Association of Subjective and Objective Measures of Sleep With Gut Microbiota Composition and Diversity in Older Men: The Osteoporotic Fractures in Men Study

Sleep duration associated with altered oral microbiome diversity and composition in the NIH AARP cohort

STUDY OBJECTIVES

The microbiome is proposed as a contributor to the adverse health impacts from altered sleep. The oral microbiome is a multifaceted microbial community that influences many health functions. However, data on the relationship between sleep and the oral microbiome are limited, and no studies have incorporated lifestyle and environmental exposures.

METHODS

Within a subset (N=1,139) of the NIH-AARP cohort, we examined the association between self-reported sleep duration and the oral microbiome via 16S rRNA gene amplicon sequencing. Statistical models were adjusted for demographic characteristics. Additional models examined the role of various lifestyle and neighborhood exposures on the sleep-oral microbiome association.

RESULTS

Compared to participants reporting the recommended 7-8 hours average sleep duration (n=702), those reporting short sleep (6 or fewer hours, n=284) had consistently decreased within-sample oral microbial diversity [e.g. number of observed amplicon sequence variants difference -8.681, p-value=0.009]. Several bacterial genera were more likely to be absent in the short sleep group. We found a higher relative abundance of Streptococcus and Rothia, and lower abundance of Fusobacterium, Atopobium, and Campylobacter in the short compared to the recommended sleep duration group. Results were consistent when controlling for lifestyle and neighborhood factors.

CONCLUSIONS

Our findings provide evidence for an association of short sleep duration with oral microbial diversity and composition. This suggests that oral bacteria may play a possible mechanistic role related to sleep health. Improved understanding of physiological pathways can aid in the design of interventions that may beneficially improve overall sleep health.

Better objective sleep quality is associated with higher gut microbiota richness in older adults

Aging is associated with disrupted sleep patterns, such as fragmented sleep and reduced efficiency, leading to negative health outcomes. There is evidence of a bidirectional relationship between sleep and gut microbiota, which plays a key role in the gut-brain axis and overall health. However, studies on this relationship in older adults have limited generalizability and show conflicting results, highlighting the need for further research. This study aimed to investigate the associations between sleep quality and gut microbiota composition in healthy Chinese older adults using subjective and objective sleep measures to capture various aspects of sleep quality and explore potential impacts on emotional well-being and cognitive performance. Subjective sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) questionnaire, while objective sleep quality was measured with actigraphy. Gut microbiota sequencing was performed on stool samples. The results show a robust positive association between gut microbiota richness and objective sleep quality in older adults, independent of subjective sleep quality and demographics, lifestyle, and health covariates. However, no significant link was found between gut microbiota richness and subjective sleep quality. Specific taxa like Bacteroidetes, Ruminococcus, Collinsella, Veillonella, and Holdemania were tentatively linked to sleep quality. These findings emphasize the connection between sleep quality and gut microbiota composition in older adults with potential research and clinical implications, improving our understanding of the mechanisms underlying the sleep-gut microbiota relationship and guiding the development of interventions for improving both sleep quality and gut health in older adults.

A Lactobacillus consortium provides insights into the sleep-exercise-microbiome nexus in proof of concept studies of elite athletes and in the general population

BACKGROUND

The complex relationship among sleep, exercise, and the gut microbiome presents a unique opportunity to improve health and wellness. Here, we conducted the first large-scale investigation into the influence of a novel elite athlete-derived probiotic, consisting of a multi-strain Lactobacillus consortium, on sleep quality, exercise recovery, and gut microbiome composition in both elite athletes (n = 11) and the general population (n = 257).

RESULTS

Our two-phase study design, which included an open-label study followed by a controlled longitudinal study in a professional soccer team, allowed us to identify key interactions between probiotics, the gut microbiome, and the host. In the placebo-controlled study, we observed significant improvements in self-reported sleep quality by 69%, energy levels by 31%, and bowel movements by 37% after probiotic intervention relative to after placebo. These improvements were associated with a significant decrease in D-ROMS (a marker of oxidative stress) and a significantly higher free-testosterone/cortisol ratio. Multi-omics analyses revealed specific changes in microbiome composition and function, potentially providing mechanistic insights into these observed effects.

CONCLUSION

This study provides novel insights into how a multi-strain Lactobacillus probiotic modulates sleep quality, exercise recovery, and gut microbiome composition in both the general population and elite athletes, and introduces potential mechanisms through which this probiotic could be influencing overall health. Our results emphasize the untapped potential of tailored probiotic interventions derived from extremely fit and healthy individuals in improving several aspects of health and performance directly in humans. Video Abstract.

Targeting Cognitive Resilience through Prebiotics: A Focused Perspective

This perspective article is a product of the work of an expert group within the Prebiotic Task Force convened by the International Life Sciences Institute Europe, a non-profit organization that brings together experts from academia, industry, and public service to catalyze nutrition science for public benefit. An expert group was conceived in October 2023 to discuss the evidence base on the use of prebiotics to promote cognitive functioning, with a focus on highlighting knowledge gaps and proposing a list of recommendations to guide this specific area of research forward. To address this, we evaluated existing systematic reviews and meta-analyses of human intervention studies that examine the effects of prebiotics on cognitive functioning. These are predominantly conducted in healthy participants under basal conditions and have, to date, revealed limited effects. In this perspective, we propose that prebiotics should be investigated as agents to promote cognitive resilience by testing their effects on cognitive performance under certain cognition-taxing factors that individuals encounter across their lifespan. These include stress, poor sleep outcomes, sedentary behavior, and unhealthy dietary patterns, all of which have been shown to be associated with altered microbiome and impact global cognition or specific cognitive domains. In addition, we recommend identifying vulnerable populations that are either subclinical or that struggle chronically or periodically with 1 or more cognition-taxing factors, to better uncover the boundary conditions for prebiotic effectiveness. By broadening the scope of research to include diverse populations and challenging conditions in daily life or experimental settings, we can expand our understanding of the role of prebiotics not only in cognitive health or impairment, but also as potential preventative agents that may promote cognitive resilience during aging and in response to various lifestyle-related challenges.

Gerontologic Biostatistics and Data Science: Aging Research in the Era of Big Data

Introduced in 2010, the subdiscipline of gerontologic biostatistics was conceptualized to address the specific challenges of analyzing data from clinical research studies involving older adults. Since then, the evolving technological landscape has led to a proliferation of advancements in biostatistics and other data sciences that have significantly influenced the practice of gerontologic research, including studies beyond the clinic. Data science is the field at the intersection of statistics and computer science, and although the term "data science" was not widely used in 2010, the field has quickly made palpable effects on gerontologic research. In this Review in Depth, we describe multiple advancements of biostatistics and data science that have been particularly impactful. Moreover, we propose the subdiscipline of "gerontologic biostatistics and data science," which subsumes gerontologic biostatistics into a more encompassing practice. Prominent gerontologic biostatistics and data science advancements that we discuss herein include cutting-edge methods in experimental design and causal inference, adaptations of machine learning, the rigorous quantification of deep phenotypic measurement, and analysis of high-dimensional -omics data. We additionally describe the need for integration of information from multiple studies and propose strategies to foster reproducibility, replicability, and open science. Lastly, we provide information on software resources for gerontologic biostatistics and data science practitioners to apply these approaches to their own work and propose areas where further advancement is needed. The methodological topics reviewed here aim to enhance data-rich research on aging and foster the next generation of gerontologic researchers.

Gut Bacterial Metabolites from Tryptophan and Phenylalanine Induce Melatonin Synthesis and Extend Sleep Duration in Mice

The human gut microbiota significantly influences various physiological systems, including immune, nervous, and metabolic systems. Recent studies suggest that gut microbiota may affect sleep quality with certain bacteria and metabolites being linked to sleep patterns. However, the underlying chemical signaling pathway remains unclear. In this study, we investigated the effect of four gut bacteria-derived metabolites, tryptamine (1), indolokine A5 (2), 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE, 3), and phenethylamine (PEA, 4), on sleep characteristics in mice and melatonin biosynthesis pathways in zebrafish. Their sleep-promoting effects were evaluated in a pentobarbital-induced sleep mouse model, revealing significant increases in sleep duration and blood melatonin levels, particularly with ITE (3) and PEA (4). Further tests in zebrafish embryos showed that ITE (3) and PEA (4) increased the expression of genes for melatonin biosynthesis (Aanat1, Aanat2, Tph1a, and Hiomt) in a concentration-dependent manner, indicating their potential as therapeutic agents for sleep disorders.

Evolution and the critical role of the microbiota in the reduced mental and physical health associated with low socioeconomic status (SES)

The evolution of the gut-microbiota-brain axis in animals reveals that microbial inputs influence metabolism, the regulation of inflammation and the development of organs, including the brain. Inflammatory, neurodegenerative and psychiatric disorders are more prevalent in people of low socioeconomic status (SES). Many aspects of low SES reduce exposure to the microbial inputs on which we are in a state of evolved dependence, whereas the lifestyle of wealthy citizens maintains these exposures. This partially explains the health deficit of low SES, so focussing on our evolutionary history and on environmental and lifestyle factors that distort microbial exposures might help to mitigate that deficit. But the human microbiota is complex and we have poor understanding of its functions at the microbial and mechanistic levels, and in the brain. Perhaps its composition is more flexible than the microbiota of animals that have restricted habitats and less diverse diets? These uncertainties are discussed in relation to the encouraging but frustrating results of attempts to treat psychiatric disorders by modulating the microbiota.