Sublethal aflatoxin B1 exposure triggers multidimensional damage in honeybee (Apis mellifera) midgut: Integrative...

Aflatoxin B1 (AFB1), a highly carcinogenic mycotoxin produced by Aspergillus fungi, has been increasingly identified as a global contaminant in bee pollen. Chronic exposure of honeybees (Apis mellifera) to AFB1-contaminated pollen poses substantial threats to colony health, yet its toxicological impacts remain poorly characterized despite the critical ecological role of these pollinators. In this study, we employed a multidimensional approach to investigate the toxicological effects of sublethal AFB1 exposure on honeybee midgut by integrated morphological, transcriptomic, and metagenomic analyses. Histopathological examination revealed severe midgut epithelium damage, including nuclear disintegration and enhanced apoptosis. Transcriptomic profiling coupled with enzyme activity assays unveiled significant dysregulation in immune response and oxidative stress-related pathways. Furthermore, metagenomic sequencing indicated substantial midgut microbiota alterations, characterized by a pronounced reduction in microbial diversity and beneficial microbe levels. These findings elucidate sublethal AFB1-induced honeybee health deterioration at cellular, molecular, and microbial levels, advancing our understanding of mycotoxin impacts on pollinators.