Measuring the impact of olive pomace enriched biscuits on the gut microbiota and its metabolic activity in mildly hypercholesterolaemic subjects.

PURPOSE: Olive pomace is a major waste product of olive oil production but remains rich in polyphenols and fibres. We measured the potential of an olive pomace-enriched biscuit formulation delivering 17.1 ± 4.01 mg/100 g of hydroxytyrosol and its derivatives, to modulate the composition and metabolic activity of the human gut microbiota. METHODS: In a double-blind, controlled parallel dietary intervention 62 otherwise healthy hypercholesterolemic (total plasma cholesterol 180-240 mg/dl) subjects were randomly assigned to eat 90 g of olive pomace-enriched biscuit (olive-enriched product, OEP) or an isoenergetic control (CTRL) for 8 weeks. Fasted blood samples, 24-h urine and faecal samples were collected before and after dietary intervention for measurement of microbiota, metabolites and clinical parameters. RESULTS: Consumption of OEP biscuits did not impact on the diversity of the faecal microbiota and there was no statistically significant effect on CVD markers. A trend towards reduced oxidized LDL cholesterol following OEP ingestion was observed. At the genus level lactobacilli and Ruminococcus were reduced in OEP compared to CTRL biscuits. A trend towards increased bifidobacteria abundance was observed after OEP ingestion in 16S rRNA profiles, by fluorescent in situ hybridization and by qPCR. Targeted LC-MS revealed significant increases phenolic acid concentrations in 24-h urine following OEP ingestion and 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid, derivatives of hydroxytyrosol, were elevated in blood. A sex effect was apparent in urine small phenolic acid concentrations, and this sex effect was mirrored by statistically significant differences in relative abundances of faecal bacteria between men and women. CONCLUSION: Ingestion of OEP biscuits led to a significant increase in the metabolic output of the gut microbiota with an apparent sex effect possibly linked to differences in microbiota makeup. Increased levels of homovanillic acid and DOPAC, thought to be involved in reducing oxidative LDL cholesterol, were observed upon OEP ingestion. However, OEP did not induce statistically significant changes in either ox-LDL or urinary isoprostane in this study.

Azospirillum baldaniorum Sp 245 inoculation affects cell wall and polyamines metabolisms in cucumber seedling roots.

Azospirillum baldaniorum Sp 245 is a model plant growth-promoting rhizobacterium. The first cross-talk with plants takes place within the roots. Roots cells growth is constrained by the primary cell wall (CW). Also, neighboring CW form the apoplast that should affect cells signaling and biochemical messages. Studies on CW phenolic composition ferulate (FA), diferulates (DFA) and p-coumarate and polyamines (PA) metabolisms of A. baldaniorum Sp 245- inoculated roots and on bacterial PA production in culture media should help to understand more about the mechanisms involved in Azospirillum-root association. For this purpose, CW-bound FA, DFA and p-coumarate contents, putrescine (put) and spermidine contents, diamine and polyamine oxidases activities, and H2O2 content of Cucumis sativus roots from dark grown seedlings inoculated with A. baldaniorum Sp 245 were determined. Also, bacterial PA production under constant agitation or static conditions was evaluated. Results showed lesser contents of all phenolics, and higher FA/DFA ratio in CW of inoculated roots that should be responsible for roots growth promotion. Also, the increased put content, DAO activity, and H2O2 production in the roots should be associated to A. baldaniorum Sp 245 growth promotion in early stages. Finally, the participation of both PA in A. baldaniorum Sp 245 biofilm formation was demonstrated.

Caracterización de aceites de girasol con cantidades variables de ácido oleico / Characterization of sunflower'oil with variable quantity of oleic acid

El aceite de girasol se puede obtener a través de semillas de diversas variedades, las cuales presentan distintas características de calidad. Su valor nutritivo y aptitud culinaria se relaciona con la composición de ácidos grasos y la concentración de tocoferoles. Los ácidos grasos instaurados ayudan a prevenir diversas patologías hepáticas biliares, la osteoporosis, enfermedades cardiovasculares y ciertos cánceres en sistemas de tejidos celulares. El contenido en ácidos grasos saturados en el aceite de girasol es bajo, lo cual es deseable para uso alimenticio. Los tocoferoles tienen actividad antioxidante que permite retardar el enranciado del aceite. Son además, precursores de la vitamina E, indispensable para la nutrición humana. Se puede establecer dentro del aceite de girasol, tres grandes grupos de aceites en función de las proporciones de ácido oleico y ácido linoleico: alto oleico, medio oleico y tradicional. En este trabajo se buscó establecer una relación entre el contenido de ácido oleico y los índices utilizados convencionalmente para su identificación. El objetivo fué caracterizar la calidad de aceites de girasol de diferentes niveles de ácido oleico utilizando distintas metodologías de análisis físicos y químicos. Se extrajo con solventes el aceite de semillas de girasol alto oleico, medio oleico y tradicional, provenientes de un solo genotipo de semilla para cada variedad. A partir de los aceites alto oleico y tradicional obtenidos, se realizaron mezclas de diferentes proporciones de cada uno. En todos los casos, se utilizaron aceites sin refinar. Se determinó en primer lugar la composición ácida y contenido de tocoferoles de las muestras y luego los índices de acidez, de refracción, de yodo y punto de humo. Tanto el índice de acidez, el de refracción como el de yodo presentaron buena correlación con el porcentaje de ácido oleico, encontrándose similitud en los valores para aceite medio oleico y la muestra conteniendo el mismo porcentaje de ácido oleico. El punto de humo arrojó valores situados por debajo de los esperados para estos tipos de aceites. En caso de los tocoferoles, no se estableció similitud en su contenido comparando el aceite medio oleico con la mezcla de igual porcentaje de ácido oleico...