Food intake modulation by insect protein through the interaction with the enteroendocrine system

Identifier:  TDX:3844

Handle: https://hdl.handle.net/20.500.11797/TDX3844

Authors:  Miguéns Gómez, Alba

Abstract:
Nowadays, animal protein and derived products are the most extended ones for human consumption as high-quality protein sources. Due to the overpopulation that the world is facing, its demand is expected to increase globally in the next years. However, meat production carries numerous negative implications for the environment. For this reason, the search for alternative environmentally friendly produced protein sources is becoming more important. Insects have been characterized as a good source of high-quality protein, also containing a significant amount of good quality fats, minerals and vitamins. Although many beneficial effects on health have been characterized, scarce information is available about their bioactivity at the intestinal level. Hence, in this thesis we aimed to characterize the ability of the insect protein to modulate the enterohormone secretion and subsequent food intake, comparing it with more traditional protein sources, and to determine if it can have long-term effects on this enteroendocrine function. We showed that insect protein, from Alphitobius diaperinus, can modulate the enterohormone secretion ex vivo in intestinal samples producing secretory profile with some differences compared with the secretome obtained from almond and beef proteins. Some of the secretions have been related to the amino acid composition of the respective protein sources. When the different protein sources were acutely administered to rats, we observed that the food intake from the insect group was increased compared with the almond and beef groups, although the protein dose was adjusted for the three treatments. After a chronic administration, this increase in food intake was lost after a week of treatment. The same occurred with Tenebrio molitor, which meant that the observed effect was not species-specific. In human subjects, the administration of a protein preload from the insect A. diaperinus modulated food intake similarly to an almond preload. We observed an increased protein intake after both preloads with a lower increase in energy intake after the insect protein preload. In conclusion, insect protein is a promising candidate to be considered as a bioactive ingredient intended for people who need to increase their food intake.