Absent tryptophan pathway in all metagenomic results

Hey folks,

I’m using HUMAnN 3.0 to analyze biochemical pathways in the human gut microbiome. When I examine the pathways, I noticed that none of my results show any readings for the tryptophan biosynthesis pathway, which I find very strange. Has anyone else experienced a similar issue?

Thanks!

Huh, that IS surprising as I think the tryptophan pathways tend to be among the “usual suspects” for the human gut. My advice for diagnosing missing pathways is to quantify ECs from your UniRef90s and then see what’s up with the individual ECs that are part of tryptophan metabolism. If they are mostly there then the pathways should also be quantified. If key ECs are missing that would explain the missing pathways.