Glucorticoid-induced obesity individuals have distinct signatures of the gut microbiome

Abstract

The human intestine and its resident microbiota are known to play an essential role in the pathogenesis of primary obesity. However, a little is known of the gut microbiota profiles in individuals with obesity induced by glucocorticoid (GC) therapy. Here, we recruited 28 people with GC-induced obesity and 27 age- and gender-matched healthy controls, whose feces have been collected separately, to delineate the gut microbial characteristics in GC-induced obesity individuals. High-throughput Illumina sequencing targeting the V4 region of the 16S rRNA gene has been applied to analyze the structure of the intestinal microbiome. Gas chromatography was also used to measure levels of short-chain fatty acids (SCFAs), a subset of key gut microbial metabolites mainly produced by Bacteroidetes. We found dramatically decreased gut microbial diversity in individuals with GC-induced obesity. In addition, the bacterial communities of the GC-induced obesity group were enriched in Firmicutes (e.g., genus Streptococcus) and depleted in Bacteroidetes. Furthermore, SCFA content was decreased in GC-induced obesity status. Overall, this study conducted a case-control study with 55 participants in which we analyzed gut microbiota to develop intestinal microbial profiles of patients undergoing long-term treatment with GCs. Concomitantly, the level of SCFAs was also detected in those study participants.

Keywords: 16S rRNA; glucocorticoid; gut microbiota; obesity; short-chain fatty acids.