Investigation on the influence of isolated environment on human psychological and physiological health

Influence of helicobacter pylori on composition and function of gastric microbiota in patients with chronic non-atrophic gastritis

Objective

Helicobacter pylori (H. pylori) plays a major role in causing and advancing gastrointestinal illnesses. Our aim is to analyze the unique makeup and functional changes in the gastric microbiota of patients with chronic non-atrophic gastritis (CNAG), regardless of the presence of H. pylori, and to determine the potential signaling pathways.

Methods

We performed metagenomic sequencing on gastric mucosa samples collected from 17 individuals with non-atrophic gastritis, comprising 6 cases were infected with H. pylori (H. pylori-infected case group) and 11 cases without (control group). The species composition was evaluated with DIAMOND software, and functional enrichment was assessed utilizing the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. We analyzed antibiotic resistance patterns using the Comprehensive Antibiotic Resistance Database as a reference (CARD).

Results

The presence of H. pylori colonization in CNAG patients was associated with increased diversity in the gastric microbiota. The Phylum Firmicutes was found to be less prevalent, while the Phylum Proteobacteria showed an increase. Functionally, pathways associated with metabolic pathways, including vitamins, auxiliaries, amino acid residue, carbon hydrate, and metabolic energy pathways, were enriched in CNAG patients with H. pylori infection. Additionally, antibiotic resistance genes correlated with antibiotic efflux pump were enriched.

Conclusions

From a holistic genomic perspective, our findings offer fresh perspectives into the gastric microbiome among CNAG patients carrying H. pylori, which is valuable for future research on CNAG.

Toward Healthy Underground Spaces: A Review of Underground Environmental Design Factors and Their Impacts on Users' Physiological and Psychological Health

OBJECTIVE

This study aims to review and synthesize what design factors are associated with the physiological and psychological health of occupants in underground spaces.

BACKGROUND

The development of underground spaces offers options to global challenges, such as traffic congestion, urban overcrowding, the revitalization of dormant underground areas, disaster mitigation, and adaptation to extreme environments. Despite these advantages, concerns persist about potential adverse effects on human health in these environments. This situation underlines the necessity of systematically identifying concerns and perceptions related to health in underground spaces.

METHODS

A narrative literature review was conducted to examine the relationship between design factors and health factors across 21 empirical studies. Based on the review of the identified literature, a relationship diagram was developed to depict the interconnections between the identified design and health factors.

RESULTS

The analysis identified design factors related to the air, sound, light, nature, transport, and spatial context of underground spaces, each of which exerted relationships with occupants' physiological and psychological health factors. The relationship diagram indicated that the psychological factor "feeling of confinement" was mentioned most frequently, suggesting that it is one of the most extensively researched factors in this context.

CONCLUSIONS

The relationship diagram aims to bridge the existing knowledge gap and set the stage for future research endeavors. The ultimate goal is to refine urban living standards by leveraging the potential of underground spaces while ensuring health and well-being.

Beneficial effects of short-term exposure to indoor biophilic environments on psychophysiological health: Evidence from electrophysiological activity and salivary metabolomics

BACKGROUND

The utilization of short-term natural exposure as a health intervention has great potential in the field of public health. However, previous studies have mostly focused on outdoor urban green spaces, with limited research on indoor biophilic environments, and the physiological regulatory mechanisms involved remain unclear.

OBJECTIVES

To explore the affective and physiological impact of short-term exposure to indoor biophilic environments and their potential regulatory mechanisms.

METHODS

A between-group design experiment was conducted, and the psychophysiological responses of participants to the indoor plants (Vicks Plant) were measured by a method combined the subjective survey, electrophysiological measurements, and salivary biochemical analysis. Volatile organic compounds (VOCs) from plants were also detected to analyze the main substances that caused olfactory stimuli.

RESULTS

Compared with the non-biophilic environment, short-term exposure to the indoor biophilic environment was associated with psychological and physiological relaxation, including reduced negative emotions, improved positive emotions, lower heart rate, skin conductance level, salivary cortisol and pro-inflammatory cytokines, and increased alpha brainwave power. Salivary metabolomics analysis revealed that the differential metabolites observed between the groups exhibited enrichment in two metabolic pathways related to neural function and immune response: phenylalanine, tyrosine and tryptophan biosynthesis, and ubiquinone and other terpenoid-quinone biosynthesis. These changes may be associated with the combined visual and olfactory stimuli of the biophilic environment, in which D-limonene was the dominant substance in plant-derived VOCs.

CONCLUSION

This research demonstrated the benefits of short-term exposure to indoor biophilic environments on psychophysiological health through evidence from both the nervous and endocrine systems.

Disrupted synaptic homeostasis and partial occlusion of associative long-term potentiation in the human cortex during social isolation

Social isolation often occurs in the military mission of soldiers but has increased in the general population since the COVID-19 epidemic. Overall synaptic homeostasis along with associative plasticity for the activity-dependent refinement of transmission across single synapses represent basic neural network function and adaptive behavior mechanisms. Here, we use electrophysiological and behavioral indices to non-invasively study the net synaptic strength and long-term potentiation (LTP)-like plasticity of humans in social isolation environments. The theta activity of electroencephalography (EEG) signals and transcranial magnetic stimulation (TMS) intensity to elicit a predefined amplitude of motor-evoked potential (MEP) demonstrate the disrupted synaptic homeostasis in the human cortex during social isolation. Furthermore, the induced MEP change by paired associative stimulation (PAS) demonstrates the partial occlusion of LTP-like plasticity, further behavior performances in a word-pair task are also identified as a potential index. Our study indicates that social isolation disrupts synaptic homeostasis and occludes associative LTP-like plasticity in the human cortex, decreasing behavior performance related to declarative memory.

Exploring the relationship between home environmental characteristics and restorative effect through neural activities

As society and the economy have advanced, the focus of architectural and interior environment design has shifted from practicality to eliciting emotional responses, such as stimulating environments and innovative inclusive designs. Of particular interest is the home environment, as it is best suited for achieving restorative effects, leading to a debate between interior qualities and restorative impact. This study explored the relationships between home characteristics, restorative potential, and neural activities using the Neu-VR. The results of the regression analysis revealed statistically significant relationships between interior properties and restorative potential. We examined each potential characteristic of the home environment that could have a restorative impact and elucidated the environmental characteristics that should be emphasized in residential interior design. These findings contribute evidence-based knowledge for designing therapeutic indoor environments. And combining different restorative potential environments with neural activity, discussed new neuro activities which may predict restorativeness, decoded the new indicators of neuro activity for environmental design.

Effects of isolation and confinement on gastrointestinal microbiota-a systematic review

Purpose

The gastrointestinal (GI) microbiota is a complex and dynamic ecosystem whose composition and function are influenced by many internal and external factors. Overall, the individual GI microbiota composition appears to be rather stable but can be influenced by extreme shifts in environmental exposures. To date, there is no systematic literature review that examines the effects of extreme environmental conditions, such as strict isolation and confinement, on the GI microbiota.

Methods

We conducted a systematic review to examine the effects of isolated and confined environments on the human GI microbiota. The literature search was conducted according to PRISMA criteria using PubMed, Web of Science and Cochrane Library. Relevant studies were identified based on exposure to isolated and confined environments, generally being also antigen-limited, for a minimum of 28 days and classified according to the microbiota analysis method (cultivation- or molecular based approaches) and the isolation habitat (space, space- or microgravity simulation such as MARS-500 or natural isolation such as Antarctica). Microbial shifts in abundance, alpha diversity and community structure in response to isolation were assessed.

Results

Regardless of the study habitat, inconsistent shifts in abundance of 40 different genera, mainly in the phylum Bacillota (formerly Firmicutes) were reported. Overall, the heterogeneity of studies was high. Reducing heterogeneity was neither possible by differentiating the microbiota analysis methods nor by subgrouping according to the isolation habitat. Alpha diversity evolved non-specifically, whereas the microbial community structure remained dissimilar despite partial convergence. The GI ecosystem returned to baseline levels following exposure, showing resilience irrespective of the experiment length.

Conclusion

An isolated and confined environment has a considerable impact on the GI microbiota composition in terms of diversity and relative abundances of dominant taxa. However, due to a limited number of studies with rather small sample sizes, it is important to approach an in-depth conclusion with caution, and results should be considered as a preliminary trend. The risk of dysbiosis and associated diseases should be considered when planning future projects in extreme environments.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022357589.

Long-term artificial/natural daytime light affects mood, melatonin, corticosterone, and gut microbiota in rats

The desynchronization of circadian rhythms affected by light may induce physiological and psychological disequilibrium. We aimed to elucidate changes of growth, depression-anxiety like behaviors, melatonin and corticosterone (CORT) secretion, and gut microbiota in rats influenced by long-term light inputs. Thirty male Sprague-Dawley rats were exposed to a 16/8 h light/dark regime for 8 weeks. The light period was set to 13 h of daylight with artificial light (AL group, n = 10), or with natural light (NL group, n = 10), or with mixed artificial-natural light (ANL group, n = 10), and 3 h of artificial night light after sunset. The obtained findings indicated that the highest weight gain and food efficiency were observed in the AL group and the lowest in NL group. In the behavioral tests, the NL and ANL groups showed lower anxiety level than AL group, and ANL groups showed lower depression level than AL group. The NL and ANL groups had delayed acrophases and maintained higher concentrations of melatonin compared to AL group. The circadian rhythm of CORT was only found in ANL group. At the phylum level, the mixed light contributed to a lower abundance of Bacteroidetes. The genus level results recommend a synergistic effect of artificial light and natural light on Lactobacillus abundance and an antagonistic effect on the Lachnospiraceae_NK4A136_group abundance. The study indicated that the mixture of artificial and natural light as well as the alignment of the proportions had beneficial influences on depression-anxiety-like levels, melatonin and corticosterone secretion, and the composition of the gut microbiota. KEY POINTS: • The mixed light can reduce the depression-anxiety level • The mixed light can maintain the secretion rhythm of melatonin and CORT • The mixed light can increase Lactobacillus and decrease Lachnospiraceae_NK4A136_group.

Impeded frontal-occipital communications during Go/Nogo tasks in humans owing to mental workload

Human brains rely on oscillatory coupling mechanisms for regulating access to prefrontal cognitive resources, dynamically communicating between the frontal and remote cortex. We worry that communications across cortical regions will be impeded when humans in extreme space environments travel with mental load work, affecting the successful completion of missions. Here, we monitored crews of workers performing a Go/Nogo task in space travel, accompanied by acquisitions of electroencephalography (EEG) signals. These data demonstrated that when the target stimulus suddenly changed to the non-target stimulus, an instantaneous communication mechanism between the frontal and occipital cortex was established by theta-gamma phase-amplitude coupling (PAC). However, this frontal-occipital communication was impeded because of the mental workload of space travel. 86 healthy volunteers who participated in the ground imitation further indicated that mental workload caused decoupled theta-gamma PAC during the Go/Nogo task, impeding frontal-occipital communications and behavioral performance. We also found that the degree of theta-gamma PAC coupling in space was significantly lower than on the ground, indicating that mental workload and other hazards worsen the impeded frontal-occipital communications of humans. These results could guide countermeasures for the inadaptability of humans working in spaceflight.

Confinement induces oxidative damage and synaptic dysfunction in mice

A confined environment is an enclosed area where entry or exit is highly restricted, which is a risk factor for a work crew's mental health. Previous studies have shown that a crew is more susceptible to developing anxiety or depression in a confined environment. However, the underlying mechanism by which negative emotion is induced by confinement is not fully understood. Hence, in this study, mice were retained in a tube to simulate short-term confinement. The mice exhibited depressive-like behavior. Additionally, the levels of H₂O₂ and malondialdehyde in the prefrontal cortex were significantly increased in the confinement group. Furthermore, a label-free quantitative proteomic strategy was applied to analyze the abundance of proteins in the prefrontal cortex of mice. A total of 71 proteins were considered differentially abundant proteins among 3,023 identified proteins. Two differentially abundant proteins, superoxide dismutase [Mn] and syntaxin-1A, were also validated by a parallel reaction monitoring assay. Strikingly, the differentially abundant proteins were highly enriched in the respiratory chain, oxidative phosphorylation, and the synaptic vesicle cycle, which might lead to oxidative damage and synaptic dysfunction. The results of this study provide valuable information to better understand the mechanisms of depressive-like behavior induced by confined environments.

Extreme conditions affect neuronal oscillations of cerebral cortices in humans in the China Space Station and on Earth

Rhythmical oscillations of neural populations can reflect working memory performance. However, whether neuronal oscillations of the cerebral cortex change in extreme environments, especially in a space station, remains unclear. Here, we recorded electroencephalography (EEG) signals when volunteers and astronauts were executing a memory task in extreme working conditions. Our experiments showed that two extreme conditions affect neuronal oscillations of the cerebral cortex and manifest in different ways. Lengthy periods of mental work impairs the gating mechanism formed by theta-gamma phase-amplitude coupling of two cortical areas, and sleep deprivation disrupts synaptic homeostasis, as reflected by the substantial increase in theta wave activity in the cortical frontal-central area. In addition, we excluded the possibility that nutritional supply or psychological situations caused decoupled theta-gamma phase-amplitude coupling or an imbalance in theta wave activity increase. Therefore, we speculate that the decoupled theta-gamma phase-amplitude coupling detected in astronauts results from their lengthy periods of mental work in the China Space Station. Furthermore, comparing preflight and inflight experiments, we find that long-term spaceflight and other hazards in the space station could worsen this decoupling evolution. This particular neuronal oscillation mechanism in the cerebral cortex could guide countermeasures for the inadaptability of humans working in spaceflight.

The effects of dynamic daylight-like light on the rhythm, cognition, and mood of irregular shift workers in closed environment

Shift workers are mostly suffered from the disruption of circadian rhythm and health problems. In this study, we designed proper light environment to maintain stable circadian rhythm, cognitive performance, and mood status of shift workers. We used five-channel light-emitting diodes to build up the dynamic daylight-like light environment. The illuminance, correlated color temperature, and circadian action factor of light were tunable in the ranges of 226 to 678 lx, 2680 to 7314 K, and 0.32 to 0.96 throughout the day (5:30 to 19:40). During the nighttime, these parameters maintained about 200 lx, 2700 K, and 0.32, respectively. In this light environment, three subjects had engaged in shift work for 38 consecutive days. We measured plasma melatonin, activity counts, continuous performance tests, and visual analogue scale on mood to assess the rhythm, cognitive performance, and mood of subjects. After 38-day shift work, the subjects' peak melatonin concentration increased significantly. Their physiological and behavioral rhythms maintained stable. Their cognitive performance improved significantly after night work, compared with that before night work. Their mood status had no significant change during the 38-day shift work. These results indicated that the light environment was beneficial to maintain circadian rhythm, cognitive performance and mood status during long-term shift work in closed environment.

Impact of Sleep Deprivation on Emotional Regulation and the Immune System of Healthcare Workers as a Risk Factor for COVID 19: Practical Recommendations From a Task Force of the Latin American Association of Sleep Psychology

Healthcare workers who are on the front line of coronavirus disease 2019 (COVID-19) and are also undergoing shift schedules face long work hours with few pauses, experience desynchronization of their circadian rhythm, and an imbalance between work hours effort and reward in saving lives, resulting in an impact on work capacity, aggravated by the lack of personal protective equipment (PPE), few resources and precarious infrastructure, and fear of contracting the virus and contaminating family members. Some consequences are sleep deprivation, chronic insomnia, stress-related sleep disorders, and post-traumatic stress disorder. These sleep alterations critically affect mental health, precipitating or perpetuating anxiety, stress, and depression, resulting in the inability to regulate positive and negative emotions. Pre-existing sleep disorders are an important risk factor for the development and maintenance of PSTD when individuals are exposed to an important stressor such as a COVID-19 pandemic. At the same time, how an individual regulates the emotion associated with worries during daytime functioning impacts nighttime sleep, precipitating and perpetuating difficulties in sleeping. All of these changes in sleep and emotional regulation also alter the immune system. Sleep deprivation is commonly associated with chronic inflammatory diseases, due to the desynchronizations in circadian rhythms, causing possible psychophysiological disorders and impaired neuroimmune-endocrine homeostasis. From this perspective, we clarify in this article how sleep disorders affect the immune system and emotional regulation, explaining their phenomenological and neurobiological mechanisms, and discussing elements of cognitive and behavioral coping for health professionals to adopt and manage a healthier sleep pattern in the COVID-19 outbreak.

Moringa oleifera polysaccharides regulates caecal microbiota and small intestinal metabolic profile in C57BL/6 mice

This study investigated the effects of Moringa oleifera polysaccharides (MOP) on the serum indexes, small intestinal morphology, small intestinal metabolic profile, and caecal microbiota of mice. A new type of polysaccharides with 104,031 Da molecular weight and triple helix structure was isolated from M. oleifera leaves for in vivo experiment. Forty male SPF C57BL/6 mice aged 4 weeks were average divided into four groups randomly according to the MOP gavaged daily (0, 20, 40 and 60 mg/kg body weight MOP). After a 7-day preliminary trial period and a 28-day official trial period, the mice were slaughtered. Results showed that MOP reduced glucose, total cholesterol, and malondialdehyde. It also improved superoxide dismutase and catalase in serum (P < 0.05). For small intestinal morphology, MOP improved the villi length and crypt depth in both ileum and jejunum (P < 0.05); the ratio of villi length to crypt depth in jejunum increased (P < 0.05). MOP could cause the increase of beneficial bacteria and the decrease of harmful bacteria in caecum, further affecting the function of microbiota. In addition, MOP regulated 114 metabolites enriched in the pathway related to the synthesis and metabolism of micromolecules. In sum, MOP exerted positive effects on the serum indexes and intestinal health of mice.

Investigation on entraining and enhancing human circadian rhythm in closed environments using daylight-like LED mixed lighting

Humans can undergo circadian disruption and misalignment when living in closed environments without sufficient daylight. Therefore, it is of great significance to investigate the effects of artificial light on the circadian rhythm. In this work, the red, green, blue, warm white, and cool white (RGBWW) five-channel light-emitting diodes (LEDs) were fabricated as the only light sources in the closed environment. The LED mixed lighting showed a high color rendering index (CRI) all the time. During the day, the light simulated the daylight and increased the tunability of the circadian action factor (CAF) and correlated color temperature (CCT). At night, it maintained low CAF and CCT. Three subjects did irregular shift work in the closed environment for 38 days. Their plasma melatonin and daily activity were measured to assess the circadian rhythm. After 38 days, the subjects' peak melatonin times did not shift significantly (p = 0.676), while their peak melatonin concentrations increased apparently (p = 0.005). The start times of the least active 5-h period (L5) in one day fluctuated in a small range. The standard deviation (SD) was <15.11 min in most times. These results demonstrated that the subjects' rhythms maintained stable and were enhanced. The periods of circular cross-correlation between activity and CAF oscillated around 24 h (SD = 15.4 min), indicating the entrainment of light on the stable 24-h rhythm. It was concluded that the daylight-like LED lighting effectively entrained and enhanced the circadian rhythm in the closed environment.