Advanced Age Impairs Intestinal Antimicrobial Peptide Response and Worsens Fecal Microbiome Dysbiosis Following Burn Injury in Mice

In this study, we combined our well-established murine model of scald burn injury with bacterial 16S-rRNA gene sequencing to investigate how burn injury affects the fecal microbiome in aged versus young mice. Of our treatment groups, the most substantial shift in gut microbial populations was observed in aged mice that underwent burn injury. We then profiled antimicrobial peptides (AMPs) in the ileum, and found that burn injury stimulated a 20-fold rise in levels of regenerating islet-derived protein 3 gamma (Reg3γ), a 16-fold rise in regenerating islet-derived protein 3 beta (Reg3β), and an 8-fold rise in Cathelicidin-related antimicrobial peptide (Cramp) in young, but not aged mice. Advanced age alone elicited 5-fold higher levels of alpha defensin-related sequence1 (Defa-rs1) in the ileum, but this increase was lost following burn. Comparison of bacterial genera abundance and AMP expression across treatment groups revealed distinct correlation patterns between AMPs and individual genera. Our results reveal that burn injury drives microbiome dysbiosis and altered AMP expression in an age-dependent fashion, and highlight potential mechanistic targets contributing to the increased morbidity and mortality observed in elderly burn patients.
Source: Shock - Category: Emergency Medicine Tags: Basic Science Aspects Source Type: research