Earthworm-Microbe Synergy and Microbiome Augmentation for ARG Mitigation in Livestock Manure Vermicomposting: Mechanisms, Strategies, and Challenges

Livestock manure is a prominent reservoir of antibiotic resistance genes (ARGs), which pose growing environmental and public health risks that require effective management. Vermicomposting offers an eco-friendly and low-cost approach for stabilizing livestock manure and attenuating ARGs under ambient conditions, yet its efficiency and stability are constrained by system variability and selective reduction capacity. Here, we present a systematic review that advances the paradigm from passive ARG attenuation to active environmental management via functional microbiome augmentation. We synthesize the occurrence, transmission, and environmental risks of ARGs in livestock manure, clarify the multi-mechanistic processes underlying ARG reduction in earthworm-microorganism synergistic systems, and reveal the contextdependent dual roles (carriers or reducers) of dominant microbial phyla. We further evaluate representative functional microbiomes, synthetic microbial consortia, and their efficacy in enhancing ARG removal during vermicomposting. Major challenges are identified, including functional strain screening, environmental adaptability, biosafety, and intelligent process control, with targeted future directions proposed. This review provides a theoretical and practical framework for sustainable livestock manure management and active ARG pollution control, supporting the development of green, safe, and scalable waste treatment technologies for agro-environmental protection.