design: In general, DNA was lysed by mechanical magnetic bead impacting and isolated by magnetic technology. The DNA was used to generate 16s rDNA libraries. The barcoded dual-index sequencing primers targeting to the 16sRNA V4 region amplify the DNA. After PCR reactions, pooled amplicon library was then sequenced on the Illumina MiSeq platform using the 500 cycle MiSeq V2 Reagent kit (catalog no. MS-102-2003) according to the manufacturer's instructions with modifications of the primer set with custom read 1/read 2 and index primers added to the reagent cartridge. The Preparing Libraries for Sequencing on the MiSeq (part 15039740, Rev. D) protocol was used to prepare libraries with a final load concentration of 5.5 pM, spiked with 15% PhiX to create diversity within the run. Fastq files were generated when the 2 x 250 bp sequencing completed.