarrhea, and 4) the use of fermented milks containing Lactobacillus rhamnosus GG to shorten the duration of diarrhea in infants with rotavirus enteritis (and probably also in gastroenteritis of other causes). Effects that are otherwise suggested for diverse probiotics include alleviation of diarrhea of miscellaneous causes; prophylaxis of gastrointestinal infections, which includes traveler's diarrhea; and immunomodulation. Trials of gastrointestinal diseases that involve the ecosystem are currently being performed, eg, Helicobacter pylori infections, inflammatory bowel disease, and colon cancer.

Saccharomyces boulardii in maintenance treatment of Crohn's disease

The possible role of Saccharomyces boulardii, a nonpathogenic yeast with beneficial effects on the human intestine, in the maintenance treatment of Crohn's disease has been evaluated. Thirty-two patients with Crohn's disease in clinical remission (CDAI < 150) were randomly treated for six months with either mesalamine 1 g three times a day or mesalamine 1 g two times a day plus a preparation of Saccharomyces boulardii 1 g daily. Clinical relapses as assessed by CDAI values were observed in 37.5% of patients receiving mesalamine alone and in 6.25% of patients in the group treated with mesalamine plus the probiotic agent. Our results suggest that Saccharomyces boulardii may represent a useful tool in the maintenance treatment of Crohn's disease. However, in view of the product's cost, further controlled studies are needed to confirm these preliminary data.

Pseudomembranous colitis after itraconazole therapy

A 53-yr-old man was admitted with new onset of abdominal pain and nonbloody diarrhea 1 month after exposure to the antifungal agent itraconazole. Flexible sigmoidoscopy demonstrated the presence of pseudomembranes, and subsequent evaluation excluded other causes of diarrhea. Disruption of the resident fungal flora of the colon by itraconazole is proposed as the mechanism by which this patient developed pseudomembranous colitis. This association has not previously been reported.

The lack of therapeutic effect of Saccharomyces boulardii in the prevention of antibiotic-related diarrhoea in elderly patients

Diarrhoea is a common side effect of antibiotic therapy, especially in the elderly. Saccharomyces boulardii is a non-pathogenic yeast which has been demonstrated to reduce the frequency of diarrhoea in patients due to a variety of causes. We set out to assess its role in preventing antibiotic-related diarrhoea. Consecutive patients over the age of 65 admitted to medical wards, and who were being prescribed antibiotics, were randomized to receive either S. boulardii 113 g twice daily or placebo for as long as they received antibiotics. Bowel habit was monitored using a record of interdefaecatory intervals (IDI) and stool form graded 1-4 (hard to liquid). Stool samples were tested every fourth day for Clostridium difficile toxin. Of the 72 patients randomized, 69 completed the study. There was no difference in sex, age, duration of antibiotic use, length of hospital stay, IDI, stool form, the proportion of patients receiving laxatives, the number of patients experiencing watery stools (seven vs. five), or the presence of C. difficile toxin (five vs. three). No side effects were attributable to S. boulardii. There was no evidence that the concomitant use of S. boulardii with antibiotics alters patients' bowel habits or prevents the appearance of C. difficile toxin in the stool. Thus, S. boulardii cannot be recommended as a 'natural' way to prevent antibiotic-related diarrhoea. This highlights the need for proper evaluation of probiotics before their unrestricted use in medical practice.

Clostridium difficile infection: a common clinical problem for the general internist

Considering the current wide use of antimicrobial agents, the general internist is commonly faced with the patient at risk for diarrhea due to C. difficile. The diagnosis should be considered for any patient with diarrhea who has received any type of antibiotic therapy in the preceding 4-6 weeks. Symptoms may range from a minor bout of diarrhea to fulminant and fatal colitis. Diagnosis usually requires demonstration of the toxin in stool; culture of the organism and fiberoptic endoscopy may play an adjunctive role in selected clinical settings. The ultimate goal in the treatment for C. difficile infection is to repopulate the normal colonic flora in the most efficacious manner. Minimally symptomatic patients may respond to discontinuing the offending antimicrobial agent or using nonspecific binding agents. Oral vancomycin continues to be the "gold standard" for specific treatment, while metronidazole therapy is considered the first-line agent for individuals with milder infection. Oral bacitracin shows promise, though large studies are lacking. Patients with multiple relapses of C. difficile diarrhea can be treated with prolonged courses of vancomycin or a combination of vancomycin and rifampin. Intensive care unit patients who are NPO have few therapeutic options besides intravenous administration of metronidazole and oral administration of vancomycin via clamped nasogastric tube. Preventive efforts are directed at cautious use of antibiotics and the use of vinyl gloves when caring for patients with known infection.

Recovery and elimination of the biotherapeutic agent, Saccharomyces boulardii, in healthy human volunteers

Saccharomyces boulardii (Sb) is a nonpathogenic yeast used to treat intestinal illnesses such as pseudomembranous colitis and antibiotic associated diarrhea. The behavior of this biotherapeutic agent in humans was determined (1) in investigating the effect of dose on the steady-state level and recovery and (2) in quantitating the effect of ampicillin on the recovery and elimination profile. As the Sb dose increased, the mean steady-state concentration of Sb increased significantly. The percentage recovery was dose independent. When a single Sb dose was administered 24 hr after beginning a course of ampicillin, there was a significant increase (P < 0.01) in both the area under the concentration versus time curve and the maximum fecal concentration compared to values obtained without ampicillin. Ampicillin increased steady-state recovery of the drug about twofold (P < 0.05) and steady-state levels about 2.4 times (P < 0.01). These studies have shown that there is a relationship between the dose and the amount of Sb recovered and that perturbation of the GI flora by ampicillin increases steady-state levels of Sb.

Saccharomyces boulardii inhibits Clostridium difficile toxin A binding and enterotoxicity in rat ileum

BACKGROUND

Saccharomyces boulardii is a nonpathogenic yeast used for the prevention and treatment of Clostridium difficile-associated diarrhea and colitis. However, the mechanism by which S. boulardii exerts its protective effects remains unclear.

METHODS

The binding of [3H]toxin A to its brush border receptor preincubated with S. boulardii-cultured suspension or filtered conditioned medium was measured in vitro. The effect of toxin A on secretion, epithelial permeability, and morphology in rat ileal loops in vivo was also examined in rats pretreated with S. boulardii.

RESULTS

S. boulardii reduced [3H]toxin A-receptor binding in a dose-dependent fashion. Sodium dodecyl sulfate polyacrylamide gel electrophoresis of ileal brush border exposed to S. boulardii-conditioned medium revealed a diminution of all brush border proteins. Treatment of rats with S. boulardii suspension reduced fluid secretion and mannitol permeability caused by toxin A.

CONCLUSIONS

S. boulardii may reduce some of the enterotoxic effects of toxin A by inhibiting toxin A-receptor binding. This effect appears to be manifested by a secreted product of the yeast, possibly a protease.

Passive immunization of hamsters against disease caused by Clostridium difficile by use of bovine immunoglobulin G concentrate

Gestating Holstein cows were vaccinated with Clostridium difficile toxoid prepared from the culture filtrate of a strain that produces high levels of toxins A and B and other antigens. A bovine immunoglobulin G (IgG) concentrate was prepared from colostrum collected at parturition. The results of our studies showed that hamsters treated prophylactically with the hyperimmune bovine IgG concentrate were protected against C. difficile disease. These results suggest that orally administered hyperimmune bovine IgG specific for C. difficile culture filtrate may be useful in prophylaxis against C. difficile disease.