Running without reference

Downstream analysis and statistics MaAsLin
1

Hello,

I ran a 16S sequencing, and I analyzed it via MOTHUR. I am trying to determine if any of the ASVs correlate with the presence of Legionella. I have 3 ‘levels’: high, low, and negative, but I do not have a reference.

Is there any way to run MAASLIN2 without a reference level like it was done with LEfSe?

Thanks,
Elliston Vallarino

2

Hi @EllistonV,

MaAsLin2 makes use of linear models which require a reference (or baseline) category to compare coefficients between. When there is only two levels within a category it will just pick one as the baseline. However, if more than two levels exist you need to determine which should be the baseline.

Thanks,
Jacob Nearing

3

Thank you so much for the answer!

So, this means that I must have reference data to use MaAslin2? If there are more than 2 levels, will changing the reference level affect the results?

Regards,
Elliston