Ulcer metagenome
DNA was extracted with QIAamp DNA Microbiome Kit (QIAGEN). Paired-end libraries were created from 400 ng of total DNA for each sample according to the manufacturers recommendations using  MGI universal library prep kit (MGI). Shotgun metagenomic sequencing was performed on DNBSEQ400 platform (MGI) according to the manufacturers recommendations using DNBSEQ-G400RS High-throughput Sequencing Set (PE150) reagent kit.