Virus-Induced Intestinal Barrier Injury: Mechanisms and Therapeutic Perspectives

The intestinal barrier is a key interface maintaining host–microbial segregation and systemic homeostasis. A broad range of viruses, including enteric, respiratory, and systemic pathogens, can disrupt this barrier through effects on epithelial integrity, vesicular transport, immune responses, and microbial ecology. Whether these diverse insults converge on shared regulatory nodes or act through distinct virus-specific pathways that ultimately result in barrier failure remains unclear. Building on this premise, this review systematically delineates the molecular and cellular mechanisms underlying virus-induced disruption of the intestinal barrier. Viral infection disrupts epithelial integrity through multiple converging processes, including disassembly of tight junction architecture, activation of programmed cell death pathways, degradation of the mucus layer, impaired regeneration driven by intestinal stem cells, and dysregulation of transcellular transport. These processes are interconnected and collectively drive epithelial dysfunction and barrier breakdown. Beyond epithelial damage, we further highlight the pivotal contribution of host immune responses to barrier breakdown. Viral infection induces dysregulated cytokine production and aberrant immune activation, which amplify epithelial damage and further increase barrier permeability. In parallel, increasing evidence supports a bidirectional interaction between viral infection and gut microbiota dysbiosis, in which each process reinforces the other to accelerate barrier disruption and disease progression. We also discuss emerging therapeutic strategies aimed at restoring intestinal homeostasis, including antiviral therapies, host-targeted interventions, and microbiota modulation. Despite recent progress, key questions remain, particularly regarding mechanisms of failed barrier repair after viral clearance and the multilayered regulatory networks linking viruses, immunity, and the microbiota. Together, this review provides a framework for understanding virus-induced intestinal barrier dysfunction and identifies potential therapeutic nodes for intervention.