Diet replacement with whole insect larvae affects intestinal morphology and microbial ecosystem of broiler chickens

Abstract A trial with 120 day-old Ross-308 broilers that were randomly allocated in three treatments with 10 birds in each pen was conducted to evaluate whether a control commercialised maize and soybean meal in mash form or this diet containing whole TM larvae at 5% (TM5) or 10% (TM10), respectively would affect either the intestinal morphometry in small intestine or intestinal microbiome on ileum or the ceca of broilers. On d35 intestinal samples were collected either in 10% buffered formalin for histopathological assessment or digesta from ileal and caecal parts were assessed for their bacterial community diversity through 16S rRNA gene high-throughput amplicon sequencing on the V3-V4 hypervariable region. Histomorphometric investigation revealed higher duodenum Vh in TM5, higher jejunum Cd but lower duodenum Cd ( P ≤ 0.05 ) in the treated groups. Intestinal bacterial microbiota showed varying implications; Lactobacilli and Staphylococci were eminent in the caecum. Bacteroides were found increased in TM5 and Lactobacilli and Cutibacterium were found increased in TM10. In the ileum of TM5, several Bacteroides and Lactobacilli species, Enterococcus durans and Streptococcus gallolyticus decreased, whereas most Lactobacilli decreased and Clostridium jejuni increased in TM10. Diet supplementation with TM larve can alter the composition of gastrointestinal microbiota both on ileum and cecum.