TABLE 2.
Characteristics of included studies examining effects of prebiotics and synbiotics on the incidence, duration, or severity of respiratory tract infections in nonelderly adults1
| Study, year; country (reference) | Study design | n (% female), age,2 y | Population | Intervention; form | Duration, wk |
|---|---|---|---|---|---|
| Prebiotic | |||||
| Childs et al., 2014; United Kingdom (40) | RCT, crossover | 44 (50), 43 ± 12 | Healthy adults | PRE: xylo-oligosaccharide (8 g/d); powderPLA: maltodextrin; powder | 3 |
| Hughes et al., 2011; United States (68) | RCT, parallel group | PRE1: 140 (50), 20 ± 1PRE2:139 (51),20 ± 1PLA: 140 (51),20 ± 1.2 | Healthy university students under academic stress and ≥1 cold in past year | PRE1: GOS (2.5 g/d); powderPRE2: GOS (5 g/d); powderPLA: sucrose, silicone dioxide; NR | 8 |
| Nieman et al., 2008; United States (69) | RCT, parallel group | PRE: 19 (0), 22 ± 4PLA: 17 (0),25 ± 9 | Healthy active cyclists | PRE: B-glucan (5.6 g); beveragePLA: cornstarch, sports drink; beverage | 2.5 |
| Synbiotic | |||||
| Childs et al., 2014; United Kingdom (40) | RCT, crossover | 44 (50), 43 ± 12 | Healthy adults | SYN: Bifidobacterium animalis subsp. lactis Bi-07 (1 × 109 CFU/d) and xylo-oligosaccharide (8 g/d); powderPLA: maltodextrin, powder | 3 |
| Pregliasco et al., 2008; Italy (70) | RCT, parallel group | SYN: 114 (NR), 39 ± 16PLA: 105 (NR), 35 ± 20SYN: 74 (NR), 38 ± 19PLA: 68 (NR),38 ± 19SYN1: 76 (NR), 42 ± 15SYN2: 78 (NR), 45 ± 16PLA: 75 (NR),42 ± 19 | Healthy adults | SYN: Lactobacillus plantarum probial LP 02-LMG P-21020 (10 × 109 CFU/d), Lactobacillus rhamnosus probial LR 04-DSM 16605 (10 × 109 CFU/d), Bifidobacterium lactis probial BS 01-LMG P-21384 (10 × 109 CFU/d), FOS (3 g/d); powderPLA: glucose, maltodextrin; powderSYN: Lactobacillus plantarum probial LP 02-LMG P-21020 (10 × 109 CFU/d), Lactobacillus rhamnosus probial LR 04-DSM 16605 (10 × 109 CFU/d), Bifidobacterium lactis probial BS 01-LMG P-21384 (10 × 109 CFU/d), FOS (3 g/d); powderPLA: glucose, maltodextrin; powderSYN1: Lactobacillus plantarum probial LP 01-LMG P-21021 (5 × 109 CFU/d), Lactobacillus plantarum probial LP 02-LMG P-21020 (5 × 109 CFU/d), Lactobacillus rhamnosus probial LR 04-DSM 16605 (5 × 109 CFU) Lactobacillus rhamnosus probial LR 05-DSM 19739 (5 × 109 CFU/d), Bifidobacterium lactis probial BS 01-LMG P-21384 (5 × 109 CFU/d), GOS (2.5 g/d); powderSYN2: Lactobacillus plantarum probial LP 01-LMG P-21021 (5 × 109 CFU/d), Lactobacillus plantarum probial LP 02-LMG P-21020 (5 × 109 CFU/d), Lactobacillus rhamnosus probial LR 04-DSM 16605 (5 × 109 CFU/d), Lactobacillus rhamnosus probial LR 05-DSM 19739 (5 × 109 CFU/d), Bifidobacturium lactis probial BS 01-LMG P-21384 (5 × 109 CFU/d), FOS (3 g/d); powderPLA: glucose, maltodextrin; powder | 12 |
1
FOS, fructo-oligosaccharide; GOS, galacto-oligosaccharide; NR, not reported; PLA, placebo; PRE, prebiotic; RCT, randomized controlled trial; SYN, synbiotic.
2
Values are means ± SDs or means (range).