Review on Gut Microbiota of Bombyx mori: Recent Advances in Nutrition, Probiotics, Immunity, Disease Resistance, and Sustainable Sericulture

The gut microbiota of Bombyx mori has emerged as a fundamental determinant of silkworm nutrition, immunity, metabolism, disease resistance, and silk production. Advances in next-generation sequencing, metagenomics, transcriptomics, metabolomics, and other multi-omics technologies have significantly expanded our understanding of the composition, diversity, and functional significance of the silkworm intestinal microbiome. Beneficial microorganisms, particularly members of the genera Lactobacillus, Enterococcus, Bacillus, Pediococcus, and Pantoea, contribute to the degradation of complex dietary components, synthesis of essential nutrients, modulation of immune responses, detoxification of plant secondary metabolites, maintenance of gut homeostasis, and enhancement of antioxidant defense systems. These microbial activities collectively improve larval growth, feed conversion efficiency, cocoon quality, and silk yield while reducing susceptibility to bacterial, viral, fungal, and microsporidian infections. Recent research has demonstrated that manipulation of the gut microbiota through probiotics, prebiotics, synbiotics, phytogenic feed additives, and optimized artificial diets represents a promising and environmentally sustainable strategy for improving silkworm health and productivity. Furthermore, microbiome-based interventions offer an effective alternative to antibiotics and chemical growth promoters, thereby supporting eco-friendly and sustainable sericulture. Nevertheless, substantial challenges remain, including limited knowledge of fungal, archaeal, and viral communities, incomplete understanding of host–microbe interactions, lack of standardized probiotic formulations, and insufficient field validation under commercial rearing conditions. These knowledge gaps emphasize the need for integrated multidisciplinary investigations combining microbiology, molecular biology, nutrition, immunology, bioinformatics, and systems biology. Future research should focus on functional microbiome engineering, precision nutrition, synthetic microbial communities, artificial intelligence-assisted microbiome prediction, and multi-omics integration to elucidate the complex mechanisms governing host–microbiota interactions. The development of standardized probiotic formulations and microbiome-guided feeding strategies will facilitate improved disease management, enhanced silk productivity, and reduced environmental impacts. Additionally, integrating genomic selection with microbiome profiling may enable the identification of silkworm strains exhibiting superior microbial associations and enhanced resistance to environmental stress and infectious diseases.Overall, the gut microbiota represents a valuable biological resource for advancing modern sericulture. Continued exploration of microbial diversity, functional mechanisms, and microbiome-based technologies will not only deepen our understanding of silkworm biology but also accelerate the development of innovative, sustainable, and precision-based sericultural practices. Such approaches have the potential to improve the economic viability of silk production while contributing to global efforts toward sustainable agriculture, environmental conservation, and the circular bioeconomy.

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