Research progress on intestinal microbiota regulating cognitive function through the gut-brain axis

The intestinal microbiota community is a fundamental component of the human body and plays a significant regulatory role in maintaining overall health and in the management disease states.The intestinal microbiota-gut-brain axis represents a vital connection in the cognitive regulation of the central nervous system by the intestinal microbiota.The impact of intestinal microbiota on cognitive function is hypothesized to manifest through both the nervous system and circulatory system. Imbalances in intestinal microbiota during the perioperative period could potentially contribute to perioperative neurocognitive dysfunction. This article concentrates on a review of existing literature to explore the potential influence of intestinal microbiota on brain and cognitive functions via the nervous and circulatory systems.Additionally, it summarizes recent findings on the impact of perioperative intestinal dysbacteriosis on perioperative neurocognitive dysfunction and suggests novel approaches for prevention and treatment of this condition.

Systematic identification of the role of gut microbiota in mental disorders: a TwinsUK cohort study

Mental disorders are complex disorders influenced by multiple genetic, environmental, and biological factors. Specific microbiota imbalances seem to affect mental health status. However, the mechanisms by which microbiota disturbances impact the presence of depression, stress, anxiety, and eating disorders remain poorly understood. Currently, there are no robust biomarkers identified. We proposed a novel pyramid-layer design to accurately identify microbial/metabolomic signatures underlying mental disorders in the TwinsUK registry. Monozygotic and dizygotic twins discordant for mental disorders were screened, in a pairwise manner, for differentially abundant bacterial genera and circulating metabolites. In addition, multivariate analyses were performed, accounting for individual-level confounders. Our pyramid-layer study design allowed us to overcome the limitations of cross-sectional study designs with significant confounder effects and resulted in an association of the abundance of genus Parabacteroides with the diagnosis of mental disorders. Future research should explore the potential role of Parabacteroides as a mediator of mental health status. Our results indicate the potential role of the microbiome as a modifier in mental disorders that might contribute to the development of novel methodologies to assess personal risk and intervention strategies.

Trihexyphenidyl Alters Its Host's Metabolism, Neurobehavioral Patterns, and Gut Microbiome Feedback Loop-The Modulating Role of Anacyclus pyrethrum

Trihexyphenidyl (THP)-a synthetic anticholinergic medication used to manage parkinsonism and extrapyramidal symptoms-has gained significant clinical recognition. However, there is a critical gap in understanding its withdrawal effects. This study investigates the intricate interplay between gut microbiota and oxidative stress during THP withdrawal. Furthermore, it explores the therapeutic potential of Anacyclus pyrethrum (AEAP) for alleviating the associated adverse effects. This comprehensive research combines behavioral tests, biochemical analysis, gut microbiome assessment utilizing matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), and oxidative stress measures. The results reveal that the chronic administration of THP leads to severe withdrawal syndrome, marked by heightened anxiety, depressive-like behaviors, increased cortisol levels, elevated oxidative stress, and gut dysbiosis. However, the administration of AEAP alongside THP shows a significant capacity to mitigate these deleterious effects. Co-treatment and post-treatment with AEAP increased bacterial density and diversity, promoting the proliferation of beneficial bacteria associated with improved gut health. Furthermore, AEAP administration reduced cortisol levels and exhibited potent antioxidant properties, effectively countering the THP-induced oxidative damage. This study highlights the withdrawal effects of THP and underscores the therapeutic potential of AEAP for managing these symptoms. The findings reveal its promising effects in alleviating behavioral and biochemical impairments, reducing oxidative stress, and restoring gut microbiota, which could significantly impact the clinical management of THP withdrawal and potentially extend to other substance withdrawal scenarios.

Impact of gut Microbiome alteration in Ulcerative Colitis patients on disease severity and outcome

BACKGROUND

Ulcerative colitis is a heterogeneous disease in terms of disease course, location, and therapeutic response. The current study was done to assess the alteration of the gut microbiome in UC patients and its relationship to severity, response to therapy, and outcome.

PATIENTS AND METHODS

The study included 96 participants who were divided into a case group (n = 48, recent onset, treatment naive ulcerative colitis patients who were subdivided into mild, moderate, and severe subgroups based on Truelove-Witts and endoscopic severity) and a healthy control group (n = 48). All were subjected to a thorough history, clinical examination, colonoscopy, routine laboratory tests, and quantitative real-time PCR to quantify Bacteroides, Lactobacilli, Faecalibacterium prausnitzii, Veillonella, and Hemophilus in fecal samples at baseline and 6 months after treatment.

RESULTS

Bacterial 16S rRNA gene sequencing revealed a significant reduction in the phylum Firmicutes in UC patients, with a significant predominance of the phylum Bacteriodetes. F. prausnitzii and lactobacilli were inversely proportional to disease severity, whereas Bacteroides, Hemophilus, and Veillonella were directly proportional to it. Six months after therapy, a statistically significant increase in F. prausnitzii and lactobacilli was observed, with a decrease in the levels of other bacteria. Lower baseline F. praustinizii (< 8.5) increased the risk of relapse; however, lower ESR (< 10), lower post-treatment CRP (< 6), lower Bacteroides (< 10.6) indefinitely protect against relapse.

CONCLUSION

The gut microbiome of recently diagnosed UC showed lower levels of Lactobacilli, Faecalibacterium, and higher levels of Bacteroides and Veillonella, and the change in their levels can be used to predict response to therapy.

The gut-brain connection: Exploring the influence of the gut microbiota on neuroplasticity and neurodevelopmental disorders

Neuroplasticity refers to the ability of brain circuits to reorganize and change the properties of the network, resulting in alterations in brain function and behavior. It is traditionally believed that neuroplasticity is influenced by external stimuli, learning, and experience. Intriguingly, there is new evidence suggesting that endogenous signals from the body's periphery may play a role. The gut microbiota, a diverse community of microorganisms living in harmony with their host, may be able to influence plasticity through its modulation of the gut-brain axis. Interestingly, the maturation of the gut microbiota coincides with critical periods of neurodevelopment, during which neural circuits are highly plastic and potentially vulnerable. As such, dysbiosis (an imbalance in the gut microbiota composition) during early life may contribute to the disruption of normal developmental trajectories, leading to neurodevelopmental disorders. This review aims to examine the ways in which the gut microbiota can affect neuroplasticity. It will also discuss recent research linking gastrointestinal issues and bacterial dysbiosis to various neurodevelopmental disorders and their potential impact on neurological outcomes.

Gut microbiota-SCFAs-brain axis associated with the antidepressant activity of berberine in CUMS rats

BACKGROUND

The anti-depressant effect of berberine (BBR) has been widely reported. However, the underlying mechanism remains unclear. The microbiota-gut-brain (MGB) axis plays a key role in the pathogenesis of depression. Therefore, we aimed to explore the anti-depressant mechanisms of BBR involving the association of the gut microbiota, neurotransmitters, BDNF, and SCFAs in chronic unpredictable mild stress (CUMS)-induced depressive rats.

METHODS

The antidepressant effects of BBR were detected by open-field test, 1 % sucrose preference test and body weight test in CUMS-induced depressive rats. 16S rDNA sequencing was performed to identify the change of gut microbiota. The concentrations of fecal SCFAs were analyzed by GC-MS targeted metabolomics. At the same time, neurotransmitters and BDNF expression were measured by enzyme linked immunosorbent assay (ELISA).

RESULTS

BBR improved depression-like behaviors in CUMS rats by increasing the expression of serotonin (5-HT), norepinephrine (NE), dopamine (DA), and BDNF in the hippocampus. BBR regulates Firmicutes, Bacteroidetes, and Lachnospiraceae in depressive rats, resulting in the alteration of the synthesis and metabolism of SCFAs, including acetic, propanoic, and isovaleric acids.

LIMITATIONS

Direct evidence that BBR improves depressive behaviors via gut microbiota-SCFAs-brain axis is lacking, and only male rats were investigated in the present study.

CONCLUSION

The anti-depressant mechanism of BBR is related to the regulation of the MGB axis via modulating the gut microbiota-SCFAs-monoamine neurotransmitters/BDNF.

Role of Bifidobacterium spp. intake in improving depressive mood and well-being and its link to kynurenine blood level: an interventional study

OBJECTIVES

Evidence for the contribution of the brain-gut-microbiota axis to the depression pathophysiology is increasing nowadays. Disturbed gut microbiota equilibrium along with bad dietary habits both lead to kynurenine pathway abnormalities contributing to the depression pathophysiology. In this respect, many studies are found but the interventional clinical trials are limited. The present interventional study aims to evaluate the impact of Bifidobacterium spp. supplementation together with improving dietary intake on depressive mood and well-being and their correlation with kynurenine blood level in adult Egyptian healthy volunteers.

METHODS

A number of 98 healthy female volunteers with a mean age of 46.96 ± 1.82 years were selected and enrolled in this study. They were given yogurt enriched with Bifidobacterium spp. daily for eight weeks. Clinical examination as well as questionnaires for the evaluation of psychological well-being and depression were done at base line and after eight weeks of intervention. Fasting blood samples and stool samples were collected from all subjects at baseline and eight weeks after the intervention for the investigation of serum kynurenine concentration, blood hemoglobin, serum transaminases (ALT & AST) serum urea and creatinine as well as fecal Bifidobacterium count.

RESULTS

Data revealed that both depression and well-being showed highly significant improvement combined with significant drop in kynurenine blood level after intervention. Also, a significant rise in fecal Bifidobacterium count and a significant improvement in hemoglobin level and activity of liver enzymes were recorded. After intervention, a significant negative correlation was recorded between depression and fecal Bifidobacterium count as well as between serum kynurenine level, and well-being.

CONCLUSION

Bifidobacterium spp. supplementation combined with improvement in dietary intake resulted in improvement of depressive mood and well-being and reduced kynurenine blood level.

Gut Microbiota and Time-Restricted Feeding/Eating: A Targeted Biomarker and Approach in Precision Nutrition

Each individual has a unique gut microbiota; therefore, the genes in our microbiome outnumber the genes in our genome by about 150 to 1. Perturbation in host nutritional status influences gut microbiome composition and vice versa. The gut microbiome can help in producing vitamins, hormones, and other active metabolites that support the immune system; harvest energy from food; aid in digestion; protect against pathogens; improve gut transit and function; send signals to the brain and other organs; oscillate the circadian rhythm; and coordinate with the host metabolism through multiple cellular pathways. Gut microbiota can be influenced by host genetics, medications, diet, and lifestyle factors from preterm to aging. Aligning with precision nutrition, identifying a personalized microbiome mandates the provision of the right nutrients at the right time to the right patient. Thus, before prescribing a personalized treatment, it is crucial to monitor and count the gut flora as a focused biomarker. Many nutritional approaches that have been developed help in maintaining and restoring an optimal microbiome such as specific diet therapy, nutrition interventions, and customized eating patterns. One of these approaches is time-restricted feeding/eating (TRF/E), a type of intermittent fasting (IF) in which a subject abstains from food intake for a specific time window. Such a dietary modification might alter and restore the gut microbiome for proper alignment of cellular and molecular pathways throughout the lifespan. In this review, we have highlighted that the gut microbiota would be a targeted biomarker and TRF/E would be a targeted approach for restoring the gut-microbiome-associated molecular pathways such as hormonal signaling, the circadian system, metabolic regulators, neural responses, and immune-inflammatory pathways. Consequently, modulation of the gut microbiota through TRF/E could contribute to proper utilization and availability of the nutrients and in this way confer protection against diseases for harnessing personalized nutrition approaches to improve human health.

Alteration of faecal microbiota balance related to long-term deep meditation

Background

Advancements in research have confirmed that gut microbiota can influence health through the microbiota-gut-brain axis. Meditation, as an inner mental exercise, can positively impact the regulation of an individual's physical and mental health. However, few studies have comprehensively investigated faecal microbiota following long-term (several years) deep meditation. Therefore, we propose that long-term meditation may regulate gut microbiota homeostasis and, in turn, affect physical and mental health.

Aims

To investigate the effects of long-term deep meditation on the gut microbiome structure.

Methods

To examine the intestinal flora, 16S rRNA gene sequencing was performed on faecal samples of 56 Tibetan Buddhist monks and neighbouring residents. Based on the sequencing data, linear discriminant analysis effect size (LEfSe) was employed to identify differential intestinal microbial communities between the two groups. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) analysis was used to predict the function of faecal microbiota. In addition, we evaluated biochemical indices in the plasma.

Results

The α-diversity indices of the meditation and control groups differed significantly. At the genus level, Prevotella and Bacteroides were significantly enriched in the meditation group. According to the LEfSe analysis, two beneficial bacterial genera (Megamonas and Faecalibacterium) were significantly enriched in the meditation group. Functional predictive analysis further showed that several pathways-including glycan biosynthesis, metabolism and lipopolysaccharide biosynthesis-were significantly enriched in the meditation group. Moreover, plasma levels of clinical risk factors were significantly decreased in the meditation group, including total cholesterol and apolipoprotein B.

Conclusions

Long-term traditional Tibetan Buddhist meditation may positively impact physical and mental health. We confirmed that the gut microbiota composition differed between the monks and control subjects. The microbiota enriched in monks was associated with a reduced risk of anxiety, depression and cardiovascular disease and could enhance immune function. Overall, these results suggest that meditation plays a positive role in psychosomatic conditions and well-being.

Implications of gut microbiota dysbiosis and fecal metabolite changes in psychologically stressed mice

Introduction

Psychological stress can induce affective disorders. Gut microbiota plays a vital role in emotional function regulation; however, the association between gut microbiota and psychological stress is poorly understood. We investigated effects of psychological stress on the gut microbiome and fecal metabolites and assessed the relationship between affective disorder behavior and altered fecal microbiota.

Methods

A psychological stress model was established in C57BL/6J mice using a communication box. Sucrose preference test, forced swim test, and open field test helped assess anxiety- and depression-like behaviors. Fecal microbiota transplantation (FMT) was conducted using fecal samples from stressed and non-stressed mice. Moreover, 16S rRNA gene sequencing and untargeted metabolomics were performed.

Results

After stress exposure for 14 days, a significant increase in anxiety- and depression-like behaviors was observed. FMT of "affective disorder microbiota" from psychologically stressed mice increased stress sensitivity relative to FMT of "normal microbiota" from non-stressed mice. 16S rRNA gene sequencing revealed decreased abundance of Bacteroides, Alistipes, and Lactobacillus and increased abundance of Parasutterella and Rikenellaceae_RC9_gut_group in stressed mice; furthermore, stressed mice showed differential metabolite profiles. KEGG pathway analysis indicated that differential metabolites were chiefly involved in the downregulated pathways of α-linolenic acid metabolism, taste transduction, and galactose metabolism. Alistipes and Bacteroides were mainly positively correlated and Parasutterella was mainly negatively correlated with diverse metabolites.

Discussion

Our findings suggest that gut microbiome dysbiosis contributes to affective disorder development in response to psychological stress.

Acupuncture May Be a Potential Complementary Therapy for Alzheimer's Disease: A Network Meta-Analysis

With Alzheimer's disease (AD) becoming a worldwide problem, traditional Chinese medicine (TCM), especially acupuncture, stands out as a complementary therapy because of its feature-"treatment based on syndrome differentiation". This systematic review and network meta-analysis (NMA) confirms the complement effect of acupuncture and explores the best combination of therapy for AD based on the total effect and activity of daily living scale (ADL). We searched relevant randomized controlled trials (RCTs) that applied acupuncture for treating AD. 58 studies with 4334 patients were included in accordance with PRISMA guidelines. The results showed that for the total effect, the order of probability for the effect: acupuncture + western medicine > acupuncture + herbal medicine > acupuncture > acupuncture + western medicine + herbal medicine. For the ADL score, the order of probability for the effect: acupuncture + western medicine > acupuncture > acupuncture + western medicine + herbal medicine > acupuncture + herbal medicine. The combination of acupuncture and medicine has a better clinical effect than acupuncture only in a way. Acupuncture + western medicine has an obvious and exact improvement in the curative effect from both total effect and ADL score, but further higher quality studies, which can detail the classification of these interventions, are still needed to verify it.

Deficiency of migration inhibitory factor influences the gut microbiota of C57BL/6 mice infected with Plasmodium berghei ANKA

Cerebral malaria (CM), as one of the most common complications in severe malaria, has threatened millions of individuals’ neurological health and even their lives. Macrophage migration inhibitory factor (MIF), a pleiotropic proinflammatory factor in humans, seems to be a risk factor for death in patients with CM, but its functional mechanism remains unclear. To verify whether affecting the intestinal microbes of the host was one of the mechanisms by which MIF regulates CM, C57BL/6 mice, including WT + PbA, MIF-KO + PbA and their uninfected controls, were sent for 16S rRNA-based sequencing targeting the V4 region of the intestinal microbiota through the Illumina MiSeq platform. The results showed that OTU clustering, alpha and beta diversity in the four groups involved had evident variation. The relative abundance at different taxonomic levels, especially the dominant intestinal flora, was obviously changed. The LEfSe analysis screened out several biomarkers, including significantly reduced Ligilactobacillus (Lactobacillus murinus) in WPbA mice compared to the WT group and Akkermansia (Akkermansia_muciniphila) in KPbA mice compared to the WPbA group. For MIF KO groups, mice infected with PbA or uninfected showed significant enrichment of producers of short-chain fatty acids, including Dubosiella and Faecalibaculum (Faecalibaculum rodentium) in KPbA, and Lachnospiraceae_NK4A136_group and Firmicutes_bacterium_M10-2 in KO. This study not only further proved the gut microbiota changes in C57BL/6 mice caused by PbA infection, but also found that MIF deletion directly affected the changes in the gut microbiota of C57BL/6 mice before and after PbA infection. This finding reveals a potential mechanism by which MIF regulates CM. Combining MIF with potential microbial biomarkers will provide a promising idea to develop combined drugs for improving CM in the future.

Mechanisms Involved in Gut Microbiota Regulation of Skeletal Muscle

Skeletal muscle is one of the largest organs in the body and is essential for maintaining quality of life. Loss of skeletal muscle mass and function can lead to a range of adverse consequences. The gut microbiota can interact with skeletal muscle by regulating a variety of processes that affect host physiology, including inflammatory immunity, protein anabolism, energy, lipids, neuromuscular connectivity, oxidative stress, mitochondrial function, and endocrine and insulin resistance. It is proposed that the gut microbiota plays a role in the direction of skeletal muscle mass and work. Even though the notion of the gut microbiota-muscle axis (gut-muscle axis) has been postulated, its causal link is still unknown. The impact of the gut microbiota on skeletal muscle function and quality is described in detail in this review.

Domestic Environment and Gut Microbiota: Lessons from Pet Dogs

Accumulating data show the involvement of intestinal microbiota in the development and maintenance of numerous diseases. Many environmental factors influence the composition and function of the gut microbiota. An animal model subjected to the same environmental constraints that will allow better characterization of the microbiota–host dialogue is awaited. The domestic dog has physiological, dietary and pathological characteristics similar to those of humans and shares the domestic environment and lifestyle of its owner. This review exposes how the domestication of dogs has brought them closer to humans based on their intrinsic and extrinsic similarities which were discerned through examining and comparing the current knowledge and data on the intestinal microbiota of humans and canines in the context of several spontaneous pathologies, including inflammatory bowel disease, obesity and diabetes mellitus.

Oxytocin and vasopressin in the hippocampus

Oxytocin (OXT) and vasopressin (AVP) are related neuropeptides that exert a wide range of effects on general health, homeostasis, development, reproduction, adaptability, cognition, social and nonsocial behaviors. The two peptides are mainly of hypothalamic origin and execute their peripheral and central physiological roles via OXT and AVP receptors, which are members of the G protein-coupled receptor family. These receptors, largely distributed in the body, are abundantly expressed in the hippocampus, a brain region particularly vulnerable to stress exposure and various lesions. OXT and AVP have important roles in the hippocampus, by modulating important processes like neuronal excitability, network oscillatory activity, synaptic plasticity, and social recognition memory. This chapter includes an overview regarding OXT and AVP structure, synthesis, receptor distribution, and functions, focusing on their relationship with the hippocampus and mechanisms by which they influence hippocampal activity. Brief information regarding hippocampal structure and susceptibility to lesions is also provided. The roles of OXT and AVP in neurodevelopment and adult central nervous system function and disorders are highlighted, discussing their potential use as targeted therapeutic tools in neuropsychiatric diseases.

The Role of MicroRNA and Microbiota in Depression and Anxiety

Depression and anxiety are devastating disorders. Understanding the mechanisms that underlie the development of depression and anxiety can provide new hints on novel treatments and preventive strategies. Here, we summarize the latest findings reporting the novel roles of gut microbiota and microRNAs (miRNAs) in the pathophysiology of depression and anxiety. The crosstalk between gut microbiota and the brain has been reported to contribute to these pathologies. It is currently known that some miRNAs can regulate bacterial growth and gene transcription while also modulate the gut microbiota composition, suggesting the importance of miRNAs in gut and brain health. Treatment and prevention strategies for neuropsychiatric diseases, such as physical exercise, diet, and probiotics, can modulate the gut microbiota composition and miRNAs expressions. Nonetheless, there are critical questions to be addressed to understand further the mechanisms involved in the interaction between the gut microbiota and miRNAs in the brain. This review summarizes the recent findings of the potential roles of microbiota and miRNA on the neuropathology of depression and anxiety, and its potential as treatment strategies.

Evaluation of the Anti-Aging Effects of a Probiotic Combination Isolated From Centenarians in a SAMP8 Mouse Model

Population aging is a prominent global problem in today’s society. However, there are currently no good methods to treat or prevent aging, so anti-aging research has crucial implications. In this research, we screened bacteria from centenarians, and finally selected four probiotics (Lactobacillus fermentum SX-0718, L. casei SX-1107, Bifidobacterium longum SX-1326, and B. animalis SX-0582) to form a probiotic combination. By using the senescence accelerated mouse prone 8 (SAMP8) model, the anti-aging effects of the probiotic combination were evaluated by using behavioural testing, neuroinflammation, intestinal inflammation, and intestinal microbiota. The results showed that probiotic combination improved the impaired spatial memory, motor dysfunction, and decreased exploratory behavior in aging mice. The probiotic combination inhibited Toll-like receptor 4 (TLR4)/nuclear factor kappa B (NFκB)-induced neuroinflammation and up-regulated the expression of Sirt 1 to protect hippocampal neurons. At the same time, the probiotic combination regulated the intestinal microbiota, reduced the relative abundance of Alistipes and Prevotella in SAMP8 mice, inhibited TLR4/NFκB-induced intestinal inflammation, and increased the expression of intestinal permeability related proteins zonula occludens-1 (ZO-1) and Occuldin. The anti-aging effects of the probiotic combination may be through the regulating intestinal microbiota and inhibiting TLR4/NFκB-induced inflammation. This research provides the basis and technical support for the future production and application of the probiotic combination.

Effect of Regular Physical Exercise on Gut Microbiota and Depressive Behaviors in Rats

Objective. The gut microbiota, as the critical mediator of the gut-brain axis, can produce and transport neuroactive substances, thus playing a significant role in the pathogenesis of depression. Although regular physical exercise is an important nondrug antidepressant, its specific effector mechanism is still unclear. Methods. Rats were randomly divided into four different groups (n = 10 for each group) as follows: normal group (G1), depression group (G2), fluoxetine treatment group (G3), and regular exercise treatment group (G4). All rats underwent forced swimming tests, tail suspension tests, open field tests, and elevated plus-maze tests to detect behavioristics. Then, corticosterone levels were detected by ELISA. Additionally, taxonomic analysis of the gut microbiota in all rats was performed after they were exercised regularly for 60 days. Results. Compared with the G1 group, the rats in the G2 group showed significant depression-like behaviors, with increased serum corticosterone levels. The proportions of Bacteroides, Actinomycetes, Proteobacteria, Saccharomyces, and Cyanobacteria in rats of the G2 group were lower than those in the G1 group, while the proportions of Firmicutes, Tenicotte, Deferrobacteria, and Fusobacteria were increased. Furthermore, after regular exercise treatment, the gut microbiota of rats was effectively improved, almost returning to the level of the G1 group, and depressive behavior and corticosterone levels were also restored, which was almost the same as the effect of fluoxetine treatment. Conclusion. Regular physical exercise could alleviate depressive-like behaviors by modulating the species and function of the gut microbiota.

Development and Validation of a Nomogram for the Prediction of Hospital Mortality of Patients With Encephalopathy Caused by Microbial Infection: A Retrospective Cohort Study

Background

Hospital mortality is high for patients with encephalopathy caused by microbial infection. Microbial infections often induce sepsis. The damage to the central nervous system (CNS) is defined as sepsis-associated encephalopathy (SAE). However, the relationship between pathogenic microorganisms and the prognosis of SAE patients is still unclear, especially gut microbiota, and there is no clinical tool to predict hospital mortality for SAE patients. The study aimed to explore the relationship between pathogenic microorganisms and the hospital mortality of SAE patients and develop a nomogram for the prediction of hospital mortality in SAE patients.

Methods

The study is a retrospective cohort study. The lasso regression model was used for data dimension reduction and feature selection. Model of hospital mortality of SAE patients was developed by multivariable Cox regression analysis. Calibration and discrimination were used to assess the performance of the nomogram. Decision curve analysis (DCA) to evaluate the clinical utility of the model.

Results

Unfortunately, the results of our study did not find intestinal infection and microorganisms of the gastrointestinal (such as: Escherichia coli) that are related to the prognosis of SAE. Lasso regression and multivariate Cox regression indicated that factors including respiratory failure, lactate, international normalized ratio (INR), albumin, SpO₂, temperature, and renal replacement therapy were significantly correlated with hospital mortality. The AUC of 0.812 under the nomogram was more than that of the Simplified Acute Physiology Score (0.745), indicating excellent discrimination. DCA demonstrated that using the nomogram or including the prognostic signature score status was better than without the nomogram or using the SAPS II at predicting hospital mortality.

Conclusion

The prognosis of SAE patients has nothing to do with intestinal and microbial infections. We developed a nomogram that predicts hospital mortality in patients with SAE according to clinical data. The nomogram exhibited excellent discrimination and calibration capacity, favoring its clinical utility.

Leaky Gut: Effect of Dietary Fiber and Fats on Microbiome and Intestinal Barrier

Intestinal tract is the boundary that prevents harmful molecules from invading into the mucosal tissue, followed by systemic circulation. Intestinal permeability is an index for intestinal barrier integrity. Intestinal permeability has been shown to increase in various diseases-not only intestinal inflammatory diseases, but also systemic diseases, including diabetes, chronic kidney dysfunction, cancer, and cardiovascular diseases. Chronic increase of intestinal permeability is termed 'leaky gut' which is observed in the patients and animal models of these diseases. This state often correlates with the disease state. In addition, recent studies have revealed that gut microbiota affects intestinal and systemic heath conditions via their metabolite, especially short-chain fatty acids and lipopolysaccharides, which can trigger leaky gut. The etiology of leaky gut is still unknown; however, recent studies have uncovered exogenous factors that can modulate intestinal permeability. Nutrients are closely related to intestinal health and permeability that are actively investigated as a hot topic of scientific research. Here, we will review the effect of nutrients on intestinal permeability and microbiome for a better understanding of leaky gut and a possible mechanism of increase in intestinal permeability.

Mediterranean Diet to Prevent the Development of Colon Diseases: A Meta-Analysis of Gut Microbiota Studies

Gut microbiota dysbiosis is a common feature in colorectal cancer (CRC) and inflammatory bowel diseases (IBD). Adoption of the Mediterranean diet (MD) has been proposed as a therapeutic approach for the prevention of multiple diseases, and one of its mechanisms of action is the modulation of the microbiota. We aimed to determine whether MD can be used as a preventive measure against cancer and inflammation-related diseases of the gut, based on its capacity to modulate the local microbiota. A joint meta-analysis of publicly available 16S data derived from subjects following MD or other diets and from patients with CRC, IBD, or other gut-related diseases was conducted. We observed that the microbiota associated with MD was enriched in bacteria that promote an anti-inflammatory environment but low in taxa with pro-inflammatory properties capable of altering intestinal barrier functions. We found an opposite trend in patients with intestinal diseases, including cancer. Some of these differences were maintained even when MD was compared to healthy controls without a defined diet. Our findings highlight the unique effects of MD on the gut microbiota and suggest that integrating MD principles into a person’s lifestyle may serve as a preventive method against cancer and other gut-related diseases.

Effect of the Intake of a Traditional Mexican Beverage Fermented with Lactic Acid Bacteria on Academic Stress in Medical Students

Dysbiosis of the gut microbiota has been associated with different illnesses and emotional disorders such as stress. Traditional fermented foods that are rich in probiotics suggest modulation of dysbiosis, which protects against stress-induced disorders. The academic stress was evaluated in medical students using the SISCO Inventory of Academic Stress before and after ingestion of an aguamiel-based beverage fermented with Lactobacillus plantarum, Lactobacillus paracasei and Lactobacillus brevis (n = 27) and a control group (n = 18). In addition, microbial phyla in feces were quantified by qPCR. The results showed that the consumption of 100 mL of a beverage fermented with lactic acid bacteria (3 × 10⁸ cfu/mL) for 8 weeks significantly reduced academic stress (p = 0.001), while the control group (placebo intervention) had no significant changes in the perception of academic stress (p = 0.607). Significant change (p = 0.001) was shown in the scores for environmental demands, and physical and psychological factors. Consumption of the fermented beverage significantly increased the phyla Firmicutes and Bacteroidetes but not Gammaproteobacteria. No significant changes were found in the control group, except for a slight increase in the phylum Firmicutes. The intake of this fermented beverage suggest a modulation of gut microbiota and possible reduction in stress-related symptoms in university students, without changing their lifestyle or diet.

Gut microbes in neurocognitive and mental health disorders

INTRODUCTION

As individuals age, the prevalence of neurocognitive and mental health disorders increases. Current biomedical treatments do not completely address the management of these conditions. Despite new pharmacological therapy the challenges of managing these diseases remain.There is increasing evidence that the Gut Microbiome (GM) and microbial dysbiosis contribute to some of the more prevalent mental health and neurocognitive disorders, such as depression, anxiety, obsessive-compulsive disorder (OCD), post-traumatic stress disorder (PTSD), schizophrenia, bipolar disorder (BP), and dementia as well as the behavioural and psychological symptoms of dementia (BPSD) through the microbiota-gut-brain axis. Methodology: Scoping review about the effect of gut microbiota on neurocognitive and mental health disorders.

RESULTS

This scoping review found there is an evolving evidence of the involvement of the gut microbiota in the pathophysiology of neurocognitive and mental health disorders. This manuscript also discusses how the psychotropics used to treat these conditions may have an antimicrobial effect on GM, and the potential for new strategies of management with probiotics and faecal transplantation.

CONCLUSIONS

This understanding can open up the need for a gut related approach in these disorders as well as unlock the door for the role of gut related microbiota management. KEY MESSAGES Challenges of managing mental health conditions remain in spite of new pharmacological therapy. Gut dysbiosis is seen in various mental health conditions. Various psychotropic medications can have an influence on the gut microbiota by their antimicrobial effect.

Bifidobacteria-Fermented Red Ginseng and Its Constituents Ginsenoside Rd and Protopanaxatriol Alleviate Anxiety/Depression in Mice by the Amelioration of Gut Dysbiosis

Gut dysbiosis is closely connected with the outbreak of psychiatric disorders with colitis. Bifidobacteria-fermented red ginseng (fRG) increases the absorption of ginsenoside Rd and protopanxatriol into the blood in volunteers and mice. fRG and Rd alleviates 2,4,6-trinitrobenzenesulfonic acid-induced colitis in mice. Therefore, to understand the gut microbiota-mediated mechanism of fRG against anxiety/depression, we examined the effects of red ginseng (RG), fRG, ginsenoside Rd, and protopanaxatriol on the occurrence of anxiety/depression, colitis, and gut dysbiosis in mice. Mice with anxiety/depression were prepared by being exposed to two stressors, immobilization stress (IS) or Escherichia coli (EC). Treatment with RG and fRG significantly mitigated the stress-induced anxiety/depression-like behaviors in elevated plus maze, light-dark transition, forced swimming (FST), and tail suspension tasks (TST) and reduced corticosterone levels in the blood. Their treatments also suppressed the stress-induced NF-κB activation and NF-κB+/Iba1+ cell population in the hippocampus, while the brain-derived neurotrophic factor (BDNF) expression and BDNF+/NeuN+ cell population were increased. Furthermore, treatment with RG or fRG suppressed the stress-induced colitis: they suppressed myeloperoxidase activity, NF-κB activation, and NF-κB+/CD11c+ cell population in the colon. In particular, fRG suppressed the EC-induced depression-like behaviors in FST and TST and colitis more strongly than RG. fRG treatment also significantly alleviated the EC-induced NF-κB+/Iba1+ cell population and EC-suppressed BDNF+/NeuN+ cell population in the hippocampus more strongly than RG. RG and fRG alleviated EC-induced gut dysbiosis: they increased Bacteroidetes population and decreased Proteobacteria population. Rd and protopanaxatriol also alleviated EC-induced anxiety/depression and colitis. In conclusion, fRG and its constituents Rd and protopanaxatriol mitigated anxiety/depression and colitis by regulating NF-κB-mediated BDNF expression and gut dysbiosis.

Signature of Gut Microbiome by Conventional and Advanced Analysis Techniques: Advantages and Disadvantages

Gut microbiota is considered as a human organ with its own specific functions and complexity. Development of novel techniques such as shut gun sequencing, metagenomics, and next-generation sequencing (NGS) has enabled bypassing the traditional culturedependent bias and has significantly expanded our understanding of the composition, diversity, and roles of the gut microbiota in human health and diseases. Although amplicon sequencing characterizes the taxonomic composition of the gut microbiome, it is impossible to cover the direct evidence of the microbial biological functions related to the gut microbial community. Hence, the critical next step for gut microbiome studies is shifting from gene/ genome-centric analysis to mechanism-centric techniques by integrating omics data with experimental results. Realizing gut microbial diversity and their bioactive metabolites function will provide insight into the clinical application of gut microbiota in diagnoses and treatments of several diseases. In this review, we focused on explaining the conventional and advanced microbiome analysis techniques regarding gut microbiota investigation with considering the advantages and disadvantages of the platforms.

A Systematic Review of the Microbiome in Children With Neurodevelopmental Disorders

Background and Purpose: A relationship between gut microbiome and central nervous system (CNS), have been suggested. The human microbiome may have an influence on brain's development, thus implying that dysbiosis may contribute in the etiology and progression of some neurological/neuropsychiatric disorders. The objective of this systematic review was to identify evidence on the characterization and potential distinctive traits of the microbiome of children with neurodevelopmental disorders, as compared to healthy children. Methods: The review was performed following the methodology described in the Cochrane handbook for systematic reviews, and was reported based on the PRISMA statement for reporting systematic reviews and meta-analyses. All literature published up to April 2019 was retrieved searching the databases PubMed, ISI Web of Science and the Cochrane Database of Systematic Reviews. Only observational studies, published in English and reporting data on the characterization of the microbiome in humans aged 0-18 years with a neurodevelopmental disorder were included. Neurodevelopmental disorders were categorized according to the definition included in the Diagnostic and Statistical Manual of Mental Disorders, version 5 (DSM-5). Results: Bibliographic searches yielded 9,237 records. One study was identified through other data sources. A total of 16 studies were selected based on their relevance and pertinence to the topic of the review, and were then applied the predefined inclusion and exclusion criteria. A total of 10 case-control studies met the inclusion criteria, and were thus included in the qualitative analysis and applied the NOS score. Two studies reported data on the gut microbiome of children with ADHD, while 8 reported data on either the gut (n = 6) or the oral microbiome (n = 2) of children with ASD. Conclusions: All the 10 studies included in this review showed a high heterogeneity in terms of sample size, gender, clinical issues, and type of controls. This high heterogeneity, along with the small sample size of the included studies, strongly limited the external validity of results. The quality assessment performed using the NOS score showed an overall low to moderate methodological quality of the included studies. To better clarify the potential role of microbiome in patients with neurodevelopmental disorders, further high-quality observational (specifically cohort) studies are needed.

Astrogliosis Associated With Behavioral Abnormality in a Non-anaphylactic Mouse Model of Cow's Milk Allergy

Etiology of neuropsychiatric disorders is complex, involving multiple factors that can affect the type and severity of symptoms. Although precise causes are far from being identified, allergy or other forms of hypersensitivity to dietary ingredients have been implicated in triggering or worsening of behavioral and emotional symptoms, especially in patients suffering from depression, anxiety, attention-deficit hyperactivity, and/or autism. Among such ingredients, cow's milk, along with wheat gluten, is commonly suspected. However, the contributory role of cow's milk in these disorders has not been elucidated due to insufficient pathophysiological evidence. In the present study, we therefore investigated neuroinflammatory changes that are associated with behavioral abnormality using a non-anaphylactic mouse model of cow's milk allergy (CMA). Male and female C57BL/6J mice were subjected to a 5-week oral sensitization procedure without or with a major milk allergen, beta-lactoglobulin (BLG). All mice were then later challenged with BLG, and their anxiety- and depression-associated behaviors were subsequently assessed during the 6th and 7th weeks. We found that BLG-sensitized male mice exhibited significantly increased anxiety- and depression-like behavior, although they did not display anaphylactic reactions when challenged with BLG. Female behavior was not noticeably affected by BLG sensitization. Upon examination of the small intestines, reduced immunoreactivity to occludin was detected in the ileal mucosa of BLG-sensitized mice although the transcriptional expression of this tight-junction protein was not significantly altered when measured by quantitative RT-PCR. On the other hand, the expression of tumor necrosis factor alpha (TNFα) in the ileal mucosa was significantly elevated in BLG-sensitized mice, suggesting the sensitization had resulted in intestinal inflammation. Inflammatory responses were also detected in the brain of BLG-sensitized mice, determined by the hypertrophic morphology of GFAP-immunoreactive astrocytes. These reactive astrocytes were particularly evident near the blood vessels in the midbrain region, resembling the perivascular barrier previously reported by others in experimental autoimmune encephalitis (EAE) mouse models. Interestingly, increased levels of COX-2 and TNFα were also found in this region. Taken together, our results demonstrated that BLG sensitization elicits inflammatory responses in the intestine and brain without overt anaphylactic signs of milk allergy, signifying food allergy as a potential pathogenic factor of neuropsychiatric disorders.

Precision Nutrition and the Microbiome, Part I: Current State of the Science

The gut microbiota is a highly complex community which evolves and adapts to its host over a lifetime. It has been described as a virtual organ owing to the myriad of functions it performs, including the production of bioactive metabolites, regulation of immunity, energy homeostasis and protection against pathogens. These activities are dependent on the quantity and quality of the microbiota alongside its metabolic potential, which are dictated by a number of factors, including diet and host genetics. In this regard, the gut microbiome is malleable and varies significantly from host to host. These two features render the gut microbiome a candidate ‘organ’ for the possibility of precision microbiomics—the use of the gut microbiome as a biomarker to predict responsiveness to specific dietary constituents to generate precision diets and interventions for optimal health. With this in mind, this two-part review investigates the current state of the science in terms of the influence of diet and specific dietary components on the gut microbiota and subsequent consequences for health status, along with opportunities to modulate the microbiota for improved health and the potential of the microbiome as a biomarker to predict responsiveness to dietary components. In particular, in Part I, we examine the development of the microbiota from birth and its role in health. We investigate the consequences of poor-quality diet in relation to infection and inflammation and discuss diet-derived microbial metabolites which negatively impact health. We look at the role of diet in shaping the microbiome and the influence of specific dietary components, namely protein, fat and carbohydrates, on gut microbiota composition.

Microbiome-The Missing Link in the Gut-Brain Axis: Focus on Its Role in Gastrointestinal and Mental Health

The central nervous system (CNS) and the human gastrointestinal (GI) tract communicate through the gut-brain axis (GBA). Such communication is bi-directional and involves neuronal, endocrine, and immunological mechanisms. There is mounting data that gut microbiota is the source of a number of neuroactive and immunocompetent substances, which shape the structure and function of brain regions involved in the control of emotions, cognition, and physical activity. Most GI diseases are associated with altered transmission within the GBA that are influenced by both genetic and environmental factors. Current treatment protocols for GI and non-GI disorders may positively or adversely affect the composition of intestinal microbiota with a diverse impact on therapeutic outcome(s). Alterations of gut microbiota have been associated with mood and depressive disorders. Moreover, mental health is frequently affected in GI and non-GI diseases. Deregulation of the GBA may constitute a grip point for the development of diagnostic tools and personalized microbiota-based therapy. For example, next generation sequencing (NGS) offers detailed analysis of microbiome footprints in patients with mental and GI disorders. Elucidating the role of stem cell⁻host microbiome cross talks in tissues in GBA disorders might lead to the development of next generation diagnostics and therapeutics. Psychobiotics are a new class of beneficial bacteria with documented efficacy for the treatment of GBA disorders. Novel therapies interfering with small molecules involved in adult stem cell trafficking are on the horizon.

Ginsenosides, catechins, quercetin and gut microbiota: Current evidence of challenging interactions

Recent studies have shown the role of gut microbiota in favoring the absorption of herbal products and the transformation of their active principles into metabolites endowed with biological activity. This review focuses on the evidence supporting the changes occurring, after metabolic reactions by specific bacteria that colonize the human gut, to ginseng-derived ginsenosides, green tea-derived catechins, and quercetin, this latter being a flavonoid aglycon bound to sugars and abundant in some vegetables and roots. Furthermore, the results of several studies demonstrating the potential beneficial effects of the active metabolites generated by these biotransformations on ginsenosides, catechins and quercetin will be reported.