design: DNA was extracted with the Zymobiomics DNA/RNA microprep extraction kit (Zymo Research Corp., California, USA), following the manufacturers instructions.The 16S amplicon sequencing of the V4-V5 hypervariable regions was performed on an Illumina MiSeq platform (Illumina, Inc. California, USA) at Integrated Microbiome Resource IMR (University of Dalhousie) using universal primers (515FB = 5'-GTGYCAGCMGCCGCGGGTAA-3' and 926R = 5'-CCGYCAATTYMTTTRAGTTT-3')