APP and Alzheimer disease: Metabolic stress is a major risk factor to the onset and aggravation of AD so the impact of the probiotic, prebiotic and combinatorial therapy on a variety of metabolic markers was assessed in aging AD Drosophila. Total glucose levels were elevated by almost 60% at day 30 in untreated APP-BACE1 controls and remained elevated in all groups except those receiving the synbiotic treatment, which had no change in glucose levels at any age (S3 Fig).