RESUMO
BACKGROUND: Obesity is a worldwide health problem and a significant risk factor for diabetes and cardiovascular diseases. Gut microbiota (GM) plays an essential role in obesity, and prebiotics such as polyphenols could be one way to improve microbial dysbiosis-induced obesity. OBJECTIVE: This study was designed to assess the effectiveness of grape seed and skin extract (GSSE), and/or orlistat on obese rats fed with high fat diet by targeting GM modulations. The impact of treatments was also studied in non-obese rats. MATERIAL AND METHODS: Rats were rendered obese or kept with a standard diet for three months. Then they were treated either with GSSE or orlistat or with the combined treatment (GSOR) during three months and then sacrificed. Adipose tissues, blood and faeces were collected and analyzed. RESULTS: In obese rats and to a lesser extent in non-obese rats, treatments decreased the weight of various adipose tissues and the serum levels of cholesterol, LDL, triglycerides, lipase, and CRP and increased HDL and adiponectin. GSOR treatment was even more efficient that orlistat. Obese rats had less GM diversity than non-obese rats and orlistat reduced it even more. However, diversity was restored with GSSE and GSOR treatments. Potential pathogenic Streptococcus alactolyticus/gallolyticus species were greatly increased in obese rats and drastically reduced with the treatments, as wells as other potential pathobionts. CONCLUSIONS: GSSE exerts beneficial effects in obese rats and restores, at least partially, the observed dysbiosis. GSOR induced the highest beneficial effect. Moreover, the various treatments could also enhance physiological and GM modifications in non obese rats.
RESUMO
The main goal of this study was to develop an improved oral delivery system for Pediococcus pentosaceus OZF, a promising probiotic bacterium, and to assess its viability under simulated gastrointestinal (GI) tract model by comparing the efficiency of microbiological and molecular approaches. Encapsulation was carried out using extrusion method and as a result, encapsulation system including 0.75 % lactulose, 1.8 % sodium alginate, 0.1 M CaCl2, and 5 min gelling time was shown to have a significantly protective effect against pH 2.0 acid stress over 3 h. However, completely loss of viability was exhibited by free OZF cells under similar conditions. To provide an additional barrier for capsules, coating process was investigated using different biopolymers, and the survival rates of free and encapsulated OZF cells upon expose to simulated GI conditions were detected by conventional culture techniques and propidium monoazide-quantitative polymerase chain reaction (PMA-qPCR) method. No significant differences between the biopolymers were detected, except the chitosan which leads totally 85 % protection and extra 25 % improvement in the survival of OZF cells compared to uncoated capsules. In conclusion, our findings indicated that chitosan-coated capsules provided an important protective effect on the viability of OZF cells against the GI system conditions encountered during the transit of food. In addition, this study was found successful in monitoring the viable OZF cells in capsules using PMA-qPCR method.
