A single arm 3-week hydration intervention will be employed where participants increase their water consumption to 2 (F) or 2.5(M) liters per day which is approximately 70% of the AI for daily water consumption. Pre-test and follow-up measures of fecal microbiota, urinary hydration status, cognitive function, circulating markers, and dietary intake will be assessed at baseline and at 3-week follow up via laboratory visits.
