Administração oral de Lactobacillus fermentum 296 reduz a pressão arterial via inibição do tônus simpático e melhora os parâmetros metabólicos em ratos dislipidêmicos

Abstract

Dyslipidemias are chronic diseases, characterized by elevation in plasma levels of total cholesterol (TC), triglycerides (TG), low density lipoprotein (LDL), associated with a decrease in plasma levels of high density lipoprotein (HDL). In part, changes in lipid metabolism are associated with the type of fatty acids ingested in the diet. The high intake of saturated and trans fatty acids contributes to the increase of the plasma levels of LDL, CT, TG and reduction of HDL. In addition, dyslipidemias may favor the development of insulin resistance, systemic arterial hypertension (SAH) and cardiovascular diseases. Studies indicate that probiotics, if consumed in adequate quantities, may play a role in the improvement of disorders in lipid metabolism, reduction of inflammatory markers, attenuation of oxidative stress and reduction of blood pressure. Thus, the general objective of this study was to investigate the effects of supplementation with the Lactobacillus fermentum 296 strain in dyslipidemic rats on cardiometabolic parameters. This was a non-clinical trial performed with male Wistar rats at 90 days of age and divided into three groups: control group (CTL), dyslipidemic (DLP), who received a dyslipidemic diet and placebo solution (PBS), and the group with L. fermentum 296 (DLP + Lf296) with dyslipidemic diet and gavage supplementation with L. fermentum 296 (1.0 x 109 CFU / mL) daily for 4 weeks. At the end of the study, blood was collected for biochemical tests, oral glucose tolerance (OGT) and insulin (TTI) tests were performed, and finally the rats were submitted to surgery for insertion of cannulas into the femoral artery for posterior measurement of the basal blood pressure, obtaining heart rate (HR) records, spectral analysis of systolic blood pressure and pulse interval, baroreflex sensitivity, sympathetic-vagal balance and sympathetic vascular tone in each group. The rats were euthanized and the organs were collected for weighing. Finally, the faeces were collected and the Lactobacillus spp count was performed. The intervention with L. fermentum 296 was able to prevent the increase of total cholesterol levels (111.5 ± 10 vs. 161 ± 18.2 mg / dl), LDL (84.9 ± 10.7 vs. 142.6 ± 20.9 mg / dl), and triglycerides (52.5 ± 4.6 vs. 85 ± 8.3 mg / dl) (p <0.05) in dyslipidemic rats. The administration of L. fermentum 296 prevented increased systolic blood pressure (149.5 ± 3.3 vs. 162.5 ± 1.6 mmHg, p <0.05), and sympathetic cardiovascular tone (-50.8 ± 3.5 vs. -63.4 ± 3.0 mmHg, p < 0.05) in rats fed a dyslipidemic diet. The administration of L. fermentum 296 was not able to prevent insulin resistance (p> 0.05) and damage in cardiac baroreflex control (p> 0.05) caused by the dyslipidemic diet. These results indicate that L. fermentum 296 presents potential for use as a probiotic with the ability to modulate biochemical and cardiovascular parameters of interest for the treatment of cardiometabolic diseases.