Dietary inclusion of black soldier fly larvae meal (Hermetia illucens) promotes gut microbiota diversity in Lohmann Brown-Lite laying hens

Insect farming is water-efficient and reduces food waste while producing quality protein, making it a potential solution to food sustainability and food security issues. Black soldier fly larvae, as an excellent source of protein, calcium, and a bacteria-fermentable polysaccharide called chitin, is a promising poultry feed ingredient. A 20-week feeding trial was conducted to evaluate the effects of dietary inclusion of black soldier fly larvae meal (BSFM) on the gut microbiota and SCFA production of Lohmann Brown-Lite laying hens. Thirty-six conventional cages, each housing five birds, were randomly assigned to receive one of three diets, including a soybean and corn meal-based control diet, a diet containing 6.5% BSFM, or a diet containing 13% BSFM. At the end of the trial, cecal digesta samples from two birds per cage were combined and analyzed for microbial profile through the 16s rRNA sequencing method, as well as SCFA profile. The inclusion of BSFM had significant impacts on both bacteria diversity and composition in the ceca. The alpha diversity indices, including observed ASVs, Chao1, Shannon, and Inverse Simpson, increased linearly with the inclusion of BSFM. Additionally, dietary inclusion of BSFM significantly altered the cecal microbial composition. The increased diversity and shift in the microbes were due to significantly increased Proteobacteria, Desulfobacterota, and Verrucomicrobiota, and decreased Actinobacteriota at the phylum level. Unexpectedly, cecal SCFA showed minimal differences between the control and BSFM treatments. Overall, our findings suggest that dietary inclusion of BSFM encourages gut microbial diversity in Lohmann Brown-Lite laying hens.

Keywords: Insect meal, gut microbiome, poultry nutrition, short-chain fatty acid.