2.2. Metagenomics
The gut microbiota was characterized by the 16S rRNA gene amplicon sequencing of the V3–4 regions using an Illumina MiSeq platform (Illumina, San Diego, CA, USA). All raw 16S rRNA gene sequencing data have been deposited in the NCBI Sequence Read Archive under the accession number SUB7459302 (BioProject PRJNA633584). Metagenomics analyses are described in detail in a previous article [