The buzz on insect-based pet food: a new hypoallergenic protein source?

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Although the consumption of edible insects is widespread in Africa, Asia, and South America, it is far less common in countries like the United States. Our perception of insects as harmful, dirty, and distasteful means that it may be a while before the practice of eating them becomes mainstream here. Nevertheless, insects offer numerous advantages. Breeding them requires less land, feed, and water—and emits fewer greenhouse gases—than breeding livestock.¹ And they are high in protein, vitamins, minerals, and lipids.

Given such benefits, the feeding of insects to animals has been more widely accepted. And research has shown the efficacy and safety of black soldier fly larvae (BSFL) in the feed of poultry, swine, and aquaculture species.^2-6 The addition of small amounts of insect meal to chicken diets has also been found to stimulate colonization by probiotic and commensal bacteria, which may help prevent bacterial infections.⁷

European countries have embraced the use of insects in pet food, and several brands of dog food containing insect protein have been sold in Europe for a number of years. Recently, Mars PetCare and Nestlé Purina launched insect-based product lines.

Regulatory approval

In January 2021, the Association of American Feed Control Officials (AAFCO) approved BSFL for use in adult dog food and treats, and thus veterinarians should expect more clients to explore diets containing BSFL, especially as a source of protein for dogs with adverse reactions to other food. Although AAFCO approved only BSFL for use in canine adult maintenance (approval in cat food is expected later this year), other promising, well-studied insects include the yellow mealworm beetle, house cricket, and silkworm.

Nutrition and digestibility

On average, the protein content of edible insects ranges from 35% to 60% (dry weight) and 10% to 25% (fresh weight), which is higher than the protein content of plants, including cereal grains, soybeans, and lentils.^8-10 At the upper range, insects provide even more protein than meat and chicken eggs.¹¹ Studies have shown that dogs can consume diets containing BSFL,^12-16 tropical house cricket,¹⁷ housefly larvae, lesser mealworm, and yellow mealworm^12,13 without adverse effects to their digestion or general health, even if the products are near-total replacements for common sources of protein.⁸ Higher fecal output was seen in dogs fed tropical house cricket, owing to the insect’s higher indigestible chitin content compared with chicken meal. However, no differences in fecal score or stool quality were observed.¹⁸

Allergenicity and cross-reactivity

Although allergic reactions may occur because of the insect protein itself (primary sensitization), they are more likely to occur because of cross-reactivity. Cross-reactivity takes place when IgE recognizes and binds to allergenic molecules present in different species. Tropomyosin and arginine kinase have been found to be responsible for cross-reactivity between insects and other arthropods. A recent study demonstrated that IgE from canine sera sensitized to storage mites bound to the protein in yellow mealworm.¹⁹ IgE binding, however, does not mean that an allergic reaction will occur, only that it may. Many reports in human medicine also suggest the possibility of cross-reactions between insects and other arthropods. Patients with shellfish allergies were found to exhibit allergic reactions after eating cicadas²⁰ and vegetable worms.²¹ In a double-blind placebo-controlled food challenge, 87% of patients allergic to shrimp—most of whom were also allergic to dust mites—displayed allergy symptoms after eating yellow mealworm.²²

Given that insects will probably become more widely used as a protein source in pet food, more research on the cross-reactivity between insects and arthropods is needed. It has been reported that atopic dermatitis may affect 3% to 15% of dogs,²³ and dust mites are the allergens most commonly recognized by the circulating IgE of dogs with atopic dermatitis. Therefore, the use of insects as a protein source in dog food must be undertaken with caution.

A factor that may affect the allergenicity of insect proteins is postharvest processing. We know that thermal and high pressure processing—and/or hydrolysis—of allergy-causing proteins affect the allergenicity of feed.19 Incorporating such methods in the processing of harvested insects may reduce their allergenicity and cross-reactivity.

References

1. Leni G, Tedeschi T, Faccini A, et al. Shotgun proteomics, in-silico evaluation and immunoblotting assays for allergenicity assessment of lesser mealworm, black soldier fly and their protein hydrolysates. Sci Rep. 2020;10(1):1228. doi:10.1038/s41598-020-57863-5
2. Freel TA, McComb A, Koutsos EA. Digestibility and safety of dry black soldier fly larvae meal and black soldier fly larvae oil in dogs. J Anim Sci. 2021;99(3):skab047. doi:10.1093/jas/skab047
3. Oluokun JA. Upgrading the nutritive value of full-fat soyabeans meal for broiler production with either fishmeal or black soldier fly larvae meal (Hermetia illucens). Niger J Animal Sci. 2000;3(2):51-61. doi:10.4314/tjas.v3i2.49768
4. Makkar HPS, Tran G, Heuzé V, Ankers P. State-of-the-art on use of insects as animal feed. Anim Feed Sci Technol. 2014;197:1-33. doi:10.1016/j.anifeedsci.2014.07.008
5. Cullere M, Tasoniero G, Giaccone V, et al. Black soldier fly as dietary protein source for broiler quails: apparent digestibility, excreta microbial load, feed choice, performance, carcass and meat traits. Animal. 2016;10(12):1923-1930. doi:10.1017/S1751731116001270
6. Abd El-Hack ME, Shafi ME, Alghamdi WY, Abdelnour SA, Shehata AM, Noreldin AE, et al. Black soldier fly (Hermetia illucens) meal as a promising feed ingredient for poultry: a comprehensive review. Agriculture. 2020;10(8):339. doi:10.3390/agriculture10080339
7. Józefiak A, Benzertiha A, Kierończyk B, Łukomska A, Wesołowska I, Rawski M. Improvement of cecal commensal microbiome following the insect additive into chicken diet. Animals (Basel). 2020;10(4):577. doi:10.3390/ani10040577
8. Melo-Ruiz V, Garcia M, Sandoval H, Jimenez HD, Calvo C. Quality proteins from edible indigenous insect food of Latin America and Asia. Emir J Food Agric. 2011;23:283–289.
9. Schlüter O, Rumpold B, Holzhauser T, Roth A, Vogel RF, Quasigroch W, et al. Safety aspects of the production of foods and food ingredients from insects. Mol Nutr Food Res. 2017;61(6):10.1002/mnfr.201600520. doi:10.1002/mnfr.201600520
10. Bukkens SGF. The nutritional value of edible insects. Ecol Food Nutr. 1997;36(2-4):287-319. doi:10.1080/03670244.1997
11. Mlcek J, Rop O, Borkovcova M, Bednarova M. A comprehensive look at the possibilities of edible insects as food in Europe–a review. Pol J Food Nutr Sci. 2014;64(3):147-157. doi:10.2478/v10222-012-0099-8
12. Bosch G, Zhang S, Oonincx DG, Hendriks WH. Protein quality of insects as potential ingredients for dog and cat foods. J Nutr Sci. 2014;3:e29. doi:10.1017/jns.2014.23
13. Beynen AC. Insect-based petfood. Creat Companion. 2018;11(9):40-41.
14. Lei XJ, Kim TH, Park JH, Kim IH. Evaluation of supplementation of defatted black soldier fly (Hermetia illucens) larvae meal in beagle dogs. Ann Anim Sci. 2019;19(3):767-777. doi:10.2478/aoas-2019-0021
15. Yamka RM, Koutsos EA, McComb A. Evaluation of black soldier fly larvae as a protein and fat source in pet foods. Presented at: Petfood Forum, 2019; Kansas City, MO.
16. Penazzi L, Schiavone A, Russo N, Nery J, Valle E, Madrid J, et al. In vivo and in vitro digestibility of an extruded complete dog food containing black soldier fly (Hermetia illucens) larvae meal as protein source. Front Vet Sci. 2021;8:653411. doi:10.3389/fvets.2021.653411
17. Kilburn LR, Carlson AT, Lewis E, Rossoni Serao MC. Cricket (Gryllodes sigillatus) meal fed to healthy adult dogs does not affect general health and minimally impacts apparent total tract digestibility. J Anim Sci. 2020;98(3):skaa083. doi:10.1093/jas/skaa083
18. Areerat S, Chundang P, Lekcharoensuk C, Kovitvadhi A. Possibility of using house cricket (Acheta domesticus) or mulberry silkworm (Bombyx mori) pupae meal to replace poultry meal in canine diets based on health and nutrient digestibility. Animals (Basel). 2021;11(9):2680. doi:10.3390/ani11092680
19. Premrov Bajuk B, Zrimšek P, Kotnik T, Leonardi A, Križaj I, Jakovac Strajn B. Insect protein-based diet as potential risk of allergy in dogs. Animals (Basel). 2021;11(7):1942. doi:10.3390/ani11071942
20. Piatt JD. Case report: Urticaria following intentional ingestion of cicadas. Am Fam Physician. 2005;71(11):2048-2050.
21. Choi GS, Shin YS, Kim JE, Ye YM, Park HS. Five cases of food allergy to vegetable worm (Cordyceps sinensis) showing cross-reactivity with silkworm pupae. Allergy. 2010;65(9):1196-1197. doi:10.1111/j.1398-9995.2009.02300.x
22. Broekman H, Verhoeckx KC, den Hartog Jager CF, Kruizinga AG, Pronk-Kleinjan M, Remington BC, et al. Majority of shrimp-allergic patients are allergic to mealworm. J Allergy Clin Immunol. 2016;137(4):1261-1263. doi:10.1016/j.jaci.2016.01.005
23. Matricoti I, Noli C. An open label clinical trial to evaluate the utility of a hydrolysed fish and rice starch elimination diet for the diagnosis of adverse food reactions in dogs. Vet Dermatol. 2018;29(5):408-e134. doi:10.1111/vde.12680