# Evaluation of the Nutritional Value of Insect-Based Complete Pet Foods
## 4 Discussion
Dogs can tolerate a fairly wide range of dietary fat content, from 5% to as high as 66% by dry weight [62], without causing diarrhea. The foods tested for fat content fit within this range. The type of fat contained in the food is also of key importance. Deficiencies in exogenous fatty acids for puppies (linoleic, arachidonic, \(\alpha\)-linolenic, eicosapentaenoic, and docosahexaenoicenoic acids) or adult dogs (linoleic acid) can lead to skin problems and poorer coat quality, impaired learning ability, or susceptibility to infection [63; 64; 65]. However, insects have a specific fat profile consisting of capric, lauric, myristic, and palmitic acids, among others [66; 23; 61]. A more comprehensive analysis in this direction could show whether the use of insects in different forms (larvae or meal) is reflected in the levels of these acids in the product. The advantage of the fat profile of insects is that it can be regulated through the use of an appropriate nutrient solution [67], so insects can be a valuable source of \(n-3\) and \(n-6\) essential fatty acids. The digestibility of diets containing insects may be a cause for concern due to the presence of chitin, a biopolymer that forms a structural component in the exoskeletons of arthropods, such as insects and crustaceans, as well as the cell walls of fungi. It is a long-chain polymer known for its elasticity. One of the primary concerns regarding the ingestion of chitin by canines is its digestibility. Dogs, being primarily carnivores, lack the enzymes required for the breakdown of components such as chitin in their digestive tract. The active enzyme (chitinase) that breaks down chitin is primarily present in omnivorous animals [68]. This indicates that dogs may encounter difficulties in digesting it effectively. Given its insolubility in water, chitin may serve as a fermentable component for the resident gastrointestinal microbiota, potentially leading to alterations at the bacterial genus level [69; 70]. The diversity of the microbiota that inhabits the gastrointestinal tract is determined by a number of factors, including the animal's health status, its living environment, and its level of stress. However, the most significant factor influencing this diversity is the type and quality of nutrients provided in the diet [71; 72]. The content of ingredients in the diet that are resistant to digestion and can be broken down by microorganisms represents a significant factor influencing dietary variation. The term \"crude fiber\" is used on nutrition labels to describe the portion of ingredients that are not completely broken down by the dog's digestive enzymes. Such components may include plant matter and, in some cases, insects that contain chitin. However, the method of determining crude fiber content does not provide comprehensive information regarding the content of indigestible carbohydrates [39]. It is notable that food products that claim an approximate level of crude fiber on their packaging may in fact have significantly different dietary fiber contents. This is evidenced by the results of the analyses conducted in this study, which revealed a discrepancy of up to 19.21 g between the NDF fraction (24.77 g/100 g DM) and the crude fiber content (5.56 g/100 g DM) in one particular food (DIF_3). This study shows that limiting the chemical analysis to the basic composition, which shows the amount of crude fiber and not the dietary fiber fraction, can lead to misinformation about the content of indigestible ingredients. In particular, products containing edible insects may not only contribute high quality protein and fatty acids to the diet but may also contribute to reduced digestibility of the diet through the presence of chitin. Canine diets deficient in indigestible carbohydrates may predispose animals to gastrointestinal disorders, including constipation. Conversely, excessive intake of these carbohydrates can precipitate diarrhea and increased gut fermentation [73].