To address your questions regarding the pathway enrichment analysis conducted in the study, here are the details extracted from the article:

1. **What tool was used for pathway enrichment analysis?**
   - The tool used for pathway enrichment analysis is MetaboAnalyst.

2. **Was a tool version number provided?**
   - A specific version number for MetaboAnalyst is not mentioned in the text; however, it refers to "MetaboAnalyst version 4.0."

3. **What gene set library was queried (e.g., GO, KEGG, Reactome or other)?**
   - The article does not specify which gene set libraries were queried for pathway enrichment analysis.

4. **Was a background gene list defined for pathway enrichment analysis?**
   - It is not described whether a specific background gene list was defined for the pathway enrichment analysis in the text provided.

5. **What statistical test was used for enrichment analysis?**
   - The article does not specify what statistical test was employed for the enrichment analysis.

6. **Was false discovery rate correction used to control the number of false positives in the pathway enrichment analysis?**
   - The article does not mention whether a false discovery rate (FDR) correction was applied during the pathway enrichment analysis. 

These details have been summarized based on the available information from the article, and any unspecified aspects are noted as "not described."