Statistical analysis:
To compare metabolome profiles among groups, orthogonal partial least
squares-discriminant analysis (OPLS-DA) was employed as a visualization
tool. Emphasis was placed on identifying differential metabolites based
on statistical significance, using Variable Importance in Projection
(VIP) values from the OPLS-DA model and P values from the Mann Whitney U
test on normalized peak areas. Specifically, metabolites with VIP values
> 1 and P values < 0.05 were considered as
differential metabolites. KEGG pathway enrichment analysis of these
metabolites utilized the Fisher’s exact test and was compared with all
identified metabolites. Correlation analysis employed Pearson’s
correlation coefficient analysis, utilizing the corrplot R package.
Student’s t -test analyses were conducted to identify group
differences. The potential predictive capability of factors for
AMN-SARS-CoV-2 was evaluated using receiver operating characteristic
(ROC) curves. The Spearman’s rank correlation test was employed to
analyze correlations between variables. For all analyses, two-tailed
probabilities were used, and significance was indicated by a two-tailed
P value < 0.05.