A meta-analysis of the effects of probiotics on various parameters in critically ill ventilated individuals

Background.According to reports, ventilator-associated pneumonia affects critically ill patients more frequently than any other nosocomial infection.Probiotic usage as a prophylactic intervention has shown promising results in numerous studies.Objectives.We performed a meta-analysis to evaluate the effect of probiotics on different parameters in critically ill ventilated subjects. Materials and methods.A systematic literature search up to June 2022 was performed and 5893 critically ill ventilated subjects at the baseline of the studies were identified; 2912 of them were using the probiotics, and there were 2981 controls.Odds ratio (OR) and mean difference (MD) with 95% confidence interval (95% CI) were calculated to assess the effect of probiotics on different parameters in critically ill ventilated subjects using the dichotomous and contentious methods with a random or fixed effects model. Results.The probiotics caused a significantly lower incidence of ventilator-associated pneumonia (OR = 0.52; 95% CI: 0.40-0.68,p < 0.001), shorter duration of mechanical ventilation (MD = -2.22;95% CI: -3.33--1.11, p < 0.001), shorter intensive care unit (ICU) stay (MD = -2.09;95% CI: -3.41--0.77,p = 0.002), shorter hospital stay (MD = -2.36;95% CI: -4.54--0.19, p = 0.03), and lower oropharyngeal colonization (OR = 0.59; 95% CI: 0.36-0.96,p = 0.03) in critically ill ventilated subjects compared with controls.However, probiotic use had no significant difference in terms of diarrhea incidence (OR = 0.74; 95% CI: 0.52-1.07,p = 0.11) and in-hospital mortality (OR = 0.90; 95% CI: 0.79-1.03,p = 0.14) in critically ill ventilated subjects compared with controls.Conclusions.Probiotics caused a significantly lower ventilator-associated pneumonia incidence, shorter duration of mechanical ventilation, shorter ICU and hospital stay, and lower oropharyngeal colonization.However, there was no significant difference in terms of diarrhea incidence and in-hospital mortality in subjects who used probiotics compared with controls.The low sample size of 9 out of 27 researches and the small number of studies in several comparisons requires attention when analyzing the results.