I read that the authors of MaAsLin do not support analysis of metabolomics data with MaAsLin2.
However, I know that many people have been experimenting with this.
I have tried several things. I originally normalize the metabolomics data using the conventional mean centering and log transformation and a density plot of such normalized data looks nice. However, pretty much nothing is significant after MaAsLin fitting with the parameter normalization=‘NONE’ When I run MaAsLin with the same normalized data, but with default MaAsLin2 normalization (TSS), few features (metabolites). appear significant A density plot of normalized metabolomics data plus TSS, also appears normal but compressed around zero (a way narrower and taller bell curve; almost like a peak). QUESTION: Is it incorrect to apply TSS to data that has already been normalized by mean entering and log transformation, as is typical for metabolomics data? THANKS!