Units of functional gene abundance from Picrust2 analysis

[Erica Dasi]

Good evening, 

Hope you are doing well. I have completed my Picrust2 analysis and have a question regarding interpreting the results. In my case, I used the KEGG ORTHOLOGY database to predict the abundance of functional genes in my samples. I was wondering if there is a specific unit that is used to describe this abundance. 

I understand that the OTU abundance of a sample is normalized during the metagenomic prediction step to account for multiple 16s rRNA copies. I'm just wondering if the units of gene abundance should be expressed per 16S copy number. 

For example, 

If there were 7,000 K00003 in Sample 1, would I interpret the results as: 7,000 copies of K00003/16S copy number in Sample 1 ?

Thank you for your time and I look forward to receiving your help!

Sincerely, 

Erica