We are planning to use metabolomics and metagenomics data from the IBD dataset in our project.
I have downloaded the metabolomic file named as “iHMP_metabolomics” from the link /products/HMP2/MBX and the metagenomic file “ecs_relab.slim” from the link /products/HMP2/MGX through the FTP server. I could not find detailed information about the values of these data files in the paper.
For both of the data files have you performed transformation/normalization? Can I use these values without any normalization step for performing the analysis? For example, In “iHMP_metabolomics” file, the values are too high, In “ecs_relab.slim” file, there are too many zero values, what does the zero mean? Is it that the enzyme does not exist in the related sample.