Hi @Benedict,
The q-value is the corrected p-value based on the BH-FDR multiple testing adjustment method (similar question here). Generally speaking, the q-value is what you should be referring to, unadjusted p-values have their place in exploratory studies, but they need to be approached with extreme caution. The standard 0.05 significant threshold is used to denote significance in the qiime2 versions of these tests.