Fat from Hermetia illucens alters the cecal gut microbiome and lowers hepatic triglyceride concentration in comparison to palm oil in obese Zucker rats.

BACKGROUND: Palm oil (PO) is the most widely utilized plant oil for food production. Owing to great ecological problems associated with PO production, sustainably produced fats, such as insect fat, might be a suitable alternative.

OBJECTIVE: The hypothesis was tested that fat from Hermetia illucens larvae (HF) compared with PO and soybean oil (SO) has no adverse effects on hepatic lipid metabolism, plasma metabolome and cecal microbiome in obese Zucker rats.

METHODS: 30 male obese Zucker rats were randomly assigned to three groups (SO, PO, HF; n = 10 rats/group), and fed three different semisynthetic diets containing either SO, PO or HF as the main fat source for 4 weeks. The effects were evaluated by measurement of liver and plasma lipid concentrations, liver transcriptomics, targeted plasma metabolomics, and cecal microbiomics.

RESULTS: Supplementation of HF reduced hepatic triglyceride (TG) concentration and mRNA levels of selected genes involved in fatty acid and TG synthesis in comparison to PO (P < 0.05). Pairwise comparison of Simpson index and Jaccard index showed a higher cecal microbial α- and β-diversity in rats fed the HF diet compared to rats fed the PO diet (P = 0.015 and P = 0.027, respectively), but no difference between rats fed the diets with SO or PO. Taxonomic analysis of the cecal microbial community revealed a lower abundance of Clostridium_sensu_stricto_1 and a higher abundance of Blautia, Mucispirillum, Anaerotruncus, Harryflintia and Peptococcus in rats supplemented with HF than in rats supplemented with PO (P < 0.05).

CONCLUSIONS: HF compared with PO has liver lipid lowering effects in obese Zucker rats, which may be caused by a shift in the gut microbial community. Thus, HF might serve as a sustainably produced fat alternative to PO for food production.

Copyright © 2023. Published by Elsevier Inc.

PMID: 37778509