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Primary prevention of Clostridium difficile infections with a specific probiotic combining Lactobacillus acidophilus, L. casei, and L. rhamnosus strains: assessing the evidence
Clostridium difficile infection (CDI) has become the leading healthcare-associated infection and cause of outbreaks around the world. Although various innovative treatments have been developed, preventive strategies using multi-faceted infection control programmes have not been successful in reducing CDI rates. The major risk factor for CDI is the disruption of the normally protective gastrointestinal microbiota, typically by antibiotic use. Supplementation with specific probiotics has been effective in preventing various negative outcomes, including antibiotic-associated diarrhoea and CDI. However, a consensus of which probiotic strains might prevent CDI has not been reached and meta-analyses report high degrees of heterogeneity when studies of different probiotic products are pooled together. We searched the literature for probiotics with sufficient evidence to assess clinical efficacy for the prevention of CDI and focused on one specific probiotic formulation comprised of three lactobacilli strains (Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R, Lactobacillus rhamnosus CLR2, Bio-K+) for its ability to prevent CDI in healthcare settings. A literature search on this probiotic formulation was conducted using electronic databases (PubMed, Google Scholar), abstracts from infectious disease and infection control meetings, and communications from the probiotic company. Supporting evidence was found for its mechanisms of action against CDI and that it has an excellent safety and tolerability profile. Evidence from randomized controlled trials and facility-level interventions that administer Bio-K+ show reduced incidence rates of CDI. This probiotic formulation may have a role in primary prevention of healthcare-associated CDI when administered to patients who receive antibiotics.
Clostridium difficile infections (CDI) have been a persistent and difficult clinical challenge for the past four decades. CDI has become the most widely reported healthcare-associated infection, accounting for >453,000 cases per year [
]. The ease of transmission of C. difficile is due to multiple factors: antibiotic-resistant spores (found on 20–50% of hospital environmental surfaces and on hands of hospital staff and patients), the ability of C. difficile vegetative cells to colonize patients with disrupted intestinal microbiomes (by antibiotics, surgery, or other procedures), and the production of toxins that cause cellular damage and initiate an inflammatory response leading to symptomatic CDI [
What’s lurking under the bed? Persistence and predominance of particular Clostridium difficile strains in a hospital and the potential role of environmental contamination.
]. In addition, the treatments for CDI may fail to eradicate the C. difficile spores, leading to 20–30% of the cases to recur within two or three months. These are major reasons why CDI is so difficult to treat and why prevention of healthcare-associated CDI has been challenging. Symptoms of CDI range from mild diarrhoea to severe colitis, and complications may include sepsis, colonic perforation, or the need for colectomy [
]. Consequences of CDI include prolonged healthcare stays, 24% higher hospital readmission rates, increased risk of other nosocomial infections, higher mortality rates (as high as 22% 90-day mortality), and higher healthcare-associated costs (reaching US$4.8 billion per year) [
]. Outbreaks of CDI in hospitals and long-term care facilities are occurring with increasing frequency across the globe despite efforts to control these outbreaks [
Efforts targeted at primary prevention of CDI have focused on multi-disciplinary infection control practices or ‘bundles’, which have resulted in reduced CDI rates but have been unable to eradicate CDI due, in part, to the difficulty in long-term sustainability of these enhanced infection control programmes and the varying efficacy of the different bundle components [
]. Because common healthcare exposures (such as antibiotics) may reduce the patient's intestinal microbial diversity resulting in osmotic and secretory changes that lead to diarrhoea, and because probiotics have been shown to help restore this disruption, this strategy seems promising [
]. Clinical trials have demonstrated efficacy for specific probiotics in preventing antibiotic-associated diarrhoea (AAD) and prevention of recurrences of CDI [
]. A recent Cochrane review found ‘moderate quality evidence’ suggesting that probiotics are both safe and effective for preventing CDI but noting a high level of heterogeneity when different studies were pooled [
]. Other meta-analyses have pooled studies of different types of probiotic products, which can result in contributing to high levels of heterogeneity and may introduce bias. Beyond specific probiotic strain(s) tested, differences in efficacy can also be a function of daily doses and formulations used [
Expert consensus document. The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic.
]. In-vitro studies across Lactobacillus spp. strains and probiotic formulations show enormous variation in competitive mechanisms and potency. For example, significant differences in antibiotic sensitivities were found among 170 strains of lactobacilli [
]. Even when comparing 13 different probiotic products of the same strain (Lactobacillus rhamnosus GG), available in different formulations (four capsule products, two commercial infant foods, three from freeze-dried products, and four from soft agar), significant differences in the ability to interfere with pathogen attachment among the products were found [
A specific formulation of Lactobacillus acidophilus CL1285, L. casei LBC80R, and L. rhamnosus CLR2 (Bio-K+) has been marketed in North America since 1996, is well characterized in terms of mechanisms of actions, safety, kinetics, and clinical efficacy in various therapeutic applications [
Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R, and Lactobacillus rhamnosus CLR2 (Bio-K+): characterization, manufacture, mechanisms of action, and quality control of a specific probiotic combination for primary prevention of Clostridium difficile infection.
]. This review examines the totality of the evidence for this specific probiotic formulation and examines its use when added to infection control bundles with new facility-level intervention studies for the primary prevention of CDI.
Methods
Search strategy
A literature search from January 1st, 2000 to January 1st, 2018 was conducted, using electronic databases (PubMed, Medline, Google Scholar, Cochrane Databases), meeting abstracts from infectious disease and infection control meetings, and communications with probiotic manufacturers. Reference lists from extracted articles or reviews were also searched. We initially searched the literature for probiotics that were being used as facility-level interventions to reduce CDI rates and restricted further searches to specific probiotics with at least two intervention trials, resulting in only one probiotic with multiple studies. The following search terms and Medical Subject Headings (MeSH) were included: ((probiotic) OR (probiotic OR Lactobacillus) OR (Bio-K+) OR (L. acidophilus CL1285) OR (L. casei LBC80R) OR (L. rhamnosus CLR2) OR (infection control) AND (prevention of Clostridium difficile)). No language restrictions were imposed.
Selection criteria
Inclusion criteria included: in-vitro studies or animal models for mechanism of action or pharmacokinetic studies, randomized controlled trials or facility-level interventions in adult or paediatric inpatients at risk for CDI, published papers or meeting abstracts of the probiotic formulation of interest. Reviews and meta-analyses were screened but not included if no new information was provided. Exclusion criteria included: probiotic not fully described (strain(s) not described, no daily dose or duration data), no control group for randomized controlled trials (no placebo group) or no pre-intervention period for facility-level studies and less than two facility-level intervention studies for prevention of CDI with the same probiotic.
Results
Literature search
Initial screening of the literature found a total of 129 articles on probiotics and prevention of CDI: 123 studies of probiotics from database searches and six from meeting abstracts. Of these, sixty-nine (reviews, commentaries, meta-analyses, duplicate studies) were excluded. Much of the evidence for reducing CDI was found from randomized controlled trials testing various probiotics for the prevention of antibiotic-associated diarrhoea, which also reported CDI rates as a secondary outcome. However, most of these trials had insufficient power to detect significant differences in CDI rates, and probiotics with fewer than two randomized trials showing significant reduction in CDI rates were excluded (N = 31). Five studies of probiotics with only one facility-level intervention study per probiotic type were then excluded [
]. One study was included that did not report CDI rates (the paper reported cases per quarter), but CDI rates were obtained from the author and one study did not specify Bio-K+ as the probiotic used in the published paper, but communication with the authors confirmed the product and dose used [
]. This resulted in 24 studies of this three-strain lactobacilli probiotic: mechanism of action or pharmacokinetic studies (N = 6), safety studies (N = 4), cost-effectiveness study (N = 1), randomized controlled trials (N = 3), and facility-level intervention studies (N = 10).
Evidence for potential efficacy
For a probiotic to be an effective preventive bundle component for CDI, it should be able to act against the pathogen itself and to survive in adequate concentrations in the gastrointestinal tract. We found evidence that this probiotic formulation survives to the target organ and has multiple mechanisms that act to reduce the effects of CDI.
Delivery to the target organ
The probiotic microbes need to survive to the target organ in adequate numbers and resist the effects of the competitive intestinal microbiome plus the effects of common healthcare exposures, such as antibiotics. Two models (simulated gastric fluid and culture plates supplemented with up to 50 g/L of bile salts) tested survival of these strains (L. acidophilus CL1285, L. casei LBC80R, and L. rhamnosus CLR2) and found that they survived well in these conditions (Table A.I, Appendix A) [
]. In another study, 29 commercially available probiotic products (capsules, fermented milks, probiotic-enriched yogurts, or powders) were also compared using these same models [
]. Enteric coated capsules (which maintain viability of freeze-dried microbes through acidic environments), including Bio-K+ capsules, had higher survival rates. Given the importance of survival to the intestine, the integrity of the formulation is routinely verified on the finished Bio-K+ capsules, following standard methods outlined in USP 701 [
Detecting living probiotic microbes in the host's stool is considered a surrogate for presence within the intestines. A higher concentration of faecal lactic acid bacteria (LAB) was detected in mice given Bio-K+ (Figure A1, Appendix A) [
]. The level of lactobacilli was not different than controls nine days after the last dose. Molecular tags now exist that can distinguish the specific strains in Bio-K+ from other lactobacilli in blood and stool samples, which may allow future studies of the kinetics of these lactobacilli strains in humans [
Antibiotics represent an important threat to the viability of living bacterial probiotics. Goldstein et al. described the genus Lactobacillus sp. as ‘taxonomically complex’ with important differences in susceptibilities to antibiotics by strain [
]. Ensuring that a probiotic is compatible with antibiotic therapy is an important consideration when designing controlled clinical studies among antibiotic users. In three placebo-controlled trials testing Bio-K+, patients were being treated with a wide variety of antibiotics (most usually β-lactams or macrolides), as shown in Figure A2 (Appendix A) [
Effect of a fermented milk combining Lactobacillus acidophilus Cl1285 and Lactobacillus casei in the prevention of antibiotic-associated diarrhea: a randomized, double-blind, placebo-controlled trial.
Dose–response efficacy of a proprietary probiotic formula of Lactobacillus acidophilus CL1285 and Lactobacillus casei LBC80R for antibiotic-associated diarrhea prophylaxis in adult patients.
Dose–response efficacy of a proprietary probiotic formula of Lactobacillus acidophilus CL1285 and Lactobacillus casei LBC80R for antibiotic-associated diarrhea prophylaxis in adult patients.
]. A precaution consistently taken in these studies was to stagger the once-daily probiotic dose 2 h apart from antibiotic administration.
Mechanisms of action
Specific probiotic strains have been found to possess multiple mechanisms of action acting at different levels, but not all probiotic strains possess all these functions. Potential targets for probiotics relating to CDI include: (i) helping to restore the normally protective intestinal microbiome; (ii) direct inhibition of C. difficile growth; (iii) neutralization of C. difficile toxins; or (iv) modulation of the inflammatory response [
]. In pre-clinical studies, Bio-K+ has been found to possess several mechanisms of action beneficial in the prevention of CDI.
Impact on intestinal microbiome
The intestinal microbiome is a complex ecology of microbes adapted to survive together in constant competition and synergy. In a mouse model, Bio-K+ (given over 18 days) was found to decrease levels of staphylococci and increase levels of lactobacilli (Figure A1, Appendix A), suggesting Bio-K+ can temporarily modify the faecal microbiome [
Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R, and Lactobacillus rhamnosus CLR2 (Bio-K+): characterization, manufacture, mechanisms of action, and quality control of a specific probiotic combination for primary prevention of Clostridium difficile infection.
]. Each strain (L. acidophilus CL1285, L. casei LBC80R, L. rhamnosus CLR2) has been shown to effectively inhibit the growth of multiple pathogens in vitro, including meticillin-resistant Staphylococcus aureus (MRSA) and widespread food-borne pathogens such as Listeria innocua, Enterococcus faecium, and Enterococcus faecalis [
]. The mechanisms underlying the protective effect of Bio-K+ may be due to bacteriocin-like substances, in addition to organic acids produced by the strains in Bio-K+ [
]. When tested against pH neutralized or gamma-radiation solutions, a protective effect was still observed, indicating that both factors (acid and bacteriocin production) have a role [
Strategy to elucidate mechanisms of action of the anti-C. difficile activity of selected probiotics. Poster presented at the Canadian Society of Microbiologists 67th Annual Conference, Toronto, Ontario, Canada.
]. To determine whether the strains in Bio-K+ could directly inhibit the growth of C. difficile, several studies were performed in vitro under anaerobic conditions, as described in Table A.I [
Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R, and Lactobacillus rhamnosus CLR2 (Bio-K+): characterization, manufacture, mechanisms of action, and quality control of a specific probiotic combination for primary prevention of Clostridium difficile infection.
Antimicrobial and anticytotoxic capacity of a probiotic formula of Lactobacillus acidophilus CL1285 and L. casei LBC80R against Clostridium difficile NAP1/027/BI. Poster presented at the 11th Biennial Congress of the Anaerobe Society of the Americas, San Francisco, CA, USA.
]. Bio-K+ effectively inhibited C. difficile growth; however, the potency of the supernatant exhibited little or no inhibition, suggesting that the lactobacilli strains needed to be in contact with C. difficile to exert their antimicrobial activity [
Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R, and Lactobacillus rhamnosus CLR2 (Bio-K+): characterization, manufacture, mechanisms of action, and quality control of a specific probiotic combination for primary prevention of Clostridium difficile infection.
The main threat from C. difficile stems from the effect of its toxins on the colonic epithelium, resulting in a disruption of the cytoskeleton and loss of cellular integrity and function. The ability of cell-free supernatants (extracellular products) from the individual strains or from a Bio-K+ fermented beverage to prevent damage induced by toxins A/B was assessed in human enterocyte-like Caco-2 and HT-29 cells [
Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R, and Lactobacillus rhamnosus CLR2 (Bio-K+): characterization, manufacture, mechanisms of action, and quality control of a specific probiotic combination for primary prevention of Clostridium difficile infection.
]. The supernatants from each of the three individual Bio-K+ strains or the combination inhibited the cytotoxic effect caused by C. difficile, allowing cells to preserve their normal structure (Figure A.3, Appendix A). To determine whether the observed effect could be attributable to a protein, supernatants were subjected to heat (99°C) or treated with proteolytic enzymes. Neither heat treatment nor trypsin/proteinase K treatments reduced the anti-cytotoxic activity [
Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R, and Lactobacillus rhamnosus CLR2 (Bio-K+): characterization, manufacture, mechanisms of action, and quality control of a specific probiotic combination for primary prevention of Clostridium difficile infection.
]. Based on Qa’Dan et al.’s study suggesting that an acidic environment prevents the binding of C. difficile toxin B to its receptor, the impact of pH of the lactobacilli supernatants was tested [
]. Above a pH of 5, no anti-cytotoxic activity was observed with the Bio-K+ supernatant. Moreover, pre-treatment of C. difficile supernatant with a solution containing ≥1% lactic acid prevented any cytotoxic effects of the toxins, suggesting that organic acid is at least partially responsible for toxin neutralization and the cells' protection.
To determine whether this protective effect was common to all lactic acid bacteria, supernatants from ten other strains were tested but L. acidophilus ATCC 832, L. acidophilus ATCC 53671, L. casei ATCC 4007, and L. rhamnosus ATCC 4796 did not have any anti-cytotoxic activity, demonstrating that this activity may not be present in all lactobacilli strains [
Antimicrobial and anticytotoxic capacity of a probiotic formula of Lactobacillus acidophilus CL1285 and L. casei LBC80R against Clostridium difficile NAP1/027/BI. Poster presented at the 11th Biennial Congress of the Anaerobe Society of the Americas, San Francisco, CA, USA.
]. In the context of this crisis, Beausoleil et al. contemplated using living bacteria to restore the intestinal microbiome that had been disrupted with antibiotics [
Effect of a fermented milk combining Lactobacillus acidophilus Cl1285 and Lactobacillus casei in the prevention of antibiotic-associated diarrhea: a randomized, double-blind, placebo-controlled trial.
]. To date, three randomized controlled trials have investigated Bio-K+ in patients receiving antibiotics (Table I). In one study, 89 inpatient adults receiving antibiotics at one hospital in Canada were enrolled and then randomized to either Bio-K+ or placebo given once daily for the duration of the antibiotic treatment and then followed for an additional three weeks for incident diarrhoea [
Effect of a fermented milk combining Lactobacillus acidophilus Cl1285 and Lactobacillus casei in the prevention of antibiotic-associated diarrhea: a randomized, double-blind, placebo-controlled trial.
]. Bio-K+ was found to significantly reduce the incidence of AAD (7/44, 15.9%, P = 0.03) compared to those given placebo (16/45, 35.6%), and a trend was found for the reduction of CDI (1/44, 2.3%, P = 0.06) in Bio-K+ treated versus placebo (7/45, 16%). This study was underpowered for the secondary outcome (CDI) and insufficient patients developed CDI to detect a significant difference.
Effect of a fermented milk combining Lactobacillus acidophilus Cl1285 and Lactobacillus casei in the prevention of antibiotic-associated diarrhea: a randomized, double-blind, placebo-controlled trial.
Dose–response efficacy of a proprietary probiotic formula of Lactobacillus acidophilus CL1285 and Lactobacillus casei LBC80R for antibiotic-associated diarrhea prophylaxis in adult patients.
In a confirmatory AAD prevention study, Sampalis et al. enrolled more subjects (N = 472), but this study was also underpowered for its secondary outcome (CDI) and failed to reach significance [
]. Of 437 who completed the study, only five cases of CDI were observed; one of 216 (0.5%) in the treatment group, and four of the 221 (1.8%) in the placebo group (P > 0.05).
A third study (Gao et al.) recruited 255 elderly inpatients, aged 50–70 years, treated with high-risk antibiotics at a single centre in Shanghai, China [
Dose–response efficacy of a proprietary probiotic formula of Lactobacillus acidophilus CL1285 and Lactobacillus casei LBC80R for antibiotic-associated diarrhea prophylaxis in adult patients.
]. Patients were randomized to one of three groups: a single dose of Bio-K+, a double dose of Bio-K+, or placebo, for the duration of the antibiotic and an additional five days and then monitored for an additional three weeks. In this patient population, the placebo-treated subjects had a much higher incidence of CDI (23.8%) compared to the two other clinical trials (1.8–16%). The double dose of Bio-K+ had a significantly lower incidence of CDI (1.2%, P = 0.002) compared to the placebo group (23.8%), as did the group treated with a single dose of Bio-K+ (9.5%, P = 0.03). Based on this study, a cost-effectiveness analysis estimated that the use of one capsule per day of Bio-K+ would save US$1968 and the use of two capsules per day would result in a cost-saving of $2661/patient [
]. No serious adverse reactions to the Bio-K+ formulation were observed in any of the three trials. The pooled results from each study found a significant reduction in CDI risk compared to the controls (relative risk (RR): 0.21; 95% confidence interval (CI): 0.11–0.40), as shown in the forest plot (Figure 1) from a meta-analysis [
]. It should be noted that the follow-up in all these trials (three weeks) may have missed community-onset healthcare facility-associated (CO-HCFA) cases of CDI, which may occur for up to three months after antibiotic exposure [
Clinical practice guidelines for Clostridium difficile infection in adults and children: 2017 update by the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA).
Figure 1Forest plot of meta-analysis of three randomized, controlled trials (four treatment arms) using Bio-K+ for the prevention of Clostridium difficile infections. Modified from McFarland
Review of observational studies in prevention of nosocomial C. difficile infection (CDI) with a specific probiotic containing L. acidophilus CL1285®, L. casei LBC80R® and L. rhamnosus CLR2®. Poster presented at the Annual Conference of the Canadian Society of Gastroenterology Nurses and Associates.
] (Table II). This probiotic was first implemented on a facility-level basis in 2003 during a period when hospitals in a Canadian province were experiencing large CDI outbreaks due to the ribotype NAP1/027/BI strain of CD [
]. After augmented standard infection control precautions had failed to abate this outbreak, one hospital added Bio-K+ as part of their preventive CDI bundle and gave every hospitalized adult receiving antibiotics this formulation, resulting in significant reductions in CDI rates (Figure 2) [
Impact of adding prophylactic probiotics to a bundle of standard preventative measures for C. difficile infection: enhanced and sustained decrease in the incidence and severity of infection at a community hospital.
]. In subsequent studies, the objective was to reduce the risk of healthcare facility-onset CDI infection in adults taking antibiotics. Some hospitals conducted the intervention hospital-wide, whereas others restricted the use to certain wards or high-risk groups [
Impact of adding prophylactic probiotics to a bundle of standard preventative measures for C. difficile infection: enhanced and sustained decrease in the incidence and severity of infection at a community hospital.
A decade of experience in primary prevention of C. difficile infection at a community hospital using the probiotic combination L. acidophilus CL1285, L. casei LBC80R and L. rhamnosus CLR2 (Bio-K+).
Effectiveness of probiotic for primary prevention of Clostridium difficile infection: A single-center before-and-after quality improvement intervention at a tertiary-care medical center.
Unite d’evaluation des technologies et des modes d’intervention en sante du CHU de Quebec (UETMIS-CHU de Quebec). Utilisation des probiotiques pour prevenir les diarrhees associees aux antibiotiques et au Clostridium difficile chez l’adulte hospitalize. [Use of probiotics for the prevention of antibiotic-associated diarrhea and C. difficile in adult inpatients.] Rapport d’evaluation UETMIS 03-14, Quebec.
Probiotics to reduce Clostridium difficile infection: clinical experience in a tertiary care center. Abstract #1255. Presented at: ID Week, San Diego CA.
]. The doses and formulations were consistent with the doses used in the clinical trials, most often two capsules per day (1 × 1011 cfu/day). The probiotic was typically given at the onset and for the duration of the antibiotic or until discharge. Several studies continued the probiotic for five to seven days post antibiotic administration [
Effectiveness of probiotic for primary prevention of Clostridium difficile infection: A single-center before-and-after quality improvement intervention at a tertiary-care medical center.
Impact of adding prophylactic probiotics to a bundle of standard preventative measures for C. difficile infection: enhanced and sustained decrease in the incidence and severity of infection at a community hospital.
A decade of experience in primary prevention of C. difficile infection at a community hospital using the probiotic combination L. acidophilus CL1285, L. casei LBC80R and L. rhamnosus CLR2 (Bio-K+).
Effectiveness of probiotic for primary prevention of Clostridium difficile infection: A single-center before-and-after quality improvement intervention at a tertiary-care medical center.
Unite d’evaluation des technologies et des modes d’intervention en sante du CHU de Quebec (UETMIS-CHU de Quebec). Utilisation des probiotiques pour prevenir les diarrhees associees aux antibiotiques et au Clostridium difficile chez l’adulte hospitalize. [Use of probiotics for the prevention of antibiotic-associated diarrhea and C. difficile in adult inpatients.] Rapport d’evaluation UETMIS 03-14, Quebec.
Probiotics to reduce Clostridium difficile infection: clinical experience in a tertiary care center. Abstract #1255. Presented at: ID Week, San Diego CA.
Figure 2Longitudinal changes in the rate of nosocomial Clostridium difficile infection (CDI) in hospitals that have implemented Bio-K+ programmes. Each data point represents the average rate of the preceding six months (for example, the data point at baseline, year 0, represents the average rate of nosocomial CDI in the preceding six months)
Review of observational studies in prevention of nosocomial C. difficile infection (CDI) with a specific probiotic containing L. acidophilus CL1285®, L. casei LBC80R® and L. rhamnosus CLR2®. Poster presented at the Annual Conference of the Canadian Society of Gastroenterology Nurses and Associates.
A decade of experience in primary prevention of C. difficile infection at a community hospital using the probiotic combination L. acidophilus CL1285, L. casei LBC80R and L. rhamnosus CLR2 (Bio-K+).
, CDI incidence for years 4, 5, and 6 and correct dose data were obtained by personal communication from B. Olson. Bio-K+ dosing at the Florida Hospital was confirmed as two capsules of 50 billion colony-forming units of Bio-K+ once daily, by personal communication with P. Louzon
Unite d’evaluation des technologies et des modes d’intervention en sante du CHU de Quebec (UETMIS-CHU de Quebec). Utilisation des probiotiques pour prevenir les diarrhees associees aux antibiotiques et au Clostridium difficile chez l’adulte hospitalize. [Use of probiotics for the prevention of antibiotic-associated diarrhea and C. difficile in adult inpatients.] Rapport d’evaluation UETMIS 03-14, Quebec.
Probiotics to reduce Clostridium difficile infection: clinical experience in a tertiary care center. Abstract #1255. Presented at: ID Week, San Diego CA.
Review of observational studies in prevention of nosocomial C. difficile infection (CDI) with a specific probiotic containing L. acidophilus CL1285®, L. casei LBC80R® and L. rhamnosus CLR2®. Poster presented at the Annual Conference of the Canadian Society of Gastroenterology Nurses and Associates.
]. Changes in infection control practices were also occurring at both hospitals at the same time, so a causal relationship in the reduction in CDI rates cannot be directly attributed to the probiotic component. At three hospitals, the probiotic intervention was given hospital-wide rather than being restricted to certain wards [
Impact of adding prophylactic probiotics to a bundle of standard preventative measures for C. difficile infection: enhanced and sustained decrease in the incidence and severity of infection at a community hospital.
A decade of experience in primary prevention of C. difficile infection at a community hospital using the probiotic combination L. acidophilus CL1285, L. casei LBC80R and L. rhamnosus CLR2 (Bio-K+).
Effectiveness of probiotic for primary prevention of Clostridium difficile infection: A single-center before-and-after quality improvement intervention at a tertiary-care medical center.
]. At one hospital (Sharp Coronado), the CDI rates were already falling due to a change in infection control practices (antibiotic stewardship, monitoring proton pump inhibitor use, and access to probiotics on the formulary (S. boulardii or Lactinex)), but, as shown in Figure 2, CDI rates fell even further when Bio-K+ replaced the prior formulary probiotics [
Impact of adding prophylactic probiotics to a bundle of standard preventative measures for C. difficile infection: enhanced and sustained decrease in the incidence and severity of infection at a community hospital.
Effectiveness of probiotic for primary prevention of Clostridium difficile infection: A single-center before-and-after quality improvement intervention at a tertiary-care medical center.
Impact of adding prophylactic probiotics to a bundle of standard preventative measures for C. difficile infection: enhanced and sustained decrease in the incidence and severity of infection at a community hospital.
Effectiveness of probiotic for primary prevention of Clostridium difficile infection: A single-center before-and-after quality improvement intervention at a tertiary-care medical center.
]. At one hospital, the reduction of CDI rates was only observed during the last six months of the one-year intervention, perhaps due to 83% compliance, when administrating the probiotic [
Effectiveness of probiotic for primary prevention of Clostridium difficile infection: A single-center before-and-after quality improvement intervention at a tertiary-care medical center.
]. The most rapid reduction of CDI rates was observed at Pierre-Le Gardeur (Lachenaie, Quebec) when the probiotic intervention was started at the peak of CDI outbreaks occurring at the time [
Impact of adding prophylactic probiotics to a bundle of standard preventative measures for C. difficile infection: enhanced and sustained decrease in the incidence and severity of infection at a community hospital.
A decade of experience in primary prevention of C. difficile infection at a community hospital using the probiotic combination L. acidophilus CL1285, L. casei LBC80R and L. rhamnosus CLR2 (Bio-K+).
]. Two hospitals with sustained, lower CDI rates (Figure 2) were correlated with good compliance rates (>90% eligible receiving the probiotic) at Sharp Coronado Hospital [
A decade of experience in primary prevention of C. difficile infection at a community hospital using the probiotic combination L. acidophilus CL1285, L. casei LBC80R and L. rhamnosus CLR2 (Bio-K+).
]. The rate of CDI at Pierre-Le Gardeur Hospital from 2005 to 2014 consistently remained two- to ten-fold lower than other hospitals in Quebec that did not administer Bio-K+ as part of their infection control bundle (neither another nearby local hospital, nor in 95 hospitals in a CDI surveillance programme across Quebec, nor in 27 other hospitals in Quebec of the same size (>250 bed) as Pierre-Le Gardeur Hospital [
A decade of experience in primary prevention of C. difficile infection at a community hospital using the probiotic combination L. acidophilus CL1285, L. casei LBC80R and L. rhamnosus CLR2 (Bio-K+).
]. Bio-K+ fermented food products (milk, soy, rice, hemp, or pea-based) and capsules have been commercially available in Canada and the USA for >20 years. Manufacturing controls and molecular methods are employed in the production of Bio-K+ products to minimize potential risks and optimize potency [
Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R, and Lactobacillus rhamnosus CLR2 (Bio-K+): characterization, manufacture, mechanisms of action, and quality control of a specific probiotic combination for primary prevention of Clostridium difficile infection.
]. Clinical research experience and epidemiological surveillance are necessary to estimate the risk of harm. Goldenberg et al. found in their meta-analysis of subjects taking antibiotics in randomized trials (N = 781) that the tolerability was good and the Bio-K+-treated subgroup had a trend for fewer adverse reactions than placebo (RR: 0.92; 95% CI: 0.76–1.1) [
]. In none of the three randomized clinical trials or facility-level programmes have more adverse reactions been noted in those treated with Bio-K+ than in control groups.
Salminen et al. gathered data from a centralized national testing laboratory in Finland and found that Lactobacillus sp. bacteraemia was rare (0.2%) [
]. Using molecular methods, this laboratory also confirmed that, over the span of six years and 25 million litres of L. rhamnosus GG fermented milk ingested, only 11 of the Lactobacillus sp. bacteraemia cases occurred with the probiotic strain. Boumis et al. reviewed the literature and found 10 cases of L. rhamnosus endocarditis in patients consuming probiotics, but they could not document that the strain consumed was identical to the L. rhamnosus strain causing the endocarditis [
]. No cases of bacteraemia from a Bio-K+ probiotic strain have been observed or reported, neither in published observational studies nor reported through product surveillance. Aroutcheva et al. published a case report of a 69-year-old man who received Bio-K+ and developed Lactobacillus sp. bacteraemia, but molecular methods confirmed that the sepsis was not due to any of the three lactobacilli strains found in Bio-K+ [
There is a dire need for strategies to prevent CDI, which may include the use of specific probiotics administered with prescribed antibiotics to inpatients. The probiotic described in this review, Bio-K+ (comprised of L. acidophilus CL1285, L. casei LBC80R, and L. rhamnosus CLR2), has a solid foundation of clinical evidence supporting its efficacy in the primary prevention of CDI and valuable pre-clinical data to explain how this occurs. These bacteria employ multiple mechanisms directed against C. difficile and are formulated to survive to the target organ. An evidence base of three randomized clinical trials and seven observational studies document the use of Bio-K+ for CDI prevention with targeted patients (patient-level) or to all at-risk patients (facility-level) with no serious adverse effects.
In 2012, the Natural Health Products Directorate Canadian regulatory body licensed two uses for Bio-K+ (50 billion cfu capsules): to reduce the risk of antibiotic-associated diarrhoea and CDI in hospitalized adults [
]. This is the first regulatory issuance for the primary prevention of CDI for any class of medication in Canada (Bio-K+ 50 billion cfu, NPN #80038453).
The benefits of using an effective probiotic formulation at a facility-level may extend beyond reduced CDI rates and lead to reductions in other types of diarrhoeal diseases. AAD, a frequently occurring consequence of antibiotics and a disrupted intestinal microbiome, could be preventable with specific probiotics, including Bio-K+ [
]. Fringe benefits of reducing non-CDI cases of diarrhoea may include less transmission of C. difficile spores from asymptomatic carriers, reduced C. difficile toxin testing, less prophylactic patient isolation, and shorter lengths of hospital stay [
A high-dose preparation of lactobacilli and bifidobacteria in the prevention of antibiotic-associated and Clostridium difficile diarrhoea in older people admitted to hospital: a multicentre, randomised, double-blind, placebo-controlled, parallel arm trial (PLACIDE).
Effect of a fermented milk combining Lactobacillus acidophilus Cl1285 and Lactobacillus casei in the prevention of antibiotic-associated diarrhea: a randomized, double-blind, placebo-controlled trial.
Dose–response efficacy of a proprietary probiotic formula of Lactobacillus acidophilus CL1285 and Lactobacillus casei LBC80R for antibiotic-associated diarrhea prophylaxis in adult patients.
Efforts to prevent CDI at healthcare facilities have included enhanced multi-disciplinary infection control practice bundles, which have reduced CDI rates by 45% to 85%, but a consensus on the best combination of components has yet to be reached [
]. To further reduce CDI rates, several types of probiotic (Saccharomyces boulardii CNCM I-745, L. plantarum 299v, L. casei Shirota, and a mix of L. acidophilus, Bifidobacterium longum and B. bifidum Bb12 and another mix of eight strains, VSL#3) have been tested in either specific wards/units or in hospital-wide studies, with varying success [
]. However, confirmatory studies on a facility-wide programme of these types of probiotic need to be conducted. By contrast, multiple facility-wide studies indicate that adding Bio-K+ to standard infection control bundles may lead to reductions in CDI rates that may be sustained over years, even when taking into account differences in types of infection control bundle used, differences in compliance rates, and scope of administration.
Limitations found when reviewing the studies include the lack of randomized, placebo-controlled trials with the prevention of CDI as the primary outcome. All of the efficacy evidence from patient-level data are from randomized trials to prevent AAD with CDI as a secondary outcome and were mostly under-powered for this outcome. The studies of facility-level efficacy for this probiotic formulation were not from randomized controlled trials, rather from quasi-experimental design that may, however, mimic ‘real-life’ situations more than rigorously conducted randomized trials.
Conclusion
The probiotic formulation containing these three lacto-bacilli strains (L. acidophilus CL1285, L. casei LBC80R, L. rhamnosus CLR2, Bio-K+) is a promising example of how a probiotic was used to prevent serious healthcare-associated infections such as CDI. This probiotic is well characterized, has an excellent safety profile, and, when applied in hospitals, showed reductions in CDI rates, sometimes sustained over years. More research is recommended for probiotics in the prevention of CDI.
Conflict of interest statement
Bio-K Plus International, Inc., owns and manufactures the product Bio-K+. L.V.M. is a paid lecturer for Lallemand and Biocodex and on the Biocodex Microbiome Foundation Board and a member of the Scientific Advisory Board for Bio-K Plus. N.S., J.A. and M.M. are employees of Bio-K Plus International.
Funding source
Funded by an educational grant from Bio-K Plus International, Inc.
Appendix A. Supplementary data
The following are the supplementary data related to this article:
Figure A.1Changes in faecal microbiome abundance with mice receiving daily intragastric feeding of 1×109 colony-forming units (CFU) Bio-K+ from day 1 to day 18. Mice were followed for an additional nine days after the last dose on day 18 (indicated as the dotted line). *Total lactic acid bacteria cfu was higher in Bio-K+-treated mice vs controls on day 18 (P ≤ 0.05). ‡Staphylococcus sp. cfu was lower in Bio-K+-treated mice vs baseline and vs controls on the same day (P ≤ 0.05). Adapted from Millette et al.
Figure A.2The types of antibiotic administered to subjects in the Clostridium difficile infection prevention randomized controlled trials. All subjects took at least one antibiotic, and some patients took more than one type of antibiotic, making it possible to have an incidence >100% [
Effect of a fermented milk combining Lactobacillus acidophilus Cl1285 and Lactobacillus casei in the prevention of antibiotic-associated diarrhea: a randomized, double-blind, placebo-controlled trial.
Dose–response efficacy of a proprietary probiotic formula of Lactobacillus acidophilus CL1285 and Lactobacillus casei LBC80R for antibiotic-associated diarrhea prophylaxis in adult patients.
]. In Beausoleil et al.’s study, clindamycin would have been considered part of the ‘other’ antibiotics, though the actual antibiotics were not specified
Effect of a fermented milk combining Lactobacillus acidophilus Cl1285 and Lactobacillus casei in the prevention of antibiotic-associated diarrhea: a randomized, double-blind, placebo-controlled trial.
Dose–response efficacy of a proprietary probiotic formula of Lactobacillus acidophilus CL1285 and Lactobacillus casei LBC80R for antibiotic-associated diarrhea prophylaxis in adult patients.
Figure A.3The cytotoxicity of the cell-free supernatant (CFS) from C. difficile culture, containing toxins A and B, is confirmed on Caco-2 cells (negative control). The CFS from L. casei LBC80R, a component of Bio-K+, preserved the integrity of the Caco-2 cells, whereas the CFS from another lactobacilli strain (L. casei ATCC 4007) became dead, rounded, and detached
Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R, and Lactobacillus rhamnosus CLR2 (Bio-K+): characterization, manufacture, mechanisms of action, and quality control of a specific probiotic combination for primary prevention of Clostridium difficile infection.
What’s lurking under the bed? Persistence and predominance of particular Clostridium difficile strains in a hospital and the potential role of environmental contamination.
Expert consensus document. The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic.
Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R, and Lactobacillus rhamnosus CLR2 (Bio-K+): characterization, manufacture, mechanisms of action, and quality control of a specific probiotic combination for primary prevention of Clostridium difficile infection.
Effect of a fermented milk combining Lactobacillus acidophilus Cl1285 and Lactobacillus casei in the prevention of antibiotic-associated diarrhea: a randomized, double-blind, placebo-controlled trial.
Dose–response efficacy of a proprietary probiotic formula of Lactobacillus acidophilus CL1285 and Lactobacillus casei LBC80R for antibiotic-associated diarrhea prophylaxis in adult patients.
Strategy to elucidate mechanisms of action of the anti-C. difficile activity of selected probiotics. Poster presented at the Canadian Society of Microbiologists 67th Annual Conference, Toronto, Ontario, Canada.
Antimicrobial and anticytotoxic capacity of a probiotic formula of Lactobacillus acidophilus CL1285 and L. casei LBC80R against Clostridium difficile NAP1/027/BI. Poster presented at the 11th Biennial Congress of the Anaerobe Society of the Americas, San Francisco, CA, USA.
Clinical practice guidelines for Clostridium difficile infection in adults and children: 2017 update by the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA).
Review of observational studies in prevention of nosocomial C. difficile infection (CDI) with a specific probiotic containing L. acidophilus CL1285®, L. casei LBC80R® and L. rhamnosus CLR2®. Poster presented at the Annual Conference of the Canadian Society of Gastroenterology Nurses and Associates.
Impact of adding prophylactic probiotics to a bundle of standard preventative measures for C. difficile infection: enhanced and sustained decrease in the incidence and severity of infection at a community hospital.
A decade of experience in primary prevention of C. difficile infection at a community hospital using the probiotic combination L. acidophilus CL1285, L. casei LBC80R and L. rhamnosus CLR2 (Bio-K+).
Effectiveness of probiotic for primary prevention of Clostridium difficile infection: A single-center before-and-after quality improvement intervention at a tertiary-care medical center.
Unite d’evaluation des technologies et des modes d’intervention en sante du CHU de Quebec (UETMIS-CHU de Quebec). Utilisation des probiotiques pour prevenir les diarrhees associees aux antibiotiques et au Clostridium difficile chez l’adulte hospitalize. [Use of probiotics for the prevention of antibiotic-associated diarrhea and C. difficile in adult inpatients.] Rapport d’evaluation UETMIS 03-14, Quebec.
Probiotics to reduce Clostridium difficile infection: clinical experience in a tertiary care center. Abstract #1255. Presented at: ID Week, San Diego CA.
A high-dose preparation of lactobacilli and bifidobacteria in the prevention of antibiotic-associated and Clostridium difficile diarrhoea in older people admitted to hospital: a multicentre, randomised, double-blind, placebo-controlled, parallel arm trial (PLACIDE).
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