Evidence-Based Complementary and Alternative Medicine / 2020 / Article / Tab 1 / Research Article
Probiotics for Preventing Upper Respiratory Tract Infections in Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials Table 1 Main characteristics of studies included in the meta-analysis.
Study author/year Country Study type Participants Age, years No. of cases Probiotics Dose (CFU/d) Administration form Duration Probiotics Placebo Berggren et al., 2011 [20 ] Sweden RCT, double-blind Healthy adults 18–65 159 159 L. plantarum HEAL9 and L. paracasei 8700 : 2 1 × 109 Powder 12 w Murata et al., 2018 [23 ] Japan RCT, double-blind Healthy females (most were students) ≥18 82 81 Heat-killed L. paracasei MCC1849 1 × 1010 Powder 12 w 78 — Heat-killed L. paracasei MCC1849 3 × 1010 Powder 12 w Shida et al., 2017 [13 ] Japan RCT Healthy males 30–49 50 50 L. casei Shirota LcS-FM 1 × 1011 Milk 12 w Langkamp-Henken et al., 2015 [22 ] USA RCT, double-blind Healthy students ≥18 146 147 L. helveticus R0052 3 × 109 Capsule 6 w 142 — B. bifidum R0071 3 × 109 Capsule 6 w 148 — B. infantis R0033 3 × 109 Capsule 6 w Hirose et al., 2013 [21 ] Japan RCT, double-blind Healthy subjects with high mental pressure 40–64 39 39 Heat-killed L. plantarum L-137 NR Tablet 12 w Smith et al., 2013 [15 ] USA RCT, double-blind Healthy students 18–25 114 117 B. animalis ssp. lactis BB-12 and L. rhamnosus LGG >1 × 109 Powder 12 w
The number of participants in an intention-to-treat population (all the participants who were randomized to their original group, regardless of whether or not they completed the study). RCT: randomized controlled trial; NR: not reported.