Chemopreventive Effects of Bioactive Peptides Derived from Black Soldier Fly Larvae Protein Hydrolysates in a Rat Model of Early-Stage Colorectal Carcinogenesis

Abstract

Bioactive peptides from black soldier fly larvae (BSFL) protein hydrolysates have gained attention for their health-promoting properties. Our previous study demonstrated the chemopreventive potential of BSFL hydrolysates prepared with Alcalase (ASBP-AH) in colon cancer cells; their in vivo efficacy has not been fully elucidated. This study evaluated the chemopreventive effects of ASBP-AH, processed by spray-drying (ASBP-AHS) or freeze-drying (ASBP-AHF), in a diethylnitrosamine (DEN) and 1,2-dimethylhydrazine (DMH)-induced rat model of early-stage colorectal carcinogenesis. Oral administration of ASBP-AHS or ASBP-AHF significantly reduced aberrant crypt foci (ACF) and downregulated PCNA, COX-2, and NF-κB expression, without affecting apoptosis. Furthermore, both treatments restored microbial species richness and shifted gut microbial diversity disrupted by carcinogen exposure. ASBP-AHS specifically enriched short-chain fatty acid (SCFA)-producing bacteria, while ASBP-AHF favored anti-inflammatory microbial signatures. Likewise, correlation analysis revealed positive associations between microbial changes and SCFA levels, particularly with ASBP-AHS. Peptidomic profiling identified identical peptides in both hydrolysates, including stable pyroglutamyl-containing sequences with potential anti-inflammatory and microbiota-modulating effects. These findings support the in vivo chemopreventive potential of ASBP-AH and its promise as a functional food ingredient for promoting gut health and reducing colorectal cancer risk.