differential abundance of two groups using one sample in one of the groups

Question

[michele.lamprillo]

hi everybody,

while studying 16S amplicon sequencing soil samples (12 samples), i discovered that one of them differed from the others thanks to the Pcoa plot of the weighted UniFrac distances.

I also noticed that sample has higher concentration of Phosphorus so i wanted di discover if there were functional differentiation (using picrust2 functional annotation) of this sample from the others, preciselly toward Phosphorus metabolizing MO's.

Unfortunately i think differential abundace analysis doesnt work, i think becouse the algorithm need at least 3 samples per group... what can i do to verify if my hypotesis is true??

Thanks in advance,

Michele