Table 3.
Responsiveness of B cells to in vitro re-stimulation with flu vaccine.
| CD25 (%) Naïve t |
CD25 (%) Memory at |
CD25 (%) Plasma t |
CD25 MFI Naïve at |
CD25 MFI Memory t |
CD25 MFI Plasma t |
|||
|---|---|---|---|---|---|---|---|---|
| Young (n = 58) | Placebo | Baseline | 6.5 ± 0.7 | 15.5 ± 1.6 | 14.4 ± 2.2 | 171 ± 21 | 363 ± 83 | 1375 ± 347 |
| 6 weeks | 9.5 ± 1.0 | 22.5 ± 2.3 | 16.3 ± 2.2 | 219 ± 24 | 550 ± 111 | 1618 ± 499 | ||
| 8 weeks | 9.8 ± 1.2 | 23.6 ± 2.2 | 17.0 ± 1.8 | 231 ± 26 | 484 ± 90 | 1704 ± 490 | ||
| Synbiotic | Baseline | 8.0 ± 0.8 | 14.2 ± 1.6 | 12.5 ± 1.4 | 204 ± 21 | 160 ± 56 | 1554 ± 347 | |
| 6 weeks | 12.0 ± 1.0ˆ | 22.6 ± 1.9ˆ | 20.5 ± 2.4 | 299 ± 26 | 405 ± 70 | 2339 ± 678 | ||
| 8 weeks | 10.0 ± 0.9 | 18.2 ± 1.9 | 18.3 ± 2.9 | 212 ± 24 | 261 ± 71 | 1447 ± 748 | ||
| Older (n = 54) | Placebo | Baseline | 9.4 ± 1.8 | 8.9 ± 2.5 | 5.0 ± 1.9* | 502 ± 129 | 674 ± 338 | 637 ± 664 |
| 6 weeks | 12.7 ± 1.9 | 13.2 ± 2.5* | 12.7 ± 2.8 | 629 ± 137 | 1401 ± 672 | 3319 ± 965 | ||
| 8 weeks | 13.9 ± 2.2 | 14.0 ± 2.8* | 18.3 ± 3.3ˆ | 665 ± 152 | 1377 ± 560 | 2953 ± 1015 | ||
| Synbiotic | Baseline | 6.1 ± 0.9 | 6.8 ± 2.6 | 7.1 ± 4.5 | 235 ± 50 | 126 ± 280 | 907 ± 367 | |
| 6 weeks | 8.8 ± 1.2 | 11.6 ± 2.3* | 13.6 ± 3.5 | 315 ± 61 | 708 ± 228 | 2083 ± 760 | ||
| 8 weeks | 9.2 ± 1.2 | 13.5 ± 2.2 | 13.1 ± 4.0 | 275 ± 41 | 721 ± 157 | 1965 ± 483 | ||
Data are mean ± SE for n = 58 young and n = 54 older subjects and were analysed using a Linear Mixed Model (LMM) with fixed factors of time (repeated measures), age and treatment. There was no significant effect of treatment for either cohort. a Denotes a significant main effect of age (P < 0.01 at least) and t denotes a significant main effect of time (P < 0.01 at least) for the combined cohorts. When the effect of time was examined separately in the young and older cohorts, there were significant effects of vaccination in all B cell subsets (P < 0.01 at least). Activation of memory B cells (% CD25+) in response to in vitro re-stimulation with the vaccine was greater in young subjects than in older subjects (LMM, effect of age, P < 0.001). *Denotes significantly different from young subjects within the same timepoint and treatment group at P < 0.01 and ˆ denotes significantly different from baseline within the same age and treatment group at P < 0.01 (post-hoc t-tests with Bonferroni correction).