A probiotic trial: tipping the balance of evidence?

The Philosophy of Evidence-Based Principles and Practice in Nutrition

The practice of evidence-based nutrition involves using the best available nutrition evidence, together with clinical experience, to conscientiously work with patients’ values and preferences to help them prevent (sometimes), resolve (sometimes), or cope with (often) problems related to their physical, mental, and social health. This article outlines the 3 fundamental principles of evidence-based practice as applied to the field of clinical nutrition. First, optimal clinical decision making requires awareness of the best available evidence, which ideally will come from unbiased systematic summaries of that evidence. Second, evidence-based nutrition provides guidance on how to decide which evidence is more or less trustworthy—that is, how certain can we be of our patients’ prognosis, diagnosis, or of our therapeutic options? Third, evidence alone is never sufficient to make a clinical decision. Decision makers must always trade off the benefits with the risks, burden, and costs associated with alternative management strategies, and, in so doing, consider their patients’ unique predicament, including their values and preferences.

Authors seldom report the most patient-important outcomes and absolute effect measures in systematic review abstracts

OBJECTIVES

Explicit reporting of absolute measures is important to ensure treatment effects are correctly interpreted. We examined the extent to which authors report absolute effects for patient-important outcomes in abstracts of systematic review (SR).

STUDY DESIGN AND SETTING

We searched OVID MEDLINE and Cochrane Database of Systematic Reviews to identify eligible SRs published in the year 2010. Citations were stratified into Cochrane and non-Cochrane reviews, with repeated random sampling in a 1:1 ratio. Paired reviewers screened articles and recorded abstract characteristics, including reporting of effect measures for the most patient-important outcomes of benefit and harm.

RESULTS

We included 96 Cochrane and 94 non-Cochrane reviews. About 117 (77.5%) relative measures were reported in abstracts for outcomes of benefit, whereas only 34 (22.5%) absolute measures were reported. Similarly, for outcomes of harm, 41 (87.2%) relative measures were provided in abstracts, compared with only 6 (12.8%) absolute measures. Eighteen (9.5%) abstracts reported both absolute and relative measures for outcomes of benefit, whereas only two (1.1%) abstracts reported both measures for outcomes of harm. Results were similar between Cochrane and non-Cochrane reviews.

CONCLUSION

SR abstracts seldom report measures of absolute effect. Journal editors should insist that authors report both relative and absolute effects for patient-important outcomes.

The Effect of Lactobacillus plantarum 299v on the Incidence of Clostridium difficile Infection in High Risk Patients Treated with Antibiotics

Background:Lactobacillus plantarum 299v (LP299v) has been used in order to reduce gastrointestinal symptoms during antibiotic exposure. However, it remains controversial whether or not probiotics are effective in the prevention of Clostridium difficile infections (CDI) among patients receiving antibiotics. The aim of this study was to analyze the CDI among patients receiving antibiotics and hospitalized in the period before and after starting routine use of LP299v as a prevention of this infection. Methods: Among 3533 patients hospitalized in the nephrology and transplantation ward during a two-year period, 23 patients with CDI were diagnosed and enrolled in this retrospective study. Since November 2013, prevention of CDI with oral use of LP299v was performed in all patients treated with antibiotics and who were at a high risk of developing CDI. The observation period was divided into two twelve-month intervals before and after initiation of the use of LP299v as a prophylactic against CDI. Results: A significant (p = 0.0001) reduction of the number of cases of CDI was found after routinely using LP299v (n = 2; 0.11% of all hospitalized patients) compared with the previous twelve-month period of observation (n = 21; 1.21% of all hospitalized patients). Conclusions: Routine use of LP299v during treatment with antibiotics may prevent C. difficile infection in the nephrology and transplantation ward.

Probiotics for the prevention of antibiotic-associated diarrhoea in older patients: a systematic review

OBJECTIVE

Here, we evaluated the efficacy of probiotic interventions in prevention of antibiotic-associated diarrhoea (AAD) and Clostridium difficile diarrhoea (CDD) in older patients.

METHODS

PubMed, Embase, CENTRAL, CINAHL, and Web of Science were comprehensively searched from their dates of inception to May 2014. Only randomised controlled trials reporting data on probiotics including Lactobacillus, Bifidobacterium, Saccharomyces, Streptococcus, Enterococcus, and Bacillus-alone or in combination-versus placebo or absence of treatment in older patients (age ≥65 years) were included. Risk ratios (RRs) for AAD and CDD relative to placebo or absence of treatment were estimated.

RESULTS

Six trials with a total of 3562 patients were included. Only one trial showed that Bacillus licheniformis was effective for preventing AAD in older patients. However, there was no preventive effect for AAD and CDD with Lactobacillus acidophilus (Florajen), Lactobacillus casei Shirota, Saccharomyces cerevisiae (boulardii) lyo, mixture of Lactobacillus acidophilus and Bifidobacterium bifidum (Cultech strains), and mixture of Lactobacillus acidophilus CUL60, CUL21, Bifidobacterium bifidum CUL20 and B. lactis CUL34.

CONCLUSIONS

Our findings indicate that probiotics may not reduce the risk of AAD and CDD in older patients. However, with current published data, it is difficult to draw concrete conclusions. To confirm these findings, sample sizes, multi-centre, double-blind studies that consider factors such as probiotic strains and types of antibiotics are required.

Nutrition economic evaluation of a probiotic in the prevention of antibiotic-associated diarrhea

Introduction: Antibiotic-associated diarrhea (AAD) is common and frequently more severe in hospitalized elderly adults. It can lead to increased use of healthcare resources. We estimated the cost-effectiveness of a fermented milk (FM) with probiotic in preventing AAD and in particular Clostridium difficile-associated diarrhea (CDAD).

Methods: Clinical effectiveness data and cost information were incorporated in a model to estimate the cost impact of administering a FM containing the probiotic Lactobacillus paracasei ssp paracasei CNCM I-1518 in a hospital setting. Preventing AAD by the consumption of the probiotic was compared to no preventive strategy.

Results: The probiotic intervention to prevent AAD generated estimated mean cost savings of £339 per hospitalized patient over the age of 65 years and treated with antibiotics, compared to no preventive probiotic. Estimated cost savings were sensitive to variation in the incidence of AAD, and to the proportion of patients who develop non-severe/severe AAD. However, probiotics remained cost saving in all sensitivity analyses.

Conclusion: Use of the fermented dairy drink containing the probiotic L. paracasei CNCM I-1518 to prevent AAD in older hospitalized patients treated with antibiotics could lead to substantial cost savings.