# Request tutorial on generating a custom database for MetaPhlAn 4 from scratch (not updating the existing database)

**URL:** https://forum.biobakery.org/t/request-tutorial-on-generating-a-custom-database-for-metaphlan-4-from-scratch-not-updating-the-existing-database/4932
**Category:** MetaPhlAn
**Created:** [March 6, 2023, 8:51pm UTC](https://forum.biobakery.org/t/request-tutorial-on-generating-a-custom-database-for-metaphlan-4-from-scratch-not-updating-the-existing-database/4932 "2023-03-06T20:51:49Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![jolespin](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.biobakery.org/jolespin/32/1838_2.png) [@jolespin](https://forum.biobakery.org/u/jolespin)
#### Post date: [March 6, 2023, 8:51pm UTC](https://forum.biobakery.org/t/request-tutorial-on-generating-a-custom-database-for-metaphlan-4-from-scratch-not-updating-the-existing-database/4932/1 "2023-03-06T20:51:49Z")

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Looking to create a custom MetaPhlaAn4 database using a target marker set but I’m not seeing any tutorials on how to do this.

I see a tutorial on customizing the database but not for creating new ones:

> **[MetaPhlAn 4](https://github.com/biobakery/MetaPhlAn/wiki/MetaPhlAn-4#customizing-the-database)**
>
> MetaPhlAn is a computational tool for profiling the composition of microbial communities from metagenomic shotgun sequencing data - biobakery/MetaPhlAn

Is this documented anywhere? If not, could you do a brief tutorial on how to do this?

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### Author: ![aitor.blancomiguez](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.biobakery.org/aitor.blancomiguez/32/86_2.png) [@aitor.blancomiguez](https://forum.biobakery.org/u/aitor.blancomiguez)
#### Post date: [March 23, 2023, 8:51am UTC](https://forum.biobakery.org/t/request-tutorial-on-generating-a-custom-database-for-metaphlan-4-from-scratch-not-updating-the-existing-database/4932/2 "2023-03-23T08:51:09Z")

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Hi @jolespin  
Unfortunatelly, there is not a tutorial on how to generate a new metaphlan 4 database from scratch but the procedure is fully described in the metaphlan 4 publication. Please, have a look at the following post: [Building a MetaPhlAn database from fasta sequences - #2 by aitor.blancomiguez](https://forum.biobakery.org/t/building-a-metaphlan-database-from-fasta-sequences/4953/2)