Aimmune Longitudinal Collaboration Study

This study will include healthy households around the Irvine, CA area (based local to employees) and Tempe, AZ and Philadelphia, PA sites that will be instructed to take a daily fiber supplement (2.5 tablespoons of chia seeds [\~10.3g of fiber] which is one serving) for two months. Participants will use a stool sampling tool to facilitate ease of stool collection, or they may donate at a study site. Half of participants will add chia seeds to their diet at the beginning of the study and then return to their baseline diet for the second half of the study; half of participants maintain their baseline diet for the first half of the study and add chia seeds to their diet at the second half of the study as a cross-over design. Households (or individual participants, if their household is not participating) will be chosen at random to decide who implements the intervention in the first half versus the second half of the study. Data measurement including metabolomics and sequencing of stool samples, blood sampling for biobanking, stool IgA analysis, stress and diet evaluations will occur initially and throughout the study. Lifestyle questionnaires including but not limited to diet surveys, stress, or depression screening may be collected through electronic forms or telephonically. During enrollment, participants may be asked to complete questionnaires focused on medical, family, dietary, and social histories.

At the end of the study, donor microbiota samples from individuals that are IgA low (undetectable) throughout the study will be evaluated from the presence of microbes that can degrade IgA. If investigators find this is the case, investigators will screen for microbes that can degrade IgA. For individuals that show persistent high fecal IgA or show a substantial improvement in IgA, investigators will transplant fecal samples or spores from fecal samples into germ-free mice to further understand the microbiome and pathophysiology relationship. For the latter, the investigator's hypothesis is that fiber exposure of a specific type will reprogram the microbiome to stimulate IgA broadly to the entire microbiome as occurs with pectin derivative treated mice. The investigator's goal will be to isolate the microbes that respond to fiber to alter levels of IgA in the gut lumen.