The gut microbiome in COPD; a case-control study

Abstract

<b>Introduction:</b> The gut microbiome in COPD patients may be associated with disease severity. We aimed to compare fecal microbiome samples in COPD patients and controls and their associations with leukocytes and lung function. <b>Methods:</b> Single center case-control study with 70 COPD patients and 64 controls. We sequenced the 16S-rRNA gene, V3V4-region (MiSeq), extracted from stool samples. Identification of amplicon sequence variants (ASVs) was done with QIIME2, and statistical analyses were run in QIIME2 and R. Alpha diversity was measured using Shannon and Faith, and groups compared using Wilcoxon rank sum test. Beta diversity was measured using Bray Curtis and weighted Unifrac, and groups compared using Permanova in COPD and controls. Differential abundance was evaluated using ANCOM-BC. Heatmap of correlation was created using Spearman9s correlation test. <b>Results:</b> We found no significant difference in alpha or beta diversity between COPD and controls. 1 genus (Class_clostridia) and 8 ASVs were found as differentially abundant between COPD and controls among smokers. Figure 1 shows that some genera were significantly correlated to lung function parameters and blood cell counts. <b>Conclusions:</b> Some microbials differed in abundance in COPD and controls, and some microbials were significantly associated with lung function and leucocytes. Both merits further investigation.