Table 4. Intervention results in fasting H2 based subgroups (post-hoc).
| Low H2 (n = 67) | High H2 (n = 33) | ||||||
|---|---|---|---|---|---|---|---|
| mean (SD) | Interaction P-value | FMP (n = 29) | Control (n = 38) | P value | FMP (n = 21) | Control (n = 12) | P value |
| Δ T0 H2 ppm | 0.06 | 2.8 (8.9) | 5.7 (9.9) | 0.31 | -12.2 (19.5) | 1.5 (27.1) | 0.004** |
| Δ T0 CH4 ppm | 0.36 | 3.2 (6.2) | 0.3 (4.5) | NA | -2.1 (11.9) | -1.5 (6.4) | NA |
| Δ H2 ppm | 0.01* | 5.6 (21.1) | 6.2 (20) | 0.79 | -6.3 (13.5) | 14 (37.7) | 0.002** |
| Δ CH4 ppm | 0.07 | 3.9 (7.0) | -0.2 (8.1) | NA | -2.5 (13.1) | 1.7 (11.8) | NA |
| Δ gas | 0.03* | 0.6 (2.4) | -1.0 (3.1) | 0.04* | -1.4 (3.7) | 0.4 (1.0) | 0.20 |
| Δ bloating | 0.18 | 0.0 (2.7) | -1.0 (3.0) | NA | -1.0 (3.5) | 0.1 (2.3) | NA |
| Δ discomfort | 0.005** | -0.1 (2.6) | -1.5 (2.9) | 0.03* | -1.9 (2.9) | 0.1 (2.2) | 0.05 |
| Δ distension | 0.20 | -0.1 (2.4) | -1.0 (3.2) | NA | -1.1 (2.8) | -0.5 (1.1) | NA |
| Δ nausea | 0.20 | -0.3 (2.9) | -0.6 (2.7) | NA | -0.5 (4.0) | 0.9 (3.0) | NA |
| Δ rumbling | 0.01* | 0.6 (2.9) | -1.2 (3.0) | 0.003** | -1.4 (2.3) | 0.1 (2.7) | 0.34 |
| Δ urgency | 0.10 | 0.4 (2.8) | -0.7 (2.6) | NA | -0.5 (2.9) | 0.6 (2.4) | NA |
| Δ pain | 0.02* | 0.3 (3.2) | -1.0 (2.2) | 0.004** | -0.4 (2.3) | 0.4 (2.5) | 0.43 |
| Δ comfort | 0.93 | 0.1 (2.1) | 0.9 (2.7) | NA | -0.7 (3.1) | 0.2 (1.4) | NA |
SD: Standard Deviation; FMP: fermented milk product (FMP); Control: non-fermented milk product; High H2: fasting H2 level≥10ppm; Low H2: fasting H2 level<10ppm; ppm: parts per million; H2: hydrogen; CH4: methane; N/A: not applicable; T0: fasting value; all statistical analyses are covariance analyses of the 4h mean change (Δ) on measured endpoints from 1st to 2nd nutrient-lactulose challenge between the two study arms adjusted for 1st challenge values; all significance tests were two-sided and conducted at the 5% significance level. Interaction was evaluated at 10% significance level
* <0.05
** <0.01