I have carried bacterial metagenomic analysis between multiple groups (five in total). The groups represent daywise changes in metagenomic contribution. To compare the data taking into account the sequencing depth and also gene length, the nearest normalization method I came across is TPM (Transcripts per million).

Is it ok to use TPM values to compare metagenomic groups and percent TPM contribution (by calculating the percentage of TPM values) of each gene/function?

Similarly, is there any better statistical method (other than TPM conversion) to compare gene abundance change by normalizing the data (Not include DE analysis)?

Thanks:)