Table 1 Outcomes, measures and methods of analysis
Outcome | Hypothesis | Outcome Measure | Methods of Analysis |
|---|---|---|---|
1.Primary 1a A between-group difference in Shannon diversity index at the 7th day | OAC increases Shannon diversity and metabolites of gut microbiota | Shannon index (continuous) | Individuals: Wilcoxon text; Intergroup: T/Wilcoxon text |
1b A between-group difference in fecal metabolites at the 7th day | Short chain fatty acids (continuous) | Individuals: FC, PCA/PLS-DA Intergroup: T/Wilcoxon text | |
2. Secondary 2a Between-group differences in other alpha diversity indexes (Simpson, Chao1) at the 7th day | OAC increases other alpha diversity and beta diversity, and changed the proportion of gut microbiota from birth to day 28. There is a Correlation between dominant microbiota and metabolites | Simpson index, Chao1 index (continuous) | Individuals: Wilcoxon text; Intergroup: T/Wilcoxon text |
2b Between-group differences in Shannon index, Simpson index and Chao1 index at the 14th, 21st and 28th days of life | Shannon index, Simpson index, Chao1 index (continuous) | Individuals: Wilcoxon text; Intergroup: T/Wilcoxon text | |
2c Between-group differences in the concentration of fecal metabolites at the 14th, 21st and 28th days of life | Short chain fatty acids (continuous) | Individuals: FC, PCA/PLS-DA Intergroup: T/Wilcoxon text | |
2d Proportion of gut microbiota (phylum and genus level) | The percentile of gut microbiota at the phylum and genus levels of the total microbiota (binary) | Individuals: Wilcoxon text; Intergroup: Chi-square test | |
2e Gut microbial beta diversity | Bray–Curtis distances with 9999 permutations (continuous) | PCOA; LDA | |
2f Correlation between dominant microbiota and metabolites | Correlation between dominant microbiota and metabolites | Partial Least Squares Discriminant Analysis | |
3.Subgroup Analysis | |||
 ≤ 28w vs. > 28w | Gestational age affects adherence | All outcomes | Same as above |