Abstract Background Vermicomposting is a sustainable biotechnology application that encompasses conversion of organic waste into nutrientrich components through the combined activity of earthworms and their associated gut microbiota. In recent years, the role of earthworm gut microbes as key drivers of organic matter decomposition, nutrient cycling, and microbial community restructuring during vermicomposting have gained increased attention. Main body The earthworm gut acts as a transient but highly active microenvironment characterized by enhanced enzymatic activity, selective microbial enrichment, and accelerated mineralization of organic substrates. Passage through the gut promotes the proliferation of functional microbial groups involved in carbon degradation, nitrogen transformation, and phosphorus solubilization, while simultaneously reducing wasteassociated and pathogenic microorganisms. Following excretion, castassociated processes further stabilize organic matter and support the development of beneficial microbial consortia in vermicompost. The resulting product is enriched in humic substances, plantavailable nutrients, and biologically active microbes that enrich soil structure, fertility, and plant growth, while contributing to pathogen suppression and sustainable waste management. Despite progress in our current knowledge, in this domain, our understanding remains largely incomplete on the earthworm-microbe interactions, microbes driven processes, shifts in microbial community during vermicomposting at the molecular level and the agronomic and environmental benefits of microbially enriched vermicompost. Conclusion Therefore this review highlights mechanistic insights on the, (i) Gut associated processes (ii) Cast associated processes and (iii) Microbial dynamics in vermicomposting (iv) Community shifts, (iv) diversity, functions, and ecological significance of earthworm gutassociated microorganisms, microbe-earthworm interactions with roles in vermicomposting, (iv) and their contributions to vermicompost quality and soil–plant health, pathogen suppression. This review also highlights the need for metatranscriptomic and metabolomics based approaches to link microbial function with process performance and the road ahead with future research directions, towards microbial inoculation strategies, functional microbiome engineering, and integration of omics-based tools to optimize vermicomposting systems at industrial scales, towards advances in optimization and wider application of vermicomposting systems.
Ghosh et al. (Wed,) studied this question.