Immune dysregulation: an “accelerator” of gut resistome expansion and multidrug-resistant organism infection risk in ICU patients

Immune dysregulation is a common and critical condition in intensive care unit (ICU) patients, significantly increasing their susceptibility to infections. Beyond heightened vulnerability, immune dysfunction plays a pivotal role in accelerating the expansion of antibiotic resistance genes (ARGs) within the gut microbiome, thereby promoting the emergence and proliferation of multidrug-resistant organisms (MDROs). This review systematically examines the mechanisms by which immune dysregulation acts as a key “accelerator” driving the amplification of the gut resistome in ICU patients and explores the intrinsic link between this process and the elevated risk of MDRO infections. We analyze multiple dimensions including immune suppression-induced gut microbial imbalance, inflammation-mediated horizontal gene transfer (HGT), antibiotic pressure fostering selective advantages, and clinical intervention strategies. Integrating the latest advances in metagenomics and immunology, this article aims to provide novel theoretical insights and clinical guidance for infection prevention and control in the ICU setting. By elucidating the central role of immune dysregulation in ARG expansion, we emphasize the necessity of precise immune modulation combined with targeted anti-infective approaches to reduce MDRO infection risk and improve patient outcomes in critical care.