Simulation of insect enriched bread consequences on gut microbiota.

Insect powders are newly regulated in Europe and can be used to fortify protein-enriched bakery products. Because protein sources influence gut microbial balance, assessing their impact on the human microbiome is essential. This study investigated how cricket (Acheta domesticus) powder affects colon microbiota and whether sourdough fermentation improves protein-enriched breads. Using an in vitro gut model combining Infogest® digestion with MICODE© colon microbiota fermentation, four bread prototypes were examined. Metabolomic and microbiomic analyses showed that sourdough breads with insect powder increased some beneficial bacteria (Bifidobacteriaceae), contained opportunists (Clostiridium group I), reduced sulfurate producers (Desulfovibrio spp.), and enhanced production of acetate and butyrate. However, they also reduced certain beneficial taxa (Verrucomicrobiaceae) and increased the level of Enterobacteriaceae. Acetate, butyrate, and hexanoate correlated positively with lactic acid bacteria, as both increased after colon microbiota fermentation of insect sourdough bread Although further studies are needed, sourdough processing appears the most promising approach for producing cricket-enriched protein breads. These findings highlight both benefits and risks of insect-based protein fortification, showing modulation of different core groups of the colon microbiota.