Prebiotics (Dried Plum) and Immune Function in Postmenopausal Women

Inclusion Criteria:

* women 60-75 years of age at the start of the study;
* 12 or more consecutive months without a menstrual period;
* willing to include dried plums in their daily diet and collect fecal samples at four time points;
* ambulatory without assistance;
* capacity to give informed consent.

Exclusion Criteria:

* women who have been on medications known to alter bone or calcium metabolism (e.g., oral bisphosphonates, raloxifene, denosumab, intermittent parathyroid hormone, growth hormone) within 12 months of starting the study. Prior use of intravenous bisphosphonates at any time.
* women who have been on hormone replacement therapy, steroids (i.e., glucocorticoids), biologics, or chronic NSAID within 3 months of starting the study.
* women with a previous diagnosis of osteoporosis (i.e., BMD T-score or history of vertebral fracture or fragility fractures of hip, wrist, humerus after the age of 50 yr) or other metabolic bone disease (e.g., osteomalacia or osteogenesis imperfect), renal disease, stroke, heart attack, type 2 diabetes, liver disease or autoimmune diseases (e.g., rheumatoid arthritis, systemic Lupus erythematosus, type 1 diabetes mellitus, IBD) that could affect bone metabolism or T cell biology will be excluded.
* women who have undergone treatment for cancer within 12 months of starting the study
* women who have been taking prebiotic or probiotic supplements or natural products that have estrogen-like effects in the past 3 months
* women who smoke, have a BMI \>40 kg/m2 or \<18.5 kg/m2, or consume \>2 alcoholic drinks per day
* women who regularly consume dried plums or prune juice (\>1 serving weekly).