design: Total microbiome genomic DNA was extracted from freshly excised granulation tissue or other tissue using the Molzym DNA isolation (Ultra-Deep Microbiome prep) kit. Then, bacterial DNA was extracted from the pellet of enriched bacteria and sent for NGS 16S rRNA amplicon metagenomic sequencing. Amplicon library of the 16S rRNA V3V4 regions were amplified with the barcoded primer pair of 341F (5-CCTAYGGGRBGCASCAG-3) and 806R (5-GGACTACNNGGGTATCTAAT-3), with inclusion of two blank controls for each sample for verifying absence of contamination. PE250 paired-end sequencing was performed on the NovaSeq 6000 Systems (Illumina, USA).