Background: Recent evidence supports a role of probiotics in preventing necrotizing enterocolitis (NEC) in preterm infants. Methods: A systematic review and network meta-analysis of randomized controlled trials (RCTs) on the role of probiotics in preventing NEC in preterm infants, focusing on the differential effect of type of feeding, was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A random-effects model was used; a subgroup analysis on exclusively human milk (HM)-fed infants vs. infants receiving formula (alone or with HM) was performed. Results: Fifty-one trials were included (10,664 infants, 29 probiotic interventions); 31 studies (19 different probiotic regimens) were suitable for subgroup analysis according to feeding. In the overall analysis, Lactobacillus acidophilus LB revealed the most promising effect for reducing NEC risk (odds ratio (OR), 0.03; 95% credible intervals (CrIs), 0.00–0.21). The subgroup analysis showed that Bifidobacterium lactis Bb-12/B94 was associated with a reduced risk of NEC stage ≥2 in both feeding type populations, with a discrepancy in the relative effect size in favour of exclusively HM-fed infants (OR 0.04; 95% CrIs <0.01–0.49 vs. OR 0.32; 95% CrIs 0.10–0.36). Conclusions: B. lactis Bb-12/B94 could reduce NEC risk with a different size effect according to feeding type. Of note, most probiotic strains are evaluated in few trials and relatively small populations, and outcome data according to feeding type are not available for all RCTs. Further trials are needed to confirm the present findings.

The effects of atenolol were investigated in car drivers participating in an amateur car rally. Atenolol or placebo were administered to two groups of 20 crews (driver and assistant) in this double-blind randomized trial. When compared with placebo, there was no deterioration in subjective appraisal of alertness and reaction ability in subjects given atenolol, and stress symptoms were markedly reduced. When compared with previous experience, the incidence of improved subjective appraisal of general driving ability was higher with atenolol (30 reports) than with placebo (5 reports). Furthermore the incidence of unchanged or worsened driving ability was significantly higher (p less than 0.001) with placebo (34 reports) than with atenolol (9 reports). At the end of the rally (16 hours after administration) subjects receiving atenolol 50 mg had significant reductions in heart rate (p less than 0.001), diastolic pressure (p less than 0.01), and systolic pressure (p less than 0.01) when compared with placebo.