Influência de quercetina e resveratrol sobre propriedades in vitro relacionadas à funcionalidade de cepas de Lactobacillus potencialmente probióticas

• Autor(a) principal: Santos, Aldeir Sabino Dos
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFPB
• Texto Completo: https://repositorio.ufpb.br/jspui/handle/123456789/15699
• topic: Polifenóis; Microbiota intestinal; Probióticos; Flavonoides; Estilbenos; Polyphenols; Gut microbiota; Probiotics; Flavonoids; Stilbenes; CNPQ::CIENCIAS DA SAUDE::NUTRICAO

Polyphenols are extensively distributed in fruits, vegetables, herbs, seeds, cereals and beverages. Among the polyphenols present in foods, quercetin (QUE) and resveratrol (RES) have received increased interest because of the strong evidence of the association of their intake with a variety of health benefits. QUE is one of the largest representatives of the class of flavonoids found naturally in apples and red wine, while RES is the main representative of the class of stilbenes, naturally present in bark and grape seeds, and in wine. However, the benefits of ingestion of polyphenols are related to their bioavailability, which is usually very low. Thus, the compounds reach the large intestine, where they are metabolized through the action of the bacteria present in the intestinal microbiota. Among these bacteria potentially capable of metabolizing polyphenols are probiotics. The potential ability of probiotics to exert health benefits on the host has been commonly associated with the compliance of in vitro pre-requisites that include a set of physiological functionalities (e.g., acid and bile salts tolerance, cell surface hydrophobicity, autoaggregation, coaggregation with pathogens and antagonistic activity against pathogens) and capability of surviving during exposure to gastrointestinal conditions. Studies have suggested that the combined intake of polyphenols and probiotics may be an effective strategy to increase their biological functionalities, but phenolic compounds may exert varied influences on specific characteristics of probiotic, which reveals the need for further studies evaluating these potential influences that polyphenols may exert on probiotics. This study assessed the effects of polyphenols QUE and RES on the growth and some in vitro functionality-related properties of six proven potentially probiotic Lactobacillus strains (L. plantarum 49, L. plantarum 53, L. paracasei 106, L. paracasei 108, L. fermentum 263 and L. fermentum 296). QUE and RES showed weak inhibitory effects on the growth of the tested Lactobacillus strain, with minimum inhibitory concentration (MIC) as high as 512 – >1024 μg/mL. In most cases, QUE and RES at all tested concentrations (i.e., MIC, 1/2 MIC and 1/4 MIC) did not affect the tolerance of the Lactobacillus strains to acidic pH and bile salts. QUE increased the cell surface hydrophobicity of most of the tested Lactobacillus strains, while increases or decrease in this property varied among some of these strains in the presence of different RES concentrations. QUE and RES increased the ability of the tested Lactobacillus strains to aggregate and coaggregate with Listeria monocytogenes and Escherichia coli. These compounds did not affect negatively the antagonistic activity of the tested Lactobacillus strains against pathogens, as well as did not decrease their survival when exposed to an in vitro digestion. In few cases, the ability of some of the tested Lactobacillus strains to antagonize pathogens as well as to survive to specific steps of the in vitro digestion were increased by QUE or RES. The combined use of QUE or RES with probiotic lactobacilli could improve functional properties exerted by these bacteria on the host; however, the concentration of these compounds should be careful considered to reach these desirable effects.