Antimicrobial Effects of Black Soldier Fly and Yellow Mealworm Fats and Their Impact on Gut Microbiota of Growing Rabbits
Sihem Dabbou,
Ilario Ferrocino,
Laura Gasco,
Achille Schiavone,
Angela Trocino,
Gerolamo Xiccato,
Ana C. Barroeta,
Sandra Maione,
Dominga Soglia,
Ilaria Biasato,
Luca Cocolin,
Francesco Gai,
Daniele Michele Nucera
Affiliations
Sihem Dabbou
Center Agriculture Food Environment (C3A), University of Trento, Via E. Mach 1, 38010 San Michele all’Adige, Italy
Ilario Ferrocino
Department of Agricultural, Forest and Food Sciences, University of Torino, Largo Paolo Braccini 2, 10095 Grugliasco, Italy
Laura Gasco
Department of Agricultural, Forest and Food Sciences, University of Torino, Largo Paolo Braccini 2, 10095 Grugliasco, Italy
Achille Schiavone
Department of Veterinary Science, University of Turin, Largo P. Braccini 2, 10095 Grugliasco, Italy
Angela Trocino
Department of Comparative Biomedicine and Food Science, University of Padova, Viale dell’Università 16, Legnaro, 35020 Padova, Italy
Gerolamo Xiccato
Department of Agronomy, Food, Natural Resources, Animal, and Environment, University of Padova, Viale dell’Università 16, 35020 Legnaro, Padova, Italy
Ana C. Barroeta
Nutrition and Animal Welfare Service, Department of Animal and Food Science, Faculty of Veterinary Medicine, Autonomous University of Barcelona, Bellaterra, 08193 Barcelona, Spain
Sandra Maione
Department of Veterinary Science, University of Turin, Largo P. Braccini 2, 10095 Grugliasco, Italy
Dominga Soglia
Department of Veterinary Science, University of Turin, Largo P. Braccini 2, 10095 Grugliasco, Italy
Ilaria Biasato
Department of Agricultural, Forest and Food Sciences, University of Torino, Largo Paolo Braccini 2, 10095 Grugliasco, Italy
Luca Cocolin
Department of Agricultural, Forest and Food Sciences, University of Torino, Largo Paolo Braccini 2, 10095 Grugliasco, Italy
Francesco Gai
Institute of Sciences of Food Production, National Research Council, Largo Paolo Braccini 2, 10095 Grugliasco, Italy
Daniele Michele Nucera
Department of Agricultural, Forest and Food Sciences, University of Torino, Largo Paolo Braccini 2, 10095 Grugliasco, Italy
This study aimed to evaluate the in vitro antimicrobial activities of two types of insect fats extracted from black soldier fly larvae (HI, Hermetia illucens L.) and yellow mealworm larvae (TM, Tenebrio molitor L.) and their effects as dietary replacement of soybean oil (S) on cecal fermentation pattern, and fecal and cecal microbiota in rabbits. A total of 120 weaned rabbits were randomly allotted to three dietary treatments (40 rabbits/group) —a control diet (C diet) containing 1.5% of S and two experimental diets (HI diet (HID) and TM diet (TMD)), where S was totally substituted by HI or TM fats during the whole trial that lasted 41 days. Regarding the in vitro antimicrobial activities, HI and TM fats did not show any effects on Salmonella growth. Yersinia enterocolitica showed significantly lower growth when challenged with HI fats than the controls. The insect fat supplementation in rabbit diets increased the contents of the cecal volatile fatty acids when compared to the control group. A metataxonomic approach was adopted to investigate the shift in the microbial composition as a function of the dietary insect fat supplementation. The microbiota did not show a clear separation as a function of the inclusion, even if a specific microbial signature was observed. Indeed, HI and TM fat supplementation enriched the presence of Akkermansia that was found to be correlated with NH3-N concentration. An increase in Ruminococcus, which can improve the immune response of the host, was also observed. This study confirms the potential of HI and TM fats as antibacterial feed ingredients with a positive influence on the rabbit cecal microbiota, thus supporting the possibility of including HI and TM fats in rabbit diets.
