Normalize for sample size in 16S a-diversity analysis

Question

[bpvalderrama]

Hi everyone!

I'm working with 6 samples of 16S microbiome data in R. When looking for correlation between sample size and diversity it seems to be a positive correlation for chao1 and observed index. Marginally not significative for shannon.

The questions are: 1) Should I normalize my samples? 2) Reading the vegan::rarefy documentation I realize that they recommend to use vegan::decostand function. What method should I use for normalization if I use decostand?

Thanks in advance