Health Impacts of Street Vended Fruits

Inclusion Criteria: * Individuals aged 18-60 years. * Residents of Mymensingh District, Bangladesh. * Willing to consume fresh-cut street-vended fruits (guava, pineapple, or watermelon) for five consecutive days. * Individuals with a self-reported history of gastric acidity issues (for the gastric acidity arms). * Individuals with no history of gastric acidity (for the non-gastric acidity arms). * Participants who have not taken antibiotics, proton pump inhibitors (PPIs), or antacids in the last two weeks. * Willing to provide detailed information on their dietary habits and gastrointestinal symptoms through surveys/questionnaires. * Participants who provide informed consent for participation. Exclusion Criteria: * Individuals under 18 years or over 60 years. * Pregnant or lactating women. * Those with a diagnosed gastrointestinal disorder (e.g., peptic ulcer disease, irritable bowel syndrome, Crohn's disease). * Individuals with a history of chronic infections or immune-compromising conditions (e.g., HIV/AIDS, cancer, diabetes). * Participants who have taken antibiotics, PPIs, or antacids within the last two weeks. * Individuals with known allergies to guava, pineapple, or watermelon. * Those who refuse to consume fresh-cut fruits from street vendors. * Participants who do not provide informed consent or are unable to complete the study period.