Comorbidity between depression and inflammatory bowel disease explained by immune-inflammatory, oxidative, and nitrosative stress; tryptophan catabolite; and gut-brain pathways

Predictors of irritable bowel syndrome-like symptoms in quiescent inflammatory bowel disease

BACKGROUND

Many patients with quiescent inflammatory bowel disease (IBD) suffer from irritable bowel syndrome (IBS)-like symptoms. Although these symptoms cause significant reductions in quality of life, evidence-based treatments are lacking as risk factors and pathophysiology of these symptoms are not clearly defined. We aimed to identify risk factors for development of IBS-like symptoms in IBD patients with quiescent disease.

METHODS

We performed a single-center retrospective cohort study of adults with IBD from 2015 to 2021. Quiescent IBD was defined by a fecal calprotectin level <250 μg/g of stool or endoscopic evidence of quiescent disease. Cox regression was performed to identify variables that were independently associated with the incident development of IBS-like symptoms in IBD patients.

KEY RESULTS

A total of 368 IBD patients were included for analysis, including 278 patients with UC and 88 with Crohn's disease. 15.5% of quiescent IBD patients developed IBS symptoms, with an incidence rate of (95% CI 48.0-82.0) 63.3 per 1000 person-years. In the multivariate model, mood disorders (including anxiety and depression) and Crohn's disease were associated with increased risk for developing IBS symptoms. Male sex and higher iron levels conferred lower risk for developing IBS symptoms. Results from the multivariable model were similar in sensitivity analysis with quiescent IBD defined by fecal calprotectin level <150 mcg/g.

CONCLUSIONS & INFERENCES

Mood disorder and Crohn's disease were positively associated with IBS-like symptoms in quiescent IBD, whereas male sex and iron levels were protective. Our results were robust to different fecal calprotectin levels, arguing against inflammation as a mechanism for IBS-like symptoms. This data suggests noninflammatory mechanisms may be important in the pathogenesis of IBS-like symptoms in quiescent IBD. Future work may address whether modifying these risk factors may alter disease course.

Anti-inflammatory and protective effects of Aripiprazole on TNBS-Induced colitis and associated depression in rats: Role of kynurenine pathway

BACKGROUND

The prevalence of depression is higher in patients with inflammatory bowel disease (IBD) than in the general population. Inflammatory cytokines and the kynurenine pathway (KP) play important roles in IBD and associated depression. Aripiprazole (ARP), an atypical antipsychotic, shows various anti-inflammatory properties and may be useful in treating major depressive disorder. This study aimed to evaluate the protective effects of ARP on TNBS-induced colitis and subsequent depression in rats, highlighting the role of the KP.

MATERIAL AND METHODS

Fifty-six male Wistar rats were used, and all groups except for the normal and sham groups received a single dose of intra-rectal TNBS. Three different doses of ARP and dexamethasone were injected intraperitoneally for two weeks in treatment groups. On the 15th day, behavioral tests were performed to evaluate depressive-like behaviors. Colon ulcer index and histological changes were assessed. The tissue levels of inflammatory cytokines, KP markers, lipopolysaccharide (LPS), nuclear factor-kappa-B (NF-κB), and zonula occludens (ZO-1) were evaluated in the colon and hippocampus.

RESULTS

TNBS effectively induced intestinal damages and subsequent depressive-like symptoms in rats. TNBS treatment significantly elevated the intestinal content of inflammatory cytokines and NF-κB expression, dysregulated the KP markers balance in both colon and hippocampus tissues, and increased the serum levels of LPS. However, treatment with ARP for 14 days successfully reversed these alterations, particularly at higher doses.

CONCLUSION

ARP could alleviate IBD-induced colon damage and associated depressive-like behaviors mainly via suppressing inflammatory cytokines activity, serum LPS concentration, and affecting the NF-κB/kynurenine pathway.

Unraveling the Role of the Blood-Brain Barrier in the Pathophysiology of Depression: Recent Advances and Future Perspectives

Depression is a highly prevalent psychological disorder characterized by persistent dysphoria, psychomotor retardation, insomnia, anhedonia, suicidal ideation, and a remarkable decrease in overall well-being. Despite the prevalence of accessible antidepressant therapies, many individuals do not achieve substantial improvement. Understanding the multifactorial pathophysiology and the heterogeneous nature of the disorder could lead the way toward better outcomes. Recent findings have elucidated the substantial impact of compromised blood-brain barrier (BBB) integrity on the manifestation of depression. BBB functions as an indispensable defense mechanism, tightly overseeing the transport of molecules from the periphery to preserve the integrity of the brain parenchyma. The dysfunction of the BBB has been implicated in a multitude of neurological disorders, and its disruption and consequent brain alterations could potentially serve as important factors in the pathogenesis and progression of depression. In this review, we extensively examine the pathophysiological relevance of the BBB and delve into the specific modifications of its components that underlie the complexities of depression. A particular focus has been placed on examining the effects of peripheral inflammation on the BBB in depression and elucidating the intricate interactions between the gut, BBB, and brain. Furthermore, this review encompasses significant updates on the assessment of BBB integrity and permeability, providing a comprehensive overview of the topic. Finally, we outline the therapeutic relevance and strategies based on BBB in depression, including COVID-19-associated BBB disruption and neuropsychiatric implications. Understanding the comprehensive pathogenic cascade of depression is crucial for shaping the trajectory of future research endeavors.

The Interaction between Stress and Inflammatory Bowel Disease in Pediatric and Adult Patients

Background: Inflammatory bowel diseases (IBDs) have seen an exponential increase in incidence, particularly among pediatric patients. Psychological stress is a significant risk factor influencing the disease course. This review assesses the interaction between stress and disease progression, focusing on articles that quantified inflammatory markers in IBD patients exposed to varying degrees of psychological stress. Methods: A systematic narrative literature review was conducted, focusing on the interaction between IBD and stress among adult and pediatric patients, as well as animal subjects. The research involved searching PubMed, Scopus, Medline, and Cochrane Library databases from 2000 to December 2023. Results: The interplay between the intestinal immunity response, the nervous system, and psychological disorders, known as the gut-brain axis, plays a major role in IBD pathophysiology. Various types of stressors alter gut mucosal integrity through different pathways, increasing gut mucosa permeability and promoting bacterial translocation. A denser microbial load in the gut wall emphasizes cytokine production, worsening the disease course. The risk of developing depression and anxiety is higher in IBD patients compared with the general population, and stress is a significant trigger for inducing acute flares of the disease. Conclusions: Further large studies should be conducted to assess the relationship between stressors, psychological disorders, and their impact on the course of IBD. Clinicians involved in the medical care of IBD patients should aim to implement stress reduction practices in addition to pharmacological therapies.

Do interventions for mood improve inflammatory biomarkers in inflammatory bowel disease?: a systematic review and meta-analysis

BACKGROUND

Psychoneuroimmunological mechanisms and the gut-brain axis appear relevant to disease activity and progression in Inflammatory Bowel Disease (IBD). A recent review showed no effect of psychological therapies on self-reported disease activity in IBD. This meta-analysis aims to establish whether interventions targeting mood outcomes (e.g., depression, anxiety and stress) impact inflammation levels in IBD and possible moderators of these effects.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed. We searched five electronic databases and included randomised controlled trials where interventions targeted mood and assessed inflammatory outcomes pre- and post-intervention in adults with IBD. Independent reviewers screened studies, extracted data, and assessed methodological quality. Data were pooled to estimate standardised mean differences (SMDs) with 95% Confidence Intervals (CIs). A random-effects robust variance estimation accounted for studies measuring multiple biomarkers. Intervention type, mood as a primary or secondary outcome, effect on mood outcomes and IBD subtype were investigated as treatment effect moderators. Where there were sufficient biomarkers, individual meta-analyses were run (Pre-registration PROSPERO: CRD42023389401).

FINDINGS

28 RCTs involving 1789 participants met inclusion criteria. Interventions demonstrated small, statistically significant effects on biomarkers (-0.35, 95% CI: -0.48, -0.22, p < 0.001) and medium effects on mood outcomes (-0.50, 95% CI: -0.73, -0.27, p < 0.001), without evidence of substantive heterogeneity or publication bias. Individual analyses showed small effects for improved faecal calprotectin (-0.19, 95% CI: -0.34, -0.03, p = 0.018) and C-Reactive Protein (-0.29, 95% CI: -0.47, -0.10, p = 0.002). Effect sizes were larger for psychological therapy interventions (compared with exercise or antidepressants) and when there was an effect (SMD ≥0.2) on mood.

INTERPRETATION

Treatments which address mood outcomes have beneficial effects on generic inflammation as well as disease-specific biomarkers (faecal calprotectin and C-Reactive Protein). Psychological interventions and interventions with larger treatment effects on mood accentuated the effect on biomarkers. More research is required to understand the biological or behavioural mechanisms underlying this effect.

FUNDING

The Medical Research Council and the National Institute for Health and Care Research (NIHR) Maudsley Biomedical Research Centre.

Position statement of the Spanish Working Group on Crohn's Disease and Ulcerative Colitis on sexuality and inflammatory bowel disease

It is widely acknowledged that inflammatory bowel disease (IBD) is associated with a high prevalence of sexual dysfunction (SD). However, there is a notable paucity of specific literature in this field. This lack of information impacts various aspects, including the understanding and comprehensive care of SD in the context of IBD. Furthermore, patients themselves express a lack of necessary attention in this area within the treatment of their disease, thus creating an unmet need in terms of their well-being. The aim of this position statement by the Spanish Working Group on Crohn's Disease and Ulcerative Colitis (GETECCU) is to provide a review on the most relevant aspects and potential areas of improvement in the detection, assessment, and management of SD in patients with IBD and to integrate the approach to sexual health into our clinical practice. Recommendations are established based on available scientific evidence and expert opinion. The development of these recommendations by GETECCU has been carried out through a collaborative multidisciplinary approach involving gastroenterologists, gynecologists, urologists, surgeons, nurses, psychologists, sexologists, and, of course, patients with IBD.

Association between metabolites in tryptophan-kynurenine pathway and inflammatory bowel disease: a two-sample Mendelian randomization

Previous observational studies have suggested an association between tryptophan (TRP)-kynurenine (KYN) pathway and inflammatory bowel disease (IBD). However, whether there is a causal relationship among them remains unclear. Therefore, a two-sample Mendelian randomization (MR) study was conducted to explore the potential causal effects of crucial metabolites in TRP-KYN pathway on IBD and its subtypes. Using summary data from genome-wide association studies, a two-sample MR was employed to evaluate the genetic associations between TRP and KYN as exposures and IBD as an outcome. The inverse variance weighted method was used as the primary MR analysis, with MR-Egger, weighted mode, simple mode, and weighted median methods as complementary analyses. The odds ratios (OR) and 95% confidence intervals (CI) were determined for TRP-IBD (OR 0.739, 95% CI [0.697; 0.783]), TRP-UC (OR 0.875, 95% CI [0.814; 0.942]), TRP-CD (OR 0.685, 95% CI [0.613; 0.765]), KYN-IBD (OR 4.406, 95% CI [2.247; 8.641]), KYN-UC (OR 2.578, 95% CI [1.368; 4.858], and KYN-CD (OR 13.516, 95% CI [4.919; 37.134]). Collectively, the MR analysis demonstrated a significant protective association between TRP and IBD, whereas KYN was identified as a risk factor for IBD.

Integrated bioinformatics and network pharmacology identifying the mechanisms and molecular targets of Guipi Decoction for treatment of comorbidity with depression and gastrointestinal disorders

BACKGROUND

Guipi decoction (GPD) not only improves gastrointestinal (GI) function, but also depressive mood. The bioinformatics study aimed to reveal potential crosstalk genes and related pathways between depression and GI disorders. A network pharmacology approach was used to explore the molecular mechanisms and potential targets of GPD for the simultaneous treatment of depression comorbid GI disorders.

METHODS

Differentially expressed genes (DEGs) of major depressive disorder (MDD) were identified based on GSE98793 and GSE19738, and GI disorders-related genes were screened from the GeneCards database. Overlapping genes between MDD and GI disorders were obtained to identify potential crosstalk genes. Protein-protein interaction (PPI) network was constructed to screen for hub genes, signature genes were identified by LASSO regression analysis, and single sample gene set enrichment analysis (ssGSEA) was performed to analyze immune cell infiltration. In addition, based on the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database, we screened the active ingredients and targets of GPD and identified the intersection targets of GPD with MDD and GI disorder-related genes, respectively. A "component-target" network was constructed using Cytoscape, the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed.

RESULTS

The MDD-corrected dataset contained 2619 DEGs, and a total of 109 crosstalk genes were obtained. 14 hub genes were screened, namely SOX2, CRP, ACE, LEP, SHH, CDH2, CD34, TNF, EGF, BDNF, FN1, IL10, PPARG, and KIT. These genes were identified by LASSO regression analysis for 3 signature genes, including TNF, EGF, and IL10. Gamma.delta.T.cell was significantly positively correlated with all three signature genes, while Central.memory.CD4.T.cell and Central.memory.CD8.T.cell were significantly negatively correlated with EGF and TNF. GPD contained 134 active ingredients and 248 targets, with 41 and 87 relevant targets for the treatment of depression and GI disorders, respectively. EGF, PPARG, IL10 and CRP overlap with the hub genes of the disease.

CONCLUSION

We found that GPD may regulate inflammatory and oxidative stress responses through EGF, PPARG, IL10 and CRP targets, and then be involved in the treatment of both depression and GI disorders.

Regulation of colonic neuropeptide Y expression by the gut microbiome in patients with ulcerative colitis and its association with anxiety- and depression-like behavior in mice

Patients with inflammatory bowel disease (IBD), including ulcerative colitis (UC), show an increased incidence of anxiety and depression; however, the association between UC-associated psychiatric disorders and the gut microbiota is unclear. This study aimed to examine whether gut microbiota from patients with UC can alter colonic gene expression, leading to anxiety- and depression-like behavior in mice receiving fecal microbiota transplantation (FMT). RNA sequencing transcriptome analyses revealed a difference in colonic gene expression between mice receiving FMT from patients with UC (UC-FMT mice) and those receiving FMT from healthy controls (HC-FMT mice). Gene ontology analysis revealed the downregulation of neuropeptide signaling pathways, including neuropeptide Y (NPY) expression, in the colons of UC-FMT mice. The protein levels of NPY also decreased in the colon and plasma of UC-FMT mice compared to those in HC-FMT mice. The oral administration of Enterococcus mundtii (EM), a bacterium isolated from the feces of patients with UC, reduced NPY expression in the colons of mice and induced intestinal inflammation, anxiety, and depression-like behavior. Reduced NPY protein levels were also observed in the plasma and hippocampus of EM-treated mice. Intraperitoneal administration of NPY significantly alleviated anxiety- and depressive-like behaviors induced by EM in mice. Capsular polysaccharide in EM was associated with EM-induced NPY downregulation in the colon. Analysis of Gene Expression Omnibus datasets showed markedly reduced NPY expression in the inflamed colons of patients with UC compared with that in the colons of healthy controls. In summary, EM-induced reduction in the colonic expression of NPY may be associated with a decrease in hippocampal NPY and anxiety- and depression-like behavior in mice.

Dietary Inflammatory Potential, Inflammation-Related Lifestyle Factors, and Incident Anxiety Disorders: A Prospective Cohort Study

It is unclear whether diet-associated inflammation is related to the development of anxiety disorders. We aimed to investigate the association between energy-adjusted dietary inflammatory index (E-DII) scores and the incidence of anxiety disorders, and explore the joint effects of E-DII scores with other inflammatory lifestyles in enhancing anxiety risk. In the UK Biobank Study of 96,679 participants, baseline E-DII scores were calculated from the average intake of at least two 24 h dietary recalls. Multivariable-adjusted Cox models were used to evaluate the associations between E-DII scores and the incidence of total anxiety disorders, and primary types and subtypes; additive and multiplicative interactions of a pro-inflammatory diet and seven inflammatory lifestyles were examined. After a median follow-up of 9.4 years, 2785 incident cases of anxiety disorders occurred. Consuming a pro-inflammatory diet was significantly associated with a higher risk of total anxiety disorders (HRQ4vsQ1 = 1.12, 95% CI = 1.00-1.25), and positive associations were consistently identified for primary types and subtypes of anxiety disorders, with HRs ranging from 1.08 to 1.52, and were present in women only. Both additive and multiplicative interactions of current smoking and a proinflammatory diet on total anxiety risk were identified. A proinflammatory diet was associated with a higher incidence of anxiety disorders, and current smoking may synergize with a proinflammatory diet to promote anxiety risk, particularly among women.

Exploring the potential function of trace elements in human health: a therapeutic perspective

A trace element, known as a minor element, is a chemical element whose concentration is very low. They are divided into essential and non-essential classes. Numerous physiological and metabolic processes in both plants and animals require essential trace elements. These essential trace elements are so directly related to the metabolic and physiologic processes of the organism that either their excess or deficiency can result in severe bodily malfunction or, in the worst situations, death. Elements can be found in nature in various forms and are essential for the body to carry out its varied functions. Trace elements are crucial for biological, chemical, and molecular cell activity. Nutritional deficits can lead to weakened immunity, increased susceptibility to oral and systemic infections, delayed physical and mental development, and lower productivity. Trace element enzymes are involved in many biological and chemical processes. These compounds act as co-factors for a number of enzymes and serve as centers for stabilizing the structures of proteins and enzymes, allowing them to mediate crucial biological processes. Some trace elements control vital biological processes by attaching to molecules on the cell membrane's receptor site or altering the structure of the membrane to prevent specific molecules from entering the cell. Some trace elements are engaged in redox reactions. Trace elements have two purposes. They are required for the regular stability of cellular structures, but when lacking, they might activate alternate routes and induce disorders. Therefore, thoroughly understanding these trace elements is essential for maintaining optimal health and preventing disease.

Polygalae Radix Oligosaccharide Esters May Relieve Depressive-like Behavior in Rats with Chronic Unpredictable Mild Stress via Modulation of Gut Microbiota

Polygalae radix (PR) is a well-known traditional Chinese medicine that is used to treat depression, and polygalae radix oligosaccharide esters (PROEs) are the main active ingredient. Although gut microbiota are now believed to play key role in depression, the effects of PROEs on depression via modulation of gut microbiota remain unknown. In this article, we investigate the effect of PROEs on the gut microbiota of a depression rat and the possible mechanism responsible. The depression rat model was induced by solitary rearing combined with chronic unpredictable mild stress (CUMS). The depression-like behavior, the influence on the hypothalamic-pituitary-adrenal (HPA) axis, the contents of monoamine neurotransmitter in the hippocampus, and the quantity of short-chain fatty acids (SCFAs) in the feces were each assessed, and the serum levels of lipopolysaccharide (LPS) and interleukin-6 (IL-6) were measured by ELISA. Additionally, ultrastructural changes of the duodenal and colonic epithelium were observed under transmission electron microscope, and the gut microbiota were profiled by using 16S rRNA sequencing. The results show that PROEs alleviated the depression-like behavior of the depression model rats, increased the level of monoamine neurotransmitters in the brain, and reduced the hyperfunction of the HPA axis. Furthermore, PROEs regulated the imbalance of the gut microbiota in the rats, relieving intestinal mucosal damage by increasing the relative abundance of gut microbiota with intestinal barrier protective functions, and adjusting the level of SCFAs in the feces, as well as the serum levels of LPS and IL-6. Thus, we find that PROEs had an antidepressant effect through the restructuring of gut microbiota that restored the function of the intestinal barrier, reduced the release of intestinal endotoxin, and constrained the inflammatory response.

The Intertwining Roads between Psychological Distress and Gut Microbiota in Inflammatory Bowel Disease

Inflammatory bowel disease represents one of the most life-altering gastrointestinal pathologies, with its multifactorial nature and unclear physiopathology. The most relevant clinical forms, ulcerative colitis and Crohn's disease, clinically manifest with mild to severe flares and remission periods that alter the patient's social, familial and professional integration. The chronic inflammatory activity of the intestinal wall determines severe modifications of the local environment, such as dysbiosis, enteric endocrine, nervous and immune system disruptions and intestinal wall permeability changes. These features are part of the gastrointestinal ecosystem that modulates the bottom-to-top signaling to the central nervous system, leading to a neurobiologic imbalance and clinical affective and/or behavioral symptoms. The gut-brain link is a bidirectional pathway and psychological distress can also affect the central nervous system, which will alter the top-to-bottom regulation, leading to possible functional digestive symptoms and local inflammatory responses. In the middle of this neuro-gastrointestinal system, the microbiome is a key player, as its activities offer basic functional support for both relays. The present article presents current scientific information that links the pathophysiology and clinical aspects of inflammatory bowel disease and psychiatric symptomatology through the complex mechanism of the gut-brain axis and the modulatory effects of the gut microbiota.

Protocol for a Single-Arm Feasibility Study of Photobiomodulation for Fatigue, Depression, and Pain in Inflammatory Bowel Disease

BACKGROUND

There are limited treatment options for mental health comorbidities associated with Inflammatory Bowel Disease (IBD), although they have been shown to negatively affect the course of IBD and multiple important areas of functioning. Photobiomodulation (PBM) is a new therapeutic intervention using laser-generated low-powered light therapy that has shown early promise in alleviating fatigue, depression, and pain in chronic illness.

METHODS

This prospective, single-arm pilot study aims to assess the feasibility and efficacy of PBM in the treatment of fatigue, depression, and pain in youth with IBD. We will recruit 28 young adults with IBD who will receive PBM in addition to treatment as usual. The primary outcome will be fatigue, while secondary outcomes will include depression, pain, quality of life, inflammatory markers, alterations in microbiome composition, physical activity, and functioning. Outcome measures will be assessed at baseline, after a 10-week control period (pre-PBM), at 20 weeks (post-PBM), and at 30 weeks. Feasibility will be assessed by attendance, recruitment rates, and participants' views of PBM. Mixed-effects linear regression modelling will be used to assess the PBM effect on continuous outcomes (fatigue, depression, anxiety and stress scores, and inflammation levels).

RESULTS

The study will provide preliminary indicators of PBM feasibility and efficacy in IBD.

Astrocyte-derived extracellular vesicles in stress-associated mood disorders. Does the immune system get astrocytic?

Life stressors can wreak havoc on our health, contributing to mood disorders like major depressive disorder (MDD), a widespread and debilitating condition. Unfortunately, current treatments and diagnostic strategies fall short of addressing these disorders, highlighting the need for new approaches. In this regard, the relationship between MDD, brain inflammation (neuroinflammation), and systemic inflammation in the body may offer novel insights. Recent research has uncovered the crucial role of astrocytes in coordinating the inflammatory response through the release of extracellular vesicles (ADEVs) during different neuroinflammatory conditions. While the contribution of ADEVs to stress and MDD remains largely unexplored, their potential to modulate immune cells and contribute to MDD pathogenesis is significant. In this article, we delve into the immunomodulatory role of ADEVs, their potential impact on peripheral immune cells, and how their microRNA (miRNA) landscape may hold the key to controlling immune cell activity. Together, these mechanisms may constitute an opportunity to develop novel therapeutic pharmacological approaches to tackle mood disorders.

A Holistic Perspective on How Photobiomodulation May Influence Fatigue, Pain, and Depression in Inflammatory Bowel Disease: Beyond Molecular Mechanisms

BACKGROUND

Numerous mechanisms, mostly molecular, have been tested and proposed for photobiomodulation. Photobiomodulation is finding a niche in the treatment of conditions that have no gold-standard treatment or only partially effective pharmacological treatment. Many chronic conditions are characterised by symptoms for which there is no cure or control and for which pharmaceuticals may add to the disease burden through side effects. To add quality to life, alternate methods of symptom management need to be identified.

OBJECTIVE

To demonstrate how photobiomodulation, through its numerous mechanisms, may offer an adjunctive therapy in inflammatory bowel disease. Rather than considering only molecular mechanisms, we take an overarching biopsychosocial approach to propose how existing evidence gleaned from other studies may underpin a treatment strategy of potential benefit to people with Crohn's disease and ulcerative colitis.

MAIN FINDINGS

In this paper, the authors have proposed the perspective that photobiomodulation, through an integrated effect on the neuroimmune and microbiome-gut-brain axis, has the potential to be effective in managing the fatigue, pain, and depressive symptoms of people with inflammatory bowel disease.

Enteric Glia and Brain Astroglia: Complex Communication in Health and Disease along the Gut-Brain Axis

Several studies have provided interesting evidence about the role of the bidirectional communication between the gut and brain in the onset and development of several pathologic conditions, including inflammatory bowel diseases (IBDs), neurodegenerative diseases, and related comorbidities. Indeed, patients with IBD can experience neurologic disorders, including depression and cognitive impairment, besides typical intestinal symptoms. In parallel, patients with neurodegenerative disease, such as Parkinson disease and Alzheimer disease, are often characterized by the occurrence of functional gastrointestinal disorders. In this context, enteric glial cells and brain astrocytes are emerging as pivotal players in the initiation/maintenance of neuroinflammatory responses, which appear to contribute to the alterations of intestinal and neurologic functions observed in patients with IBD and neurodegenerative disorders. The present review was conceived to provide a comprehensive and critical overview of the available knowledge on the morphologic, molecular, and functional changes occurring in the enteric glia and brain astroglia in IBDs and neurologic disorders. In addition, our intent is to identify whether such alterations could represent a common denominator involved in the onset of comorbidities associated with the aforementioned disorders. This might help to identify putative targets useful to develop novel pharmacologic approaches for the therapeutic management of such disturbances.

Gut Microbiota in Anxiety and Depression: Unveiling the Relationships and Management Options

The gut microbiota is critical for maintaining human health and the immunological system. Several neuroscientific studies have shown the significance of microbiota in developing brain systems. The gut microbiota and the brain are interconnected in a bidirectional relationship, as research on the microbiome-gut-brain axis shows. Significant evidence links anxiety and depression disorders to the community of microbes that live in the gastrointestinal system. Modified diet, fish and omega-3 fatty acid intake, macro- and micro-nutrient intake, prebiotics, probiotics, synbiotics, postbiotics, fecal microbiota transplantation, and 5-HTP regulation may all be utilized to alter the gut microbiota as a treatment approach. There are few preclinical and clinical research studies on the effectiveness and reliability of various therapeutic approaches for depression and anxiety. This article highlights relevant research on the association of gut microbiota with depression and anxiety and the different therapeutic possibilities of gut microbiota modification.

Peripheral control of psychiatric disorders: Focus on OCD. Are we there yet?

"We are all in this together" - we often hear this phrase when we want to flag up a problem that is not for a single individual but concerns us all. A similar reflection has been recently made in the field of mental disorders where brain-centric scientists have started to zoom out their brain-focused graphical representations of the mechanisms regulating psychiatric diseases to include other organs or mediators that did not belong historically to the world of neuroscience. The brain itself - that has long been seen as a master in command secluded in its fortress (the blood brain barrier), has now become a collection of Airbnb(s) where all sorts of cells come in and out and sometimes even rearrange the furniture! Under this new framework of reference, mental disorders have become multisystem pathologies where different biological systems - not just the CNS -contribute 'all together' to the development and severity of the disease. In this narrative review article, we will focus on one of the most popular biological systems that has been shown to influence the functioning of the CNS: the immune system. We will specifically highlight the two main features of the immune system and the CNS that we think are important in the context of mental disorders: plasticity and memory.

Intraoperative Low-Dose S-Ketamine Reduces Depressive Symptoms in Patients with Crohn's Disease Undergoing Bowel Resection: A Randomized Controlled Trial

Background: Patients with Crohn's disease (CD) undergoing bowel resection often suffer from depression and acute pain, which severely impairs their recovery. We aimed to investigate the effects of S-ketamine preconditioning on postoperative depression in patients with CD undergoing a bowel resection with mild to moderate depression and to observe whether it can relieve postoperative pain and anti-inflammation. Methods: A total of 124 adult patients were randomized into one of the two groups. Patients in the S-ketamine group received a 0.25 mg/kg S-ketamine intravenous drip under general anesthesia induction, followed by a continuous infusion of S-ketamine with 0.12 mg/kg/h for more than 30 min through target-controlled infusion. Patients in the placebo group received 0.9% saline at an identical volume and rate. The primary outcome measure was the 17-item Hamilton depression Scale (HAMD-17). The secondary outcomes were scores on the following questionnaires: a nine-item patient health questionnaire (PHQ-9); a quality of recovery (QoR-15) form; and a numeric rating scale (NRS). Additional secondary outcomes included the levels of C-reactive protein (CRP) and interleukin 6 (IL-6) on postoperative days (PODs) 1, 3, and 5, the length of hospital stay, and opioid use throughout the hospital stay. Results: The scores of PHQ-9 and HAMD-17 in the S-ketamine group were lower than those in the placebo group on postoperative days (PODs) 1, 2, and 7 (p < 0.05). The scores of QoR-15 in the S-ketamine group were higher than those in the placebo group on postoperative days (PODs) 3 and 5 (p < 0.05). The NRS scores of PACU, postoperative days 1 and 2 in the S-ketamine group were lower than those in the placebo group (p < 0.05). There was no significant difference in the CRP and IL-6 levels on postoperative days (PODs) 1, 3, and 5, postoperative complications, and hospital stay between the two groups (p > 0.05). Conclusions: The trial indicated that the intraoperative administration of low-dose S-ketamine could alleviate mild-to-moderate depressive symptoms and postoperative pain in patients with Crohn's disease undergoing bowel resection without worsening their safety.

Effects of dietary tryptophan on the antioxidant capacity and immune response associated with TOR and TLRs/MyD88/NF-κB signaling pathways in northern snakehead, Channa argus (Cantor, 1842)

Introduction

Dietary tryptophan (Trp) has been shown to influence fish feed intake, growth, immunity and inflammatory responses. The purpose of this study was to investigate the effect and mechanism of Trp on immune system of juvenile northern snakehead (Channa argus Cantor, 1842).

Methods

A total of 540 fish (10.21 ± 0.11 g) were fed six experimental diets containing graded levels of Trp at 1.9, 3.0, 3.9, 4.8, 5.9 and 6.8 g/kg diet for 70 days, respectively.

Results and Discussion

The results showed that supplementation of 1.9-4.8 g/kg Trp in diets had no effect on the hepatosomatic index (HSI) and renal index (RI), while dietary 3.9 and 4.8 g/kg Trp significantly increased spleen index (SI) of fish. Dietary 3.9, 4.8, 5.9 and 6.8 g/kg Trp enhanced the total hemocyte count (THC), the activities of total antioxidant capacity (T-AOC) and superoxide dismutase (SOD). Malondinaldehyde (MDA) levels in the blood were significantly decreased by consuming 3.9 and 4.8 g/kg Trp. Fish fed with 3.0 and 3.9 g/kg Trp diets up-regulated interleukin 6 (il-6) and interleukin 8 (il-8) mRNA levels. The expression of tumor necrosis factor α (tnf-α) was highest in fish fed with 3.0 g/kg Trp diet, and the expression of interleukin 1β (il-1β) was highest in fish fed with 3.9 g/kg Trp diet. Dietary 4.8, 5.9 and 6.8 g/kg Trp significantly decreased il-6 and tnf-α mRNA levels in the intestine. Moreover, Trp supplementation was also beneficial to the mRNA expression of interleukin 22 (il-22). Additionally, the mRNA expression levels of target of rapamycin (tor), toll-like receptor-2 (tlr2), toll-like receptor-4 (tlr4), toll-like receptor-5 (tlr5) and myeloid differentiation primary response 88 (myd88) of intestine were significantly up-regulated in fish fed 1.9, 3.0 and 3.9 g/kg Trp diets, and down-regulated in fish fed 4.8, 5.9 and 6.8 g/kg Trp diets. Dietary 4.8 and 5.9 g/kg Trp significantly increased the expression of inhibitor of nuclear factor kappa B kinase beta subunit (ikkβ) and decreased the expression of inhibitor of kappa B (iκbα), but inhibited nuclear transcription factor kappa B (nf-κb) mRNA level. Collectively, these results indicated that dietary 4.8 g/kg Trp could improve antioxidant capacity and alleviate intestinal inflammation associated with TOR and TLRs/MyD88/NF-κB signaling pathways.

Assessing the effect of interaction between gut microbiome and inflammatory bowel disease on the risks of depression

Background

Gut microbiome and inflammatory bowel disease (IBD) are implicated in the development of depression, but the effect of their interactions on the risk of depression remains unclear. We aim to analyze the effect of interactions between gut microbiome and IBD on the risk of depression, and explore candidate genes involving the interactions.

Methods

Using the individual genotype and depression traits data from the UK Biobank, we calculated the polygenetic risk scores (PRS) of 114 gut microbiome, ulcerative colitis (UC), Crohn's disease (CD), and total IBD (CD + UC) respectively. The effects of interactions between gut microbiome and IBD on depression were assessed through a linear regression model. Moreover, for observed significant interactions between gut microbiome PRS and IBD PRS, PLINK software was used to test pair-wise single nucleotide polymorphisms (SNPs) interaction of corresponding gut microbiome PRS and IBD PRS on depression.

Results

We found 64 candidate interactions between gut microbiome and IBD on four phenotypes of depression, such as F_Lachnospiraceae (RNT) × (CD + UC) for patient health questionnaire-9 (PHQ-9) score (P = 1.48 × 10^-3), F_Veillonellaceae (HB) × UC for self-reported depression (P = 2.83 × 10^-3) and P_Firmicutes (RNT) × CD for age at first episode of depression (P = 8.50 × 10^-3). We observed interactions of gut-microbiome-associated SNPs × IBD-associated SNPs, such as G_Alloprevotella (HB)-associated rs147650986 (GPM6A) × IBD-associated rs114471990 (QRICH1) (P = 2.26 × 10^-4).

Conclusion

Our results support the effects of interactions between gut microbiome and IBD on depression risk, and reported several novel candidate genes for depression.

The Tryptophan Catabolite or Kynurenine Pathway in a Major Depressive Episode with Melancholia, Psychotic Features and Suicidal Behaviors: A Systematic Review and Meta-Analysis

Major depressive disorder (MDD) and bipolar disorder (BD) with melancholia and psychotic features and suicidal behaviors are accompanied by activated immune-inflammatory and oxidative pathways, which may stimulate indoleamine 2,3-dioxygenase (IDO), the first and rate-limiting enzyme of the tryptophan catabolite (TRYCAT) pathway resulting in increased tryptophan degradation and elevated tryptophan catabolites (TRYCTAs). The purpose of the current study is to systematically review and meta-analyze levels of TRP, its competing amino acids (CAAs) and TRYCATs in patients with severe affective disorders. Methods: PubMed, Google Scholar and SciFinder were searched in the present study and we recruited 35 studies to examine 4647 participants including 2332 unipolar (MDD) and bipolar (BD) depressed patients and 2315 healthy controls. Severe patients showed significant lower (p < 0.0001) TRP (standardized mean difference, SMD = −0.517, 95% confidence interval, CI: −0.735; −0.299) and TRP/CAAs (SMD = −0.617, CI: −0.957; −0.277) levels with moderate effect sizes, while no significant difference in CAAs were found. Kynurenine (KYN) levels were unaltered in severe MDD/BD phenotypes, while the KYN/TRP ratio showed a significant increase only in patients with psychotic features (SMD = 0.224, CI: 0.012; 0.436). Quinolinic acid (QA) was significantly increased (SMD = 0.358, CI: 0.015; 0.701) and kynurenic acid (KA) significantly decreased (SMD = −0.260, CI: −0.487; −0.034) in severe MDD/BD. Patients with affective disorders with melancholic and psychotic features and suicidal behaviors showed normal IDO enzyme activity but a lowered availability of plasma/serum TRP to the brain, which is probably due to other processes such as low albumin levels.

Bidirectional brain-gut axis effects influence mood and prognosis in IBD: a systematic review and meta-analysis

OBJECTIVE

The role of the brain-gut axis is of increasing interest in IBD, as the link between common mental disorders and GI inflammation may be bidirectional. We performed a systematic review examining these issues.

DESIGN

We searched EMBASE Classic and EMBASE, Medline, and APA PsychInfo (to 11 July 2021) for longitudinal follow-up studies examining effect of symptoms of anxiety or depression on subsequent adverse outcomes in IBD, or effect of active IBD on subsequent development of symptoms of anxiety or depression. We pooled relative risks (RRs) and HRs with 95% CIs for adverse outcomes (flare, escalation of therapy, hospitalisation, emergency department attendance, surgery or a composite of any of these) according to presence of symptoms of anxiety or depression at baseline, or RRs and HRs with 95% CIs for new onset of symptoms of anxiety or depression according to presence of active IBD at baseline.

RESULTS

We included 12 separate studies, recruiting 9192 patients. All 12 studies examined brain-to-gut effects. Anxiety at baseline was associated with significantly higher risks of escalation of therapy (RR=1.68; 95% CI 1.18 to 2.40), hospitalisation (RR=1.72; 95% CI 1.01 to 2.95), emergency department attendance (RR=1.30; 95% CI 1.21 to 1.39), or a composite of any adverse outcome. Depression at baseline was associated with higher risks of flare (RR=1.60; 95% CI 1.21 to 2.12), escalation of therapy (RR=1.41; 95% CI 1.08 to 1.84), hospitalisation (RR=1.35; 95% CI 1.17 to 1.57), emergency department attendance (RR=1.38; 95% CI 1.22 to 1.56), surgery (RR=1.63; 95% CI 1.19 to 2.22) or a composite of any of these. Three studies examined gut-to-brain effects. Active disease at baseline was associated with future development of anxiety or depression (RR=2.24; 95% CI 1.25 to 4.01 and RR=1.49; 95% CI 1.11 to 1.98, respectively).

CONCLUSION

Bidirectional effects of the brain-gut axis are present in IBD and may influence both the natural history of the disease and psychological health.

Deletion of ghrelin alters tryptophan metabolism and exacerbates experimental ulcerative colitis in aged mice

A major component of aging is chronic, low-grade inflammation, attributable in part by impaired gut barrier function. We previously reported that deletion of ghrelin, a peptidergic hormone released mainly from the gut, exacerbates experimental muscle atrophy in aged mice. In addition, ghrelin has been shown to ameliorate colitis in experimental models of inflammatory bowel disease (IBD), although the role of endogenous ghrelin in host-microbe interactions is less clear. Here, we showed that 22-month-old global ghrelin knockout (Ghrl^-/-) mice exhibited significantly increased depressive-like behaviors, while anxiety levels and working memory were similar to littermate wild-type (WT) mice. Furthermore, old Ghrl^-/- mice showed significantly increased intestinal permeability to fluorescein isothiocyanate (FITC)-dextran, significantly higher colonic interleukin (IL-1β) levels, and trends for higher colonic IL-6 and tumor necrosis factor-α (TNF-α) compared to WT mice. Interestingly, young Ghrl^-/- and WT mice showed comparable depressive-like behavior and gut permeability, suggesting age-dependent exacerbation in gut barrier dysfunction in Ghrl^-/- mice. While fecal short-chain fatty acids levels were comparable between old Ghrl^-/- and WT mice, serum metabolome revealed alterations in metabolic cascades including tryptophan metabolism. Specifically, tryptophan and its microbial derivatives indole-3-acetic acid and indole-3-lactic acid were significantly reduced in old Ghrl^-/-mice. Furthermore, in an experimental model of dextran sulfate sodium (DSS)-induced colitis, Ghrl^-/- mice showed exacerbated disease symptoms, and higher levels of chemoattractant and pro-inflammatory cytokines in the colon. Overall, these data demonstrated that ghrelin deficiency is associated with gut barrier dysfunction, alterations in microbially derived tryptophan metabolites, and increased susceptibility to colitis. These data suggested that endogenous ghrelin contributes to maintaining a healthy host-microbe environment, ultimately impacting on brain function.

Pneumococcal pep27-mutant inhibits Wnt5a expression via the regulation of T helper cells to attenuate colitis

Inflammatory bowel disease (IBD) is a chronic gut inflammatory disease characterized by extensive colitis and remission of the symptoms. The incidence rate and prevalence of IBD are increasing worldwide; IBD affects millions of people, has poorly defined etiology, and often results in a failure of pharmacological interventions. Regardless of the cause, mucosal healing is indispensable for the regeneration of inflamed mucosa to ensure intestinal homeostasis. Intranasal immunization with the pneumococcal pep27 mutant (Δpep27) has been reported as an avirulent and live vaccine that has been proposed to suppress immune-regulated disorders, eliciting long-lasting immunity. The dose-dependent activity of Δpep27 in the lungs was measured by transcriptome analysis to investigate the long-lasting immunogenic response against IBD. Novel therapeutic targets based on the modulation of Wnt signaling and T regulatory cells interconnected with other signaling cascades in the context of IBD were investigated by qPCR and immunoblotting. M1/M2 macrophages were quantified by FACS analysis. Dextran sulfate sodium-induced colitis induced significant upregulation of Th2 and Th17 as well as noncanonical Wnt5, which subsequently inhibited regulatory T (Treg) expression. In contrast, Δpep27 immunization significantly attenuated the levels of Wnt5, proinflammatory cytokines, oxidative stress parameters, and infiltration of inflammatory cells and enhanced barrier integrity via T helper cell homeostasis and upregulation of M2 macrophages. The data of the present study suggested that Δpep27-elicited Tregs were able to repress Wnt5a expression, assisting with the restoration of immunological tolerance and providing a robust regenerative and antioxidant milieu.

Brain-immune interaction mechanisms: Implications for cognitive dysfunction in psychiatric disorders

Objectives

Cognitive dysfunction has been identified as a major symptom of a series of psychiatric disorders. Multidisciplinary studies have shown that cognitive dysfunction is monitored by a two‐way interaction between the neural and immune systems. However, the specific mechanisms of cognitive dysfunction in immune response and brain immune remain unclear.

Materials and methods

In this review, we summarized the relevant research to uncover our comprehension of the brain–immune interaction mechanisms underlying cognitive decline.

Results

The pathophysiological mechanisms of brain‐immune interactions in psychiatric‐based cognitive dysfunction involve several specific immune molecules and their associated signaling pathways, impairments in neural and synaptic plasticity, and the potential neuro‐immunological mechanism of stress.

Conclusions

Therefore, this review may provide a better theoretical basis for integrative therapeutic considerations for psychiatric disorders associated with cognitive dysfunction.

Stress and Inflammatory Bowel Disease: Clear Mind, Happy Colon

Inflammatory bowel disease (IBD) is a condition whose prevalence in the general population worldwide is increasing at an exponential pace. Many risk factors affect the incidence, progression, and overall outcome of IBD, one of them being psychological stress. This study examined the relationship between psychological stress and inflammatory bowel disease.

A search for relevant studies was conducted using PubMed, Google Scholar, ResearchGate, and SCOPUS. A systematic review was conducted on the relevant articles after critical appraisal.

This article mainly focused on studies that evaluated the presence of inflammatory markers observed in individuals who have been diagnosed with IBD and have high levels of psychological stress. It also assessed if lowering an individual’s psychological stress could help improve the outcomes of IBD.

Psychological stress can have a detrimental effect on individuals diagnosed with IBD. There is a need to conduct studies that can further confirm the association between psychological stressors, mental health conditions, and IBD. We should also encourage medical practitioners to educate patients who have been diagnosed with IBD regarding the benefits of stress reduction.

Phenome-wide screening of the putative causal determinants of depression using genetic data

Depression is one of the most common mental health disorders and one of the top causes of disability throughout the world. The present study sought to identify putative causal associations between depression and hundreds of complex human traits through a genome-wide screening of genetic data and a hypothesis-free approach. We leveraged genome-wide association studies (GWAS) summary statistics for depression and 1504 complex traits and investigated potential causal relationships using the latent causal variable method. We identified 559 traits genetically correlated with depression risk at FDR < 5%. Of these, 46 were putative causal genetic determinants of depression, including lifestyle factors, diseases of the nervous system, respiratory disorders, diseases of the musculoskeletal system, traits related to the health of the gastrointestinal system, obesity, vitamin D levels, and the use of prescription medications, among others. No phenotypes were identified as potential outcomes of depression. Our results suggest that genetic liability to multiple complex traits may contribute to a higher risk for depression. In particular, we show a putative causal genetic effect of pain, obesity, and inflammation on depression. These findings provide novel insights into the potential causal determinants of depression and should be interpreted as testable hypotheses for future studies to confirm, which may facilitate the design of new prevention strategies to reduce depression's burden.

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.

Inflammation and nitro-oxidative stress in current suicidal attempts and current suicidal ideation: a systematic review and meta-analysis

A meta-analysis showed a significant association between activated immune-inflammatory and nitro-oxidative (IO&NS) pathways and suicide attempts (SA). There is no data on whether recent suicidal ideation (SI) is accompanied by activated IO&NS pathways and whether there are differences between recent SA and SI. The current study searched PubMed, Google Scholar, and Web of Science, for articles published from inception until May 10, 2021, and systematically reviewed and meta-analysed the association between recent SA/SI (<3 months) and IO&NS biomarkers. We included studies which compared psychiatric patients with and without SA and SI and controls (either healthy controls or patients without SA/SI) and used meta-analysis (random-effect model with restricted maximum-likelihood) to delineate effect sizes with 95% confidence intervals (CI). Our search included 59 studies comprising 4.034 SA/SI cases and 12.377 controls. Patients with SA/SI showed activated IO&NS pathways (SMD: 0.299; CI: 0.200; 0.397) when compared to controls. The immune profiles were more strongly associated with SA than with SI, particularly when compared to healthy controls, as evidenced by activated IO&NS (SMD: 0.796; CI: 0.503; 1.089), immune (SMD: 1.409; CI: 0.637; 1.462), inflammatory (SMD: 1.200; CI: 0.584; 1.816), and neurotoxic (SMD: 0.904; CI: 0.431; 1.378) pathways. The effects sizes of the IO&NS, immune and inflammatory profiles were significantly greater in SA than in SI. In conclusion: activated IO&NS pathways are associated with recent SA and SI, and inflammation, T helper-1 activation, nitro-oxidative stress, lowered neuroprotection, and increased neurotoxicity explain at least in part why psychiatric patients show increased suicidal behaviours, especially SA.

Emerging Evidence for the Widespread Role of Glutamatergic Dysfunction in Neuropsychiatric Diseases

The monoamine model of depression has long formed the basis of drug development but fails to explain treatment resistance or associations with stress or inflammation. Recent animal research, clinical trials of ketamine (a glutamate receptor antagonist), neuroimaging research, and microbiome studies provide increasing evidence of glutamatergic dysfunction in depression and other disorders. Glutamatergic involvement across diverse neuropathologies including psychoses, neurodevelopmental, neurodegenerative conditions, and brain injury forms the rationale for this review. Glutamate is the brain's principal excitatory neurotransmitter (NT), a metabolic and synthesis substrate, and an immune mediator. These overlapping roles and multiple glutamate NT receptor types complicate research into glutamate neurotransmission. The glutamate microcircuit comprises excitatory glutamatergic neurons, astrocytes controlling synaptic space levels, through glutamate reuptake, and inhibitory GABA interneurons. Astroglia generate and respond to inflammatory mediators. Glutamatergic microcircuits also act at the brain/body interface via the microbiome, kynurenine pathway, and hypothalamus-pituitary-adrenal axis. Disruption of excitatory/inhibitory homeostasis causing neuro-excitotoxicity, with neuronal impairment, causes depression and cognition symptoms via limbic and prefrontal regions, respectively. Persistent dysfunction reduces neuronal plasticity and growth causing neuronal death and tissue atrophy in neurodegenerative diseases. A conceptual overview of brain glutamatergic activity and peripheral interfacing is presented, including the common mechanisms that diverse diseases share when glutamate homeostasis is disrupted.

Dextran sulfate sodium-induced colitis in C57BL/6J mice increases their susceptibility to chronic unpredictable mild stress that induces depressive-like behavior

AIMS

In patients with colitis, the high comorbidity of depressive disorders is well-known, but the detailed mechanisms remain unresolved. In this study, we examined whether colitis induced by dextran sulfate sodium (DSS) increased the susceptibility to chronic unpredictable mild stress (CUMS) in C57BL/6J mice with resilience to CUMS.

MAIN METHODS

To induce experimental colitis and depressive-like behaviors, male 7-weeks old C57BL/6J mice were administered ad libitum 1% DSS solution for 11 days, and subjected to various mild stressors in a chronic, inevitable and unpredictable way according to a random schedule for 21 days, respectively.

KEY FINDINGS

In naïve mice exposed to CUMS, their immobility times in a forced swim (FS) test were almost equal to those in control mice. The DSS administration to naïve mice induced colitis without depressive-like behavior, and at 18 days after termination of the DSS administration, the colitis had recovered to control levels, while altered diversity and composition of bacterial genera such as Bacteroides spp., Alistipes spp., etc., were found in the gut microbiota. Exposure of mice with DSS-induced colitis to CUMS (DSS + CUMS) significantly increased the immobility times in the FS test. In the gut microbiota of DSS + CUMS mice, the alteration profile of the relative abundance of bacterial genera differed from in the DSS ones.

SIGNIFICANCE

These findings indicate that mice with colitis exhibit increased susceptibility to psychological stress, resulting in induction of depressive-like behavior, and this might be due, at least in part, to altered characteristics of the gut microbiota.

[Gut microbiome as a therapeutic target in the treatment of depression and anxiety]

There is a bi-directional connection between the gut microbiome and the brain. Changes in the composition of the microbiome affect emotions, behavior, and the stress response involved in the pathogenesis of depression. Depression and anxiety are often associated with dysbiosis and inflammatory bowel disease. Dysbiosis enhances stress response and low-grade systemic inflammation, and vice versa. This vicious circle may be responsible for the formation of depression. Antidepressants therapy should be accompanied by the elimination of dysbiosis. For these purposes diet, prebiotics, probiotics and faecal microbiota transplantation can be used. The advantages and disadvantages of each method are considered. The manipulation of microbiome composition has been shown to have great therapeutic potential in the treatment of depression and anxiety.

Prebiotics, Probiotics, Synbiotics, Paraprobiotics and Postbiotic Compounds in IBD

The increasing incidence of inflammatory bowel diseases (IBD) and the increasing severity of the course of these diseases create the need for developing new methods of therapy. The gut microbiome is extensively studied as a factor influencing the development and course of IBD. The composition of intestinal microbiota can be relatively easily modified by diet (i.e., prebiotics, mainly dietary fibers) and bacterial supplementation using beneficial bacteria strains called probiotics. Additionally, the effects of the improved microbiome could be enhanced or gained by using paraprobiotics (non-viable, inactivated bacteria or their components) and/or postbiotics (products of bacterial metabolism or equal synthetic products that beneficially modulate immunological response and inflammation). This study summarizes the recent works on prebiotics, probiotics, synbiotics (products merging pre- and probiotics), paraprobiotics and postbiotics in IBD.

Psychological intervention to treat distress: An emerging frontier in cancer prevention and therapy

Psychological distress, such as chronic depression and anxiety, is a topical problem. In the context of cancer patients, prevalence rates of psychological distress are four-times higher than in the general population and often confer worse outcomes. In addition to evidence from epidemiological studies confirming the links between psychological distress and cancer progression, a growing body of cellular and molecular studies have also revealed the complex signaling networks which are modulated by psychological distress-derived chronic stress during cancer progression. In this review, aiming to uncover the intertwined networks of chronic stress-driven oncogenesis and progression, we summarize physiological stress response pathways, like the HPA, SNS, and MGB axes, that modulate the release of stress hormones with potential carcinogenic properties. Furthermore, we discuss in detail the mechanisms behind these chronic stimulations contributing to the initiation and progression of cancer through direct regulation of cancer hallmarks-related signaling or indirect promotion of cancer risk factors (including obesity, disordered circadian rhythms, and premature senescence), suggesting a novel research direction into cancer prevention and therapy on the basis of psychological interventions.

Psychological aspect of patients with inflammatory bowel disease, which may be related to the quality of life, sleep and disease characteristics

OBJECTIVES

Inflammatory bowel disease (IBD) usually present with systemic and gastrointestinal problems. This may result in both physical and psychological burden. The aim of the study was to investigate the association between psychological burden and Health Related Quality of Life (HRQoL), sleep quality and disease characteristics.

METHODS

A total of 106 patients and 165 general populations were enrolled in this study. The demographic information, disease characteristics of participants were investigated. The SCL-90 was self-administered to evaluate psychometric properties. SF-36 and IBDQ were both used to the assessment of HRQoL, and PSQI to quality of sleep.

RESULTS

The SCL-90 score of IBD was significantly higher than that of the control (p = .0007), especially in somatization, anxiety, depression, hostility and psychosis dimensions. Similar to IBDQ (p < .0001), the results of SF-36 (p < .0001) showed that the HRQoL of both Ulcerative colitis (UC) and Crohn's disease (CD) were somehow inferior to control. However, undifferentiated results were noted in patients between UC and CD. Good linear relationship between disease activity and SCL-90 (R_UC = 0.53, p_UC = .001; R_CD = 0.36, p_CD = .002), SF-36 (R_UC = -0.42, p_UC = .01; R_CD = -0.49, p_CD < .0001), IBDQ (R_UC = -0.57, p_UC = .0005; R_CD = -0.52, p_CD < .0001), PSQI (R_UC = 0.50, p_UC = .003; R_CD = 0.27, p_CD = .02) were observed. With the score of SCL-90 of patients increased, the SF-36 (R = -0.78, p < .0001) and IBDQ decreased (R = -0.74, p < .0001), PSQI increased (R = -0.70, p < .0001). Multiple stepwise regression analysis revealed that disease activity, extraintestinal manifestations, weight loss may contribute to identify the psychological anomalies.

CONCLUSIONS

Altered psychological status can be found in IBD, reflecting the necessity of providing psychological care for them. The disease itself results in lower HRQoL. Better HRQoL and sleep quality are in concordance with better psychological health.

Bacterial Translocation Associates With Aggression in Schizophrenia Inpatients

Objective: Accumulating evidence indicates that inflammation abnormalities may contribute to aggression behaviors in psychotic patients, however, the possible sources of inflammation remain elusive. We aimed to evaluate the associations among aggression, inflammation, and bacterial translocation (BT) in aggression-affected schizophrenia (ScZ) inpatients with 2 weeks of antipsychotics discontinuation.

Methods: Serum specimens collected from 112 aggression and 112 non-aggression individuals with ScZ and 56 healthy adults were used for quantifications of inflammation- or BT-related biomarkers. Aggression severity was assessed by Modified Overt Aggression Scale (MOAS).

Results: Proinflammation phenotype dominated and leaky gut-induced BT occurred only in cases with ScZ with a history of aggression, and the MOAS score positively related to levels of C-reactive protein, interleukin (IL)-6, IL-1β, and tumor necrosis factor-α. Furthermore, serum levels of BT-derived lipopolysaccharide (LPS), as well as LPS-responded soluble CD14, were not only positively correlated with levels of above proinflammation mediators but also the total MOAS score and subscore for aggression against objects or others.

Conclusion: Our results collectively demonstrate the presence of leaky gut and further correlate BT-derived LPS and soluble CD14 to onset or severity of aggression possibly by driving proinflammation response in inpatients with ScZ, which indicates that BT may be a novel anti-inflammation therapeutic target for aggression prophylaxis.

How Inflammation Affects the Brain in Depression: A Review of Functional and Structural MRI Studies

This narrative review discusses how peripheral and central inflammation processes affect brain function and structure in depression, and reports on recent peripheral inflammatory marker-based functional and structural magnetic resonance imaging (MRI) studies from the perspective of neural-circuit dysfunction in depression. Chronic stress stimulates the activity of microglial cells, which increases the production of pro-inflammatory cytokines in the brain. In addition, microglial activation promotes a shift from the synthesis of serotonin to the synthesis of neurotoxic metabolites of the kynurenine pathway, which induces glutamate-mediated excitotoxicity in neurons. Furthermore, the region specificity of microglial activation is hypothesized to contribute to the vulnerability of specific brain regions in the depression-related neural circuits to inflammation-mediated brain injury. MRI studies are increasingly investigating how the blood levels of inflammatory markers such as C-reactive protein, interleukin (IL)-1β, IL-6, and tumor necrosis factor-α are associated with functional and structural neuroimaging markers in depression. Functional MRI studies have found that peripheral inflammatory markers are associated with aberrant activation patterns and altered functional connectivity in neural circuits involved in emotion regulation, reward processing, and cognitive control in depression. Structural MRI studies have suggested that peripheral inflammatory markers are related to reduced cortical gray matter and subcortical volumes, cortical thinning, and decreased integrity of white matter tracts within depression-related neural circuits. These neuroimaging findings may improve our understanding of the relationships between neuroinflammatory processes at the molecular level and macroscale in vivo neuralcircuit dysfunction in depression.

Mindfulness based cognitive therapy for youth with inflammatory bowel disease and depression - Findings from a pilot randomised controlled trial

BACKGROUND

Mindfulness-based cognitive therapy (MBCT) is a promising adjunctive treatment for adolescents and young adults (AYAs) with Inflammatory Bowel Disease (IBD) and comorbid depression.

OBJECTIVES

This pilot randomised controlled trial (RCT) aimed to evaluate feasibility and efficacy of an adapted MBCT program for AYA, aged 16-29, with IBD.

METHODS

Sixty-four AYAs were randomly allocated to MBCT (n = 33) or treatment as usual (TAU) (n = 31). Primary outcome measure was the depression score on Depression, Anxiety and Stress Scale. Secondary outcomes included anxiety, stress, IBD-related quality of life, coping, mindfulness, post-traumatic growth, medication adherence, IBD activity, inflammatory markers, microbiome characteristics and brain functional connectivity.

RESULTS

Study recruitment rate was 75%, retention rate 70%, and session attendance 92%. Intention to treat analyses revealed that, compared to TAU group, MBCT group had significantly lower depression (∆ = -6.0; 95%CI = -10.8 to -1.2; P = 0.015) and stress (∆ = -5.1; 95%CI = -10.1 to -0.0; P = 0.049), higher active coping (∆ = 1.0;95%CI = 0.1-1.9; P = 0.022), and total mindfulness scores (∆ = 10.9;95%CI = 1.1-20.8; P = 0.030) at 8 weeks (post-therapy), and improved coping by positive reframing (∆ = 1.1;95%CI = 0.0-2.2; P = 0.043) and planning (∆ = 0.9;95%CI = 0.0-1.9; P = 0.045), mindful awareness (∆ = 5.2.;95%CI = 2.0-8.5; P = 0.002) and total mindfulness scores (∆ = 10.8.;95%CI = 0.4-21.1; P = 0.042) at 20 weeks. On per protocol analysis, MBCT group had significantly lower depression (∆ = -6.3; 95%CI = -11.4 to -1.2; P = 0.015), stress (∆ = -6.0; 95%CI = -11.2 to -0.5; P = 0.032), increased active coping (∆ = 0.9;95%CI = 0-1.7; P = 0.05) at 8 weeks, and mindful awareness (∆ = 5.4; 95%CI = 2.1-8.6; P = 0.001) at 20 weeks.

CONCLUSION

In AYAs with IBD, MBCT is feasible and beneficial in improving depression, stress, mindfulness and adaptive coping. It holds promise as an important component of integrated IBD care. Trial registration number ACTRN12617000876392, U1111-1197-7370; Pre-results.

Biomarkers and Utility of the Antioxidant Potential of Probiotic Lactobacilli and Bifidobacteria as Representatives of the Human Gut Microbiota

Lactobacilli and bifidobacteria are an important part of human gut microbiota. Among numerous benefits, their antioxidant properties are attracting more and more attention. Multiple in vivo and in vitro studies have demonstrated that lactobacilli and bifidobacteria, along with their cellular components, possess excellent antioxidant capacity, which provides a certain degree of protection to the human body against diseases associated with oxidative stress. Recently, lactobacilli and bifidobacteria have begun to be considered as a new source of natural antioxidants. This review summarizes the current state of research on various antioxidant properties of lactobacilli and bifidobacteria. Special emphasis is given to the mechanisms of antioxidant activity of these bacteria in the human gut microbiota, which involve bacterial cell components and metabolites. This review is also dedicated to the genes involved in the antioxidant properties of lactobacilli and bifidobacteria strains as indicators of their antioxidant potential in human gut microbiota. Identification of the antioxidant biomarkers of the gut microbiota is of great importance both for creating diagnostic systems for assessing oxidative stress and for choosing strategies aimed at restoring the normal functioning of the microbiota and, through it, restoring human health. In this review, the practical application of probiotic strains with proven antioxidant properties to prevent oxidative stress is also considered.

High Levels of Psychological Resilience Are Associated With Decreased Anxiety in Inflammatory Bowel Disease

BACKGROUND

Anxiety and depression are comorbid disorders with IBD and are associated with poor outcomes. Resilience is an innate but modifiable trait that may improve the symptoms of psychological disorders. Increasing resilience may decrease the severity of these comorbid disorders, which may improve IBD outcomes. The aim of this study was to describe the association between resilience, anxiety, and depression in IBD patients.

METHODS

We performed a cross-sectional study of IBD patients. Patients completed a questionnaire consisting of the Connor-Davidson Resilience Scale (CD-RISC), a measure of resilience, the Generalized Anxiety Disorder 7 (GAD-7), and the Patient Health Questionnaire-9. Primary outcome was severity of anxiety and depression in patients with high resilience. Multivariable linear regression analysis evaluated the association between severity of anxiety and depression and level of resilience.

RESULTS

A sample of 288 patients was analyzed. Bivariable linear regression analysis showed a negative association between resilience and anxiety (Pearson rho = -0.47; P < .0001) and between resilience and depression (Pearson rho = -0.53; P < .0001). Multivariable linear regression indicated that high resilience is independently associated with lower anxiety and that for every 1-unit increase in CD-RISC, the GAD-7 score decreased by 0.04 units (P = .0003). Unlike anxiety, the association between resilience and depression did not remain statistically significant on multivariable analysis.

CONCLUSIONS

High resilience is independently associated with lower anxiety in IBD patients, and we report a quantifiable decrease in anxiety score severity for every point of increase in resilience score. These findings suggest that IBD patients with higher resilience may have better coping mechanisms that buffer against the development of anxiety.

Longitudinal follow-up study: effect of psychological co-morbidity on the prognosis of inflammatory bowel disease

BACKGROUND

Psychological co-morbidity is more common in patients with inflammatory bowel disease (IBD), compared with the general population, but little is known about the cumulative effect of increasing psychological burden on disease behaviour.

AIMS

To examine the effect of psychological co-morbidity on inflammatory bowel disease in a longitudinal follow-up study.

METHODS

We collected complete demographic, symptom and psychological co-morbidity data (anxiety, depression and somatisation scores) at baseline from adults with IBD in biochemical remission (faecal calprotectin <250 µg/g). Objective markers of disease activity, including glucocorticosteroid prescription or flare of disease activity, escalation of therapy, hospitalisation or intestinal resection, were reviewed ≥2 years of follow-up. We performed multivariate Cox regression, controlling for patient characteristics and follow-up duration, to examine cumulative effect of psychological co-morbidities on subsequent IBD behaviour.

RESULTS

Among 218 participants, 48 (22.0%) had one, 13 (6.0%) two and nine (4.1%) three psychological co-morbidities at baseline. Following multivariate Cox regression analysis, glucocorticosteroid prescription or flare, and escalation of medical therapy were significantly higher among those with two (hazard ratio [HR] = 3.18; 95% confidence interval [CI] 1.44-7.02, and HR = 2.48; 95% CI 1.03-5.93, respectively) or three (HR = 3.53; 95% CI 1.26-9.92, and HR = 8.19; 95% CI 2.88-23.23, respectively) psychological co-morbidities. Occurrence of at least one endpoint of interest was significantly higher with increasing psychological co-morbidity (HR = 1.74; 95% CI 1.07-2.82 for one, HR = 2.47; 95% CI 1.12-5.46 for two and HR = 4.93; 95% CI 1.84-13.17 for three psychological co-morbidities).

CONCLUSIONS

Individuals with IBD in biochemical remission experienced a worse disease course with increasing psychological co-morbidity at baseline.

Glutathione Participation in the Prevention of Cardiovascular Diseases

Cardiovascular diseases (CVD) (such as occlusion of the coronary arteries, hypertensive heart diseases and strokes) are diseases that generate thousands of patients with a high mortality rate worldwide. Many of these cardiovascular pathologies, during their development, generate a state of oxidative stress that leads to a deterioration in the patient’s conditions associated with the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS). Within these reactive species we find superoxide anion (O₂^•–), hydroxyl radical (^•OH), nitric oxide (NO^•), as well as other species of non-free radicals such as hydrogen peroxide (H₂O₂), hypochlorous acid (HClO) and peroxynitrite (ONOO^–). A molecule that actively participates in counteracting the oxidizing effect of reactive species is reduced glutathione (GSH), a tripeptide that is present in all tissues and that its synthesis and/or regeneration is very important to be able to respond to the increase in oxidizing agents. In this review, we will address the role of glutathione, its synthesis in both the heart and the liver, and its importance in preventing or reducing deleterious ROS effects in cardiovascular diseases.

The neuroprotective effects of polyphenols, their role in innate immunity and the interplay with the microbiota

Neurodegenerative disorders, particularly in the elderly population, represent one of the most pressing social and health-care problems in the world. Besides the well-established role of both oxidative stress and inflammation, alterations of the immune response have been found to be closely linked to the development of neurodegenerative diseases. Interestingly, various scientific evidence reported that an altered gut microbiota composition may contribute to the development of neuroinflammatory disorders. This leads to the proposal of the concept of the gut-brain-immune axis. In this scenario, polyphenols play a pivotal role due to their ability to exert neuroprotective, immunomodulatory and microbiota-remodeling activities. In the present review, we summarized the available literature to provide a scientific evidence regarding this neuroprotective and immunomodulatory effects and the interaction with gut microbiota of polyphenols and, the main signaling pathways involved that can explain their potential therapeutic application in neurodegenerative diseases.

Psychological factors associated with inflammatory bowel disease

BACKGROUND

Both depression and anxiety are identified as significant experiences in inflammatory bowel disease (IBD); whether these are a consequence of the disease or an active contributor to the disease remains controversial. This review aimed to identify and critique recent evidence regarding mental health in IBD.

SOURCES OF DATA

PubmedⓇ, OvidⓇ, EmbaseⓇ, EBSCO PsychInfo and Google-Scholar were searched within the last 5 years (2016-2020).

AREAS OF AGREEMENT

Overall, both depression and anxiety affect disease activity, relapse and healthcare utilization.

AREAS OF CONTROVERSY

There is some controversy on whether depression and anxiety affect IBD outcomes differently depending on IBD subtype.

GROWING POINTS

The data support the need for depression and anxiety assessment to be incorporated in the routine management of IBD patients; prompt psychiatric and psychological management may ultimately reduce disease activity, relapses and healthcare costs.

AREAS TIMELY FOR DEVELOPING RESEARCH

More longitudinal research may further enlighten the role of depression and anxiety in IBD. Similarly, randomized controlled trials to investigate and clarify the effect of psychiatric/psychological management on IBD outcomes.

Depression, psychosocial correlates, and psychosocial resources in individuals with mast cell activation syndrome

Individuals with Mast Cell Activation Syndrome (MCAS), a rare chronic disease, experience unpredictable physical symptoms and diagnostic challenges resulting in poor emotional states. The prevalence and correlates of depressive symptoms were examined among 125 participants who completed the CES-D and relevant instruments. The majority reported a clinically-significant level of depression which was especially common among younger participants and those who reported greater loneliness or more disease-specific stressors. Greater magnitude of depressive symptoms was associated with greater illness intrusiveness, less social support, and lower optimism. Results highlight the value of interventions targeting loneliness and stressors unique to this population.

Does Genetic Predisposition Contribute to the Exacerbation of COVID-19 Symptoms in Individuals with Comorbidities and Explain the Huge Mortality Disparity between the East and the West?

The elderly and patients with several comorbidities experience more severe cases of coronavirus disease 2019 (COVID-19) than healthy patients without underlying medical conditions. However, it is unclear why these people are prone to developing alveolar pneumonia, rapid exacerbations, and death. Therefore, we hypothesized that people with comorbidities may have a genetic predisposition that makes them more vulnerable to various factors; for example, they are likely to become more severely ill when infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To test this hypothesis, we searched the literature extensively. Polymorphisms of genes, such as those that encode angiotensin-converting enzyme 1 (ACE1), have been associated with numerous comorbidities, such as cardiovascular disease, hypertension, diabetes, chronic kidney disease, and obesity, and there are potential mechanisms to explain these associations (e.g., DD-type carriers have greater ACE1 activity, and patients with a genetic alpha-1 anti-trypsin (AAT) deficiency lack control over inflammatory mediators). Since comorbidities are associated with chronic inflammation and are closely related to the renin–angiotensin–aldosterone system (RAAS), these individuals may already have a mild ACE1/ACE2 imbalance before viral infection, which increases their risk for developing severe cases of COVID-19. However, there is still much debate about the association between ACE1 D/I polymorphism and comorbidities. The best explanation for this discrepancy could be that the D allele and DD subtypes are associated with comorbidities, but the DD genotype alone does not have an exceptionally large effect. This is also expected since the ACE1 D/I polymorphism is only an intron marker. We also discuss how polymorphisms of AAT and other genes are involved in comorbidities and the severity of SARS-CoV-2 infection. Presumably, a combination of multiple genes and non-genetic factors is involved in the establishment of comorbidities and aggravation of COVID-19.