Human Catestatin Alters Gut Microbiota Composition in Mice

Area of Science:

• Microbiology
• Gastroenterology
• Biochemistry

Background:

• Mammalian gut microbiota is crucial for intestinal homeostasis.
• Enterochromaffin cells secrete chromogranin A (CgA), a precursor to bioactive peptides like catestatin (CST).
• CST's impact on gut microbiota composition and function requires investigation.

Purpose of the Study:

• To evaluate the in vivo effect of catestatin (CST) on gut microbiota composition and predicted functional capacity in a mouse model.
• To determine if CST influences bacterial richness, diversity, and relative abundance of major phyla.
• To explore potential therapeutic applications of CST in gastrointestinal inflammatory conditions.

Main Methods:

• Intrarectal administration of CST or saline to C57BL/6 male mice for 6 days.
• Collection of fecal and colonic mucosa samples for DNA extraction and 16S rRNA gene sequencing.
• Analysis of alpha- and beta-diversity, genus-level composition (PLS-DA), and predicted microbial functions (PICRUSt).

Main Results:

• CST treatment did not alter bacterial richness but significantly modified microbiota composition.
• A decrease in Firmicutes and an increase in Bacteroidetes were observed in fecal samples.
• CST treatment associated with specific bacterial taxa and altered predicted microbial functional pathways in both fecal and mucosal samples.

Conclusions:

• CST treatment modulates gut microbiota composition and predicted functions in mice under non-pathophysiological conditions.
• The findings support CST's potential as a therapeutic agent for gastrointestinal inflammatory diseases.
• Further validation in larger experiments is needed to confirm these results and explore therapeutic applications.