Healthy Prebiotic and Postbiotic Effects of Peanuts and Peanut Butter: College Intervention Trial

Identification and quantification of polyphenols will be determined using a high performance liquid chromatography-high resolution mass spectrometry (HPLC-HRMS) method (Sasot et al., 2017) and quantified by ultra high-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UHPLC-QqQ-MS/MS) methodology (Martínez-Huélamo et al., 2015).

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).

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, the 16s metagenomic analysis will be performed.

To measure intelligence and cognitive ability, the Wechsler Adult Intelligence Scale IV (WAIS IV) will be used.

To measure memory function, the Wechsler Memory Scale IV (WSM IV) will be used.

To measure language and executive function, lexical fluency tests will be used.

The 48-items Coping Orientation to Problems Experienced questionnaire (COPE-48) will be performed to assay how healthy college students cope with highly demanding situations demanding situations of healthy college students.

To measure the levels of anxiety and depression of healthy college students the Hospital Anxiety and Depression Scale (HAD) will be used.

Body mass index (kg/m^2) are calculated after measure weight (kg) and height (meter).

To evaluate waist-to-hip ratio, waist and hip circumferences (cm) are measured in triplicate

Total adiposity are measured by bioelectrical impedance (percentage of fat).

Systolic and diastolic blood pressure (mmHg) are measured with an automatic blood pressure monitor in triplicate.

Heart rate (bpm) is measured with an automatic monitor in triplicate.

Total cholesterol, HDL-cholesterol, LDL-cholesterol and triglycerides (mg/dL) are measured by molecular absorption spectrometry.

Glucose (mg/dL) is measured by molecular absorption spectrometry.

Cortisol (nmol/l) is measured by immunochemiluminescence

Cytokines (pg/mL), tumor necrosis factor α (TNF-α) (pg/mL) and C-reactive protein (CRP) (mg/dL) will be assayed by immunoenzymatic methods.

Dietary changes are evaluated with a 151-item semi-quantitative food frequency questionnaire (Fernández-Ballart et al., 2010). In addition, a 7-day food recall on the day of the intervention are used to validated this results. These were analyzed using a software called Programa de Càlcul Nutricional Professional (PCN Pro).

Physical activity is measured by the validated Spanish version of the Minnesota Leisure-Time Physical Activity Questionnaire (Elosua et al., 1994).