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

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.

We performed a meta-analysis to evaluate the effect of probiotics on different parameters in critically ill ventilated subjects.

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.

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.

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.