2.2. Inclusion and Exclusion Criteria
Eligible volunteers of any gender were enrolled in the study if, following informed signed consent, they fulfilled the inclusion criteria. The key inclusion criteria were as follows: male or female, self-reported to be healthy, age 18–65 years, BMI 18.5–29.9 kg/mA further exclusion criterion was the habitual consumption of more than four servings per day of high-fiber food or an extreme dietary habit low in carbohydrates. The former was pragmatically assessed with the habitual dietary fiber intake short food frequency questionnaire (DFI-FFQ) [Moreover, participants who had any score of a “severe” symptom for any of the symptoms included in the Gastrointestinal Symptom Rating Scale (GSRS), a validated questionnaire exploring the presence and severity of gastrointestinal (GI) symptoms over the previous 7 days [