Microbiome profiles, sleep, and cognition among mid-life adults

Modified Abstract Section: FIU-RCMI Research Project #2 ABSTRACT Emerging evidence suggests a bidirectional relationship between sleep disturbance and alterations in the gut microbiome. This study aims to examine the effect of sleep health and dysfunction in influencing cognition while accounting for the role of the gut microbiome in a community-based sample of Latino midlife adults. Despite its importance, studies exploring the effect of sleep on the gut microbiome and the subsequent impact on cognition are extremely limited. Of the preliminary investigations that do exist, none have been conducted with Latino community-living samples. Our proposed study is innovative in that it includes cognitive measures, cortisol sampling, and objective measures of sleep. There is an urgent need for studies of this kind, given that the gut microbiome may have a direct effect on cognition and sleep, positioning it as a modifiable risk factor for cognitive decline. Sleep disturbance, a modifiable risk factor for cognitive decline, including Alzheimer’s disease, is bidirectionally related to the gut microbiome, variations in sleep patterns affect the structure and variation of the gut microbiota, and the gut microbiome is influential in circadian cycles and hormones related to sleep and waking. Investigations examining the microbiota-gut-brain axis are essential in community-based samples to identify modifiable risk factors for cognitive decline and inform novel interventions. We will recruit 150 midlife Latino adults residing in South Florida through staggered recruitment and leveraging our existing resources. Each participant will be administered a battery of neurocognitive and sleep assessments and will provide objective sleep data through a wrist-worn actigraphy device, 3 saliva samples in one day to assess salivary cortisol, and a stool sample to examine the gut microbiome through whole-genome shotgun sequencing. Using this data, we will examine four aims: Aim 1. Using integrated microbiome analyses, we will examine correlations between gut microbiome profiles and measures of cognition. Aim 2. We will examine the bivariate relationship between sleep and gut microbiome profiles. Aim 3a: We will examine the relation between sleep and measures of cognition. Aim 3b: We will examine the interconnections between gut microbiome profiles, measures of cognition, and sleep using two mediation models. Aim 4: We will examine the interrelations between gut microbiome profiles, stress (salivary cortisol), measures of cognition, and sleep. Using an integrated analysis of the gut microbiome, cognition, stress through salivary cortisol, and sleep measurements, our study will be among the first to explore the interrelations of gut microbiome and microbial profiles, stress, cognition, and sleep to conduct future life course longitudinal studies and understand the changing effects over time.