Flavonoids are polyphenolic compound mainly found in fruits and vegetables with numerous beneficial health effects as protection against cardiovascular diseases by an antihypertensive effect. The intestinal microbiota plays a key role in the metabolization of these compounds, so that differences in the composition and activity of the microbiota between individuals can generate different metabotypes. Flavonoids are found mainly in their conjugated form linked to the monosaccharide rhamnose and need to be metabolized by the intestinal bacteria, releasing the rhamnose, to be absorbed and, thus, bioactive. The bacterial enzyme responsible of rhamnose hydrolysis is α-L-rhamnosidase, whose activity can vary considerably depending on the composition of the microbiota. In fact, a great interindividual variability has been observed in the ability to absorb flavonoids, which allows to classify individuals according to the corresponding metabotype. In a previous project, the investigators confirmed the interindividual differences in the bioavailability of hesperidin and narirutin, two flavonoids naturally present in orange juice. However, the role of the intestinal microbiota in the metabolism of hesperidin and narirutin needs to be elucidated. On this basis, the following hypothesis is presented: individuals with arterial hypertension can be classified into 3 different metabotypes that are the result of the ability to absorb hesperidin and narirutin, determined by the urinary excretion of their respective metabolites, and these metabotypes are associated with different microbiota enterotypes and with different fecal α-L-rhamnosidase activity.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
67
The product is a concentrated orange juice provided by the CITRUS Department of Florida (USA: www.FloridaCitrus.org).
Centro Tecnológico de Nutrición y Salud (Eurecat-Reus)
Reus, Tarragona, Spain
Percentage of absorption of hesperidin and narirutin
Quantification of the metabolites derived from hesperidin and narirutin in basal and 24-hour urine samples, using Liquid Chromatography coupled to Mass Spectrometry (LC-QqQ). From the profile of metabolites detected in urine, the percentage of absorption of hesperidin and narirutin with respect to the amount ingested will be quantified to determine the metabotypes, based on the urinary excretion corresponding to each volunteer:
Time frame: After 24 hours of juice consumption
Fecal α-L-rhamnosidase activity
Quantification of α-L-rhamnosidase activity in fecal samples by incubation of the samples with the substrate p-nitrophenyl α-Lrhamnopyranoside and the subsequent measurement of the aborsbance to a length wavelength of 405 nM in a spectrophotometer.
Time frame: Basal
Gut microbiota composition
Metagenomic analysis in fecal samples. The bacteria DNA will be extracted and massive sequenced by the Ion Torrent platform. The relative abundances of the different bacterial populations will be determined in fecal samples at different taxonomic levels, and microbial diversity will be analyzed.
Time frame: Basal
Enterotype classification
Metagenomic analysis in fecal samples. The bacteria DNA will be extracted and massive sequenced by the Ion Torrent platform. Enterotypes will be analyzed to classify volunteers in 3 enterotypes based on their intestinal microbiota composition.
Time frame: Basal
Creatinine levels
Quantification of creatinine concentration in basal urine and 24 hours urine samples by a colorimetric assay.
Time frame: Basal and after 24 hours of juice consumption
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