METHODS: RCTs that compared probiotics or synbiotics to usual care or placebo and reported clinical and diarrheal outcomes were searched in 4 electronic databases from inception to March 8, 2022 without language restriction. Four reviewers independently extracted data and assessed the study qualities using the Critical Care Nutrition (CCN) Methodological Quality Scoring System. Random-effect meta-analysis and trial sequential analysis (TSA) were used to synthesize the results. The primary outcome was ventilator-associated pneumonia (VAP). The main subgroup analysis compared the effects of higher versus lower quality studies (based on median CCN score).

RESULTS: Seventy-five studies with 71 unique trials (n = 8551) were included. In the overall analysis, probiotics significantly reduced VAP incidence (risk ratio [RR] 0.70, 95% confidence interval [CI] 0.56-0.88; I2 = 65%; 16 studies). However, such benefits were demonstrated only in lower (RR 0.47, 95% CI 0.32, 0.69; I2 = 44%; 7 studies) but not higher quality studies (RR 0.89, 95% CI 0.73, 1.08; I2 = 43%; 9 studies), with significant test for subgroup differences (p = 0.004). Additionally, TSA showed that the VAP benefits of probiotics in the overall and subgroup analyses were type-1 errors. In higher quality trials, TSA found that future trials are unlikely to demonstrate any benefits of probiotics on infectious complications and diarrhea. Probiotics had higher adverse events than control (pooled risk difference: 0.01, 95% CI 0.01, 0.02; I2 = 0%; 22 studies).

CONCLUSION: High-quality RCTs did not support a beneficial effect of probiotics on clinical or diarrheal outcomes in critically ill patients. Given the lack of benefits and the increased incidence of adverse events, probiotics should not be routinely administered to critically ill patients.

Methods: We searched for articles from PubMed, Embase, Cochrane, Web of Science, Scopus, and CINAHL plus. From 2002 to 2015, 31 articles meeting the inclusion criteria were identified in the literature. Risk of bias and heterogeneity were assessed. Network meta-analyses (NMA) were performed using random-effects modeling to obtain estimates for study outcomes. Risk ratios (RRs) and 95% confidence intervals (CIs) were estimated. We then ranked the comparative effects of all regimens with the surface under the cumulative ranking (SUCRA) probabilities.

Results: A total of 2,952 patients were included. We found that synbiotic therapy was the best regimen in reducing surgical site infection (SSI) (RR = 0.28; 95% CI, 0.12-0.64) in adult surgical patients. Synbiotic therapy was also the best intervention to reduce pneumonia (RR = 0.28; 95% CI, 0.09-0.90), sepsis (RR = 0.09; 95% CI, 0.01-0.94), hospital stay (mean = 9.66 days, 95% CI, 7.60-11.72), and duration of antibiotic administration (mean = 5.61 days, 95% CI, 3.19-8.02). No regimen significantly reduced mortality.

METHOD: The meta-analysis included all studies that examined the effect of prebiotic, probiotic, and synbiotic supplements on one or more renal function parameters and had a control group. We searched July 1967 through to March 2016 MEDLINE, Scopus, and Google Scholar databases.

RESULTS: Of 437 studies, 13 were eligible for inclusion in the meta-analysis. GFR levels tended to be reduced; whereas creatinine levels increased in the intervention group compared with the placebo group, both in a non-significant manner. The pooled effect on BUN demonstrated a significant decline compared with the placebo group (MD, -1.72 mmol/L; 95% confidence interval [CI], -2.93 to -0.51; P = 0.005). Urea significantly decreased after intervention (-0.46 mmol/L; 95% CI, -0.60 to -0.32; P <0.0001). The UA levels significantly increased in the intervention group compared with the placebo group (12.28 µmol/L; 95% CI, 0.85-23.71; P = 0.035).