Microbiota-Influenced Toxicological Responses in Caenorhabditis elegans Exposed to Strawberry and Menthol E-Liquids

Electronic nicotine delivery systems are marketed as safer than cigarettes, but their flavoring agents may be toxic. We evaluated reproductive effects of menthol- and strawberry-flavored e-liquids in Caenorhabditis elegans using wild-type and chemosensory-defective mutants ( ocr-2 ; osm-9 ; ocr-1 ; trpa-1 ). L4-stage worms were exposed to flavored e-liquids on peptone-free media with Escherichia coli or natural microbiota ( Lelliottia amnigena , Stenotrophomonas indicatrix , Comamonas piscis ). Flavored exposure reduced brood size; menthol delayed egg-laying. Microbiota mitigated effects in most strains except ocr-2 ; osm-9 ; ocr-1 with strawberry. Findings show flavored e-liquids harm reproduction, and microbiota may protect against flavor-induced toxicity.