Antimicrobial resistance (AMR) is a pressing threat to human health, both locally and globally. AMR genes increase the resistance of microbes against common antibiotics, making infections increasingly difficult to treat. Different microbes may bear different AMR genes, and different AMR genes may confer variable resistance against different antimicrobials. All AMR genes in a community constitute the resistome of the microbial community and opportunistic pathogens of the community may interchange AMR genes of the resistome through horizontal gene transfer. Studies illustrate that environmental changes may shift both the microbiome and resistome. Gulf War (GW) veterans who participated in Operation Desert Shield/Desert Storm in 1990-1991 show a chronic multisystem illness, Gulf War Illness (GWI), which is characterized by persistent inflammation with elevated IL-6, TNF-R1 and IL-1β levels in the blood. These veterans are also more prone to antimicrobial-resistant infections. In this study, shotgun metagenomic sequencing of the fecal microbiomes of persistent inflammatory GWI patients by CosmosID suggested an association between the illness and an increase in AMR genes on mobile genetic elements when compared to the healthy controls. The finding of an altered resistome correlated with serum IL-6 levels in the GWI mouse model. Mouse IL-6 levels strongly correlated with intestinal inflammation and negatively with synaptic plasticity. Symptoms were reversed with a fecal microbiota transplant from healthy mice. The findings illustrate the risks of treating hospital-acquired infections in Gulf War veterans and potential avenues of research for their alleviation. Here is the study.