Table 2.

Associations of weight Z-score with microbiome phase, nutrition, and clinical covariates

Significant covariates	p value	Beta value
Ratio of proteins to total calories (g/cal) * phase 2	0.0071	10.95
Ratio of lipids to total calories (g/cal) * phase 2	0.0437	5.658
Phase 2	0.0003	− 0.7766
Calories/kilogram past week	< 0.0001	− 0.626
Proportion of calories enteral	< 0.0001	− 0.5566
Corticosteroids past week * phase 1	0.0035	0.3669
Diuretics past week * phase 1	0.0002	0.3393
Diuretics past week * phase 2	< 0.0001	0.3306
Motility agents past week * phase 2	0.0003	− 0.3144
Diuretics past week	< 0.0001	− 0.2266
Antibiotics past week	< 0.0001	− 0.2176
Motility agents past week	0.0087	0.1522
Gestational age at birth	0.0165	0.059

Multiple regression associations of weight Z-score (as the outcome variable) with microbiome phase, nutrition, and other clinical covariates, as well as the interactions between phases and clinical covariates (interaction terms denoted with an asterisk). P values indicate the significance of each association while beta values indicate the direction and magnitude of the relationship between weight Z-score and the covariates