The intestinal microbiome forms dynamic ecosystem whose balanced composition and functioning are essential for maintaining overall gut health and well-being in living organisms. In broilers, dysbiosis disrupts the microbiota-host balance, often without obvious clinical symptoms but with intestinal inflammation, leading to impaired animal performance and significant economic losses. This study utilizes an in vivo model of dysbiosis to investigate the blood proteome response of broilers to intestinal imbalance. Microscopic histological changes in the gut (shorter villi, increased crypt depth, p<0.0001) were observed in the duodenal and jejunal tissue of challenged birds. Elevated levels of permeability markers faecal ovotransferrin (p < 0.0001) and serum iohexol (p= 0.0009) additionally indicated increased intestinal permeability in challenged group compared to control. The MS/MS-based proteomics analysis was performed on broilers’ blood plasma enabling identification of 388 proteins, 25 of which demonstrated significant difference between the groups. Functional analysis showed activation of immune response, signalling, and interspecies interaction, while proteins related to cellular physiology, cell-cell communication, and extracellular matrix (ECM) processes were suppressed. Protein-protein interaction (PPI) analysis revealed two clusters of downregulated proteins involved in ECM organization and cell adhesion. These results suggest that the dysbiosis challenge alters plasma protein expression as the host prioritizes immune defense over structural maintenance. The activation of immune processes and suppression of ECM pathways highlight potential biomarkers and therapeutic targets for addressing dysbiosis.