Almonds: Digestive Health and Immune Function of Adults and Children

This is a randomized, crossover study. After obtaining informed consent, healthy adults aged 18-40 years with children aged 3-6 years will be randomized to either consume almonds and almond paste during the first arm of the study or during the second arm of the study. During the intervention period, adult participants will consume 1.5 ounces of almonds per day, and children will consume 0.5 ounces of almonds per day for 3 weeks. After a 4-week washout period, participants will be crossed to the other treatment (no almond consumption or almond consumption).

Participants will complete daily questionnaires throughout the intervention period, and one week before and after each intervention period. Blood samples will be collected from adults at the baseline and final time points of each intervention. Stool samples will be collected during the pre-baseline and final weeks of each intervention. Dietary intake will be assessed weekly during each intervention period. Gastrointestinal symptoms questionnaires will be completed weekly during each intervention.

Inclusion criteria

To participate in the study, adult participants must:

• Be 18 to 40 years old.
• Have a 3 to 6 year old child that you are willing to enroll in the study.
• Live with your child for on average at least 6 days of the week.
• Be willing and able to complete the Informed Consent Form in English.
• Not be currently pregnant or planning to become pregnant in the next 5 months.
• Be willing to consume 1.5 ounces of almonds (~43 nuts) each day for three weeks.
• Be willing to feed your child 0.5 ounces of almond paste (~2 tablespoons) per day for three weeks.
• Be willing monitor your child's daily intake over the course of the study.
• Be willing to provide 4 blood samples, 4 stool samples, and 4 saliva samples over the course of the study.
• Be willing to assist your child in providing 4 stool samples and 4 saliva samples over the course of the study.
• Be willing and able to complete daily and weekly questionnaires for you and your child regarding general wellness, bowel function, gastrointestinal symptoms, stress and anxiety, and dietary intake.
• Must be available for 14 consecutive weeks to participate in the study.

Exclusion criteria

To participate in the study, adult and child participants:

• Must not have any known nut or tree nut allergies.
• Must discontinue any immune-enhancing dietary supplements (e.g., prebiotics and fiber supplements, probiotics, fish oil, vitamin E >400% of the Recommended Dietary Allowance (RDA) or >60 mg/day, and yogurts with live, active cultures).
• Must not be currently taking any medications for constipation or diarrhea on a regular basis.
• Must not be currently taking any large doses of anti-inflammatory drugs (i.e., aspirin in doses >600 mg/d) on a regular basis.
• Must not have received antibiotic therapy or a colonoscopy in the past two months.
• Must not be currently being treated for or have any of the following physician-diagnosed diseases or conditions: HIV/AIDS; immune modulating diseases (autoimmune disease, hepatitis, cancer); kidney disease; pancreatitis; pulmonary disease; hepatic or biliary disease; or gastrointestinal diseases/conditions such as diverticulitis, ulcerative colitis, Crohn's disease, Celiac disease, short bowel disease, ileostomy, or colostomy, but not including gastroesophageal reflux disease; or have a central venous catheter.