I met a couple of questions of the PICRUSt2, could you please give me some clue? Thanks in advance!

(1) When preforming PICRUSt2 in Qiime2, how could i know the ASV contribution of each predicted function and the NSTI value of each pathway, which parameter could make it?

(2) You mentioned that “As in PICRUSt1, ASVs are corrected by their 16S rRNA gene copy number and then multiplied by their functional predictions to produce a predicted metagenome”. Which correction method you used and why? Did you use negative binomial regression or zero inflation negative binomial regression?

(3) You used a “null reference”, but i don’t understand how did you make it and the purpose you used it?