Tomatoes and tomato-based products could play an important role in modulating microbiota-gut-brain axis (MGBA) interactions due to their high content of fiber and phytochemicals. Phytochemical metabolites derived from the consumption of tomato-based products can act directly as neurotransmitters in the central nervous system, crossing the blood-brain barrier, or indirectly by modulating the MGBA. These metabolites can thus alter gut bacterial composition and brain biochemistry. Therefore, researchers propose a new interventional study to assess the impact of daily tomato consumption in the organism, and to evaluate the effect on the MGBA. The final aim of this study is to spread a message of the health benefits of tomato consumption for the general population.
To evaluate the possible changes in microbiota and cognitive skills after consumption of tomato paste in a crossover randomized controlled study. Fifty healthy adults subjects (aged 40-55 years and consisting of 50% males and 50% females to assess possible sex-based responses) will be included. Participants will sign the informed consent and carry out a washout period without consuming any tomatoes or tomato-based products during 1 week. Participants will consume a daily amount of 0.5 g of tomato paste / kg of body weight following the regular diet plus consumption of low to moderate tomato or tomato-based products and other sources of lycopene (experimental intervention), and the normal diet plus consumption of low to moderate tomato or tomato-based products and other sources of lycopene (control intervention) during 3 months. Biological samples (plasma, peripheral blood mononuclear cells, serum, 24-hours urine, feces, and saliva) will be obtained at baseline and the end of each arm of the trial.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
NONE
Enrollment
47
Participants will consume a daily amount of 0.5 g of tomato paste / kg of body weight following the regular diet plus consumption of low to moderate tomato or tomato-based products and lycopene containing foods
Participants will consume the regular diet plus consumption of low to moderate tomato or tomato-based products and lycopene containing foods
Department of Nutrition, Food Sciences and Gastronomy. School of Farmacy and Food Sciences. University of Barcelona.
Barcelona, Barcelona, Spain
Changes in brain-derived neurotrophic factor (BDNF) after each intervention with tomato paste and the control intervention.
Serum samples will be analysed for mature BDNF using a Mature BDNF Rapid ELISA kit.
Time frame: Baseline and after completed each intervention (3 months)
Changes in cognitive function (executive) after each intervention with tomato paste and the control intervention.
The Wisconsin Sorting Cards Test (WSCT) will assess strategic planning, organized searching, utilizing environmental feedback to shift cognitive sets, directing behaviour towards achieving a goal and modulating impulsive responding.
Time frame: Baseline and after completed each intervention (3 months)
Changes in cognitive function (attention) after each intervention with tomato paste and the control intervention.
The d2 Test will meausure selective and sustained attention and visual scanning speed. Processing speed, rule compliance, and quality of performance will be assess in participants.
Time frame: Baseline and after completed each intervention (3 months)
Changes in cognitive function (memory) after each intervention with tomato paste and the control intervention.
The face-name associative memory exam (FNAME) will assess associative memory function.Participants will be asked to remember a set of faces and the names they are paired with. After a 5-25 minute delay, participants will recall which of the faces and names they saw earlier.
Time frame: Baseline and after completed each intervention (3 months)
Changes in cerebrovascular function after each intervention with tomato paste and the control intervention.
Cerebrovascular function will be measured using functional magnetic resonance imaging (FMRI), a non-invasive method for assessing brain activity. FMRI maps blood oxygenation levels in the brain and estimates changes in the blood flow that depends on metabolic function and is correlated with specific brain region activities
Time frame: Baseline and after completed each intervention (3 months)
Changes in the gut microbiota after each intervention with tomato paste and the control intervention.
Fecal samples will be collected by the volunteers using a system for easy self-collection and stabilization of microbial DNA for gut microbiome profiling (OMNIgene - GUT). The genomic DNA will be extracted from fecal samples using the DNeasy PowerSoil Kit. Then, microbial profiling using 16S ribosomal RNA (rRNA) sequencing will be used to study microbial communities, specially bacterial phylogeny and taxonomy.
Time frame: Baseline and after completed each intervention (3 months)
Changes in the polyphenols and carotenoids and their metabolites after each intervention with tomato paste and the control intervention.
Carotenoids and polyphenols, and their metabolites derived from intestinal gut microbiota will be identified and quantified in human plasma, urine, feces, and saliva samples using High Performance Liquid Chromatography HPLC-LTQ-Orbitrap-MS/MS and HPLC-MS/MS techniques.
Time frame: Baseline and after completed each intervention (3 months)
Changes in the short-chain fatty acids in plasma and feces samples after each intervention with tomato paste and the control intervention.
After acidifying the fecal samples with formic acid, a quantification of short-chain fatty acids will be performed using gas chromatography by direct injection according to previously described methodology (Zhao et al., 2006).
Time frame: Baseline and after completed each intervention (3 months)
Changes in bile acids in plasma and feces samples after each intervention with tomato paste and the control intervention.
Bile acids will be assayed using a validated liquid chromatography-mass spectrometry (LC-MS) method
Time frame: Baseline and after completed each intervention (3 months)
Changes in Body mass index after each intervention with tomato paste and the control intervention.
Body mass index (kg/m\^2) will be calculated after measuring weight (kg) and height (meters).
Time frame: Baseline and after completed each intervention (3 months)
Changes in waist-to-hip ratio with tomato paste and the control intervention.
Waist and hip circumferences (cm) will be measured in triplicate and then combined to report waist-to-hip ratio.
Time frame: Baseline and after completed each intervention (3 months)
Changes in anthropometric measurements after each intervention with tomato paste and the control intervention.
Body mass index (kg/m\^2) will be calculated after measure weight (kg) and height (meters). To evaluate waist-to-hip ratio, waist and hip circumferences (cm) will be measured in triplicate.
Time frame: Baseline and after completed each intervention (3 months)
Changes in body composition after each intervention with tomato paste and the control intervention.
Body fat percentage will be measured using a bioelectrical impedance analysis monitor.
Time frame: Baseline and after completed each intervention (3 months)
Changes in blood pressure after each intervention with tomato paste and the control intervention.
Diastolic and systolic blood pressure will be measured by a blood pressure monitor in triplicate.
Time frame: Baseline and after completed each intervention (3 months)
Changes in heart rate after each intervention with tomato paste and the control intervention.
Heart rate (bpm) will be measured with an automatic monitor in triplicate.
Time frame: Baseline and after completed each intervention (3 months)
Changes in lipidic profile after each intervention with tomato paste and the control intervention.
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Total cholesterol, HDL-cholesterol, LDL-cholesterol and triglycerides (mg/dL) will be measured by molecular absorption spectrometry.
Time frame: Baseline and after completed each intervention (3 months)
Changes in liver function after each intervention with tomato paste and the control intervention.
Alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP) and albumin will be assayed by immunoenzymatic methods.
Time frame: Baseline and after completed each intervention (3 months)
Changes in glucose after each intervention with tomato paste and the control intervention.
Glucose (mg/dL) will be measured by molecular absorption spectrometry.
Time frame: Baseline and after completed each intervention (3 months)
Changes in pro- and anti-inflammatory biomarkers after each intervention with tomato paste and the control intervention.
Cytokines (pg/mL), tumor necrosis factor α (TNF-α) (pg/mL) and C-reactive protein (CRP) (mg/dL) will be assayed by immunoenzymatic methods.
Time frame: Baseline and after completed each intervention (3 months)
Changes in nutrients and energy intake after each intervention with tomato paste and the control intervention.
A 7-day food recall will be used. The data will be analyzed using a software called Programa de Càlcul Nutricional Professional (PCN Pro).
Time frame: Baseline and after completed each intervention (3 months)
Changes in quality of the diet after each intervention with tomato paste and the control intervention.
Participants will fill the validated questionnaire measuring adherence to the Mediterranean diet.
Time frame: Baseline
Changes in physical activity after each intervention with tomato paste and the control intervention.
Physical activity will be assessed with the ActiGraph® wGT3X-BT accelerometer.
Time frame: Baseline and after completed each intervention (3 months)
Changes in sleep quality after each intervention with tomato paste and the control intervention.
Sleep quality will be assessed with the ActiGraph® wGT3X-BT accelerometer.
Time frame: Baseline and after completed each intervention (3 months)
Changes in quality of life after each intervention with tomato paste and the control intervention.
Quality of life will be assessed with the WHOQOL-BREF.
Time frame: Baseline and after completed each intervention (3 months)
Sensory threshold and organoleptic analysis
The recognition threshold of the five basic tastes will be determined through a classical sensory analysis test, employing a battery of solutions containing the molecules of interest. This test will include an organoleptic analysis of tomato paste to evaluate its aroma, taste (including acidity, sweetness, saltiness, umami), and hedonic sensation.
Time frame: Baseline