Lacticaseibacillus casei CSL3: viabilidade em sorvete funcional e efeito em modelo in vivo de imunossupressão induzida

Abstract

Changes in the food profile of the world's population have driven food production to develop new functional products. The intake of probiotics can provide benefits such as modulation of the intestinal microbiota and immune response and regulation of cholesterol levels and glycemic indexes. However, in each strain needs to analyze these benefits to validate your probiotic properties. Probiotic foods are generally restricted to fermented milk and cheese, which has only sometimes helped the consumer, especially a portion of the population restricted to lactose. In this context, the objective was to evaluate the viability of L. casei CSL3 in functional and lactose-free ice cream during storage, the conditions of the simulated gastrointestinal tract (GIT), and the acceptability of the product, as well as to evaluate the effect of administering CSL3, regarding biochemical, oxidative, histological and immunological stress parameters, in an in vivo model of induced immunosuppression. A study was also carried out on the consumption of ice cream in Brazilian regions and consumers' motivations and purchase intentions using an online platform. To make the ice cream, an infusion of ginger and honey was produced and supplemented with 1014 CFU.mL-1 of CSL3, with storage under freezing for 180 days. Bacterial viability analyzes were carried out during storage and when passing through the simulated TGI and, in the product, analyses of proximal composition, phenolic compounds, antioxidants, color, pH, melting, density, overrun, and sensory analysis. For the in vivo study, 40 Swiss male mice were divided into four groups (Control, L. casei CSL3, Cyclophosphamide, L. casei CSL3+Cyclophosphamide), where two groups were immunosuppressed with 250 mg.kg-1 of cyclophosphamide and two groups supplemented daily with 1010 CFU.mL- 1 of CSL3. Blood count, total cholesterol, , IL-4, IL-23, TNF- and NF-κβ gene expression, kidney, liver, and brain oxidative stress, resistant lactic acid bacteria (LAB) count were analyzed to bile in the stool and, histology of the liver, kidney, and intestine. The ice cream was an effective matrix in maintaining the microorganism's viability and contributing to the product's nutritional quality through the high antioxidant activity presented; moreover, it obtained an acceptability index and purchase intention greater than 95%. Concerning the in vivo study, it was observed that the supplementation was safe, not presenting mortality and negative alterations in the expression of cytokines; the animals that received CSL3 did not show a reduction in the leukogram and hepatic lipidosis when compared to the other groups and, an increase of 1 log CFU.g-1 in the BAL count in the feces, in addition the reduction in the levels of total cholesterol. It is concluded that ice cream is an effective matrix in maintaining the viability of Lacticaseibacillus casei CSL3, presenting probiotic potential and, together with bioactive compounds, can be considered a functional food with a high acceptability index. In the in vivo study, supplementation, in addition to being safe in the model used, influenced the lipid profile of the animals, assisting total cholesterol and hepatic lipidosis and, in the immune response, through the increase in leukogram and expression of cytokines, suggesting its immunomodulatory potential. However, as the probiotic effects are strain and dose-dependent, other protocols with different dosages, exposure periods, and pathologies should be observed better to elucidate the probiotic potential of Lacticaseibacillus casei CSL3.