Alternative approach to rarefying in 16S rRNA analysis

Question

[zhangdengwei]

Hi all,

I have over 200 samples with incredibly varied sequencing depths, with the rarefaction curve shown below.

I was struggling with how to rarefy an optimal sample size. Even rarefying to 10000 reads (first red line), 169 samples would be removed. However, if I select a smaller one, the diversity would be underestimated. I wonder whether there is an alternative way to normalize the data rather than rarefying.