Cecal volatilome and microbiota profile of organic chickens supplemented with black soldier fly live larva

Insects have shown to be a potential nutritional replacement in poultry nutrition as substitute of traditional protein sources, with positive effects on gut microbiota. However, only few studies have investigated the effects of live black soldier fly (BSF) live larvae provision on short-chain fatty acids (SCFAs) and microbiota composition in chicken's gut. Label naked neck (LNN, n. 240) chickens were reared in an organic production system from 21 to 82 days of age and randomly allocated into four experimental groups (10 birds/pen, 6 replicates/treatment) according to bird gender and larvae provision. Experimental groups were fed with 10% supplementation of BSF live larvae, based on the expected daily feed intake (DFI). At slaughter, samples of cecal digesta were collected from 60 animals (15 birds/treatment), frozen and stored at -80°C until to be analyzed by SPME-CG-MS and DNA sequencing techniques, respectively. Results showed that seven SCFAs were identified, with butyrate as the most abundant. Even if no significant differences were found between treatments, the cecal SCFAs concentration in insect-fed animals were noticed to be less variable than control group. Cecal microbiota analyses of birds fed with BSF live larvae, showed a higher incidence of Coprobacillus, Synergistaceae and Christensenellaceae, with the latter to having the potential to degrade chitin's insect meal, a compound with immunoregulatory properties. In conclusion, results showed that even a dietary 10% supplementation of BSF live larvae can slightly improve microbiota profile and potentially, SCFAs production in LNN chickens. These results confirm what observed in recent studies on broilers, but with lower (5% of DFI) live larvae inclusion levels. Financial support for Poultrynsect project was provided by transnational funding bodies under the Joint SUSFOOD2/CORE Organic Call 2019.