Altered Intestinal Permeability Biomarkers in Schizophrenia: A Possible Link with Subclinical Inflammation

Lipopolysaccharide-binding protein levels, obstructive sleep apnea, and depression: A cross-sectional study of adults

Obstructive sleep apnea (OSA) and depression are highly comorbid. Increased intestinal permeability has been hypothesized to play a role in the pathogenesis of both. The current study aimed to assess the severity of OSA symptoms, comorbid depressive symptoms, and lipopolysaccharide-binding protein (LBP) levels in adult patients being diagnosed for OSA syndrome. The study population consisted of 176 subjects. An apnea-hypopnea index (AHI) ≥ 5/hour was used for the diagnosis of OSA syndrome. Depressive symptoms were assessed with the Beck Depression Inventory-2. LBP levels were measured in the blood serum by enzyme-linked immunosorbent assay (ELISA). Associations between clinical symptom profiles or severity and LBP as an intestinal permeability biomarker marker were tested. LBP levels were not different between patients with different OSA severity, as assessed with AHI or daily sleepiness. Nor were LBP levels different in subjects with different depressiveness severity. Daily sleepiness was weakly positively correlated with depression score, and LBP levels correlated positively with a neutrophils-to-lymphocytes ratio. Finally, LBP levels were not explained by multiple linear regression models, including sleep-related parameter values and depression score. Intestinal permeability, as measured with LBP level, may not explain the comorbidity of depression and daily sleepiness in the course of OSA syndrome.

Differences in Blood Leukocyte Subpopulations in Schizophrenia: A Systematic Review and Meta-Analysis

Importance

This study aims to provide robust evidence to support or challenge the immune hypothesis of schizophrenia.

Objective

To conduct a meta-analysis of reports on blood leukocyte subpopulations in schizophrenia vs healthy controls, examining disease- and treatment-related differences as well as potential confounders.

Data Sources

Systematic database search for English and non-English peer-reviewed articles in PubMed, Web of Science, Scopus, and Cochrane Library databases, with the last search in January 2024.

Study Selection

Cross-sectional, case-control, and longitudinal studies comparing leukocyte numbers in patients with schizophrenia and healthy controls. After duplicates were removed, 3691 studies were identified for screening.

Data Extraction and Synthesis

Data extraction and quality assessment were conducted following PRISMA and MOOSE guidelines. Data were independently extracted by 2 authors and pooled using random-effects models.

Main Outcomes and Measures

The planned primary outcomes were differences in leukocyte subpopulation counts between individuals with schizophrenia and healthy controls to increase our understanding of the immune system dysfunction in schizophrenia.

Results

Sixty-four relevant articles were identified (60 cross-sectional/case-control studies and 4 longitudinal studies) with data on leukocyte numbers from 26 349 individuals with schizophrenia and 16 379 healthy controls. Neutrophils (g = 0.69; 95% CI, 0.49 to 0.89; Bonferroni-adjusted P < .001; n = 40 951 [47 between-group comparisons]) and monocytes (g = 0.49; 95% CI, 0.24 to 0.75; Bonferroni-adjusted P < .001; n = 40 513 [44 between-group comparisons]) were higher in schizophrenia compared with control participants. Differences were greater in first-episode vs chronic schizophrenia and in patients who were not treated vs treated with antipsychotic medication. There were no significant differences in eosinophils (g = 0.02; 95% CI, -0.16 to 0.20; Bonferroni-adjusted P > .99; n = 3277 [18 between-group comparisons]), basophils (g = 0.14; 95% CI, -0.06 to 0.34; Bonferroni-adjusted P = .85; n = 2614 [13 between-group comparisons]), or lymphocytes (g = -0.08; 95% CI, -0.21 to 0.06; Bonferroni-adjusted P > .99; n = 41 693 [59 between-group comparisons]). Neutrophils decreased longitudinally (g = -0.30; 95% CI, -0.45 to -0.15; Bonferroni-adjusted P < .001; n = 896 [4 within-group comparisons]) and eosinophils increased longitudinally (g = 0.61; 95% CI, 0.52 to 0.71; Bonferroni-adjusted P < .001; n = 876 [3 within-group comparisons]) after successful treatment of acute psychosis.

Conclusions and Relevance

Our findings of increased blood neutrophils and monocytes support the immune hypothesis of schizophrenia, particularly highlighting the role of innate immune activation. As these effects were more pronounced in early disease stages and also reflected clinical improvement, they may pave the way for innovative treatment strategies based on immunological and inflammatory pathways and help revolutionize the treatment landscape for schizophrenia.

Comparative analysis of gut microbiota in major depressive disorder and schizophrenia during hospitalisation - the case-control, post hoc study

The aim of this study was to investigate the relationship between gut microbiota and major depressive disorder (MDD) and schizophrenia (SCZ) by comparing 36 inpatients with these conditions to 29 healthy controls (HC) matched for age, sex, and body mass index (BMI). Individuals with SCZ exhibited greater microbiota richness compared to HC (FDR P(Q)=0.028). Taxonomically, while no significant differences were observed between the microbiota of MDD and SCZ patients in a head-to-head comparison, both patient groups differed significantly when compared to HC. Interestingly, besides common patterns (such as a higher abundance of Erysipelotrichaceae UCG-003 and Streptococcus, and a lower abundance of Lachnospiraceae ND3007 group), unique patterns were exhibited only in MDD (with a higher abundance of Anaerostipes, Q=0.004) or SCZ (with a higher abundance of Sutterella, Q=0.001, and a lower abundance of Clostridium sensu stricto 1, Q=0.002). The Random Forest algorithm identified Ruminococcus torques group, Lachnospiraceae UCG-001, and Erysipelotrichaceae UCG-003 as highly discriminative features for both SCZ and MDD, while Suturella and Holdemania were unique features for SZC, and Lachnospiraceae genus CAG-56 and Anaerostipes for MDD. Additionally, between 50 % and 60 % of the differentially abundant taxa were found among the top 10 influential features in the RF models. In conclusion, while no significant differences were found between the microbiota of MDD and SCZ patients, distinct microbial patterns were found in each group when compared to HC. The study did not confirm universal microbial biomarkers reported in other studies but showed that the observed differences concern the bacteria associated with inflammation, the production of short chain fatty acids (SCFA), and the synthesis of metabolites linked to mental health (lactic acid, gamma-aminobutyric acid - GABA). The application of machine learning holds promise for further understanding the complex relationship between microbiota and these psychiatric disorders. The observed results should be treated with caution due to the limitations of this study (mainly sample size), therefore further researches under standardized environmental conditions with consistent analytical and bioinformatics approaches are warranted.

Intestinal permeability biomarkers in patients with schizophrenia: Additional support for the impact of lifestyle habits

BACKGROUND

Emerging evidence suggests a potential association between "leaky gut syndrome" and low-grade systemic inflammation in individuals with psychiatric disorders, such as schizophrenia. Gut dysbiosis could increase intestinal permeability, allowing the passage of toxins and bacteria into the systemic circulation, subsequently triggering immune-reactive responses. This study delves into understanding the relationship between plasma markers of intestinal permeability and symptom severity in schizophrenia. Furthermore, the influence of lifestyle habits on these intestinal permeability markers was determined.

METHODS

Biomarkers of intestinal permeability, namely lipopolysaccharide-binding protein (LBP), lipopolysaccharides (LPS), and intestinal fatty acid binding protein (I-FABP), were analyzed in 242 adult schizophrenia patients enrolled in an observational, cross-sectional, multicenter study from four centers in Spain (PI17/00246). Sociodemographic and clinical data were collected, including psychoactive drug use, lifestyle habits, the Positive and Negative Syndrome Scale to evaluate schizophrenia symptom severity, and the Screen for Cognitive Impairment in Psychiatry to assess cognitive performance.

RESULTS

Results revealed elevated levels of LBP and LPS in a significant proportion of patients with schizophrenia (62% and 25.6%, respectively). However, no statistically significant correlation was observed between these biomarkers and the overall clinical severity of psychotic symptoms or cognitive performance, once confounding variables were controlled for. Interestingly, adherence to a Mediterranean diet was negatively correlated with I-FABP levels (beta = -0.186, t = -2.325, p = 0.021), suggesting a potential positive influence on intestinal barrier function.

CONCLUSIONS

These findings underscore the importance of addressing dietary habits and promoting a healthy lifestyle in individuals with schizophrenia, with potential implications for both physical and psychopathological aspects of the disorder.

Probiotic Formulation for Patients With Bipolar or Schizophrenia Spectrum Disorder: A Double-Blind, Randomized Placebo-Controlled Trial

BACKGROUND AND HYPOTHESIS

Probiotic augmentation offers a promising treatment for bipolar disorder (BD) and schizophrenia spectrum disorder (SSD). By targeting microbiome deviations, they may improve both gut and brain health.

STUDY DESIGN

In this double-blind, randomized, placebo-controlled trial with the multi-strain probiotic formulation Ecologic BARRIER, we aimed to improve psychiatric and cognitive symptoms, intestinal permeability, and gastrointestinal symptoms in patients with BD or SSD. A total of 131 patients were randomized 1:1 to receive either the probiotic supplement (n = 67) or a placebo (n = 64) for 3 months, in addition to treatment-as-usual. The primary outcomes were symptom severity assessed by the Brief Psychiatric Rating Scale and cognitive functioning by the Brief Assessment of Cognition in Schizophrenia.

STUDY RESULTS

No significant effect of probiotics was observed on psychiatric symptoms, but borderline significant improvement was observed in the cognition category of verbal memory (Linear Mixed Model (LMM) 0.33; adjusted P = .059). Probiotics beneficially affected markers of intestinal permeability and inflammation, including zonulin (LMMserum = -18.40; adjusted P = .002; LMMfecal = -10.47; adjusted P = .014) and alpha-1 antitrypsin (LMM 9.26; adjusted P = .025). Indigestion complaints significantly decreased in male participants in the probiotics group (LMM = -0.70; adjusted P = .010). Adverse events were similar between groups.

CONCLUSIONS

Our study observed significant advantages of probiotics for gut health in BD and SSD, with excellent safety and tolerability. A borderline effect on verbal memory was also indicated. These results underscore the need for further research into microbiome-targeted interventions for patients with complex brain disorders.

Looking Inside of the Intestinal Permeability Regulation by Protein-Derivatives from Bovine Milk

The prime function of the epithelium is to regulate the intestinal permeability; the latter is a quantitative parameter that refers to the measurement of the rate of passage of solutes through the epithelial monolayer. Function of epithelial monolayer depends on the expression of protein complexes known as tight junction proteins; whose function and expression can be disrupted under conditions of inflammation including irritable bowel disease (IBD), intestinal infections, and high-fat diets, among others. This manuscript is focused to outline the effects of bovine milk protein derivatives on the intestinal permeability addressed mostly in animal models in which the intestinal barrier is disrupted. At present, the properties of bovine milk protein derivatives on intestinal permeability have been scarcely documented in humans, but evidence raised from clinical trials provides promising findings of potential application of colostrum to control of the intestinal permeability in critically ill patients, users of non-steroid anti-inflammatory drugs, like athletes and militia members.

Experimental colitis is comorbid with social interaction deficits and anxiety-like behaviors in mice: mechanistic intuitions into neuroinflammation and Claudin 5 expression in the hippocampus

Inflammatory bowel disease (IBD) is accompanied by psychiatric disorders, including Schizophrenic-like manifestations. Although incompletely illustrated, intestinal mucosal membrane damage and blood-brain barrier (BBB) penetrability may have significant roles in psychiatric symptoms of IBD. This study aimed to investigate role of the Claudin-5 (CLDN5) (a regulator of the permeability of BBB) and neuroinflammatory response in the comorbid behavioral disorders in experimental colitis in mice. Acetic acid was used to induce colitis in mice. 7 days after induction of colitis, behaviors including social interaction and locomotor activity as well as anxiety-like behaviors were evaluated. Then, the colon was extracted for gross and microscopic evaluations. The expression of CLDN5, TNF-α, IL1β and IL23 was measured by RT-PCR in the colon and hippocampus. Histopathologic evaluations demonstrated mucosal, submucosal, and crypt-related damages in the colon. The negative and positive number of social interactions significantly increased in the colitis group. A considerable increase in locomotor activities (horizontal and vertical components) shown in the colitis group. Mice in colitis group spent less time in the central zone in the open field apparatus. Gene expressions of TNF-α, IL1β, and IL23 increased and CLDN5 decreased in the colitis group. The barrier function of the intestine and brain would be impaired, partially at least, following colitis (as we observed decrease in CLDN5 gene expression). Furthermore, we found that beside inflammatory response in the colon, a neuro-immune response triggered in the hippocampus following colitis. These alterations probably, mediated comorbid behavioral disorders in acetic acid-induced colitis in mice.

Western diet components that increase intestinal permeability with implications on health

Intestinal permeability is a physiological property that allows necessary molecules to enter the organism. This property is regulated by tight junction proteins located between intestinal epithelial cells. However, various factors can increase intestinal permeability (IIP), including diet. Specific components in the Western diet (WD), such as monosaccharides, fat, gluten, salt, alcohol, and additives, can affect the tight junctions between enterocytes, leading to increased permeability. This review explains how these components promote IIP and outlines their potential implications for health. In addition, we describe how a reduction in WD consumption may help improve dietary treatment of diseases associated with IIP. Research has shown that some of these components can cause changes in the gut microbiota, leading to dysbiosis, which can promote greater intestinal permeability and displacement of endotoxins into the bloodstream. These endotoxins include lipopolysaccharides derived from gram-negative bacteria, and their presence has been associated with various diseases, such as autoimmune, neurological, and metabolic diseases like diabetes and cardiovascular disease. Therefore, nutrition professionals should promote the reduction of WD consumption and consider the inclusion of healthy diet components as part of the nutritional treatment for diseases associated with increased intestinal permeability.

Gastrointestinal and brain barriers: unlocking gates of communication across the microbiota-gut-brain axis

Crosstalk between gut and brain has long been appreciated in health and disease, and the gut microbiota is a key player in communication between these two distant organs. Yet, the mechanisms through which the microbiota influences development and function of the gut-brain axis remain largely unknown. Barriers present in the gut and brain are specialized cellular interfaces that maintain strict homeostasis of different compartments across this axis. These barriers include the gut epithelial barrier, the blood-brain barrier and the blood-cerebrospinal fluid barrier. Barriers are ideally positioned to receive and communicate gut microbial signals constituting a gateway for gut-microbiota-brain communication. In this Review, we focus on how modulation of these barriers by the gut microbiota can constitute an important channel of communication across the gut-brain axis. Moreover, barrier malfunction upon alterations in gut microbial composition could form the basis of various conditions, including often comorbid neurological and gastrointestinal disorders. Thus, we should focus on unravelling the molecular and cellular basis of this communication and move from simplistic framing as 'leaky gut'. A mechanistic understanding of gut microbiota modulation of barriers, especially during critical windows of development, could be key to understanding the aetiology of gastrointestinal and neurological disorders.

Association of Blast Exposure in Military Breaching with Intestinal Permeability Blood Biomarkers Associated with Leaky Gut

Injuries and subclinical effects from exposure to blasts are of significant concern in military operational settings, including tactical training, and are associated with self-reported concussion-like symptomology and physiological changes such as increased intestinal permeability (IP), which was investigated in this study. Time-series gene expression and IP biomarker data were generated from "breachers" exposed to controlled, low-level explosive blast during training. Samples from 30 male participants at pre-, post-, and follow-up blast exposure the next day were assayed via RNA-seq and ELISA. A battery of symptom data was also collected at each of these time points that acutely showed elevated symptom reporting related to headache, concentration, dizziness, and taking longer to think, dissipating ~16 h following blast exposure. Evidence for bacterial translocation into circulation following blast exposure was detected by significant stepwise increase in microbial diversity (measured via alpha-diversity p = 0.049). Alterations in levels of IP protein biomarkers (i.e., Zonulin, LBP, Claudin-3, I-FABP) assessed in a subset of these participants (n = 23) further evidenced blast exposure associates with IP. The observed symptom profile was consistent with mild traumatic brain injury and was further associated with changes in bacterial translocation and intestinal permeability, suggesting that IP may be linked to a decrease in cognitive functioning. These preliminary findings show for the first time within real-world military operational settings that exposures to blast can contribute to IP.

Associations of gut microbiota alterations with clinical, metabolic, and immune-inflammatory characteristics of chronic schizophrenia

The present study had the following aims: 1) to compare gut microbiota composition in patients with schizophrenia and controls and 2) to investigate the association of differentially abundant bacterial taxa with markers of inflammation, intestinal permeability, lipid metabolism, and glucose homeostasis as well as clinical manifestation. A total of 115 patients with schizophrenia during remission of positive and disorganization symptoms, and 119 controls were enrolled. Altogether, 32 peripheral blood markers were assessed. A higher abundance of Eisenbergiella, Family XIII AD3011 group, Eggerthella, Hungatella, Lactobacillus, Olsenella, Coprobacillus, Methanobrevibacter, Ligilactobacillus, Eubacterium fissicatena group, and Clostridium innocuum group in patients with schizophrenia was found. The abundance of Paraprevotella and Bacteroides was decreased in patients with schizophrenia. Differentially abundant genera were associated with altered levels of immune-inflammatory markers, zonulin, lipid profile components, and insulin resistance. Moreover, several correlations of differentially abundant genera with cognitive impairment, higher severity of negative symptoms, and worse social functioning were observed. The association of Methanobrevibacter abundance with the level of negative symptoms, cognition, and social functioning appeared to be mediated by the levels of interleukin-6 and RANTES. In turn, the association of Hungatella with the performance of attention was mediated by the levels of zonulin. The findings indicate that compositional alterations of gut microbiota observed in patients with schizophrenia correspond with clinical manifestation, intestinal permeability, subclinical inflammation, lipid profile alterations, and impaired glucose homeostasis. Subclinical inflammation and impaired gut permeability might mediate the association of gut microbiota alterations with psychopathological symptoms and cognitive impairment.

Radix Bupleuri aqueous extract attenuates MK801-induced schizophrenia-like symptoms in mice: Participation of intestinal flora

Schizophrenia (SCZ) is a psychotic mental disorder characterized by cognitive, behavioral, and social impairments. However, current pharmacological treatment regimens are subpar in terms of effectiveness. This study aimed to investigate the function of Radix Bupleuri aqueous extract in SCZ in mouse models. The SCZ mouse model was established by MK-801 injection and feeding of Radix Bupleuri aqueous extract or combined antibiotics. Radix Bupleuri aqueous extract significantly improved the aberrant behaviors and neuronal damage in SCZ mice, upregulated SYP and PSD-95 expression and BDNF levels in hippocampal homogenates, down-regulated DA and 5-HT levels, and suppressed microglial activation in SCZ mice. Moreover, Radix Bupleuri aqueous extract improved the integrity of the intestinal tract barrier. The 16 S rRNA sequencing of feces showed that Radix Bupleuri extract modulated the composition of gut flora. Lactobacillus abundance was decreased in SCZ mice and reversed by Radix Bupleuri aqueous extract administration which exhibited a significant negative correlation with IL-6, IL-1β, DA, and 5-HT, and a significant positive correlation with BDNF levels in hippocampal tissues. The abundance of Parabacteroides and Alloprevotella was increased in SCZ mice. It was reversed by Radix Bupleuri aqueous extract administration, which exhibited a positive correlation with IL-6, IL-1β, and 5-HT and a negative correlation with BDNF. In conclusion, Radix Bupleuri aqueous extract attenuates the inflammatory response in hippocampal tissues and modulates neurotransmitter levels, exerting its neuroprotective effect in SCZ. Meanwhile, the alteration of intestinal flora may be involved in this process, which is expected to be an underlying therapeutic option in treating SCZ.

Increased IgA-mediated responses to the gut paracellular pathway and blood-brain barrier proteins predict delirium due to hip fracture in older adults

Introduction

Delirium is accompanied by immune response system activation, which may, in theory, cause a breakdown of the gut barrier and blood-brain barrier (BBB). Some results suggest that the BBB is compromised in delirium, but there is no data regarding the gut barrier. This study investigates whether delirium is associated with impaired BBB and gut barriers in elderly adults undergoing hip fracture surgery.

Methods

We recruited 59 older adults and measured peak Delirium Rating Scale (DRS) scores 2-3 days after surgery, and assessed plasma IgG/IgA levels (using ELISA techniques) for zonulin, occludin, claudin-6, β-catenin, actin (indicating damage to the gut paracellular pathway), claudin-5 and S100B (reflecting BBB damage), bacterial cytolethal distending toxin (CDT), LPS-binding protein (LBP), lipopolysaccharides (LPS), Porphyromonas gingivalis, and Helicobacter pylori.

Results

Results from univariate analyses showed that delirium is linked to increased IgA responses to all the self-epitopes and antigens listed above, except for LPS. Part of the variance (between 45-48.3%) in the peak DRS score measured 2-3 days post-surgery was explained by independent effects of IgA directed to LPS and LBP (or bacterial CDT), baseline DRS scores, and previous mild stroke. Increased IgA reactivity to the paracellular pathway and BBB proteins and bacterial antigens is significantly associated with the activation of M1 macrophage, T helper-1, and 17 cytokine profiles.

Conclusion

Heightened bacterial translocation, disruption of the tight and adherens junctions of the gut and BBB barriers, elevated CDT and LPS load in the bloodstream, and aberrations in cell-cell interactions may be risk factors for delirium.

From gut to brain: A network model of intestinal permeability, inflammation, and psychotic symptoms in schizophrenia

Impaired intestinal permeability has recently been suggested as a possible source of chronic inflammation in schizophrenia, but its association with specific psychopathological features remains uncertain. This study aimed to explore the interaction between intestinal permeability, inflammation, and positive and negative symptoms in schizophrenia using a network analysis approach. The study sample comprised 281 adults with schizophrenia (age 40.29 ± 13.65 years, 63.0 % males), enrolled in a cross-sectional observational study assessing intestinal permeability. We estimated the network with a Gaussian graphical model, incorporating scores from 14 individual items of the Positive and Negative Syndrome Scale (PANSS), along with body mass index (BMI), and plasma C-reactive protein (CRP) and lipopolysaccharide-binding protein (LBP) levels. We calculated strength centrality and expected influence and used bridge centrality statistics to identify the bridge nodes. Distinct but highly interconnected clusters emerged for positive and negative symptoms. The biological variables were closely associated with each other. LBP was positively linked with CRP and BMI, but only indirectly connected to psychopathology. CRP exhibited direct positive relationships with various PANSS items and bridged LBP and BMI with psychopathology. Bridge nodes included Conceptual Disorganisation (P2), Active Social Avoidance (G16), Suspiciousness/Persecution (P6), and CRP. These findings support the role of gut-derived inflammation as a mechanism underlying greater symptom severity in schizophrenia and emphasise the importance of addressing dietary habits not only to enhance physical health but also to contribute to improving psychotic symptoms.

Serum trimethylamine N-oxide and lipopolysaccharide binding protein levels among children diagnosed with autism spectrum disorder

In the literature, there have been several studies available investigating the relationship between autism spectrum disorder and intestinal permeability. In this study, it is aimed to examine the relationship between the levels of trimethylamine N-oxide (TMAO), which is a parameter associated with intestinal permeability, and lipopolysaccharide binding protein (LBP), which is a marker associated with bacterial translocation from the intestine, in patients with autism spectrum disorder (ASD) and healthy controls. Fifty-three children with ASD as the patient group and 30 healthy children as the control group have been included in the study. The diagnostic evaluation has been made according to DSM-5 criteria. According to the obtained results, there has been no significant difference between groups in terms of serum TMAO and LBP levels. Considering the existence of various studies that found different results on ASD and intestinal permeability, it is thought that the studies conducted in this field that did not find statistically different results will also make a contribution to the literature.

Vascular-related biomarkers in psychosis: a systematic review and meta-analysis

Background

While the molecular underpinnings of vascular dysfunction in psychosis are under active investigation, their implications remain unclear due to inconsistent and sometimes sparse observations. We conducted a comprehensive meta-analysis to critically assess the alterations of vascular-related molecules in the cerebrospinal fluid (CSF) and blood of patients with psychotic disorders compared with healthy individuals.

Methods

Databases were searched from inception to February 23, 2023. Meta-analyses were performed using a random-effects model. Meta-regression and subgroup analyses were conducted to assess the effects of clinical correlates.

Results

We identified 93 eligible studies with 30 biomarkers investigated in the CSF and/or blood. Among the biomarkers examined, psychotic disorders were associated with elevated CSF-to-serum albumin ratio (standardized mean difference [SMD], 0.69; 95% confidence interval [CI], 0.35-1.02); blood S100B (SMD, 0.88; 95% CI, 0.59-1.17), matrix metalloproteinase-9 (MMP-9; SMD, 0.66; 95% CI, 0.46-0.86), and zonulin (SMD, 1.17; 95% CI, 0.04-2.30). The blood levels of S100B, MMP-9, nerve growth factor (NGF), vascular endothelial growth factor (VEGF), intercellular adhesion molecule 1 (ICAM-1), and vascular adhesion molecule 1 (VCAM-1) were altered in patient subgroups differing in demographic and clinical characteristics. Blood S100B level was positively correlated with age and duration of illness. Substantial between-study heterogeneity was observed in most molecules.

Conclusion

The alterations in certain vascular-related fluid markers in psychotic disorders suggest disturbances in normal vascular structures and functions. However, not all molecules examined displayed clear evidence of changes. While potential impacts of clinical factors, including the administered treatment, were identified, the exploration remained limited. Further studies are needed to investigate the diverse patterns of expression, and understand how these abnormalities reflect the pathophysiology of psychosis and the impact of clinical factors.

Comparison of gut microbiome profile in patients with schizophrenia and healthy controls - A plausible non-invasive biomarker?

The human gut microbiome regulates brain function through the microbiome-gut-brain axis and is implicated in several neuropsychiatric disorders. However, the relationship between the gut microbiome and the pathogenesis of schizophrenia (SCZ) is poorly defined, and very few studies have examined the effect of antipsychotic treatment response. We aim to study the differences in the gut microbiota among drug-naïve (DN SCZ) and risperidone-treated SCZ patients (RISP SCZ), compared to healthy controls (HCs). We recruited a total of 60 participants, from the clinical services of a large neuropsychiatric hospital, which included DN SCZ, RISP SCZ and HCs (n = 20 each). Fecal samples were analyzed using 16s rRNA sequencing in this cross-sectional study. No significant differences were found in taxa richness (alpha diversity) but microbial composition differed between SCZ patients (both DN and RISP) and HCs (PERMANOVA, p = 0.02). Linear Discriminant Analysis Effect Size (LEfSe) and Random Forest model identified the top six genera, which significantly differed in abundance between the study groups. A specific genus-level microbial panel of Ruminococcus, UCG005, Clostridium_sensu_stricto_1 and Bifidobacterium could discriminate SCZ patients from HCs with an area under the curve (AUC) of 0.79, HCs vs DN SCZ (AUC: 0.68), HCs vs RISP SCZ (AUC: 0.93) and DN SCZ vs RISP SCZ (AUC: 0.87). Our study identified distinct microbial signatures that could aid in the differentiation of DN SCZ, RISP SCZ, and HCs. Our findings contribute to a better understanding of the role of the gut microbiome in SCZ pathophysiology and suggest potential targeted interventions.

The deficit subtype of schizophrenia is associated with a pro-inflammatory phenotype but not with altered levels of zonulin: Findings from a case-control study

There is evidence that subclinical inflammation and increased gut permeability might be involved in the pathophysiology of schizophrenia. Less is known about these phenomena in patients with the deficit subtype of schizophrenia (D-SCZ) characterized by primary and enduring negative symptoms. Therefore, in the present study we aimed to compare the levels of zonulin (the marker of gut permeability) and immune-inflammatory markers in patients with D-SCZ, those with non-deficit schizophrenia (ND-SCZ) and healthy controls (HCs). A total of 119 outpatients with schizophrenia and 120 HCs were enrolled. The levels of 26 immune-inflammatory markers and zonulin were determined in serum samples. The following between-group differences were significant after adjustment for multiple testing and the effects of potential confounding factors: 1) higher levels of interleukin(IL)- 1β and C-reactive protein (CRP) in patients with D-SCZ compared to those with ND-SCZ and HCs; 2) higher levels of tumor necrosis factor-α and RANTES in both groups of patients with schizophrenia compared to HCs and 3) higher levels of IL-17 in patients with D-SCZ compared to HCs. No significant between-group differences in zonulin levels were found. Higher levels of IL-1β and CRP were associated with worse performance of attention after adjustment for age, education and chlorpromazine equivalents. Also, higher levels of IL-1β were correlated with greater severity of negative symptoms after adjustment for potential confounding factors. In conclusion, individuals with D-SCZ are more likely to show subclinical inflammation. However, findings from the present study do not support the hypothesis that this phenomenon is secondary to increased gut permeability.

Mental Illnesses in Inflammatory Bowel Diseases: mens sana in corpore sano

Background and aims: Inflammatory bowel diseases (IBD) are chronic disorders associated with a reduced quality of life, and patients often also suffer from psychiatric comorbidities. Overall, both mood and cognitive disorders are prevalent in chronic organic diseases, especially in the case of a strong immune component, such as rheumatoid arthritis, multiple sclerosis, and cancer. Divergent data regarding the true incidence and prevalence of mental disorders in patients with IBD are available. We aimed to review the current evidence on the topic and the burden of mental illness in IBD patients, the role of the brain-gut axis in their co-existence, and its implication in an integrated clinical management. Methods: PubMed was searched to identify relevant studies investigating the gut-brain interactions and the incidence and prevalence of psychiatric disorders, especially of depression, anxiety, and cognitive dysfunction in the IBD population. Results: Among IBD patients, there is a high prevalence of psychiatric comorbidities, especially of anxiety and depression. Approximately 20-30% of IBD patients are affected by mood disorders and/or present with anxiety symptoms. Furthermore, it has been observed that the prevalence of mental illnesses increases in patients with active intestinal disease. Psychiatric comorbidities continue to be under-diagnosed in IBD patients and remain an unresolved issue in the management of these patients. Conclusions: Psychiatric illnesses co-occurring in IBD patients deserve acknowledgment from IBD specialists. These comorbidities highly impact the management of IBD patients and should be studied as an adjunctive therapeutic target.