Wageningen Academic P u b l i s h e r s
Beneficial Microbes, 2014; 5(3): 285-293
http://www.wageningenacademic.com/doi/pdf/10.3920/BM2013.0056 - Monday, September 25, 2017 8:36:23 AM - Göteborgs Universitet IP Address:130.241.16.16
Meta-analysis: Lactobacillus reuteri strain DSM 17938 (and the original strain ATCC 55730) for treating acute gastroenteritis in children H. Szajewska1, M. Urbańska1, A. Chmielewska1, Z. Weizman2 and R. Shamir3 1Department
of Paediatrics, The Medical University of Warsaw, Dzialdowska 1, 01-184 Warsaw, Poland; 2Pediatric Gastroenterology and Nutrition Unit, Soroka Medical Center, Ben-Gurion University, P.O. Box 151, Beer-Sheva, Israel; 3Institute of Gastroenterology, Nutrition and Liver Diseases, Schneider Children’s Medical Center of Israel, Sackler Faculty of Medicine, Tel-Aviv University, P.O. Box 559, Petach Tikvah 49202, Israel; [email protected] Received: 24 September 2013 / Accepted: 10 November 2013 © 2014 Wageningen Academic Publishers
RESEARCH ARTICLE Abstract Lactobacillus reuteri ATCC 55730 has been shown to provide a moderate clinical effect in the treatment of acute gastroenteritis (AGE) in children. However, as the L. reuteri ATCC 55730 strain was found to carry potentially transferable resistance traits for tetracycline and lincomycin, it was replaced by a new strain, L. reuteri DSM 17938, without unwanted plasmid-borne antibiotic resistance. Bioequivalence of the two strains has been suggested. We aimed to systematically evaluate data on the effectiveness of L. reuteri DSM 17938 and the original strain, L. reuteri ATCC 55730, in the treatment of AGE in children. The Cochrane Library, MEDLINE, and EMBASE databases, reference lists, and abstract books of major scientific meetings were searched in August 2013, with no language restrictions, for relevant randomised controlled trials (RCTs). Two RCTs (n=196) that evaluated L. reuteri DSM 17938 and three RCTs (n=156) that evaluated L. reuteri ATCC 55730, which involved hospitalised children aged 3 to 60 months, met the inclusion criteria. Compared with placebo or no treatment, DSM 17938 significantly reduced the duration of diarrhoea (mean difference -32 h, 95% confidence interval (CI): -41 to -24) and increased the chance of cure on day 3 (relative risk: 3.5, 95% CI: 1.2 to 10.8, random effects model). Similar results were obtained with the original strain, L. reuteri ATCC 55730. In conclusion, in hospitalised children, use of both strains of L. reuteri reduced the duration of diarrhoea, and more children were cured within 3 days. Data from outpatients and countryspecific cost-effectiveness analyses are needed. Given the limited data and the methodological limitations of the included trials, the evidence should be viewed with caution. Keywords: RCT, systematic review, L. reuteri, probiotics, microbiota, diarrhoea, infants
1. Introduction In 2008, the European Society for Paediatric Gastro enterology, Hepatology and Nutrition and the European Society of Paediatric Infectious Diseases introduced evidence-based guidelines for the management of acute gastroenteritis (AGE). With regard to probiotics, these guidelines concluded that probiotics with documented efficacy, such as Lactobacillus rhamnosus GG and Saccharomyces boulardii, may be considered as an adjunct to rehydration for the management of AGE in children (Guarino et al., 2008). Moreover, it was also stated that other probiotics may be used provided their efficacy is
documented in high quality randomised controlled trials (RCTs) or in meta-analyses. Previously, the analysis of data from two RCTs (Shornikova et al., 1997a,b) found that in otherwise healthy children aged 6 to 36 months with AGE, the use of Lactobacillus reuteri ATCC 55730 compared with placebo was associated with a reduction in the duration and severity of diarrhoea, particularly of rotaviral aetiology (Chmielewska et al., 2008). However, the L. reuteri ATCC 55730 strain was found to carry potentially transferable resistance traits for tetracycline and lincomycin. It was replaced by a new strain, L. reuteri DSM 17938, without unwanted plasmid-borne
ISSN 1876-2833 print, ISSN 1876-2891 online, DOI 10.3920/BM2013.0056285
H. Szajewska et al.
http://www.wageningenacademic.com/doi/pdf/10.3920/BM2013.0056 - Monday, September 25, 2017 8:36:23 AM - Göteborgs Universitet IP Address:130.241.16.16
resistance, which was removed by protoplast formation as described in detail by Rosander et al. (2008). The main objective of this study was to systematically evaluate data on the effectiveness of L. reuteri DSM 17938 and its original strain, L. reuteri ATCC 55730, in the treatment of AGE in children. Currently, only L. reuteri DSM 17938 is commercially available. However, we chose to focus on both strains, as there are studies suggesting their bioequivalence (Egervärn et al., 2010; Rosander et al., 2008). If so, the data on both strains may be relevant for the efficacy assessment. This review was initiated as part of the update of the guidelines for the management of AGE in children (Guarino et al., 2008).
2. Materials and methods Criteria for considering studies All relevant RCTs that compared the use of L. reuteri DSM 17938 or ATCC 55730 as a single ingredient (in all delivery vehicles and formulations) with use of placebo or no treatment were eligible for inclusion. The primary outcome measures were stool output and the duration of diarrhoea (time until permanent cessation). In addition to these outcomes, a priori we decided to extract other data reported by the investigators that are clinically relevant to the current review.
Search methods for identification of studies The Co chrane Central Reg ister of Controlle d Trials (CEN TR AL, the Cochrane Librar y; www. thecochranelibrary.com), MEDLINE (www.ncbi.nlm. nih.gov), and EMBASE (www.elsevier.com/online-tools/ embase) databases were searched in August 2013. The principal search text word terms and MESH headings used were as follows: diarrhea/diarrhoea, diarrh*, gastroenteritis, probiotic*, and L. reuteri. No language restrictions were imposed. The reference lists from identified studies and key review articles, including previously published systematic reviews with or without a meta-analysis, were also searched to identify any other relevant studies. The conference abstract books of the following organisations were reviewed to identify potentially eligible studies published only in abstract form: European Paediatric Gastroenterology, Hepatology and Nutrition, North American Pediatric Gastroenterology, Hepatology and Nutrition, American Gastroenterological Association, and United European Gastroenterology Federation (all from 2010 to 2013). The abstracts and proceedings from scientific meetings were included only if a full set of data was obtained from the authors. In this regard, we contacted one author for further information, who by email provided missing information regarding the study (E.C. Dinleyici, personal communication). The principle manufacturer of L. reuteri 286
(BioGaia AB, Stockholm, Sweden) was contacted to assist in identifying any other published or unpublished work, but no additional studies were identified. The ClinicalTrials.gov website (clinicaltrials.gov) and EU Clinical Trials Register website (www.clinicaltrialsregister.eu) were searched for RCTs that were registered but not yet published.
Data collection and analysis The reviewers, using a standardised approach, indepen dently undertook the literature search, data extraction, and quality assessment. The data sought included baseline characteristics of the participants, details related to the use of experimental and control interventions (including dose and duration), setting, and funding. One major discussion among the reviewers was with regard to the bioequivalence of the two strains, as well as pooling the data of the two L. reuteri strains. The opinion of the external expert was taken into account, and a consensus was reached through discussion. In one RCT, participants were randomly assigned to 3 groups: an intervention group that received oral rehydration solution (ORS) plus L. reuteri ATCC 55730 at a daily dose of 1010 cfu or at a daily dose of 1011 cfu, or a control group that received ORS only (Shornikova et al., 1997b). Because the objective of our review was to compare supplementation with placebo or no supplementation, we combined both experimental arms into a single experimental group according to the method of Hogg and Craig (1995).
Assessment of risk of bias in included studies The reviewers independently, but without being blinded to the authors or journal, assessed the risk of bias in the studies that met the inclusion criteria. The Cochrane Collaboration’s tool for assessing risk of bias was used, which includes the following criteria: adequacy of sequence generation, allocation concealment, and blinding of participants, personnel and outcome assessors; and extent of loss to follow-up, i.e. the proportion of patients in whom the investigators were not able to determine outcomes (incomplete outcome data). In all cases, an answer of ‘yes’ indicates a low risk of bias, and an answer of ‘no’ indicates a high risk of bias (Higgins et al., 2013).
Measures of treatment effect The dichotomous outcomes, the results from individual studies, and pooled statistics are reported as the risk ratio (RR) between the experimental and control groups with 95% confidence intervals (95% CI). The continuous outcomes are reported as the mean difference (MD) between the treatment and control groups with 95% CI.
Beneficial Microbes 5(3)
Lactobacillus reuteri for treating acute gastroenteritis
http://www.wageningenacademic.com/doi/pdf/10.3920/BM2013.0056 - Monday, September 25, 2017 8:36:23 AM - Göteborgs Universitet IP Address:130.241.16.16
Assessment of heterogeneity
Risk of bias in included studies
Heterogeneity was quantified by χ2 and I 2, which can be interpreted as the percentage of the total variation between studies that is attributable to heterogeneity rather than to chance. A value of 0% indicates no observed heterogeneity, and larger values show increasing heterogeneity. If significant heterogeneity was revealed (typically considered to be present if I2≥50%), we used and compared both random and fixed effect models (Higgins et al., 2013).
The studies were heterogeneous in quality (Table 2). The major limitations were unclear sequence generation or unclear allocation concealment. One of the trials that evaluated the effects of L. reuteri DSM 17938 was a singleblind RCT. Except for one trial, outcome assessment was not blinded. No or unclear intention-to-treat analysis was noted in some trials.
Assessment of reporting biases To test for publication bias, we planned to use a test for asymmetry of the funnel plot proposed by Egger et al. (1997). However, the publication bias was not formally assessed using a funnel plot due to the small number of studies (
Beneficial Microbes, 2014; 5(3): 285-293
http://www.wageningenacademic.com/doi/pdf/10.3920/BM2013.0056 - Monday, September 25, 2017 8:36:23 AM - Göteborgs Universitet IP Address:130.241.16.16
Meta-analysis: Lactobacillus reuteri strain DSM 17938 (and the original strain ATCC 55730) for treating acute gastroenteritis in children H. Szajewska1, M. Urbańska1, A. Chmielewska1, Z. Weizman2 and R. Shamir3 1Department
of Paediatrics, The Medical University of Warsaw, Dzialdowska 1, 01-184 Warsaw, Poland; 2Pediatric Gastroenterology and Nutrition Unit, Soroka Medical Center, Ben-Gurion University, P.O. Box 151, Beer-Sheva, Israel; 3Institute of Gastroenterology, Nutrition and Liver Diseases, Schneider Children’s Medical Center of Israel, Sackler Faculty of Medicine, Tel-Aviv University, P.O. Box 559, Petach Tikvah 49202, Israel; [email protected] Received: 24 September 2013 / Accepted: 10 November 2013 © 2014 Wageningen Academic Publishers
RESEARCH ARTICLE Abstract Lactobacillus reuteri ATCC 55730 has been shown to provide a moderate clinical effect in the treatment of acute gastroenteritis (AGE) in children. However, as the L. reuteri ATCC 55730 strain was found to carry potentially transferable resistance traits for tetracycline and lincomycin, it was replaced by a new strain, L. reuteri DSM 17938, without unwanted plasmid-borne antibiotic resistance. Bioequivalence of the two strains has been suggested. We aimed to systematically evaluate data on the effectiveness of L. reuteri DSM 17938 and the original strain, L. reuteri ATCC 55730, in the treatment of AGE in children. The Cochrane Library, MEDLINE, and EMBASE databases, reference lists, and abstract books of major scientific meetings were searched in August 2013, with no language restrictions, for relevant randomised controlled trials (RCTs). Two RCTs (n=196) that evaluated L. reuteri DSM 17938 and three RCTs (n=156) that evaluated L. reuteri ATCC 55730, which involved hospitalised children aged 3 to 60 months, met the inclusion criteria. Compared with placebo or no treatment, DSM 17938 significantly reduced the duration of diarrhoea (mean difference -32 h, 95% confidence interval (CI): -41 to -24) and increased the chance of cure on day 3 (relative risk: 3.5, 95% CI: 1.2 to 10.8, random effects model). Similar results were obtained with the original strain, L. reuteri ATCC 55730. In conclusion, in hospitalised children, use of both strains of L. reuteri reduced the duration of diarrhoea, and more children were cured within 3 days. Data from outpatients and countryspecific cost-effectiveness analyses are needed. Given the limited data and the methodological limitations of the included trials, the evidence should be viewed with caution. Keywords: RCT, systematic review, L. reuteri, probiotics, microbiota, diarrhoea, infants
1. Introduction In 2008, the European Society for Paediatric Gastro enterology, Hepatology and Nutrition and the European Society of Paediatric Infectious Diseases introduced evidence-based guidelines for the management of acute gastroenteritis (AGE). With regard to probiotics, these guidelines concluded that probiotics with documented efficacy, such as Lactobacillus rhamnosus GG and Saccharomyces boulardii, may be considered as an adjunct to rehydration for the management of AGE in children (Guarino et al., 2008). Moreover, it was also stated that other probiotics may be used provided their efficacy is
documented in high quality randomised controlled trials (RCTs) or in meta-analyses. Previously, the analysis of data from two RCTs (Shornikova et al., 1997a,b) found that in otherwise healthy children aged 6 to 36 months with AGE, the use of Lactobacillus reuteri ATCC 55730 compared with placebo was associated with a reduction in the duration and severity of diarrhoea, particularly of rotaviral aetiology (Chmielewska et al., 2008). However, the L. reuteri ATCC 55730 strain was found to carry potentially transferable resistance traits for tetracycline and lincomycin. It was replaced by a new strain, L. reuteri DSM 17938, without unwanted plasmid-borne
ISSN 1876-2833 print, ISSN 1876-2891 online, DOI 10.3920/BM2013.0056285
H. Szajewska et al.
http://www.wageningenacademic.com/doi/pdf/10.3920/BM2013.0056 - Monday, September 25, 2017 8:36:23 AM - Göteborgs Universitet IP Address:130.241.16.16
resistance, which was removed by protoplast formation as described in detail by Rosander et al. (2008). The main objective of this study was to systematically evaluate data on the effectiveness of L. reuteri DSM 17938 and its original strain, L. reuteri ATCC 55730, in the treatment of AGE in children. Currently, only L. reuteri DSM 17938 is commercially available. However, we chose to focus on both strains, as there are studies suggesting their bioequivalence (Egervärn et al., 2010; Rosander et al., 2008). If so, the data on both strains may be relevant for the efficacy assessment. This review was initiated as part of the update of the guidelines for the management of AGE in children (Guarino et al., 2008).
2. Materials and methods Criteria for considering studies All relevant RCTs that compared the use of L. reuteri DSM 17938 or ATCC 55730 as a single ingredient (in all delivery vehicles and formulations) with use of placebo or no treatment were eligible for inclusion. The primary outcome measures were stool output and the duration of diarrhoea (time until permanent cessation). In addition to these outcomes, a priori we decided to extract other data reported by the investigators that are clinically relevant to the current review.
Search methods for identification of studies The Co chrane Central Reg ister of Controlle d Trials (CEN TR AL, the Cochrane Librar y; www. thecochranelibrary.com), MEDLINE (www.ncbi.nlm. nih.gov), and EMBASE (www.elsevier.com/online-tools/ embase) databases were searched in August 2013. The principal search text word terms and MESH headings used were as follows: diarrhea/diarrhoea, diarrh*, gastroenteritis, probiotic*, and L. reuteri. No language restrictions were imposed. The reference lists from identified studies and key review articles, including previously published systematic reviews with or without a meta-analysis, were also searched to identify any other relevant studies. The conference abstract books of the following organisations were reviewed to identify potentially eligible studies published only in abstract form: European Paediatric Gastroenterology, Hepatology and Nutrition, North American Pediatric Gastroenterology, Hepatology and Nutrition, American Gastroenterological Association, and United European Gastroenterology Federation (all from 2010 to 2013). The abstracts and proceedings from scientific meetings were included only if a full set of data was obtained from the authors. In this regard, we contacted one author for further information, who by email provided missing information regarding the study (E.C. Dinleyici, personal communication). The principle manufacturer of L. reuteri 286
(BioGaia AB, Stockholm, Sweden) was contacted to assist in identifying any other published or unpublished work, but no additional studies were identified. The ClinicalTrials.gov website (clinicaltrials.gov) and EU Clinical Trials Register website (www.clinicaltrialsregister.eu) were searched for RCTs that were registered but not yet published.
Data collection and analysis The reviewers, using a standardised approach, indepen dently undertook the literature search, data extraction, and quality assessment. The data sought included baseline characteristics of the participants, details related to the use of experimental and control interventions (including dose and duration), setting, and funding. One major discussion among the reviewers was with regard to the bioequivalence of the two strains, as well as pooling the data of the two L. reuteri strains. The opinion of the external expert was taken into account, and a consensus was reached through discussion. In one RCT, participants were randomly assigned to 3 groups: an intervention group that received oral rehydration solution (ORS) plus L. reuteri ATCC 55730 at a daily dose of 1010 cfu or at a daily dose of 1011 cfu, or a control group that received ORS only (Shornikova et al., 1997b). Because the objective of our review was to compare supplementation with placebo or no supplementation, we combined both experimental arms into a single experimental group according to the method of Hogg and Craig (1995).
Assessment of risk of bias in included studies The reviewers independently, but without being blinded to the authors or journal, assessed the risk of bias in the studies that met the inclusion criteria. The Cochrane Collaboration’s tool for assessing risk of bias was used, which includes the following criteria: adequacy of sequence generation, allocation concealment, and blinding of participants, personnel and outcome assessors; and extent of loss to follow-up, i.e. the proportion of patients in whom the investigators were not able to determine outcomes (incomplete outcome data). In all cases, an answer of ‘yes’ indicates a low risk of bias, and an answer of ‘no’ indicates a high risk of bias (Higgins et al., 2013).
Measures of treatment effect The dichotomous outcomes, the results from individual studies, and pooled statistics are reported as the risk ratio (RR) between the experimental and control groups with 95% confidence intervals (95% CI). The continuous outcomes are reported as the mean difference (MD) between the treatment and control groups with 95% CI.
Beneficial Microbes 5(3)
Lactobacillus reuteri for treating acute gastroenteritis
http://www.wageningenacademic.com/doi/pdf/10.3920/BM2013.0056 - Monday, September 25, 2017 8:36:23 AM - Göteborgs Universitet IP Address:130.241.16.16
Assessment of heterogeneity
Risk of bias in included studies
Heterogeneity was quantified by χ2 and I 2, which can be interpreted as the percentage of the total variation between studies that is attributable to heterogeneity rather than to chance. A value of 0% indicates no observed heterogeneity, and larger values show increasing heterogeneity. If significant heterogeneity was revealed (typically considered to be present if I2≥50%), we used and compared both random and fixed effect models (Higgins et al., 2013).
The studies were heterogeneous in quality (Table 2). The major limitations were unclear sequence generation or unclear allocation concealment. One of the trials that evaluated the effects of L. reuteri DSM 17938 was a singleblind RCT. Except for one trial, outcome assessment was not blinded. No or unclear intention-to-treat analysis was noted in some trials.
Assessment of reporting biases To test for publication bias, we planned to use a test for asymmetry of the funnel plot proposed by Egger et al. (1997). However, the publication bias was not formally assessed using a funnel plot due to the small number of studies (
