# Using Maaslin2 with centered log ratio transformation

**URL:** <https://forum.biobakery.org/t/using-maaslin2-with-centered-log-ratio-transformation/2352>\
**Category:** MaAsLin\
**Created:** [July 12, 2021, 8:48am UTC](https://forum.biobakery.org/t/using-maaslin2-with-centered-log-ratio-transformation/2352 "2021-07-12T08:48:35Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![jjsimz](https://avatars.discourse-cdn.com/v4/letter/j/c77e96/32.png) [@jjsimz](https://forum.biobakery.org/u/jjsimz)\
**Post date:** [July 12, 2021, 8:48am UTC](https://forum.biobakery.org/t/using-maaslin2-with-centered-log-ratio-transformation/2352/1 "2021-07-12T08:48:35Z")

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Hi, I have a question about data transformation prior to input into Maaslin2.

I am thinking of transforming a metagenomics abundance dataset using centered log ratio, then input into Maaslin2 with parameters `transform = "none", normalization ="None"`. Other parameters remain default.

Is this allowed?

Reason for doing so is because I wanted to use Maaslin2’s capability to control for covariates but I could not find any other tool that is compatible with both covariate adjustment and centered log ratio transformation.

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**Author:** ![Kelsey\_Thompson](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.biobakery.org/kelsey_thompson/32/65_2.png) [@Kelsey\_Thompson](https://forum.biobakery.org/u/Kelsey_Thompson)\
**Post date:** [July 12, 2021, 10:22am UTC](https://forum.biobakery.org/t/using-maaslin2-with-centered-log-ratio-transformation/2352/2 "2021-07-12T10:22:31Z")

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Hi @jjsimz,

I believe CLR is an option in MaAsLin 2, see [here](https://github.com/biobakery/Maaslin2#options) under the normalization section. Therefore, if you have already CLR normalized your data, yes your suggestions above should work just fine under the hood.

This [post](https://forum.biobakery.org/t/choosing-analysis-method-for-maaslin2/2107/2), also includes a bit more information on the different methods that MaAsLin has available.

I hope this helps!  
Best,  
Kelsey

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**Author:** ![jjsimz](https://avatars.discourse-cdn.com/v4/letter/j/c77e96/32.png) [@jjsimz](https://forum.biobakery.org/u/jjsimz)\
**Post date:** [July 12, 2021, 12:44pm UTC](https://forum.biobakery.org/t/using-maaslin2-with-centered-log-ratio-transformation/2352/3 "2021-07-12T12:44:08Z")

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Hi @Kelsey_Thompson,  
I somehow thought that CLR wasn’t supported by Maaslin2, but it seems that I was mistaken. Many thanks for the correction!