Microbiota Metabolite Profiles and Dietary Intake in Older Individuals with Insomnia of Short vs. Normal Sleep Duration.

Recent evidence suggests that the gut microbiota plays a role in insomnia pathogenesis. This study compared the dietary habits and microbiota metabolites of older adults with insomnia of short vs. normal sleep duration (ISSD and INSD, respectively). Data collection included sleep assessment through actigraphy, dietary analysis using the Food Frequency Questionnaire, and metabolomic profiling of stool samples. The results show that ISSD individuals had higher body mass index and a greater prevalence of hypertension. Significant dietary differences were observed, with the normal sleep group consuming more kilocalories per day and specific aromatic amino acids (AAAs) phenylalanine and tyrosine and branch-chain amino acid (BCAA) valine per protein content than the short sleep group. Moreover, metabolomic analysis identified elevated levels of the eight microbiota metabolites, benzophenone, pyrogallol, 5-aminopental, butyl acrylate, kojic acid, deoxycholic acid (DCA), trans-anethole, and 5-carboxyvanillic acid, in the short compared to the normal sleep group. The study contributes to the understanding of the potential role of dietary and microbial factors in insomnia, particularly in the context of sleep duration, and opens avenues for targeted dietary interventions and gut microbiota modulation as potential therapeutic approaches for treating insomnia.

The relationship between quick return shift schedules and burnout among nurses: A prospective repeated measures multi-source study.

BACKGROUND: In today's world, essential health care services are expected round the clock, leading to distinct shift work requirements. A notable aspect is the "quick return," where the rest interval between nursing shifts is <11 h. Preliminary research suggests a potential association between quick return schedules, diminished sleep quality, and possible nurse burnout. Yet, the motivation of nurses could potentially moderate this relationship. OBJECTIVE: To examine a moderated-mediation model, whereby sleep duration and nurse's motivation act together to mediate the link between quick return schedules and nurse's burnout. DESIGN: A prospective repeated measures (4-5 nursing shifts per nurse) multi-source (self-report and objective measures) study. SETTING: Internal and surgical departments across one large and one medium scale teaching hospitals in Israel. PARTICIPANTS: Registered nurses who provide direct patient care (n = 79) across 369 shifts. METHODS: Nurses completed a questionnaire containing personal information and information regarding their shifts during the study week. They wore an accelerometer (a wrist worn device that monitors and records an individual's activity level) during a work-week to objectively determine their sleep duration, completed a motivation questionnaire at the beginning of each shift, and completed a burnout questionnaire at the end of the week. Mixed-model regression analysis was used to test a moderated-mediation model following Hayes' recommendations, whereby the joint effect of sleep duration and motivation mediates the link between quick return schedules and burnout. RESULTS: The moderated-mediation model was supported. Quick return schedules were negatively statistically significantly associated with sleep duration (b = -126.54, SE = 20.85, p < 0.001); so that more frequent quick return schedules were related to shorter sleep duration. However, no direct correlation was observed between sleep duration and burnout (p = 0.171). A statistically significant interaction was observed between sleep duration and motivation (b = 0.00, SE = 0.00, p < 0.001) concerning burnout. Thus, nurses with lower motivation were prone to experiencing higher levels of burnout with shorter sleep duration compared to nurses with higher motivation. CONCLUSIONS: The mediating role of sleep duration, moderated by motivation, plays a role in the connection between quick return schedules and burnout. This indicates that nurses can sustain their work motivation even within the demands of quick return schedules, consequently mitigating burnout levels. To prioritize employees' well-being, organizations should adopt shift work structures that minimize quick return schedules and extend nurses' sleep duration. Consequently, managers must employ strategies to enhance nurses' motivation when addressing scenarios that necessitate quick return schedules.

The European Insomnia Guideline: An update on the diagnosis and treatment of insomnia 2023.

Progress in the field of insomnia since 2017 necessitated this update of the European Insomnia Guideline. Recommendations for the diagnostic procedure for insomnia and its comorbidities are: clinical interview (encompassing sleep and medical history); the use of sleep questionnaires and diaries (and physical examination and additional measures where indicated) (A). Actigraphy is not recommended for the routine evaluation of insomnia (C), but may be useful for differential-diagnostic purposes (A). Polysomnography should be used to evaluate other sleep disorders if suspected (i.e. periodic limb movement disorder, sleep-related breathing disorders, etc.), treatment-resistant insomnia (A) and for other indications (B). Cognitive-behavioural therapy for insomnia is recommended as the first-line treatment for chronic insomnia in adults of any age (including patients with comorbidities), either applied in-person or digitally (A). When cognitive-behavioural therapy for insomnia is not sufficiently effective, a pharmacological intervention can be offered (A). Benzodiazepines (A), benzodiazepine receptor agonists (A), daridorexant (A) and low-dose sedating antidepressants (B) can be used for the short-term treatment of insomnia (≤ 4 weeks). Longer-term treatment with these substances may be initiated in some cases, considering advantages and disadvantages (B). Orexin receptor antagonists can be used for periods of up to 3 months or longer in some cases (A). Prolonged-release melatonin can be used for up to 3 months in patients ≥ 55 years (B). Antihistaminergic drugs, antipsychotics, fast-release melatonin, ramelteon and phytotherapeutics are not recommended for insomnia treatment (A). Light therapy and exercise interventions may be useful as adjunct therapies to cognitive-behavioural therapy for insomnia (B).

Cannabis and Alcohol Use and Their Associations with Sleep: A Daily Diary Investigation of Single-Use and Co-Use in College Students.

Introduction: Sleep continuity problems are widespread among college students and may be influenced by single-use and co-use of alcohol and cannabis. We examined the within-person associations of alcohol and cannabis use with subsequent sleep experiences in the everyday life of college students. Materials and Methods: A sample of 80 college students reported prior-night alcohol and cannabis use and sleep experiences for 14 consecutive days. Mixed-effects models examined the within-person relationships between alcohol and cannabis use (single- and co-use) and subsequent (1) sleep-onset latency, (2) total sleep time, (3) number of awakenings, and (4) early awakenings that night. Results: Compared to no-use evenings, alcohol and cannabis, used separately or together (co-use), were associated with shorter sleep-onset latency and longer total sleep time. Students reported more nightly awakenings after alcohol-only use compared to no-use and after co-use, and they reported fewer early awakenings after no-use and co-use. Conclusions: In line with previous experimental findings, we found that alcohol and cannabis use in the everyday life of college students were associated with sleep-inducing effects, and that alcohol use was associated with disturbed sleep continuity. The results suggest that cannabis may curb alcohol's detrimental effect on the number of awakenings and may reduce the incidence of early awakenings. Yet, due to lack of control for potentially important confounders (e.g., quantity of cannabis/alcohol consumed, withdrawal) the current results may be best seen as preliminary and further research is needed before causal inferences can be reached.

Variation in Gut Microbiota Composition is Associated with Sleep Quality and Cognitive Performance in Older Adults with Insomnia.

Purpose: Insomnia, a chronic condition affecting 50% of older adults, is often accompanied by cognitive decline. The mechanism underlying this comorbidity is not fully understood. A growing literature suggests the importance of gut microbiota for brain function. We tested associations between sleep quality and cognitive performance with gut microbiota in older adults with insomnia. Patients and Methods: Seventy-two older adults with insomnia (age 73.2 ± 5.73 years, 56 females) provided stool samples for gut microbial sequencing. Microbiota profile was determined using the DADA2 bioinformatics pipeline. Cognition was assessed with the Cambridge Neuropsychological Test Automated Battery. Objective sleep quality was monitored by a two-week actigraphic recording, and participants completed the Insomnia Severity Index (ISI). We used partial canonical correspondence analysis (pCCA) to examine the relative contribution of insomnia, based on actigraphic sleep efficiency (SE) and ISI, and of cognitive status, based on the Multitasking test of Median Reaction Latency (MTTLMD) and the Spatial Working Memory Between Errors (SWMBE), to variance in microbiota composition. We used Pearson correlations to correlate insomnia and cognitive status parameters with microbiota amplicon sequence variants, genera, and families. Results: The pCCA revealed that sleep quality and cognitive performance explained a variation of 7.5-7.9% in gut microbiota composition in older adults with insomnia. Correlation analysis demonstrated that Lachnoclostridium (genus) correlates positively with SE (r=0.42; P=0.05) and negatively with MTTLMD (r=-0.29; P=0.03), whereas Blautia (genus) correlates negatively with MTTLMD (r=-0.31; P=0.01). Conclusion: Findings demonstrate the associations of sleep quality and cognitive performance with variance in gut microbiota composition and with specific genus abundance in older adults with insomnia. Further studies should validate the findings, determine causal relationships, and evaluate potential interventions for the comorbidity of insomnia and cognitive impairment in older adults with insomnia.

The Relationships of Fibrinogen and C-Reactive Protein With Gait Performance: A 20-Year Longitudinal Study.

Background: Gait speed, a central marker of aging, has been linked to various health outcomes, such as cognitive and physical functions in middle-aged adults. Although long-term systemic low-grade inflammation is considered a mechanism underlying a variety of aging-related risk factors, the longitudinal associations between inflammation markers and gait speed are yet to be fully investigated. Objective: To explore the associations of CRP and fibrinogen levels, measured two decades ago, with gait speed among community dwelling adults, considering the contribution of cardio-metabolic factors and cognition. Methods: Study participants took part in two phases of the of the "Kibbutzim Family Study" (i.e., Phase II, 1999-2000 and Phase III, 2017-2019). Blood samples collected in Phase II (baseline) were used to determine level of inflammatory markers. Gait speed was assessed under single-task (ST) and dual-task (DT) conditions in Phase III. Demographic, anthropometric and clinical data were collected in both phases. Linear regression models were used to assess the adjusted associations of inflammation and gait speed. Results: A total of 373 individuals aged 34-99 (mean 64 ± 13 years) in Phase III were included in the study. Gait speed under ST was negatively associated with baseline levels of fibrinogen (b per standard deviation (SD) = -0.053, p = 0.0007) and CRP (b per SD = -0.043, p = 0.010), after adjusting for baseline and concurrent cardiometabolic risk factors. Accounting for executive functions, associations of fibrinogen with gait under ST were somewhat attenuated, yet associations remained statistically significant (p < 0.05). Associations with CRP were attenuated to the null. In contrast, there were no associations between inflammation markers and gait under DT. Conclusion: Our findings demonstrate that in a sample including younger to older adults, higher systemic inflammatory activity was linked with gait 20 years later, beyond age and cardiometabolic health, and to a certain extent, beyond executive functions. Thus, systemic inflammation may serve as an early marker to identify individuals at risk for gait decline.

Assessment of Sleep Duration and Number of Awakenings Based on Ankle and Wrist Actigraphy in Medical Hospitalized Older Patients.

BACKGROUND: Most studies performed in the hospital assess sleep using self-reports; few rely on actigraphy. Although wrist actigraphy is commonly used for sleep assessment in field studies, in-hospital assessment may be challenging and cumbersome because other more necessary monitoring devices are often attached to patients' upper limbs; these may affect interpretation of wrist activity data. Placement on the ankle may be a viable solution. OBJECTIVE: To compare total sleep time (TST) and number of awakenings (NOA) using concomitant wrist and ankle actigraphy, as well as self-reports in a sample of older adult patients hospitalized in medical units. METHODS: This was a prospective observational study. Objective sleep data were collected using ankle and wrist actigraphy, and subjective data using sleep diary. Repeated measures mixed model analysis was performed, adjusting for age, gender, sleep medications, symptoms severity, interaction between types of measure, and night number. RESULTS: Twenty-one older adults (65+) wore ankle and wrist actigraphy devices and subjectively estimated sleep parameters for an average of (2.15 ± 1.01) nights, with 40 nights available for analysis. TST was lower for wrist than ankle actigraphy (F(2,87) = 7.92, p = .0007). Neither differed from self-reports. NOA differed between all types of measure (ankle, 8.58 ± 6.66; wrist, 15.49 ± 7.47; self-report, 1.81 ± 1.83; F(2,85) = 47.66, p < .001). No significant within-subject variations and no interaction between devices and repeated measures were found. CONCLUSIONS: Despite differences between ankle and wrist assessments, all three methods provided consistent TST estimation within participants. Findings provide preliminary support for the use of ankle actigraphy for sleep assessment in hospital settings.

The association between objective measurements of sleep quality and postural control in adults: A systematic review.

We systematically reviewed the association between objective sleep quality and postural control based on objective measurements. We searched the electronic databases PUBMED, CINAHL, SCOPUS and Web of Science for studies assessing the relationship between objective measurements of sleep and postural control or gait performance among adults above age 18. All types of articles until April 2020 were considered. The search yielded 2967 articles, and out of these, inclusion criteria were met by five cross-sectional and two longitudinal studies (N = 7). Three studies found a positive correlation between sleep efficiency and gait speed, three studies found a negative correlation between wake time after sleep onset (WASO) and gait speed or postural control, and one study found no association between sleep parameters and gait speed. Objectively measured sleep quality parameters such as sleep efficiency and WASO were associated with objective measures of posture and gait. More studies with longitudinal designs are needed to expose causal pathways and mechanisms underlying these relationships.

The Effects of Parental Intervention on Sleep Patterns and Electronic Media Exposure in Young Adolescents.

Objective: This study evaluated the effectiveness of a parent-focused intervention aimed at the promotion of healthy sleep patterns and controlled exposure to electronic media (EM) in young adolescents. Participants: The sample included 70 dyads of parents (68 mothers and 2 fathers) and adolescents. Intervention and control groups each consisted of 35 young adolescents with a mean age of 10.7 (0.9) years old. Methods: Three waves of data collection included baseline, post-intervention, and 3 month follow-up. In each wave, adolescents reported habitual electronic media exposure and sleep patterns for a week and wore an actigraph for five nights. Parents in the intervention group participated in a six-session interactive workshop, while parents in the control group received equivalent written information by mail. Results: The intervention led to earlier bedtimes (p < 0.001), increased sleep efficiency (p < 0.01), increased sleep duration (p < 0.001) and reduced video games exposure (p < 0.01). Benefits were maintained at the follow-up. Conclusion: Interventions tailored for parents can create lasting positive changes in sleep patterns and EM exposure in young adolescents.

Increased physical activity improves gut microbiota composition and reduces short-chain fatty acid concentrations in older adults with insomnia.

Physical activity (PA) can improve functional abilities, well-being, and independence in older adults with insomnia. Studies have shown that PA may be linked to changes in the gut microbiota composition and its metabolites' concentrations. This association among older adults with insomnia, however, is yet to be determined. We explored the relationships between physical activity (PA) levels, gut microbiota composition, and short-chain fatty acid (SCFA) levels in this population. Forty-nine community-dwelling adults with insomnia symptoms, aged 65 and older, participated in this study. Their average daily step-count and sleep continuity measures over a two-week period were calculated based on Actigraphic recordings. Each participant provided fecal samples for the microbiome and SCFA analyses, anthropometric measures, and information via questionnaires on medical history and food consumption. The gut microbiota composition and SCFA concentrations were determined by next-generation sequencing and Gas chromatography-mass spectrometry, respectively. Participants were divided into two groups (more and less active) according to their median step/day count. We compared the microbiota abundance and SCFA concentrations between groups and performed correlation analysis between gut microbiota abundances and study variables. Different microbiota taxa in each PA group and increased SCFAs in feces of less active individuals were found. Changes in step counts were positively or negatively associated with the relative abundance of 19 ASVs, 3 microorganisms at the family level, and 11 microorganisms at the genus level. Furthermore, significant associations were discovered among physical activity, gut microbiota, SCFAs, and sleep parameters. Our findings provide new insights on the relationship between PA, gut microbiota composition, and primary metabolites in older adults with insomnia.

Metagenomic analysis reveals the signature of gut microbiota associated with human chronotypes.

Patterns of diurnal activity differ substantially between individuals, with early risers and late sleepers being examples of opposite chronotypes. Growing evidence suggests that the late chronotype significantly impacts the risk of developing mood disorders, obesity, diabetes, and other chronic diseases. Despite the vast potential of utilizing chronotype information for precision medicine, those factors that shape chronotypes remain poorly understood. Here, we assessed whether the various chronotypes are associated with different gut microbiome compositions. Using metagenomic sequencing analysis, we established a distinct signature associated with chronotype based on two bacterial genera, Alistipes (elevated in "larks") and Lachnospira (elevated in "owls"). We identified three metabolic pathways associated with the early chronotype, and linked distinct dietary patterns with different chronotypes. Our work demonstrates an association between the gut microbiome and chronotype and may represent the first step towards developing dietary interventions aimed at ameliorating the deleterious health correlates of the late chronotype.

Age-associated differences in sleep duration in the US population: potential effects of disease burden.

OBJECTIVES: We contrasted the relative risks (RR) of short [<7 h] and long [>8 h] sleep experienced by middle-aged (45-64 years) and older (≥65 years) adults, compared with young adults (20-44 years). METHODS: We utilized NHANES data (2005-2016), capturing sociodemographic, socioeconomic, and health-related data among US adults. RESULTS: The Relative Risk (RR) of short sleep between young and middle-aged adults did not differ [RR = 1.02, NS]. However, the RR of short sleep was significantly reduced among older participants [RR = 0.81, p < 0.01]. Middle-aged adults had significantly lower RR of long sleep [RR = 0.80, p < 0.01], whereas older adults had significantly greater RR of long sleep [RR = 1.41, p < 0.01]. Compared with young adults, older adults with or without increased disease burden had significantly lower RR of short sleep [RR = 0.81, p < 0.01 and RR = 0.80, p < 0.01], respectively. However, for middle-aged adults, the RR of short sleep did not differ whether they reported a greater disease burden. Relative to young adults, older adults with or without disease burden had higher RRs of long sleep [RR = 1.39, p < 0.01] and [RR = 1.45, p < 0.01], respectively. For middle-aged adults without disease burden, the RR of long sleep was lower than among young adults [RR = 0.72, p < 0.01]. CONCLUSIONS: Compared with young adults, older adults were not at increased risk for short sleep. Rather, they reported longer sleep time regardless of the presence of disease burden. Future studies should investigate longitudinal effects of aging on objective sleep time, with or without common diseases.

Sleepiness is a signal to go to bed: data and model simulations.

STUDY OBJECTIVES: Assess the validity of a subjective measure of sleepiness as an indicator of sleep drive by quantifying associations between intraindividual variation in evening sleepiness and bedtime, sleep duration, and next morning and subsequent evening sleepiness, in young adults. METHODS: Sleep timing and sleepiness were assessed in 19 students in late autumn and late spring on a total of 771 days. Karolinska Sleepiness Scales (KSS) were completed at half-hourly intervals at fixed clock times starting 4 h prior to participants' habitual bedtime, and in the morning. Associations between sleepiness and sleep timing were evaluated by mixed model and nonparametric approaches and simulated with a mathematical model for the homeostatic and circadian regulation of sleepiness. RESULTS: Intraindividual variation in evening sleepiness was very large, covering four or five points on the 9-point KSS scale, and was significantly associated with subsequent sleep timing. On average, a one point higher KSS value was followed by 20 min earlier bedtime, which led to 11 min longer sleep, which correlated with lower sleepiness next morning and the following evening. Associations between sleepiness and sleep timing were stronger in early compared to late sleepers. Model simulations indicated that the directions of associations between sleepiness and sleep timing are in accordance with their homeostatic and circadian regulation, even though much of the variance in evening sleepiness and details of its time course remain unexplained by the model. CONCLUSION: Subjective sleepiness is a valid indicator of the drive for sleep which, if acted upon, can reduce insufficient sleep.

The prevalence and prescribing patterns of benzodiazepines and Z-drugs in older nursing home residents in different European countries and Israel: retrospective results from the EU SHELTER study.

BACKGROUND: Benzodiazepines (BZDs) and Z-drugs have high potential for developing frequent adverse drug events in older adults (e.g., psychomotor sedation, drug-related dementia, deliria, drug dependence, etc.). Knowledge of the prevalence and patterns of the use of BZDs/Z-drugs in vulnerable older patients is important in order to prevent and reduce the burden caused by their drug-related complications. Our study focused on international comparisons of the prevalence, country-specific prescribing patterns and risk factors of regular BZD/Z-drug use in nursing home (NH) residents. METHODS: This cross-sectional study retrospectively analysed data of 4156 NH residents, prospectively assessed in the Services and Health in the Elderly in Long TERm care (SHELTER) project conducted from 2009 to 2014. Residents aged 65+ in 57 NHs in 7 European countries and Israel were assessed by the InterRAI Long-Term Care Facilities instrument. Descriptive statistics and multiple logistic regression models were used to describe the country-specific prevalence, patterns and risk factors of BZD/Z-drug use. RESULTS: The mean age of the participants was 83.4 ± 9.4 years, 73% were female and 27.7% used BZDs/Z-drugs. The prevalence of BZD/Z-drug use differed significantly across countries, ranging from 44.1% in Israel to 14.5% in Germany. The most frequently prescribed were zopiclone (17.8%), lorazepam (17.1%) and oxazepam (16.3%). Lorazepam, oxazepam and diazepam were used in most of the countries. Brotizolam, temazepam and zolpidem showed highest prevalence in Israel (99.4% of all regular users of this medication in the sample), the Netherlands (72.6%) and France (50.0%), respectively. Residing in Israel was the most significant factor associated with the use of BZDs/Z-drugs or BZDs only (odds ratio [OR] 6.7; 95% confidence interval [CI] 4.8-9.2 and OR 9.7, 95%CI 6.5-14.5, respectively). The use of Z-drugs only was most significantly associated with residing in France (OR 21.0, 95%CI 9.0-48.9). CONCLUSIONS: Despite global recommendations and warnings, the preference for and extent of use of individual BZDs and Z-drugs in vulnerable NH residents differ significantly across countries. The strong association with country of residence compared to clinical and functional factors denotes that prescribing habits, social, cultural, behavioural, and regulatory factors still play an important role in the current diverse use of these medications.

Why Do They Fall? The Impact of Insomnia on Gait of Older Adults: A Case-Control Study.

STUDY OBJECTIVES: To compare gait and cognitive performance conducted separately as a single- (ST) and simultaneously as a dual-task (DT), ie, when a cognitive task was added, among community-dwelling older adults with and without insomnia. METHODS: Participants included: 39 (28 females) community-dwelling older adults with insomnia, 34 (21 females) controls without insomnia. Subject groups were matched for age, gender, and education. Sleep quality was evaluated based on two-week actigraphy. Gait speed and cognition were assessed as ST and DT performance. DT costs (DTCs) were calculated for both tasks. Outcomes were compared via independent samples t-tests or Mann-Whitney U-tests. RESULTS: Older adults with insomnia demonstrated significantly slower gait speed during ST (1 ± 0.29 vs 1.27 ± 0.17 m/s, p<0.001) and DT (0.77 ± 0.26 vs 1.14 ± 0.20 m/s, p<0.001) and fewer correct responses in the cognitive task during ST (21 ± 7 vs 27 ± 11, p=0.009) and DT (19 ± 7 vs 23 ± 9, p=0.015) compared to control group. DTC for the gait task was higher among older adults with insomnia (18.32%, IQR: 9.48-30.93 vs 7.81% IQR: 4.43-14.82, p<0.001). However, no significant difference was observed in DTC for the cognitive task (14.71%, IQR: -0.89-38.84 vs 15%, IQR: -0.89-38.84%, p=0.599). CONCLUSION: Older adults with insomnia have lower gait speed and poorer cognitive performance during ST and DT and an inefficient pattern of task prioritization during walking, compared to counterparts without insomnia. These findings may explain the higher risk of falls among older adults with insomnia. Geriatric professionals should be aware of potential interrelationships between sleep and gait.

Associations between fecal short-chain fatty acids and sleep continuity in older adults with insomnia symptoms.

Insomnia is a disorder characterized by difficulty falling asleep and poor sleep continuity and is associated with increased risks for physical and cognitive decline. Insomnia with short sleep duration is considered the most biologically severe phenotype of the disorder. Evidence suggests that short-chain fatty acids (SCFAs), the main byproducts of fiber fermentation in the gut, may affect sleep via gut-brain communications. This study explores associations between SCFAs and sleep continuity and compares SCFA concentrations in short vs. normal sleep insomnia phenotypes in older adults. Fifty-nine participants with insomnia symptoms (≥ 65 years), completed 2 weeks of objective sleep monitoring (actigraphy), and were divided into short and normal sleep duration phenotypes via cluster analysis. Sleep measures included total sleep time (TST), sleep onset latency (SOL), sleep efficiency (SE), and wake after sleep onset (WASO). Stool samples were collected and fecal SCFA concentrations were determined by gas-chromatography-mass-spectrometry (GCMS). Higher concentrations of acetate, butyrate, and propionate, and total SCFAs, were associated with lower SE and longer SOL after controlling for Body Mass Index (BMI). Concentrations were higher in the short sleep duration phenotype. Age, BMI, TST, and SOL explained 40.7% of the variance in total SCFAs. Findings contribute to understanding pathways along the gut-brain axis and may lead to the use of SCFAs as biomarkers of insomnia phenotypes.

Attributes of Physical Activity and Gut Microbiome in Adults: A Systematic Review.

Growing evidence shows the contribution of physical activity interventions to the gut microbiome. However, specific physical activity characteristics that can modify the gut microbiome are unknown. This review's aim was to explore the contribution of physical activity intervention characteristics on human gut microbiome composition, in terms of diversity, specific bacterial groups, and associated gut microbiome metabolites. A literature search in PubMed; Cochrane Library; CINAHL-EBSCO; SCOPUS; Web of Science; ClinicalTrials.gov; PROSPERO; and ProQuest. Five studies met the inclusion criteria of a physical activity intervention duration of at least five weeks, with any description of the type or dose used. All included studies reported an endurance training; two studies used endurance and an additional muscle-strengthening training regimen. All studies reported using a dietary intervention control. Reported gut microbiome α-diversity changes were non-significant, ß-diversity changes were mixed (three studies reported an increase, two reported non-significant changes). All studies reported significant changes in the abundances of specific bacterial/archaea groups and bacteria-related metabolites following interventions. In conclusion, physical activity (regardless of specific characteristics) has significant contribution to gut microbiome composition and associated metabolites. There are no current recommendations for physical activity to promote gut microbiome composition. Future studies should focus on the contribution of current recommended physical activity dose to gut microbiome composition.

Is time elapsed between cannabis use and sleep start time associated with sleep continuity? An experience sampling method.

BACKGROUND: A substantial proportion of people using cannabis report using it to improve sleep. Yet, little research exists on the associations between the timing of cannabis use and sleep. This study examines the time elapsed between cannabis use and sleep start time and its association with two of the main indicators of sleep continuity: (1) sleep onset latency (SOL) and (2) number of awakenings (NOA) throughout the night. METHODS: Each morning, for 7 consecutive days, daily cannabis users (n = 54) reported on the timing of previous night's cannabis use and sleep indicators on their smartphones. Mixed effects models examined the relations of within- and between-subjects' time elapsed between previous night cannabis use and sleep start time, with (1) SOL and (2) NOA. RESULTS: Within subjects, shorter time elapsed between cannabis use and sleep start time was associated with shorter SOL (ß = 0.519, p = 0.010), but not NOA (ß = -0.030, p = 0.535). Furthermore, between individuals, the time gap between the previous night cannabis use and sleep start time was not associated with SOL or NOA (p > 0.05). CONCLUSIONS: It is possible that cannabis use proximal to bedtime is associated with shorted sleep onset latency but not nighttime awakenings. Cannabis users should be informed about both the potential sleep aid effects of cannabis and its limitations. Pending further evidence of the effects of cannabis on sleep, cannabis users experiencing sleep problems should be provided with evidence-based alternatives to improve sleep, e.g., pharmacological and behavioral treatments.