A brief period of sleep deprivation leads to subtle changes in mouse gut microbiota

Interplay between gut microbiota and exosome dynamics in sleep apnea

Sleep-disordered breathing (SDB) is characterized by recurrent reductions or interruptions in airflow during sleep, termed hypopneas and apneas, respectively. SDB impairs sleep quality and is linked to substantive health issues including cardiovascular and metabolic disorders, as well as cognitive decline. Recent evidence suggests a link between gut microbiota (GM) composition and sleep apnea. Indeed, GM, a community of microorganisms residing in the gut, has emerged as a potential player in various diseases, and several studies have identified associations between sleep apnea and GM diversity along with shifts in bacterial populations. Additionally, the concept of "leaky gut," a compromised intestinal barrier with potentially increased inflammation, has emerged as another key player in the potential bidirectional relationship between GM and sleep apnea. One of the potential effectors could be extracellular vesicles (EVs) underlying gut-brain communication pathways that are relevant to sleep regulation and function. Thus, therapeutic implications afforded by targeting the GM or exosomes for sleep apnea management have surfaced as promising areas of research. This review explores current understanding of the relationship between GM, exosomes and sleep apnea, highlighting key research dynamics and potential mechanisms. A comprehensive review of the literature was conducted, focusing on studies investigating GM composition, intestinal barrier function and gut-brain communication in relation to sleep apnea.

Alterations in gut microbiota and metabolites contribute to postoperative sleep disturbances

BACKGROUND

The composition of the intestinal flora and the resulting metabolites affect patients' sleep after surgery.

METHODS

We intended to elucidate the mechanisms by which disordered intestinal flora modulate the pathophysiology of postoperative sleep disturbances in hosts. In this study, we explored the impacts of anesthesia, surgery, and postoperative sleep duration on the fecal microbiota and metabolites of individuals classified postprocedurally as poor sleepers (PS) and good sleepers (GS), as diagnosed by the bispectral index. We also performed fecal microbiota transplantation in pseudo-germ-free (PGF) rats and applied Western blotting, immunohistochemistry, and gut permeability analyses to identify the potential mechanism of its effect.

RESULTS

Research finding shows the PS group had significantly higher postoperative stool levels of the metabolites tryptophan and kynurenine than the GS group. PGF rats that received gut microbiota from PSs exhibited less rapid eye movement (REM) sleep than those that received GS microbiota (GS-PGF: 11.4% ± 1.6%, PS-PGF: 4.8% ± 2.0%, p < 0.001). Measurement of 5-hydroxytryptophan (5-HTP) levels in the stool, serum, and prefrontal cortex (PFC) indicated that altered 5-HTP levels, including reduced levels in the PFC, caused sleep loss in PGF rats transplanted with PS gut flora. Through the brain-gut axis, the inactivity of tryptophan hydroxylase 1 (TPH1) and TPH2 in the colon and PFC, respectively, caused a loss of REM sleep in PGF rats and decreased the 5-HTP level in the PFC.

CONCLUSIONS

These findings indicate that postoperative gut dysbiosis and defective 5-HTP metabolism may cause postoperative sleep disturbances. Clinicians and sleep researchers may gain new insights from this study.

Sleep deprivation-induced shifts in gut microbiota: Implications for neurological disorders

Sleep deprivation is a prevalent issue in contemporary society, with significant ramifications for both physical and mental well-being. Emerging scientific evidence illuminates its intricate interplay with the gut-brain axis, a vital determinant of neurological function. Disruptions in sleep patterns disturb the delicate equilibrium of the gut microbiota, resulting in dysbiosis characterized by alterations in microbial composition and function. This dysbiosis contributes to the exacerbation of neurological disorders such as depression, anxiety, and cognitive decline through multifaceted mechanisms, including heightened neuroinflammation, disturbances in neurotransmitter signalling, and compromised integrity of the gut barrier. In response to these challenges, there is a burgeoning interest in therapeutic interventions aimed at restoring gut microbial balance and alleviating neurological symptoms precipitated by sleep deprivation. Probiotics, dietary modifications, and behavioural strategies represent promising avenues for modulating the gut microbiota and mitigating the adverse effects of sleep disturbances on neurological health. Moreover, the advent of personalized interventions guided by advanced omics technologies holds considerable potential for tailoring treatments to individualized needs and optimizing therapeutic outcomes. Interdisciplinary collaboration and concerted research efforts are imperative for elucidating the underlying mechanisms linking sleep, gut microbiota, and neurological function. Longitudinal studies, translational research endeavours, and advancements in technology are pivotal for unravelling the complex interplay between these intricate systems.

Appraising the role of biotics and fermented foods in gut microbiota modulation and sleep regulation

Sleep disturbances are increasingly prevalent, significantly impacting physical and mental health. Recent research reveals a bidirectional relationship between gut microbiota and sleep, mediated through the microbiota-gut-brain axis. This review examines the role of gut microbiota in sleep physiology and explores how biotics, including probiotics, prebiotics, synbiotics, postbiotics, and fermented foods, can enhance sleep quality. Drawing from animal and human studies, we discuss neurobiological mechanisms by which biotics may influence sleep, including modulation of neurotransmitters, immune responses, and hormonal regulation. Key microbial metabolites, such as short-chain fatty acids, are highlighted for their role in supporting sleep-related neurochemical processes. Additionally, this review presents dietary strategies and food processing technologies, like fermentation, as innovative approaches for sleep enhancement. Although promising, the available research has limitations, including small sample sizes, variability in biotic strains and dosages, and reliance on subjective sleep assessments. This review underscores the need for standardized protocols, objective assessments such as polysomnography, and personalized biotic interventions. Emerging findings highlight the therapeutic potential of gut microbiota modulation for sleep improvement, though further large-scale human trials are essential to refine strain selection, dosage, and formulation. This interdisciplinary exploration seeks to advance food-based interventions and holistic strategies for managing sleep disorders and improving quality of life.

Eucalyptus essential oil exerted a sedative-hypnotic effect by influencing brain neurotransmitters and gut microbes via the gut microbiota-brain axis

Sleep disorders are becoming more and more common, leading to many health problems. However, most of current available medications to treat sleep disorders are addictive and even impair cognitive abilities. Therefore, it is important to find a natural and safe alternative to treat sleep disorders. In this study, twenty-four 8-week-old male ICR mice (25 ± 2 g) were equally divided into three groups: the control group (gavage of 0.9% saline), the eucalyptus essential oil (EEO) group (10 mg/kg B.W.), and the diazepam group (1 mg/kg B.W.). Firstly, open field test and sleep induction test were used to determine the sedative-hypnotic effect of EEO. Secondly, the effect of EEO on neurotransmitters in the mice brain was determined. Finally, based on the gut microbiota-brain axis (GMBA), the effect of EEO on the intestinal flora of mice was explored. It was found that EEO significantly reduce the activity and prolong the sleep duration of mice, exhibiting a good sedative-hypnotic effect. In the brain, EEO could increase the levels of sleep-promoting neurotransmitters, such as glutamine, Gamma-aminobutyric acid (GABA), glycine, tryptophan, N-acetylserotonin, and 5-hydroxyindoleacetic acid (5-HIAA). In the intestine, EEO was found to increase the diversity of gut microbes, the abundance of short chain fatty acid (SCFA) producing flora, and the abundance of functional flora synthesizing GABA and glycine neurotransmitters. These studies suggested that EEO exerted a sedative-hypnotic effect by acting on gut microbes and neurotransmitters in the brain. EEO has the potential to become a natural and safe alternative to traditional hypnotic sedative drugs.

Modifications in the Composition of the Gut Microbiota in Rats Induced by Chronic Sleep Deprivation: Potential Relation to Mental Disorders

Introduction

Sleep deprivation(SD) has numerous negative effects on mental health. A growing body of research has confirmed the implication of gut microbiota in mental disorders. However, the specific modifications in mammalian gut microbiota following SD exhibit variations across different studies.

Methods

Male specific-pathogen-free Wistar rats were given a modified multiple-platform exposure for 7 days of SD. Fecal samples were obtained from the control and SD groups both at baseline and after 7 days of SD. We utilized 16S rDNA gene sequencing to investigate the gut microbial composition and functional pathways in rats.

Results

Analysis of the microbiota composition revealed a significant change in gut microbial composition after chronic SD, especially at the phylum level. The relative abundances of p_Firmicutes, g_Romboutsia, and g_Enterococcus increased, whereas those of p_Bacteroidetes, p_Verrucomicrobia, p_Fusobacteria, g_Akkermansia, and g_Cetobacterium decreased in animals after chronic SD compared with controls or animals before SD. The ratio of Firmicutes to Bacteroidetes exhibited an increase following SD. The relative abundance of gut microbiota related to the functional pathways of GABAergic and glutamatergic synapses was observed to be diminished in rats following SD compared to pre-SD.

Conclusion

Collectively, these findings suggest that chronic SD causes significant alterations in both the structural composition and functional pathways of the gut microbiome. Further researches are necessary to investigate the chronological and causal connections among SD, the gut microbiota and mental disorders.

NLRP3-mediated autophagy dysfunction links gut microbiota dysbiosis to tau pathology in chronic sleep deprivation

Emerging evidence indicates that sleep deprivation (SD) can lead to Alzheimer's disease (AD)-related pathological changes and cognitive decline. However, the underlying mechanisms remain obscure. In the present study, we identified the existence of a microbiota-gut-brain axis in cognitive deficits resulting from chronic SD and revealed a potential pathway by which gut microbiota affects cognitive functioning in chronic SD. Our findings demonstrated that chronic SD in mice not only led to cognitive decline but also induced gut microbiota dysbiosis, elevated NLRP3 inflammasome expression, GSK-3β activation, autophagy dysfunction, and tau hyperphosphorylation in the hippocampus. Colonization with the "SD microbiota" replicated the pathological and behavioral abnormalities observed in chronic sleep-deprived mice. Remarkably, both the deletion of NLRP3 in NLRP3 -/- mice and specific knockdown of NLRP3 in the hippocampus restored autophagic flux, suppressed tau hyperphosphorylation, and ameliorated cognitive deficits induced by chronic SD, while GSK-3β activity was not regulated by the NLRP3 inflammasome in chronic SD. Notably, deletion of NLRP3 reversed NLRP3 inflammasome activation, autophagy deficits, and tau hyperphosphorylation induced by GSK-3β activation in primary hippocampal neurons, suggesting that GSK-3β, as a regulator of NLRP3-mediated autophagy dysfunction, plays a significant role in promoting tau hyperphosphorylation. Thus, gut microbiota dysbiosis was identified as a contributor to chronic SD-induced tau pathology via NLRP3-mediated autophagy dysfunction, ultimately leading to cognitive deficits. Overall, these findings highlight GSK-3β as a regulator of NLRP3-mediated autophagy dysfunction, playing a critical role in promoting tau hyperphosphorylation.

Sleep apnoea, gut dysbiosis and cognitive dysfunction

Sleep disorders are becoming increasingly common, and their distinct effects on physical and mental health require elaborate investigation. Gut dysbiosis (GD) has been reported in sleep-related disorders, but sleep apnoea is of particular significance because of its higher prevalence and chronicity. Cumulative evidence has suggested a link between sleep apnoea and GD. This review highlights the gut-brain communication axis that is mediated via commensal microbes and various microbiota-derived metabolites (e.g. short-chain fatty acids, lipopolysaccharide and trimethyl amine N-oxide), neurotransmitters (e.g. γ-aminobutyric acid, serotonin, glutamate and dopamine), immune cells and inflammatory mediators, as well as the vagus nerve and hypothalamic-pituitary-adrenal axis. This review also discusses the pathological role underpinning GD and altered gut bacterial populations in sleep apnoea and its related comorbid conditions, particularly cognitive dysfunction. In addition, the review examines the preclinical and clinical evidence, which suggests that prebiotics and probiotics may potentially be beneficial in sleep apnoea and its comorbidities through restoration of eubiosis or gut microbial homeostasis that regulates neural, metabolic and immune responses, as well as physiological barrier integrity via the gut-brain axis.

Gut microbiota in neurological diseases: Melatonin plays an important regulatory role

Melatonin is a highly conserved molecule produced in the human pineal gland as a hormone. It is known for its essential biological effects, such as antioxidant activity, circadian rhythm regulator, and immunomodulatory effects. The gut is one of the primary known sources of melatonin. The gut microbiota helps produce melatonin from tryptophan, and melatonin has been shown to have a beneficial effect on gut barrier function and microbial population. Dysbiosis of the intestinal microbiota is associated with bacterial imbalance and decreased beneficial microbial metabolites, including melatonin. In this way, low melatonin levels may be related to several human diseases. Melatonin has shown both preventive and therapeutic effects against various conditions, including neurological diseases such as Alzheimer's disease, Parkinson's disease, and multiple sclerosis. This review was aimed to discuss the role of melatonin in the body, and to describe the possible relationship between gut microbiota and melatonin production, as well as the potential therapeutic effects of melatonin on neurological diseases.

Accelerometer-based sleep metrics and gut microbiota during adolescence: Association findings from a Brazilian population-based birth cohort

BACKGROUND

Sleep and gut microbiota are emerging putative risk factors for several physical, mental, and cognitive conditions. Sleep deprivation has been shown to be linked with unhealthy microbiome environments in animal studies. However, in humans, the results are mixed. Epidemiological studies evaluating the effect of accelerometer-based sleep measures on gut microbiome are scarce. This study aims to explore the relationship between sleep duration and efficiency with the gut microbiota in adolescence.

METHODS

A subsample of 352 participants from the 2004 Pelotas (Brazil) Birth Cohort Study with sleep and fecal microbiota data available were included in the study. Sleep duration and sleep efficiency were obtained from actigraphy information at 11 years old whereas microbiota information from fecal samples was collected at 12 years. The fecal microbiota was analyzed via Illumina MiSeq (16S rRNA V3-V4 region) and the UNOISE pipeline. Alpha was assessed in QIIME2. Association measures for sleep variables and microbial α-diversity, and bacterial relative abundance were assessed through generalized models (linear and logistic regression), adjusting for maternal and child variables confounders.

RESULTS

Adjusted models showed that sleep duration was positively associated with Simpson index of α-diversity (β = 0.003; CI95 %: 0.00004; 0.01). Both sleep duration (OR = 0.43; CI95 % 0.25; 0.74) and efficiency (OR = 0.55; CI95 % 0.38; 0.78) were associated with lower Bacteroidetes abundance.

CONCLUSION

Our results suggest that sleep duration and efficiency are linked to gut microbiota diversity and composition even with 1-2 years gap from exposure to outcome. The findings support the role of sleep in the gut-brain axis as well as provide insights on how to improve microbiota health.

A bidirectional Mendelian randomization study investigating the causal role between gut microbiota and insomnia

Background

It has emerged that disturbances of the gut microbiota (GM) are linked to insomnia. However, the causality of the observed associations remains uncertain.

Methods

We conducted a two-sample Mendelian randomization analysis based on genome-wide association study data to explore the possible causal link between GM and insomnia. The GM data were from the MiBioGen consortium, while the summary statistics of insomnia were obtained from the FinnGen consortium R9 release data. Cochran's Q statistics were used to analyze instrumental variable heterogeneity.

Results

According to the inverse variance weighted estimates, the family Ruminococcaceae (odds ratio = 1.494, 95% confidence interval:1.004-2.223, p = 0.047) and the genus Lachnospiraceae (odds ratio = 1.726, 95% confidence interval: 1.191-2.501, p = 0.004) play a role in insomnia risk. In contrast, the genus Flavonifractor (odds ratio = 0.596, 95% confidence interval: 0.374-0.952, p = 0.030) and the genus Olsenella (odds ratio = 0.808, 95% confidence interval: 0.666-0.980, p = 0.031) tended to protect against insomnia. According to the reverse MR analysis, insomnia can also alter GM composition. Instrumental variables were neither heterogeneous nor horizontal pleiotropic.

Conclusion

In conclusion, our Mendelian randomization study provides evidence of a causal relationship between GM and insomnia. The identified GM may be promising gut biomarkers and new therapeutic targets for insomnia. This investigation also provides a foundation for future studies examining the influence of GM on sleep disorders beyond insomnia, with potential implications for redefining the mechanisms governing sleep regulation.

Causal Effects of Gut Microbiota on Sleep-Related Phenotypes: A Two-Sample Mendelian Randomization Study

Increasing evidence suggests a correlation between changes in the composition of gut microbiota and sleep-related phenotypes. However, it remains uncertain whether these associations indicate a causal relationship. The genome-wide association study summary statistics data of gut microbiota (n = 18,340) was downloaded from the MiBioGen consortium and the data of sleep-related phenotypes were derived from the UK Biobank, the Medical Research Council-Integrative Epidemiology Unit, Jones SE, the FinnGen consortium. To test and estimate the causal effect of gut microbiota on sleep traits, a two-sample Mendelian randomization (MR) approach using multiple methods was conducted. A series of sensitive analyses, such as horizontal pleiotropy analysis, heterogeneity test, MR Steiger directionality test and "leave-one-out" analysis as well as reverse MR analysis, were conducted to assess the robustness of MR results. The genus Anaerofilum has a negative causal effect on getting up in the morning (odd ratio = 0.977, 95% confidence interval: 0.965-0.988, p = 7.28 × 10-5). A higher abundance of order Enterobacteriales and family Enterobacteriaceae contributed to becoming an "evening person". Six and two taxa were causally associated with longer and shorter sleep duration, respectively. Specifically, two SCFA-produced genera including Lachnospiraceae UCG004 (odd ratio = 1.029, 95% confidence interval = 1.012-1.046, p = 6.11 × 10-4) and Odoribacter contribute to extending sleep duration. Two obesity-related genera such as Ruminococcus torques (odd ratio = 1.024, 95% confidence interval: 1.011-1.036, p = 1.74 × 10-4) and Senegalimassilia were found to be increased and decreased risk of snoring, respectively. In addition, we found two risk taxa of insomnia such as the order Selenomonadales and one of its classes called Negativicutes. All of the sensitive analysis and reverse MR analysis results indicated that our MR results were robust. Our study revealed the causal effect of gut microbiota on sleep and identified causal risk and protective taxa for chronotype, sleep duration, snoring and insomnia, which has the potential to provide new perspectives for future mechanistic and clinical investigations of microbiota-mediated sleep abnormal patterns and provide clues for developing potential microbiota-based intervention strategies for sleep-related conditions.

Intestinal dysbiosis mediates cognitive impairment via the intestine and brain NLRP3 inflammasome activation in chronic sleep deprivation

Growing evidence suggests the involvement of the microbiota-gut-brain axis in cognitive impairment induced by sleep deprivation (SD), however how the microbiota-gut-brain axis work remains elusive. Here, we discovered that chronic SD induced intestinal dysbiosis, activated NLRP3 inflammasome in the colon and brain, destructed intestinal/blood-brain barrier, and impaired cognitive function in mice. Transplantation of "SD microbiota" could almost mimic the pathological and behavioral changes caused by chronic SD. Furthermore, all the behavioral and pathological abnormalities were practically reversed in chronic sleep-deprived NLRP3^-/- mice. Regional knockdown NLRP3 expression in the gut and hippocampus, respectively. We observed that down-regulation of NLRP3 in the hippocampus inhibited neuroinflammation, and ameliorated synaptic dysfunction and cognitive impairment induced by chronic SD. More intriguingly, the down-regulation of NLRP3 in the gut protected the intestinal barrier, attenuated the levels of peripheral inflammatory factors, down-regulated the expression of NLRP3 in the brain, and improved cognitive function in chronic SD mice. Our results identified gut microbiota as a driver in chronic SD and highlighted the NLRP3 inflammasome as a key regulator within the microbiota-gut-brain axis.

Integrated analysis of the microbiota-gut-brain axis in response to sleep deprivation and diet-induced obesity

INTRODUCTION

Sleep deprivation (SD) and obesity are common in modern societies. SD and obesity frequently coexist, but research on the combined consequences of SD and obesity has been limited. In this study, we investigated the gut microbiota and host responses to SD and high-fat diet (HFD)-induced obesity. In addition, we attempted to identify key mediators of the microbiota-gut-brain axis.

METHODS

C57BL/6J mice were divided into four groups based on whether they were sleep deprived and whether they were fed a standard chow diet (SCD) or HFD. We then performed fecal microbiome shotgun sequencing, gut transcriptome analysis using RNA sequencing, and brain mRNA expression analysis using the nanoString nCounter Mouse Neuroinflammation Panel.

RESULTS

The gut microbiota was significantly altered by the HFD, whereas the gut transcriptome was primarily influenced by SD. Sleep and diet are both important in the inflammatory system of the brain. When SD and the HFD were combined, the inflammatory system of the brain was severely disrupted. In addition, inosine-5' phosphate may be the gut microbial metabolite that mediates microbiota-gut-brain interactions. To identify the major drivers of this interaction, we analyzed the multi-omics data. Integrative analysis revealed two driver factors that were mostly composed of the gut microbiota. We discovered that the gut microbiota may be the primary driver of microbiota-gut-brain interactions.

DISCUSSION

These findings imply that healing gut dysbiosis may be a viable therapeutic target for enhancing sleep quality and curing obesity-related dysfunction.

Caffeine-Induced Sleep Restriction Alters the Gut Microbiome and Fecal Metabolic Profiles in Mice

Insufficient sleep is becoming increasingly common and contributes to many health issues. To combat sleepiness, caffeine is consumed daily worldwide. Thus, caffeine consumption and sleep restriction often occur in succession. The gut microbiome can be rapidly affected by either one's sleep status or caffeine intake, whereas the synergistic effects of a persistent caffeine-induced sleep restriction remain unclear. In this study, we investigated the impact of a chronic caffeine-induced sleep restriction on the gut microbiome and its metabolic profiles in mice. Our results revealed that the proportion of Firmicutes and Bacteroidetes was not altered, while the abundance of Proteobacteria and Actinobacteria was significantly decreased. In addition, the content of the lipids was abundant and significantly increased. A pathway analysis of the differential metabolites suggested that numerous metabolic pathways were affected, and the glycerophospholipid metabolism was most significantly altered. Combined analysis revealed that the metabolism was significantly affected by variations in the abundance and function of the intestinal microorganisms and was closely relevant to Proteobacteria and Actinobacteria. In conclusion, a long-term caffeine-induced sleep restriction affected the diversity and composition of the intestinal microbiota in mice, and substantially altered the metabolic profiles of the gut microbiome. This may represent a novel mechanism by which an unhealthy lifestyle such as mistimed coffee breaks lead to or exacerbates disease.

Intervention Effects of Okra Extract on Brain-Gut Peptides and Intestinal Microorganisms in Sleep Deprivation Rats

Objective

Okra, possessing various bioactive components, is used to treat different diseases. This study sought to estimate the intervention effects of okra extract (OE) on brain-gut peptides (BGPs) and intestinal microorganisms in sleep deprivation (SD) rats.

Methods

SD rat models were established using the modified multiple platform method and then treated with normal saline, diazepam tablets, or different doses of OE. Body weight and average daily water consumption of rats were recorded. Depressive behaviors of rats were assessed by the open field test and sucrose preference test. Serum levels of noradrenaline, melatonin, inflammatory factors (IL-1β/IL-6/TNF-α/IL-4/IL-10), and BGP indexes, including gastrin (GAS), motilin (MTL), 5-hydroxytryptamine (5-HT), cholecystokinin (CCK), and vasoactive intestinal peptide (VIP) were measured by ELISA. Additionally, the DNA relative contents of representative intestinal microorganisms in the collected rat feces were determined using RT-qPCR.

Results

SD decreased body weight and average daily water consumption and induced depressive behaviors as well as stress and inflammatory responses in rats. SD rats exhibited lowered GAS, MTL, 5-HT, and VIP but elevated CCK and showed diminished DNA relative contents of Bacteroidetes and probiotics (Bifidobacteria and Lactobacilli) but increased Clostridium perfringens. OE at different doses ameliorated the depressive behaviors and mitigated the stress and inflammatory responses in SD rats, raised the serum contents of GAS, MTL, 5-HT, and VIP, reduced CCK level, elevated the DNA relative contents of Bacteroidetes and probiotics, but diminished Clostridium perfringens. OE exhibited similar intervention effects to diazepam tablets (positive control).

Conclusion

OE exerts intervention effects on BGPs and intestinal microorganisms in SD rats.

The Component and Functional Pathways of Gut Microbiota Are Altered in Populations with Poor Sleep Quality - A Preliminary Report

With the development of genome sequencing, many researchers have investigated the mechanism by which the intestinal microbiota influences sleep across the brain-gut axis. However, the relationship between gut microbiota and sleep disorder remains unclear. Thus, we studied the difference in gut microbiota composition between poor sleep quality- and normal populations, which helps set the ground for future research. The recruited college students provided baseline information and stool samples and completed the Pittsburgh Sleep Quality Index (PSQI). We compared the two groups’ gut microbiota composition and functional differentiation by using the 16S rRNA gene sequencing analysis. The main bacterial difference and the most critical effect were mainly concentrated within Tenericutes and Elusimicrobia. Compared with the healthy control group, some functions of the gut microbiota were impaired in the poor sleep quality group, such as butanoate metabolism and propanoate metabolism. Bacterial taxa with significant differences raised the possibility for future diagnosis and treatment of sleep problems.

Maternal sleep deprivation induces gut microbial dysbiosis and neuroinflammation in offspring rats

Maternal sleep deprivation (MSD) is a global public health problem that affects the physical and mental development of pregnant women and their newborns. The latest research suggests that sleep deprivation (SD) disrupts the gut microbiota, leading to neuroinflammation and psychological disturbances. However, it is unclear whether MSD affects the establishment of gut microbiota and neuroinflammation in the newborns. In the present study, MSD was performed on pregnant Sprague-Dawley rats in the third trimester of pregnancy (gestational days 15-21), after which intestinal contents and brain tissues were collected from offspring at different postnatal days (P1, P7, P14, and P56). Based on microbial profiling, microbial diversity and richness increased in pregnant rats subjected to MSD, as reflected by the significant increase in the phylum Firmicutes. In addition, microbial dysbiosis marked by abundant Firmicutes bacteria was observed in the MSD offspring. Furthermore, quantitative real-time polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) showed that the expression levels of proinflammatory cytokines interleukin 1β (IL-1β) and tumor necrosis factor α (TNF-α) were significantly higher in the MSD offspring at adulthood (P56) than in the control group. Through Spearman correlation analysis, IL-1β and TNF-α were also shown to be positively correlated with Ruminococcus_1 and Ruminococcaceae_UCG-005 at P56, which may determine the microbiota-host interactions in MSD-related neuroinflammation. Collectively, these results indicate that MSD changes maternal gut microbiota and affects the establishment of neonatal gut microbiota, leading to neuroinflammation in MSD offspring. Therefore, understanding the role of gut microbiota during physiological development may provide potential interventions for cognitive dysfunction in MSD-impacted offspring.

Alterations of the Gut Microbiota in Response to Total Sleep Deprivation and Recovery Sleep in Rats

INTRODUCTION

Accumulating evidence suggests that both sleep loss and gut dysbiosis can lead to metabolic disorders. However, less is known about the impact of total sleep deprivation (SD) and sleep recovery on the composition, function, and metabolic dynamics of the gut microbiota.

METHODS

Specific-pathogen free Sprague-Dawley rats were subjected to 48 h of SD with gentle handling and then allowed to recover for 1 week. Taxonomic profiles of fecal microbiota were obtained at baseline, 24 h of SD, 48 h of SD, and 1 week of recovery. We used 16S rRNA gene sequencing to analyze the gut microbial composition and function and further characterize microbiota-derived metabolites in rats.

RESULTS

The microbiota composition analysis revealed that gut microbial composition and metabolites did not change in the rats after 24 h of SD but were significantly altered after 48 h of SD. These changes were reversible after 1 week of sleep recovery. A functional analysis was performed based on Kyoto Encyclopedia of Genes and Genomes (KEGG) annotations, indicating that 19 KEGG pathways were significantly altered in the gut microbiota in SD rats. These functional changes occurred within 24 h of SD, were more apparent after 48 h of SD, and did not fully recover after 1 week of sleep recovery.

CONCLUSION

These results indicate that acute total SD leads to significant compositional and functional changes in the gut microbiota, and these changes are reversible.

Sleep and the gut microbiota in preschool-aged children

Sleep plays a significant role in the mental and physical development of children. Emerging evidence in animals and human adults indicates a relationship between sleep and the gut microbiota; however, it is unclear whether the sleep of preschoolers during a key developmental period, associates with features of their gut microbiota. The objective of this study was to assess the relationship between sleep and gut microbiota in preschool-aged children (4.37 ± 0.48 years, n = 143). Sleep measures included total night-time sleep (TST), sleep efficiency (SE), and wake-time after sleep onset (WASO) assessed using actigraphy. Beta-diversity differences between children with low and high TST (p = .048) suggest gut microbiota community differences. Particularly, relative abundance of Bifidobacterium was higher in the high TST group and Bacteroides, was higher in children who had greater SE and less WASO (LDA score >2). In contrast, some Lachnospiraceae members including Blautia and Coprococcus 1 were associated with shorter night-time sleep duration and less efficiency, respectively. We also found a group of fecal metabolites, including specific neuroactive compounds and immunomodulating metabolites were associated with greater sleep efficiency and less time awake at night. Notably, tryptophan and its metabolizing products were higher in children who had higher SE or lower WASO (LDA score >2); concentration of propionate was higher in children with less WASO (p = .036). Overall, our results reveal a novel association between sleep and gut microbiota in preschool-aged children. Longer night-time sleep and greater sleep efficiency were associated with specific commensal bacteria that may regulate sleep through modulating neurotransmitter metabolism and the immune system.

Armillaria mellea fermentation liquor ameliorates p-chlorophenylalanine-induced insomnia associated with the modulation of serotonergic system and gut microbiota in rats

In China, Armillaria mellea (Vahl) P. Kumm. has been used as a folk medicine to treat insomnia for several hundred years. However, the underlying mechanisms involved are currently unknown. In this study, the anti-insomnia efficacy of A. mellea fermentation liquor (AFL) was evaluated in p-chlorophenylalanine-induced insomnia rats by measuring the serotonergic systems and gut microbiota. Our results demonstrate that all doses of AFL significantly reduced locomotor activity and alleviated decreasing weights in insomnia rats. Further, AFL exhibited better sedative effects by reducing sleep latency and increasing sleep duration in pentobarbital-treated rats. AFL treatment also elevated serum glutathione peroxidase and superoxide dismutase levels, while reducing serum interleukin-6, tumor necrosis factor-α, and interleukin-1β levels. Furthermore, AFL alleviated insomnia by enhancing 5-hydroxytryptamine content and the expression 5-HT_1A and 5-HT_2A receptor in the hippocampus. Meanwhile, AFL treatment normalized the composition of gut microbiota in insomnia-model rats, while increasing relative abundance of Lachnospiraceae, Ruminococcaceae, and Saccharimonadaceae restores the gut microbial ecosystem altered in insomnia rats. The experiments show that A. mellea alleviated insomnia by modulating serotonergic system and gut microbiota. PRACTICAL APPLICATIONS: Insomnia has become a serious health issue of global concern. As a well-known traditional Chinese medicine, Armillaria mellea has been clinically employed in the treatment of insomnia for centuries in Asia with significant efficacy. In the present study, we firstly reported A. mellea fermentation liquor potentially relieved insomnia rats by alteration of gut microbiota and serotonergic systems and could guide future clinical studies. As a popular edible and medicinal mushroom, A. mellea also can be potentially used in the development and production of novel food products in the future.

Altered functional connectivity strength in chronic insomnia associated with gut microbiota composition and sleep efficiency

BACKGROUND

There is limited evidence on the link between gut microbiota (GM) and resting-state brain activity in patients with chronic insomnia (CI). This study aimed to explore the alterations in brain functional connectivity strength (FCS) in CI and the potential associations among altered FCS, GM composition, and neuropsychological performance indicators.

MATERIALS AND METHODS

Thirty CI patients and 34 age- and gender-matched healthy controls (HCs) were recruited. Each participant underwent resting-state functional magnetic resonance imaging (rs-fMRI) for the evaluation of brain FCS and was administered sleep-, mood-, and cognitive-related questionnaires for the evaluation of neuropsychological performance. Stool samples of CI patients were collected and subjected to 16S rDNA amplicon sequencing to assess the relative abundance (RA) of GM. Redundancy analysis or canonical correspondence analysis (RDA or CCA, respectively) was used to investigate the relationships between GM composition and neuropsychological performance indicators. Spearman correlation was further performed to analyze the associations among alterations in FCS, GM composition, and neuropsychological performance indicators.

RESULTS

The CI group showed a reduction in FCS in the left superior parietal gyrus (SPG) compared to the HC group. The correlation analysis showed that the FCS in the left SPG was correlated with sleep efficiency and some specific bacterial genera. The results of CCA and RDA showed that 38.21% (RDA) and 24.62% (CCA) of the GM composition variation could be interpreted by neuropsychological performance indicators. Furthermore, we found complex relationships between Alloprevotella, specific members of the family Lachnospiraceae, Faecalicoccus, and the FCS alteration, and neuropsychological performance indicators.

CONCLUSION

The brain FCS alteration of patients with CI was related to their GM composition and neuropsychological performance indicators, and there was also an association to some extent between the latter two, suggesting a specific interaction pattern among the three aspects: brain FCS alteration, GM composition, and neuropsychological performance indicators.

Sleep, circadian rhythm and gut microbiota: alterations in Alzheimer's disease and their potential links in the pathogenesis

ABSTRATCIn recent years, emerging studies have observed gut microbiota (GM) alterations in Alzheimer's disease (AD), even in individuals with mild cognitive impairment (MCI). Further, impaired sleep and circadian patterns are common symptoms of AD, while sleep and circadian rhythm disruption (SCRD) is associated with greater β-amyloid (Aβ) burden and AD risk, sometimes years before the clinical onset of AD. Moreover, reports have demonstrated that GM and its metabolites exhibit diurnal rhythmicity and the role of SCRD in dampening the GM rhythmicity and eubiosis. This review will provide an evaluation of clinical and animal studies describing GM alterations in distinct conditions, including AD, sleep and circadian disruption. It aims to identify the overlapping and distinctive GM alterations in these conditions and their contributions to pathophysiology. Although most studies are observational and use different methodologies, data indicate partial commonalities in GM alterations and unanimity at functional level. Finally, we discuss the possible interactions between SCRD and GM in AD pathogenesis, as well as several methodological improvements that are necessary for future research.

The Influence of Gut Microbiota on the Cardiovascular System Under Conditions of Obesity and Chronic Stress

PURPOSE OF REVIEW

Based on the available data, it can be assumed that microbiota is an integral part of the human body. The most heavily colonized area of the human body is the gut, with bacterial accumulation ranging from 101-103 cells/g in the upper intestine to 1011-1012 cells/g in the colon. However, colonization of the gut is not the same throughout, as it was shown that there are differences between the composition of the microbiota in the intestine lumen and in the proximity of the mucus layer.

RECENT FINDINGS

Gut microbiota gradient can be differentially regulated by factors such as obesity and chronic stress. In particular, a high fat diet influences the gut microbial composition. It was also found that chronic stress may cause the development of obesity and thus change the organization of the intestinal barrier. Recent research has shown the significant effect of intestinal microflora on cardiovascular function. Enhanced absorption of bacterial fragments, such as lipopolysaccharide (LPS), promotes the onset of "metabolic endotoxemia," which could activate toll-like receptors, which mediates an inflammatory response and in severe cases could cause cardiovascular diseases. It is presumed that the intestinal microbiota, and especially its metabolites (LPS and trimethylamine N-oxide (TMAO)), may play an important role in the pathogenesis of arterial hypertension, atherosclerosis, and heart failure. This review focuses on how gut microbiota can change the morphological and functional activity of the cardiovascular system in the course of obesity and in conditions of chronic stress.

Sleep and the gut microbiome in psoriasis: clinical implications for disease progression and the development of cardiometabolic comorbidities

Background

Sleep dysfunction and sleep disorders are important comorbidities of psoriasis. Not only do these sleep comorbidities contribute to reduced quality of life, but they may also lead to worsening psoriasis and increased susceptibility to cardiometabolic diseases. While psoriasis and sleep dysfunction are thought to be linked by itch, depression, and immune system dysregulation, the relationship between psoriasis and sleep dysfunction is not yet fully understood.

Objective

We sought to compare previous studies characterizing the gut microbiome in psoriasis and sleep dysfunction and examine the potential relevance of shared findings on cardiometabolic and overall health.

Methods

We performed literature searches of PubMed and Embase databases to find studies evaluating the gut microbiome in psoriasis, sleep dysfunction, and cardiometabolic diseases.

Results

Studies characterizing the gut microbiome in psoriasis and sleep dysfunction reveal shared findings, specifically an increased Firmicutes to Bacteroidetes ratio and reduced abundance of short chain fatty acid-producing bacteria. These dysbiotic features have also been shown to promote systemic inflammation and cardiometabolic disease.

Conclusion

In favoring an increased Firmicutes to Bacteroidetes ratio and reduced abundance of short chain fatty acid-producing bacteria, sleep dysfunction could be contributing to worsening psoriasis and cardiometabolic comorbidities through intestinal dysbiosis. Future studies are needed to determine whether gut- and sleep-targeting interventions could be therapeutic in psoriasis patients with poor sleep.

A brief period of sleep deprivation leads to subtle changes in mouse gut microbiota

Not getting enough sleep is a common problem in our society and contributes to numerous health problems, including high blood pressure, diabetes and obesity. Related to these observations, a wealth of studies has underscored the negative impact of both acute and chronic sleep deprivation on cognitive function. More recently it has become apparent that the gut microbiota composition can be rapidly altered, modulates brain function and is affected by the aforementioned health problems. As such, changes in the microbiota composition may contribute to the behavioural and physiological phenotypes associated with sleep deprivation. It is unclear, however, whether a brief period of sleep deprivation can also negatively impact the gut microbiota. Here, we examined the impact of 5 hr of sleep deprivation on gut microbiota composition of male C57Bl6/J mice. Despite the fact that the overall microbial composition did not change between the control- and sleep-deprived groups, the relative abundance of the Clostridiaceae and Lachnospiraceae were slightly altered in sleep-deprived animals compared to controls. Together, these data suggest that depriving mice of sleep for 5 hr leads to subtle changes in the gut microbiota composition.

Dexmedetomidine alleviates sleep-restriction-mediated exaggeration of postoperative immunosuppression via splenic TFF2 in aged mice

Major abdominal procedures could induce dysfunction in the immune system and lead to postoperative immunosuppression. Sleep dysfunction is associated with impaired immune activity. However, the effects of postoperative sleep dysfunction on postoperative immune function remain unclear. In this study, we found that sleep-restriction (SR) after surgery increased the spleen weight and the percentage of myeloid-derived suppressor cells (MDSCs) in the spleen, and inhibited splenic CD8⁺ T cells activity, which was via inhibiting subdiaphragmatic vagus nerve (SVN)-mediated trefoil factor 2 (TFF2) expression in the spleen of aged mice. Dexmedetomidine could alleviate SR-induced these changes via modulating gut microbiota, which acted through SVN. Moreover, we showed essential roles of splenic TFF2 in attenuating SR-induced reduced protective ability against Escherichia coli (E. coli) pneumonia, increased expression of IL-4 and IL-13 in the lung and M2 polarization of alveolar macrophages (AMs), and decreased phagocytic activity of AMs. Dexmedetomidine improved SR-induced reduced protective ability against E. coli pneumonia via splenic TFF2, and subsequently decreasing IL-4 and IL-13 expression in the lung via modulating gut microbiota/SVN, increasing the compromised phagocytic activity of AMs, and ultimately decreasing M2 polarization of AMs. Taken together, dexmedetomidine-induced increase in splenic TFF2 expresssion could alleviate SR-induced exaggeration of postoperative immunosuppression.

Repeated sleep disruption in mice leads to persistent shifts in the fecal microbiome and metabolome

It has been established in recent years that the gut microbiome plays a role in health and disease, potentially via alterations in metabolites that influence host physiology. Although sleep disruption and gut dysbiosis have been associated with many of the same diseases, studies investigating the gut microbiome in the context of sleep disruption have yielded inconsistent results, and have not assessed the fecal metabolome. We exposed mice to five days of sleep disruption followed by four days of ad libitum recovery sleep, and assessed the fecal microbiome and fecal metabolome at multiple timepoints using 16S rRNA gene amplicons and untargeted LC-MS/MS mass spectrometry. We found global shifts in both the microbiome and metabolome in the sleep-disrupted group on the second day of recovery sleep, when most sleep parameters had recovered to baseline levels. We observed an increase in the Firmicutes:Bacteroidetes ratio, along with decreases in the genus Lactobacillus, phylum Actinobacteria, and genus Bifidobacterium in sleep-disrupted mice compared to control mice. The latter two taxa remained low at the fourth day post-sleep disruption. We also identified multiple classes of fecal metabolites that were differentially abundant in sleep-disrupted mice, some of which are physiologically relevant and commonly influenced by the microbiome. This included bile acids, and inference of microbial functional gene content suggested reduced levels of the microbial bile salt hydrolase gene in sleep-disrupted mice. Overall, this study adds to the evidence base linking disrupted sleep to the gut microbiome and expands it to the fecal metabolome, identifying sleep disruption-sensitive bacterial taxa and classes of metabolites that may serve as therapeutic targets to improve health after poor sleep.