Lacticaseibacillus casei CSL3: imobilização e aplicação em matriz alimentar, influência nos parâmetros bioquímicos, de estresse oxidativo e modulação da resposta inflamatória

Abstract

Probiotics are microorganisms that, when consumed in adequate concentrations, confer health benefits on the host. To be characterized as probiotics, microorganisms must prove their positive influence through in vitro, in situ and in vivo tests. Therefore, the objective of the present study was to evaluate the viability of Lacticaseibacillus casei CSL3 immobilized in pineapple pieces and applied in Petit-suisse cheese, as well as the probiotic action in vitro and in vivo in biochemical, oxidative stress, histological parameters and modulation of inflammatory response. Lacticaseibacillus casei CSL3, was immobilized in pineapple pieces and applied in a food system to evaluate the viability during storage of the product, as well as after its passage through the simulated gastrointestinal tract. Physical-chemical (pH, acidity, water activity, moisture, protein and syneresis) and sensory (acceptance index and purchase intent) analyzes were performed to characterize the product. The evaluation of the cytotoxicity of the isolate and production of nitric oxide were carried out in cells (in vitro). After L. casei CSL3 was administered to mice in the experimental period of 30 days and challenged with Salmonella Typhimurium and Escherichia coli O157:H7, analyzes of the serum levels of glucose, total cholesterol, ALT, AST, blood triglycerides of oxidative stress were performed in tissue and catalase production, colonization of the gastrointestinal tract, histopathology of kidneys, livers and intestines and the relative expression of pro-inflammatory cytokines. Lacticaseibacillus casei CSL3 maintained its viability higher than 8 log CFU g-1 when immobilized in pineapple pieces and inserted into Petit Suisse cheese during storage and higher than 7 log CFU g-1 after passing through the simulated GIT. Regarding the assessment of toxicity and influence on the production of nitric oxide, in vitro, the bacterium proved to be safe for application at concentrations of 8 log CFU g-1 and it was observed that with increasing concentration, the production of nitric oxide increased. In the biochemical tests, the results show that L. casei CSL3 influenced the reduction of the concentration of glucose and serum triglycerides and the oxidative stress in the tissues of the animals. By competing with Salmonella Typhimurium and Escherichia coli O157H7, the probiotic colonized the gastrointestinal tract of mice, protected liver and intestine tissues and positively stimulated the relative expression of the cytokine IL-2, and negatively of IL-4 and TNF-α. At the end of the study, it can be concluded that L. casei CSL3 has proven probiotic characteristics through the maintenance of its viability when immobilized and inserted into a food matrix (in situ), biochemical, histological and inflammatory parameters (in vitro and in vivo).