P25 | Microbiome of Acheta domesticus and Locusta migratoria-based foods using a metabarcoding approach: preliminary study

A. Mottola¹, C. Intermite¹, L. Lorusso¹, L. Ranieri¹, R. Piredda^2|3, A. Di Pinto¹ | ¹Department of Veterinary Medicine, University of Bari Aldo Moro, Valenzano (BA), Italy; ²Marine Organism Taxonomy Core Facility – MOTax, Stazione Zoologica Anton Dohrn, Villa Comunale, Naples, Italy; ³NBFC, National Biodiversity Future Center, Palermo, Italy

Purpose. The growing global demand for alternative and sustainable food sources has sparked renewed interest in entomophagy, including in Europe, where only a few insect species (Tenebrio molitor, Locusta migratoria, Acheta domesticus, and Alphitobius diaperinus) are currently authorized for human consumption. However, available knowledge on the microbiological quality of insect-based foods remains limited and raises significant questions about their food safety. Therefore, this preliminary study aims to analyze, using DNA metabarcoding, the microbial profiles of various insect-based products purchased thru European and Asian e-commerce platforms, in order to identify potential microbiological risks associated with human consumption and contribute to the definition of safety criteria for ABIs. Methods. The experimental plan included the analysis of 6 insect-based food samples, 3 of which were based on Acheta domesticus and 3 on Locusta migratoria. Each sample underwent DNA extraction and purification, followed by amplification and metabarcoding sequencing of the V3–V4 region of the 16S gene using the Illumina MiSeq platform. The obtained sequences were analyzed using the DADA2 package in R. Finally, taxonomic assignment was performed using the SILVA v132 database. Results. Preliminary results from the metabarcoding analysis showed that, despite variability in production and processing methods, the insect-based foods analyzed retain a "microbial fingerprint" attributable to the insect species used. Additionally, bacterial DNA was detected that was associated with a broad and diverse microbial community, including spoilage bacteria (Carnobacterium), opportunistic bacteria (Spiroplasma, Streptococcus), and potential pathogens (Escherichia/Shigella, Staphylococcus, Bacillus, Salmonella, and Clostridia). These microorganisms could presumably be of endogenous origin and therefore attributable to the insect's gut microbiota, or exogenous, introduced during the production, processing, and storage processes. Conclusions. In conclusion, although preliminary, the results obtained indicate that the DNA metabarcoding approach applied to the study of the insect-based food microbiome represents a promising tool for guiding future investigations into the safety and traceability of this emerging food category. A deeper understanding of the microbiome associated with insect-based foods could support competent authorities and control bodies in defining more appropriate criteria for microbiological risk assessment, thus contributing to the development of a more transparent, safe, and sustainable food chain – a strategic element for an innovative food safety management system.