Almonds, Gut Microbiome and Kids

This 8-week parallel-arm randomized controlled trial (N=70; ages 6-13) will determine the impact of daily almond butter consumption on gut microbiome composition and function, intestinal barrier integrity, and cardiometabolic health in school-aged children. Participants will be randomized to either a once-daily snack of personalized-portion almond butter (ALB; 16g, Creamy Natural Almond Butter) or an isocaloric nut-free chocolate spread control (CTL; 16g, Cadbury Milk Chocolate), each served on two plain unsalted saltine crackers, added to their habitual diet. The primary outcomes include oro-gut microbial composition and diversity, gut microbial functional capacity and metabolomics (SCFAs, bile acids, amino acid metabolites), and intestinal barrier integrity. Secondary outcomes include fasting cardiometabolic markers, systemic inflammation, appetite-regulatory and metabolic hormones, and sleep-related biomarkers. Feasibility, adherence (weekly logs; serum α-tocopherol), and precision nutrition potential will also be assessed, with stratified analyses by age, sex, BMI, ethnicity, and pubertal stage. This pilot trial will generate the first multi-omics characterization of almond butter's effects on the gut-immune-metabolic axis in children.

Inclusion Criteria: * Enrolled in elementary or middle school (grades 1-8) * Aged 6-13 years old * Ability to speak and read in English Exclusion Criteria: * Intake of antibiotics in the last 3 months * Intake of pre/pro/postbiotics in the last 3 months * Food allergy to study foods ◦ Any allergy to nuts or almonds * Any allergy to the isocaloric snack (chocolate or wheat) * Regular consumption of nuts or almonds greater than 2 servings / week * Gastrointestinal disease (ulcerative colitis, Crohn's disease, diverticulosis, peptic ulcers, small intestinal bacterial overgrowth, short bowel syndrome, irritable bowel syndrome, gastroesophageal reflux disease), neurological (multiple sclerosis, meningitis, recent stroke) or endocrine disorders (uncontrolled thyroid disorders, growth hormone disorders, adrenal gland disorders, uncontrolled diabetes - A1C \> 9%).