Invasion legacy reshapes resident microbiome multifunctionality through the Matthew effect

Microbial invasions fundamentally alter ecosystem functioning, yet their persistent legacy effects remain poorly characterized. Using beneficial bacterial inoculation as an experimentally tractable model, we investigated invasion-driven community restructuring through comprehensive temporal monitoring of four bacterial inoculants with distinct taxonomic backgrounds and disease suppression capabilities. We reveal a universal "Matthew effect" whereby invasion benefits abundant taxa while diminishing rare taxa, creating community polarization that persists long after invader extinction. This ecological reorganization drives predictable functional consequences: enhanced resource acquisition and nutrient cycling at the expense of stress tolerance and resilience capacities. Mechanistically, invasion legacy accelerates replacement of slow-growing taxa with fast-growing taxa, fundamentally altering community assembly from deterministic processes during invasion to predominantly stochastic thereafter. Meta-analysis across diverse invasion scenarios confirms cross-system generalizability of these patterns. Our findings establish a unifying framework for understanding how transient microbial invasions create lasting ecological imbalances that cascade from community structure to ecosystem multifunctionality.