Table 1. Bacterial organisms identified in the follicular microbiome of the three groups.
| Phylum | Reference species | Acne (n = 38) |
Healthy age-matched (n = 30) |
Healthy 55 + (n = 4) |
Acne vs. age-matched healthy | Acne vs. all healthy | |||
|---|---|---|---|---|---|---|---|---|---|
| Average relative abundance | Prevalence (percentage) | Average relative abundance | Prevalence (percentage) | Average relative abundance | Prevalence (percentage) | P-value | P-value | ||
| Actinobacteria | P. acnes | 88.50% | 38 (100%) | 93.80% | 30 (100%) | 91.60% | 4 (100%) | 0.663 | 0.810 |
| P. humerusii | 3.60% | 21 (55%) | 1.66% | 22 (73%) | 1.40% | 2 (50%) | 0.654 | 0.586 | |
| P. granulosum | 0.90% | 9 (24%) | 2.19% | 17 (57%) | 2.12% | 3 (75%) | 0.002 | 0.001 | |
| P. avidum | 0.37% | 6 (16%) | 0.43% | 9 (30%) | 0.55% | 0 | 0.859 | 0.469 | |
| Other | 0.08% | — | 0.07% | — | 0.24% | — | — | — | |
| Firmicutes | S. epidermidis | 1.01% | 9 (24%) | 0.64% | 6 (20%) | 0.95% | 1 (25%) | 0.568 | 0.666 |
| Other | 2.34% | — | 0.48% | — | 0.46% | — | — | — | |
| Proteobacteria | 1.88% | — | 0.36% | — | 1.83% | — | — | — | |
| Cyanobacteria | 1.02% | — | 0.23% | — | 0% | — | — | — | |
| Bacteroidetes | 0.26% | — | 0.07% | — | 0% | — | — | — | |
Wilcoxon Rank-Sum Test (U-test) was performed on the prevalent species (found in ≥20% of the subject population). Significance level was adjusted to P < 0.005 after Bonferroni correction.