Table 4.
Multivariable model for relative abundance (RA) of short chain fatty acid (SCFA) producers after 72 hours in the ICU.
| Exposure Variables | Median Increase in RA of SCFA Producers | Estimate IQR | p-value |
|---|---|---|---|
| Fiber, per 10 g increase | +0.30% | +0.10 to +0.46% | <0.01 |
| Antibiotics | |||
| None | Reference | --- | --- |
| Narrow-spectrum only | +1.0% | −2.4 to +4.4% | 0.56 |
| Broad-spectrum | −0.62% | −3.6 to +2.4% | 0.69 |
| APACHE IV score at admission, per 10-point increase | +0.27% | −0.15 to +0.69% | 0.21 |
| Mechanical ventilation | +0.40% | −3.1 to +3.9% | 0.82 |
| Vasopressors | −1.7% | −4.7 to +1.3% | 0.26 |
This kernel-based least squares regression model estimates the median independent effect of each exposure variable on the outcome of relative abundance of SCFA producers after 72 hours in the ICU. This model was selected because the relative abundance of SCFA producers is non-linear (left skewed) data. See text for additional details. IQR: interquartile range (25th to 75th percentile).