The Effects of a High Protein Diet on Microbiota, Gastrointestinal Function and Wellness in Older Women

Older women will be randomized to a 18-week crossover study design. During each treatment period participants will be provided with a weight maintenance diet providing approximately 2 g/kg/day of protein. Following a two-week baseline and in random order will have the following diets assigned: The participants will be provided with a weight maintenance, high protein diet for two weeks, then for two-weeks will resume their normal diet; The participants will come back into clinic and for the next two weeks to receive a high protein diet with a multi-strain probiotic for two weeks, then for two-weeks will resume their normal diet; The participants will come back into clinic and for the next two weeks will receive a high protein diet with a prebiotic, then for two-weeks will resume their normal diet; The participants will come back into clinic and for the next two weeks will receive a high protein diet with the synbiotic combination. then for two-weeks will resume their normal diet Participants and researchers will be blinded for each treatment period (participants will receive a probiotic or placebo capsule, and a prebiotic or placebo sachet). The following will be performed during the clinic visits: Questionnaires will assess quality of life (QoL), wellness, gastrointestinal symptoms, bowel movement frequency, and compliance. Hand-grip strength will be measured. Blood and urine samples will be collected at baseline and at weeks 2, 6,10 and 14. Stool samples will be collected at baseline and at weeks 2, 4, 6, 8,10, 12, 14 and 16.