Wake-up Call to Clinicians: The Impact of Sleep Dysfunction on Gastrointestinal Health and Disease

Circadian rhythm regulates the function of immune cells and participates in the development of tumors

Circadian rhythms are present in almost all cells and play a crucial role in regulating various biological processes. Maintaining a stable circadian rhythm is essential for overall health. Disruption of this rhythm can alter the expression of clock genes and cancer-related genes, and affect many metabolic pathways and factors, thereby affecting the function of the immune system and contributing to the occurrence and progression of tumors. This paper aims to elucidate the regulatory effects of BMAL1, clock and other clock genes on immune cells, and reveal the molecular mechanism of circadian rhythm's involvement in tumor and its microenvironment regulation. A deeper understanding of circadian rhythms has the potential to provide new strategies for the treatment of cancer and other immune-related diseases.

Long-term exposure to traffic noise and risk of incident colon cancer: A pooled study of eleven Nordic cohorts

Background Colon cancer incidence is rising globally, and factors pertaining to urbanization have been proposed involved in this development. Traffic noise may increase colon cancer risk by causing sleep disturbance and stress, thereby inducing known colon cancer risk-factors, e.g. obesity, diabetes, physical inactivity, and alcohol consumption, but few studies have examined this. Objectives The objective of this study was to investigate the association between traffic noise and colon cancer (all, proximal, distal) in a pooled population of 11 Nordic cohorts, totaling 155,203 persons. Methods We identified residential address history and estimated road, railway, and aircraft noise, as well as air pollution, for all addresses, using similar exposure models across cohorts. Colon cancer cases were identified through national registries. We analyzed data using Cox Proportional Hazards Models, adjusting main models for harmonized sociodemographic and lifestyle data. Results During follow-up (median 18.8 years), 2757 colon cancer cases developed. We found a hazard ratio (HR) of 1.05 (95% confidence interval (CI): 0.99-1.10) per 10-dB higher 5-year mean time-weighted road traffic noise. In sub-type analyses, the association seemed confined to distal colon cancer: HR 1.06 (95% CI: 0.98-1.14). Railway and aircraft noise was not associated with colon cancer, albeit there was some indication in sub-type analyses that railway noise may also be associated with distal colon cancer. In interaction-analyses, the association between road traffic noise and colon cancer was strongest among obese persons and those with high NO₂-exposure. Discussion A prominent study strength is the large population with harmonized data across eleven cohorts, and the complete address-history during follow-up. However, each cohort estimated noise independently, and only at the most exposed façade, which may introduce exposure misclassification. Despite this, the results of this pooled study suggest that traffic noise may be a risk factor for colon cancer, especially of distal origin.

Positive Association Between Sleep Disturbance and Prevalence of Functional Dyspepsia in Japanese Young People

BACKGROUND

Evidence regarding the association between sleep disturbance and functional dyspepsia (FD) remains limited in the young population.

AIMS

This study aimed to investigate the association between sleep disturbance and FD including subgroups among Japanese young people.

METHODS

Study subjects were 8923 university students. FD was defined according to the Rome III criteria. Subjects with FD were further categorized as having postprandial distress syndrome (PDS) or epigastric pain syndrome (EPS). Subjects completed a self-reported questionnaire assessing self-reported sleep duration, sleep disturbance, difficulty falling asleep, deep sleep disorder, nocturnal awakening, early awakening, and daytime sleepiness.

RESULTS

The prevalence of FD was 1.9%. After adjustment, all types of sleep disturbances were independently positively associated with FD (total sleep disturbance: OR 4.11 [95% CI: 2.89-5.78], difficulty falling asleep: OR 3.97 [95% CI: 2.53-6.01], deep sleep disorder: OR 4.85 [95% CI: 3.06-7.40], nocturnal awakening: OR 4.35 [95% CI: 1.90-8.67], early awakening: OR 4.50 [95% CI: 1.97-8.97], and daytime sleepiness: OR 2.83 [95% CI: 1.25-5.56]). While nocturnal awakening and daytime sleepiness were not associated with EPS, the other types of sleep disturbance were independently positively associated with EPS and PDS. No association between self-reported sleep duration and FD was found.

CONCLUSIONS

Sleep disturbance may be independently positively associated with the prevalence of FD among Japanese young people. Nocturnal awakening and daytime sleepiness were not associated with EPS; the other types of sleep disturbance were independently positively associated with EPS and PDS.

Recent advances in the utilization of tea active ingredients to regulate sleep through neuroendocrine pathway, immune system and intestinal microbiota

Sleep disorders have received widespread attention nowadays, which have been promoted by the accelerated pace of life, unhealthy diets and lack of exercise in modern society. The chemical medications to improve sleep has shown serious side effects and risks with high costs. Therefore, it is urgent to develop efficient nutraceuticals from natural sources to ensure sleep quality as a sustainable strategy. As the second most consumed beverage worldwide, the health-promoting effects of tea have long been widely recognized. However, the modulatory effect of teas on sleep disorders has received much less attention. Tea contains various natural sleep-modulating active ingredients such as L-theanine (LTA), caffeine, tea polyphenols (TPP), tea pigments, tea polysaccharides (TPS) and γ-aminobutyric acid (GABA). This review focuses on the potential influence and main regulating mechanisms of different tea active ingredients on sleep, including being absorbed by the small intestine and then cross the blood-brain barrier to act on neurons in the brain as neurotransmitters, manipulating the immune system and further affect sleep-wake cycle by regulating the levels of cytokines, and controlling the gut microbes to maintain the homeostasis of circadian rhythm. Current research progress and limitations are summarized and several future development directions are also proposed. This review hopes to provide new insights into the future elucidation of the sleep-regulating mechanisms of different teas and their natural active ingredients and the development of tea-based functional foods for alleviating sleep disorders. HighlightsNatural sleep-modulating active ingredients in tea have been summarized.Influences of drinking tea or tea active ingredients on sleep are reviewed.Three main regulating mechanisms of tea active ingredients on sleep are explained.The associations among nervous system, immune system and intestinal microbiota are investigated.The potential of developing delivery carriers for tea active ingredients is proposed.

Differential Effect of Light and Dark Period Sleep Fragmentation on Composition of Gut Microbiome and Inflammation in Mice

Bi-directional interactions amongst the gut microbiota, immune system, and brain function are thought to be critical mediators of health and disease. The role sleep plays in mediating these interactions is not known. We assessed the effects of sleep fragmentation (SF) on the microbiota–gut–brain axis. Male C57BL/6NCrl mice (4 to 5 per cage, fed standard lab chow) experienced SF via mechanical stimulation at 2 min intervals during the light (SF) and dark (DD, dark disturbances) periods. Home cage (HC) controls were undisturbed. After 10 days, fecal samples were collected at light onset, midday, light offset, and midnight. Samples were also collected after 10 days without SF. Subsequently, the mice were randomized across groups and allowed 20 additional days of recovery followed by 10 days of SF or DD. To assess effects on the microbiota, 16S rRNA sequencing was used, and mesenteric lymph nodes (MLNs) and cortex and medial prefrontal cortex were analyzed using cytokine arrays. SF and DD produced significant alterations in the microbiota compared to HC, and DD had greater impact than SF on some organisms. SF produced marked suppression in MLNs of chemokines that regulate inflammation (CCL3, CCL4 and their receptor CCR5) and maintain the immune mucosal barrier (Cxcl13) at the same time that cortical cytokines (IL-33) indicated neuroinflammation. DD effects on immune responses were similar to HC. These data suggest that SF alters the microbiome and suppresses mucosal immunity at the same time that mediators of brain inflammation are upregulated. The translational implications for potential application to clinical care are compelling.

Correlation between lifestyle and social factors in functional dyspepsia among college freshmen

Objective

We aimed to examine the relationship between the prevalence of functional dyspepsia (FD) and lifestyle habits, to identify social factors that may contribute to psychosocial disorders.

Methods

We enrolled 759 university freshmen in this study, who were categorized into the FD group and healthy group. All participants completed the validated Self-Rating Depression Scale and Self-Rating Anxiety Scale questionnaires, to assess lifestyle and social factors among participants.

Results

The proportion of participants with FD was 16.86%, and 67.97% were women. Diet irregularities and sleep impairment may have an effect on FD. Tea consumption may play a role in preventing FD. Participants with FD were more likely to have mood disorders than healthy participants. Most participants with FD who had mood disorders experienced mild anxiety or depression. Participants’ main sources of stress arose from daily life, development, social life, life events, and participants’ daily schedule.

Conclusion

Sex and lifestyle habits, including sleeping patterns and dietary habits, can have an impact on FD. Social stress and mood disorders also have an effect on FD. FD may be prevented by adjusting lifestyle habits and psychological counseling.

Correlation between sleep impairment and functional dyspepsia

Objective

Sleeping habits may greatly impact the prevalence of functional dyspepsia (FD). This study examined relationships between aspects of sleep impairment and FD.

Methods

This prospective study included university student volunteers. Following enrolment, FD was diagnosed based on the Rome IV criteria, dividing participants into an FD group or controls. The FD group was further subdivided into long-term (disease course >6 months) and short-term (disease course 3–6 months) FD groups. Participants completed the Pittsburgh Sleep Quality Index (PSQI), the Rome IV Diagnostic Questionnaire for Gastrointestinal Disorders in Adults, and a visual analogue scale (VAS).

Results

Out of 418 participants in total, sleep quality, latency, and duration, habitual sleep efficiency, sleep disturbances, sleep medication use, daytime dysfunction, and PSQI scores were higher in the FD groups versus controls. Components of PSQI scores emerged as risk factors, and were higher in the long-term versus short-term dyspepsia group. Moreover, these components were positively correlated with frequency/severity of postprandial distress syndrome and early satiation. Total PSQI scores were positively correlated with VAS scores.

Conclusion

Several PSQI components are associated with FD occurrence, symptom frequency, and symptom severity.

Sleep Loss Can Cause Death through Accumulation of Reactive Oxygen Species in the Gut

The view that sleep is essential for survival is supported by the ubiquity of this behavior, the apparent existence of sleep-like states in the earliest animals, and the fact that severe sleep loss can be lethal. The cause of this lethality is unknown. Here we show, using flies and mice, that sleep deprivation leads to accumulation of reactive oxygen species (ROS) and consequent oxidative stress, specifically in the gut. ROS are not just correlates of sleep deprivation but drivers of death: their neutralization prevents oxidative stress and allows flies to have a normal lifespan with little to no sleep. The rescue can be achieved with oral antioxidant compounds or with gut-targeted transgenic expression of antioxidant enzymes. We conclude that death upon severe sleep restriction can be caused by oxidative stress, that the gut is central in this process, and that survival without sleep is possible when ROS accumulation is prevented. VIDEO ABSTRACT.

The Association of Insomnia, Perceived Immune Functioning, and Irritable Bowel Syndrome Complaints

BACKGROUND

Irritable bowel syndrome (IBS) can have a significant negative impact on quality of life, mood and wellbeing. The aim of this study was to investigate the association between experiencing IBS symptoms and insomnia, and perceived health status.

METHOD

An online survey was conducted among n = 1950 Dutch university students (83.6% women). IBS was assessed with the Birmingham IBS Symptom Questionnaire, quality of life with the WHO-5 wellbeing index, and sleep outcomes with the SLEEP-50 questionnaire. Perceived immune functioning and general health were assessed using 1-item scales.

RESULTS

IBS symptom severity was significantly associated with insomnia complaints (r = 0.32, p = 0.0001), sleep quality (r = -0.21, p = 0.0001), sleep onset latency (r = 0.11, p = 0.0001) and the number of nightly awakenings (r = 0.24, p = 0.0001). Total sleep time was not significantly associated with IBS symptom severity. Significant correlations were also found between IBS symptom severity and perceived general health (r = -0.30, p = 0.0001), perceived immune functioning (r= -0.25, p = 0.0001), and quality of life (r = -0.24, p = 0.0001).

CONCLUSIONS

Experiencing IBS complaints is associated with reduced perceived immune functioning, a poorer perception of general health, and sleep disturbances. These effects are reflected in a significantly lower reported quality of life in subjects with more IBS and/or sleep complaints.