Stress and the brain-gut axis in functional and chronic-inflammatory gastrointestinal diseases: A transdisciplinary challenge

The Impact of Alpha-Neurofeedback Training on Gastric Slow Wave Activity and Heart Rate Variability in Humans

INTRODUCTION

Neuromodulation of cortical brain regions associated with the gut-brain axis may have the potential to modulate gastric function. Previous studies have shown phase-amplitude coupling between the electroencephalogram (EEG) alpha band frequency of the insula (Ins) and gastric slow wave (GSW) activity. This study investigated the first evidence of alpha band EEG-neurofeedback (EEG-NF) training to explore its effects on GSW activity and heart rate variability (HRV).

METHODS

A randomized crossover design was employed with 20 healthy participants attending two separate sessions [active-training: uptraining left posterior Insula (LPIns) and active-control: uptraining primary visual cortex (PVC Brodmann area 17)] following the baseline recording period. A 5-min water loading test (5WLT) was conducted following the EEG-NF sessions. Finally, a post EEG-NF/5WL period was also recorded. Participants were blinded to the training program, and the sessions were randomized and conducted at least 48 h apart. Electrocardiogram (ECG), EEG, and electrogastrogram (EGG) data were recorded throughout theexperiment. In addition, the duration of successful NF training was also extracted. Correlation analysis was performed to assess the relationships between outcome variables.

RESULTS

Pearson correlation coefficient analysis revealed a significant relationship between the duration of successful NF training and HRV metrics (RMSSD: r = 0.59; p = 0.005, SI: r = -0.59; p = 0.006) in the LPIns training group and EGG-gastric rhythm index (r = -0.40; p = 0.028) in the PVC training group. Moreover, the duration of successful LPIns NF correlated with EEG activity of the infraslow band over the left anterior Ins (r = 0.45; p = 0.043), slow band over the right posterior Ins (r = -0.5; p = 0.022), and beta band over the left (r = 0.44; p = 0.04) and right anterior Ins (r = 0.45; p = 0.04). Significant correlations were also observed between LPIns NF duration and connectivity in the beta and gamma bands between cortical regions of interest.

CONCLUSION

The alpha band EEG-NF training of LPIns demonstrated significant association with HRV, and EEG (activity and functional connectivity)measures and did not show a negative correlation with Gastric Alimetry Rhythm Index (GA-RI) following the 5WLT as in the PVC training group. These findings underscore the importance of considering the duration of successful NF as an important variable when evaluating NF training efficacy in future studies.

The effect of corticotropin-release hormone on duodenal permeability and immune activation in healthy volunteers in a double-blind placebo-controlled study

In functional dyspepsia, increased gut permeability, low-grade inflammation, and altered sensorimotor function have been reported. Both stress and corticotropin-release hormone (CRH) have been shown to increase small bowel permeability in a mast-cell-dependent manner. Moreover, eosinophil-derived CRH has been implicated in mast cell activation. The aim of this study was to evaluate whether CRH administration alters duodenal permeability and immune activation in healthy volunteers (HVs). An intravenous bolus of 100-µg CRH or placebo was administered in HVs in a crossover, double-blind, randomized manner. Two hours later, a gastroscopy was performed to measure permeability in Ussing chambers and to count mast cells and eosinophils on duodenal biopsies. Supernatant was assessed for eosinophil-derived neurotoxin (EDN), tryptase, and chymase. In addition, CRH was administrated ex vivo to baseline biopsies pretreated with or without lodoxamide. Results are described as means ± SD. P values < 0.05 were considered significant. Twenty HVs completed the study. Mast cell or eosinophil counts were not significantly altered after CRH versus Placebo (respectively P = 0.31 and P = 0.069). Tryptase, but not chymase, significantly decreased after CRH (respectively P = 0.037 and P = 0.44) with a trend for a decrease in EDN (P = 0.053). Permeability was unaltered comparing both conditions. Ex vivo, transepithelial electrical resistance significantly decreased after CRH exposure compared with baseline (P = 0.010), which was not prevented by pretreatment with lodoxamide. In vivo CRH administration reduced tryptase levels in the supernatant of duodenal biopsies without affecting permeability, whereas ex vivo duodenal permeability increased regardless of mast cell stabilization. These results suggest the involvement of mast cells in regulating gut permeability in HVs in response to CRH, possibly influenced by in vivo compensatory mechanisms.NEW & NOTEWORTHY Our investigation breaks new ground by directly examining the effects of corticotropin-release hormone (CRH) on duodenal alterations, including permeability and immune activation, in healthy subjects. Intriguingly, our findings highlight disparities between ex vivo and in vivo pathways affecting duodenal permeability, offering novel insights into the potential pathophysiology of CRH on the duodenum.

Digital Gut-Directed CBT May Improve Fecal Incontinence in IBS

INTRODUCTION

Fecal incontinence (FI) occurs in up to 20% of irritable bowel syndrome (IBS) patients, with a negative impact on quality of life, psychologic symptoms, and work impairment. We aimed to evaluate the impact of an app-based gut-directed cognitive behavioral therapy (CBT) program on IBS-associated fecal incontinence (FI) using real-world evidence from user data.

METHODS

The study population was selected from 1,383 Mahana™ IBS users who had completed a 3-month access period for a prescription CBT program between August 2021 and February 2024. Patients completed at least one of the 10-session program, completed ≥ 2 symptom log entries, reported ≥ 1 FI episode during the program, and completed assessments of symptom severity (IBS Symptom Severity Scoring System; IBS-SSS). Mixed-effects linear regression models analyzed the number of FI episodes/user during each session and changes in IBS-SSS as a function of session progression.

RESULTS

Sixty-six patients met inclusion criteria with mean age of 49 ± 18 years and a baseline IBS-SSS of 286 ± SD 104. IBS-SSS decreased to 206 ± 125 and 193 ± 129 at sessions 5 and 10, respectively (p < 0.0001). Mean FI episodes/user decreased from 5 ± 11 in session 1 to 0.5 ± 1.5 and 0.1 ± 0.3 in sessions 5 and 10, respectively (p < 0.0001). Responder analysis found that 100% of patients who completed 2 + sessions met the criteria of ≥ 50% reduction in FI episodes between their first and last session.

DISCUSSION

Our findings suggest that gut-directed digital CBT may reduce the frequency of IBS-associated FI. Future studies should evaluate how brain-gut behavioral therapies can affect anorectal mechanosensory phenomena.

Effect of Bacteroides on Crohn's disease

Crohn's disease (CD), also known as cicatrizing enteritis, is an inflammatory bowel disease that occurs in the distal ileum and right colon of unknown cause and is also called inflammatory bowel disease (IBD) with ulcerative colitis (UC). In recent years, intestinal biota have been confirmed to play a significant role in various gastrointestinal diseases. Studies have found that intestinal microbiota disorders are closely associated with the onset and progression of Crohn's disease. Bacteroidetes, the second largest microbiota in the intestine, are crucial for equilibrium in the microbiota and intestinal environment. Certain Bacteroides can induce the development of Crohn's disease and aggravate intestinal inflammation directly or through their metabolites. Conversely, certain Bacteroides can reduce intestinal inflammation and symptoms of Crohn's disease. This article reviews the effect of several intestinal Bacteroides in the onset and progression of Crohn's disease and their impact on its treatment.

Stress and the gut microbiota-brain axis

The gut microbiota-brain axis is a complex system that links the bacteria in our gut with our brain, it plays a part in what way we respond to stress. This chapter explores how stress affects the types of bacteria in the gut and shows the two-way connection between them. Stress can change the bacteria in our gut, which can cause various problems related to stress, like depression, anxiety, and irritable bowel syndrome (IBS). Figuring out how these interactions may help us develop new treatments that focus on the connection between gut bacteria and the brain. This chapter looks at how gut bacteria could help identify stress-related problems. It also discusses the difficulties and possibilities of using this research in medical practice. In the end, the chapter talks about what comes next in this quickly changing area. It highlights how important it is to include research about the gut-brain connection in overall public health plans.

Intervention and research progress of gut microbiota-immune-nervous system in autism spectrum disorders among students

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterized by difficulties in social interaction and communication, repetitive and stereotyped behaviors, restricted interests, and sensory abnormalities. Its etiology is influenced by both genetic and environmental factors, with no definitive cause identified and no specific pharmacological treatments available, posing a significant burden on patients' families and society. In recent years, research has discovered that gut microbiota dysbiosis plays a crucial role in the pathogenesis of ASD. The gut microbiota can influence brain function and behavior through the gut-brain axis via the nervous system, immune system, and metabolic pathways. On the one hand, specific gut microbes such as Clostridium and Prevotella species are found to be abnormal in ASD patients, and their metabolic products, like short-chain fatty acids, serotonin, and GABA, are also involved in the pathological process of ASD. On the other hand, ASD patients exhibit immune system dysfunction, with gut immune cells and related cytokines affecting neural activities in the brain. Currently, intervention methods targeting the gut microbiota, such as probiotics, prebiotics, and fecal microbiota transplantation, have shown some potential in improving ASD symptoms. However, more studies are needed to explore their long-term effects and optimal treatment protocols. This paper reviews the mechanisms and interrelationships among gut microbiota, immune system, and nervous system in ASD and discusses the challenges and future directions of existing research, aiming to provide new insights for the prevention and treatment of ASD.

Exploring the Therapeutic Potential of Medicinal Plants in the Context of Gastrointestinal Health: A Review

Medicinal plants represent promising sources for the treatment of gastrointestinal disorders because of their abundance in bioactive compounds with therapeutic properties. Throughout history, various plant species have been used to alleviate digestive ailments, and studies have revealed the presence of metabolites with anti-inflammatory, antibacterial, antiviral, antiparasitic, antidiarrheal, antioxidant, and anticancer activities. The secondary metabolites responsible for these properties include alkaloids, terpenoids, and phenolic compounds, with the latter, particularly flavonoids, being the most associated with their bioactivities. Gastrointestinal diseases, such as gastritis, peptic ulcers, gastroesophageal reflux disease, inflammatory bowel disease, irritable bowel syndrome, and gastrointestinal cancer, are caused primarily by bacteria, parasites, viruses, and the consumption of raw or undercooked foods. These conditions significantly impact human health, necessitating the development of safer and more effective therapeutic alternatives. After an extensive literature review, several plant species with widespread use in the treatment of these disorders were identified, including Matricaria chamomilla, Mentha spicata, Melissa officinalis, Artemisia ludoviciana, Flourensia cernua, Phoradendron californicum, and Turnera difusa. This study revealed that the analyzed plants are rich in bioactive compounds, which confer their medicinal properties. However, many other plants commonly used to treat digestive disorders have been scarcely studied, highlighting the need for further research.

Network analysis and experimental validation to investigate chenpi against functional dyspepsia through TLR4/MyD88 by regulating the gut microbial structure

Functional dyspepsia (FD) is a prevalent functional gastrointestinal disorder characterized by the absence of organic lesions; it affects nearly one-fifth of the global population. There is currently no specific drug for treating it. Citri reticulatae Pericarpium (CRP) has been utilized in China for millennia as a therapeutic agent for alleviating bloating and spleen-stomach disharmony. Nonetheless, the curative efficacy and precise molecular mechanisms implicated in FD warrant further investigation. This study aims to address this gap by investigating the potential mechanisms of CRP against FD using HPLC-ESI-QTOF-MS, network analysis prediction, and experimental validation. In this study, 90 CRP metabolites were identified by HPLC-ESI-QTOF-MS; 70 common targets of CRP and FD were extracted, and the top ten overlapped targets included MAPK1, MAPK2, and MAPK3. KEGG enrichment analysis revealed that the MAPK pathways were predominant and involved the TLR4 signaling pathway. In vivo experiments demonstrated that after 14 days of treatment, CRP improved body weight, gastric emptying rate, intestinal transit rate, and the pathological structure of the gastric tissue. Serum IL-6, TNF-α, and IL-1β were downregulated, and the expressions of TLR4, MyD88, p-NF-κB, and MAPKs were suppressed in gastric tissue. Furthermore, CRP increased the relative abundance of Patescibateria and Bacteroidota, accompanied by a reduction in the relative abundance of Verrucomicrobota and Proteobacteria. In brief, CRP could attenuate dyspepsia by reducing the activation of inflammation-related TLR4/MyD88 and MAPK signaling pathways and by mediating gut microbial structure and composition. This study provides a unique perspective for further research on drugs for treating FD.

Dysbiotic oral microbiota-derived kynurenine, induced by chronic restraint stress, promotes head and neck squamous cell carcinoma by enhancing CD8+ T cell exhaustion

BACKGROUND

Chronic restraint stress (CRS) is a tumour-promoting factor. However, the underlying mechanism is unknown.

OBJECTIVE

We aimed to investigate whether CRS promotes head and neck squamous cell carcinoma (HNSCC) by altering the oral microbiota and related metabolites and whether kynurenine (Kyn) promotes HNSCC by modulating CD8+ T cells.

DESIGN

4-nitroquinoline-1-oxide (4NQO)-treated mice were exposed to CRS. Germ-free mice treated with 4NQO received oral microbiota transplants from either CRS or control mouse donors. 16S rRNA gene sequencing and liquid chromatography-mass spectrometry were performed on mouse saliva, faecal and plasma samples to investigate alterations in their microbiota and metabolites. The effects of Kyn on HNSCC were studied using the 4NQO-induced HNSCC mouse model.

RESULTS

Mice subjected to CRS demonstrated a higher incidence of HNSCC and oral microbial dysbiosis than CRS-free control mice. Pseudomonas and Veillonella species were enriched while certain oral bacteria, including Corynebacterium and Staphylococcus species, were depleted with CRS exposure. Furthermore, CRS-altered oral microbiota promoted HNSCC formation, caused oral and gut barrier dysfunction, and induced a host metabolome shift with increased plasma Kyn in germ-free mice exposed to 4NQO treatment. Under stress conditions, we also found that Kyn activated aryl hydrocarbon receptor (AhR) nuclear translocation and deubiquitination in tumour-reactive CD8+ T cells, thereby promoting HNSCC tumourigenesis.

CONCLUSION

CRS-induced oral microbiota dysbiosis plays a protumourigenic role in HNSCC and can influence host metabolism. Mechanistically, under stress conditions, Kyn promotes CD8+ T cell exhaustion and HNSCC tumourigenesis through stabilising AhR by its deubiquitination.

Using metabolomics to investigate the relationship between the metabolomic profile of the intestinal microbiota derivatives and mental disorders in inflammatory bowel diseases: a narrative review

Individuals with inflammatory bowel disease (IBD) are at a higher risk of developing mental disorders, such as anxiety and depression. The imbalance between the intestinal microbiota and its host, known as dysbiosis, is one of the factors, disrupting the balance of metabolite production and their signaling pathways, leading to disease progression. A metabolomics approach can help identify the role of gut microbiota in mental disorders associated with IBD by evaluating metabolites and their signaling comprehensively. This narrative review focuses on metabolomics studies that have comprehensively elucidated the altered gut microbial metabolites and their signaling pathways underlying mental disorders in IBD patients. The information was compiled by searching PubMed, Web of Science, Scopus, and Google Scholar from 2005 to 2023. The findings indicated that intestinal microbial dysbiosis in IBD patients leads to mental disorders such as anxiety and depression through disturbances in the metabolism of carbohydrates, sphingolipids, bile acids, neurotransmitters, neuroprotective, inflammatory factors, and amino acids. Furthermore, the reduction in the production of neuroprotective factors and the increase in inflammation observed in these patients can also contribute to the worsening of psychological symptoms. Analyzing the metabolite profile of the patients and comparing it with that of healthy individuals using advanced technologies like metabolomics, aids in the early diagnosis and prevention of mental disorders. This approach allows for the more precise identification of the microbes responsible for metabolite production, enabling the development of tailored dietary and pharmaceutical interventions or targeted manipulation of microbiota.

Stress regulatory hormones and cancer: the contribution of epinephrine and cancer therapeutic value of beta blockers

The word "cancer" evokes myriad emotions, ranging from fear and despair to hope and determination. Cancer is aptly defined as a complex and multifaceted group of diseases that has unapologetically led to the loss of countless lives and affected innumerable families across the globe. The battle with cancer is not only a physical battle, but also an emotional, as well as a psychological skirmish for patients and for their loved ones. Cancer has been a part of our history, stories, and lives for centuries and has challenged the ingenuity of health and medical science, and the resilience of the human spirit. From the early days of surgery and radiation therapy to cutting-edge developments in chemotherapeutic agents, immunotherapy, and targeted treatments, the medical field continues to make significant headway in the fight against cancer. However, even after all these advancements, cancer is still among the leading cause of death globally. This urges us to understand the central hallmarks of neoplastic cells to identify novel molecular targets for the development of promising therapeutic approaches. Growing research suggests that stress mediators, including epinephrine, play a critical role in the development and progression of cancer by inducing neoplastic features through activating adrenergic receptors, particularly β-adrenoreceptors. Further, our experimental data has also shown that epinephrine mediates the growth of T-cell lymphoma by inducing proliferation, glycolysis, and apoptosis evasion via altering the expression levels of key regulators of these vital cellular processes. The beauty of receptor-based therapy lies in its precision and higher therapeutic value. Interestingly, the enhanced expression of β-adrenergic receptors (ADRBs), namely ADRB2 (β2-adrenoreceptor) and ADRB3 (β3-adrenoreceptor) has been noted in many cancers, such as breast, colon, gastric, pancreatic, and prostate and has been reported to play a pivotal role in facilitating cancer growth mainly by promoting proliferation, evasion of apoptosis, angiogenesis, invasion and metastasis, and chemoresistance. The present review article is an attempt to summarize the available findings which indicate a distinct relationship between stress hormones and cancer, with a special emphasis on epinephrine, considered as a key stress regulatory molecule. This article also discusses the possibility of using beta-blockers for cancer therapy.

A systematic review of preclinical studies targeted toward the management of co-existing functional gastrointestinal disorders, stress, and gut dysbiosis

Modern dietary habits and stressed lifestyle have escalated the tendency to develop functional gastrointestinal disorders (FGIDs) through alteration in the gut-brain-microbiome axis. Clinical practices use symptomatic treatments, neglect root causes, and prolong distress in patients. The past decade has seen the evolution of various interventions to attenuate FGIDs. But clinical translation of such studies is very rare mostly due to lack of awareness. The aim of this review is to meticulously integrate different studies and bridge this knowledge gap. Literature between 2013 and 2023 was retrieved from PubMed, ProQuest, and Web of Science. The data was extracted based on the PRISMA guidelines and using the SYRCLE's risk of bias and the Cochrane Risk of Bias tools, quality assessment was performed. The review has highlighted molecular insights into the coexistence of FGIDs, stress, and gut dysbiosis. Furthermore, novel interventions focusing on diet, probiotics, herbal formulations, and phytoconstituents were explored which mostly had a multitargeted approach for the management of the diseases. Scientific literature implied positive interactions between the interventions and the gut microbiome by increasing the relative abundance of beneficial bacteria and reducing stress-related hormones. Moreover, the interventions reduced intestinal inflammation and regulated the expression of epithelial tight junction proteins in different in vivo models. This systematic review delves deep into the preclinical interventions to manage coexisting FGIDs, stress, and gut dysbiosis. However, in most of the discussed studies, long-term risks and toxicity profile of the interventions are lacking. So, it is necessary to highlight them for improved clinical outcomes.

Sex differences in the reactivity of gastric myoelectrical activity and heart rate variability as putative psychophysiological markers in human pain research

Background

This study explored the potential of electrogastrography (EGG) and heart rate variability (HRV) as psychophysiological markers in experimental pain research related to the gut-brain axis. We investigated responses to the experience of pain from the visceral (rectal distension) and somatic (cutaneous heat) pain modalities, with a focus on elucidating sex differences in EGG and HRV responses.

Methods

In a sample of healthy volunteers (29 males, 43 females), EGG and ECG data were collected during a baseline and a pain phase. Data were analyzed for changes in gastric myoelectrical activity and cardiac autonomic regulation, with special attention to sex-specific patterns and correlations with perceptual responses to visceral and somatic pain stimuli, assessed by visual analogue scale ratings.

Results

Acute pain induced significant instability in EGG slow-wave frequency and amplitude, increased tachygastria, and decreased normogastric spectral power, without evidence of sex differences. HRV analyses revealed increases in SDNN, RMSSD, and pNN50 during pain, indicating sympathovagal regulation changes. While there were no significant sex differences in EGG responses, only female participants exhibited significant correlations between visceral pain unpleasantness and EGG alterations. HRV measures, particularly time-domain parameters, showed sex differences, independent of pain-induced autonomic reactivity.

Conclusion

The experience of pain in the lower abdominal region may induce impaired gastric motility. EGG and HRV are sensitive to acute pain and offer insight into pain mechanisms along the gut-brain axis. While EGG responses were consistent across sexes, HRV revealed sex-specific differences, suggesting that autonomic regulation and gastric motility may be modulated differently by pain and psychosocial factors. Further research in patients with chronic visceral pain is warranted.

Daily intake of a dairy-based nutritional supplement improved self-reported gastrointestinal symptoms and modulated microbiota in adult Chinese volunteers

Mild and persisting gastrointestinal symptoms (MPGS) as bloating, constipation or diarrhea are widespread in older adults and often accompanied by gut microbiota dysbiosis. Nutritional interventions help to regulate and restore microbiota and gut function. In this non-randomized continuous prospective cohort study, we evaluated the effects of a 21-day intervention using a dietary dairy-based supplement (AGIJOY™) on self-reported gastrointestinal (GI) symptoms, fecal microbiota composition and short chain fatty acids (SCFA) levels in a cohort of Chinese adults (N = 46, age 27-73) suffering from MPGS. Questionnaire data and fecal samples were collected at baseline (D0), on day 7 and 21 of intervention (D7 and D21). The results showed significant improvement in the self-reported GI symptoms on D21 and a gradual shift in the fecal microbiota composition. In the first week of intervention, the relative abundance (RA) of fecal bifidobacteria significantly increased and the RA of Bacteroides and Helicobacter decreased (p < 0.05). The levels of fecal SCFA remained unchanged during the study. To our knowledge, this is the first study testing the effect of this prebiotic and postbiotic containing milk-based supplement blend on gut microbiota and MPGS among Chinese population under a real living environment.

Participants' perspectives on a multimodal stress management and comprehensive lifestyle modification program for patients with Crohn's disease-A qualitative interview study

BACKGROUND

Crohn's disease (CD) is a type of inflammatory bowel disease (IBD) that is prevalent worldwide and associated with reduced quality of life for patients. Multimodal therapy approaches, which emphasize lifestyle modifications such as mindfulness and stress reduction, can be promising in enhancing health-related quality of life for IBD patients. However, research on multimodal therapy approaches for CD remains insufficient.

METHOD

This qualitative interview study is part of a mixed-methods approach that is embedded in a randomized controlled trial. It investigates the impact of a comprehensive 10-week day clinic lifestyle modification program on the health condition and quality of life of CD patients. Telephone interviews (n = 19) were conducted three months after the program to examine individuals' viewpoints on the intervention, including perceived changes and transfer of elements into daily life. Reflexive thematic analysis was performed using MAXQDA software.

RESULTS

The results indicate that CD can have very individual and comprehensive impacts (psychological, physical, social), leading to reduced perceived quality of life and well-being. By participating in the program, patients wanted to find self-help options to complement conventional pharmacotherapy and actively manage their disease. Patients expressed high satisfaction with the program, feeling it provided valuable support for daily disease management. They were able to integrate adequate therapy elements into their routines to complement their care. Patients recognized significant improvements in various domains, mainly in the psychological domain, e.g., improved self-efficacy, symptom management, and, also partly physical/symptomatic and social improvements.

CONCLUSION

A multimodal stress reduction and lifestyle modification day clinic appears to be beneficial as a complementary therapy for CD patients. It offers additional options and helps patients to address individual symptoms and needs, improve their understanding of the disease and their quality of life. Although promising, further research is needed to assess its long-term effects.

TRIAL REGISTRATION

ClinicalTrials.gov, identifier: NCT05182645.

Influence of Psychological Stress on the Response to Periodontal Treatment: Protocol for a Systematic Review

BACKGROUND

The interaction between stress and periodontal treatment is a topic of growing interest. It stands out as a field of research that sheds light on the complexity of oral health in individuals subjected to high levels of emotional stress.

OBJECTIVE

This paper aims to provide a protocol for a systematic review to examine the scientific evidence related to the influence of psychological stress on the response to periodontal treatment.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines will be followed, and the study is based on a formulation of PECO (Participants, Exposure, Comparators, and Outcomes) questions. This systematic review will involve a literature search covering studies published from January 2000 to May 2024. It will include searching the PubMed, Web of Science, EBSCOHost, Scopus, and ProQuest databases to identify relevant studies. After selection, data extraction and quality assessment (using the Ottawa-Newcastle Scale) of the included studies will be carried out. The objective is to integrate high-quality evidence on how psychological stress impacts the outcomes of periodontal treatment. Depending on the number and methodological consistency of included studies, the results may be presented by meta-analysis or qualitative synthesis.

RESULTS

The current stage of the study consists of selecting studies for the systematic review as outlined by this protocol. The search, screening, and data extraction began in January 2024. The final results are expected by July 2024, with final manuscript submission planned for November 2024.

CONCLUSIONS

This review will help clarify how psychological factors, such as stress, influence the results of periodontal treatment, providing valuable guidelines for future research and helping clinicians make decisions about the best treatment options for patients.

TRIAL REGISTRATION

Open Science Framework (OSF) Registries qfs6p; https://osf.io/qfs6p.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/56765.

Disease-specific alterations in central fear network engagement during acquisition and extinction of conditioned interoceptive fear in inflammatory bowel disease

Interoceptive fear, which is shaped by associative threat learning and memory processes, plays a central role in abnormal interoception and psychiatric comorbidity in conditions of the gut-brain axis. Although animal and human studies support that acute inflammation induces brain alterations in the central fear network, mechanistic knowledge in patients with chronic inflammatory conditions remains sparse. We implemented a translational fear conditioning paradigm to elucidate central fear network reactivity in patients with quiescent inflammatory bowel disease (IBD), compared to patients with irritable bowel syndrome (IBS) and healthy controls (HC). Using functional magnetic resonance imaging, conditioned differential neural responses within regions of the fear network were analyzed during acquisition and extinction learning. In contrast to HC and IBS, IBD patients demonstrated distinctly altered engagement of key regions of the central fear network, including amygdala and hippocampus, during differential interoceptive fear learning, with more pronounced responses to conditioned safety relative to pain-predictive cues. Aberrant hippocampal responses correlated with chronic stress exclusively in IBD. During extinction, differential engagement was observed in IBD compared to IBS patients within amygdala, ventral anterior insula, and thalamus. No group differences were found in changes of cue valence as a behavioral measure of fear acquisition and extinction. Together, the disease-specific alterations in neural responses during interoceptive fear conditioning in quiescent IBD suggest persisting effects of recurring intestinal inflammation on central fear network reactivity. Given the crucial role of interoceptive fear in abnormal interoception, these findings point towards inflammation-related brain alterations as one trajectory to bodily symptom chronicity and psychiatric comorbidity. Patients with inflammatory conditions of the gut-brain axis may benefit from tailored treatment approaches targeting maladaptive interoceptive fear.

Stress increases sperm respiration and motility in mice and men

Semen quality and fertility has declined over the last 50 years, corresponding to ever-increasing environmental stressors. However, the cellular mechanisms involved and their impact on sperm functions remain unknown. In a repeated sampling human cohort study, we identify a significant effect of prior perceived stress to increase sperm motility 2-3 months following stress, timing that expands upon our previous studies revealing significant stress-associated changes in sperm RNA important for fertility. We mechanistically examine this post-stress timing in mice using an in vitro stress model in the epididymal epithelial cells responsible for sperm maturation and find 7282 differentially H3K27me3 bound DNA regions involving genes critical for mitochondrial and metabolic pathways. Further, prior stress exposure significantly changes the composition and size of epithelial cell-secreted extracellular vesicles that when incubated with mouse sperm, increase mitochondrial respiration and sperm motility, adding to our prior work showing impacts on embryo development. Together, these studies identify a time-dependent, translational signaling pathway that communicates stress experience to sperm, ultimately affecting reproductive functions.

Role of stress and early-life stress in the pathogeny of inflammatory bowel disease

Numerous preclinical and clinical studies have shown that stress is one of the main environmental factor playing a significant role in the pathogeny and life-course of bowel diseases. However, stressful events that occur early in life, even during the fetal life, leave different traces within the central nervous system, in area involved in stress response and autonomic network but also in emotion, cognition and memory regulation. Early-life stress can disrupt the prefrontal-amygdala circuit thus favoring an imbalance of the autonomic nervous system and the hypothalamic-pituitary adrenal axis, resulting in anxiety-like behaviors. The down regulation of vagus nerve and cholinergic anti-inflammatory pathway favors pro-inflammatory conditions. Recent data suggest that emotional abuse at early life are aggravating risk factors in inflammatory bowel disease. This review aims to unravel the mechanisms that explain the consequences of early life events and stress in the pathophysiology of inflammatory bowel disease and their mental co-morbidities. A review of therapeutic potential will also be covered.

Food-Intolerance Genetic Testing: A Useful Tool for the Dietary Management of Chronic Gastrointestinal Disorders

The rise in food intolerances and celiac disease, along with advanced diagnostic techniques, has prompted health professionals to seek effective and economical testing methods. This study evaluates combining genetic tests with routine carbohydrate-absorption breath tests to classify patients with chronic gastrointestinal disorders into therapeutic groups, enhancing dietary management and improving gut health and quality of life. Forty-nine patients with suspected carbohydrate intolerance underwent genetic testing for lactase non-persistence, hereditary fructose intolerance, and celiac disease risk. Simultaneously, breath tests assessed lactose and fructose absorption. The lactase non-persistence genotype appeared in 36.7% of cases, with one hereditary fructose-intolerance case in a heterozygous condition. Celiac disease risk markers (HLA-DQ2/8 haplotypes) were found in 49.0% of the population. Secondary lactose and/or fructose malabsorption was present in 67.3% of patients, with 66.1% of lactase non-persistence individuals showing secondary lactose malabsorption. Fructose malabsorption was prevalent in 45.8% of patients at risk for celiac disease. Two main treatment groups were defined based on genetic results, indicating primary and irreversible gastrointestinal disorder causes, followed by a sub-classification using breath test results. Genetic testing is a valuable tool for designing dietary management plans, avoiding unnecessary diet restrictions, and reducing recovery times.

Ex Vivo Study of Colon Health, Contractility and Innervation in Male and Female Rats after Regular Exposure to Instant Cascara Beverage

Instant Cascara (IC) is a sustainable beverage made from dried coffee cherry pulp, a by-product of coffee processing. It is rich in nutrients and bioactive compounds and has a high concentration of antioxidants. This study explored the impact of regular IC consumption on colonic motor function and innervation. Over a period of 4 weeks, male and female healthy rats were given drinking water containing 10 mg/mL of IC. Thereafter, colon samples were obtained to evaluate the longitudinal (LM) and circular (CM) smooth muscle contractile response to acetylcholine (ACh) and electrical field stimulation (EFS) in an organ bath, before and after atropine administration (10-6 M). Histological and immunohistochemical analyses assessed colon damage, muscle thickness, and immunoreactivity to substance P (SP) and neuronal nitric oxide synthase (nNOS). ACh and EFS induced similar responses across groups, but the CM response to EFS was greater in females compared with males, despite their lower body weight. Atropine completely blocked the response to ACh but only partially antagonized the neural response to EFS, particularly that of CM in females treated with IC, which had a greater liquid intake than those exposed to water. However, in the myenteric ganglia, no statistically significant differences were observed in SP or nNOS. Our results suggest that regular IC exposure may enhance specific neural pathway functions, particularly in females, possibly due to their increased IC consumption.

Potential Risk Factors of Disorders of Gut-Brain Interaction in Undergraduates and Postgraduates: Partially Mediated by Life Stress and Lifestyle

INTRODUCTION

This study aimed to investigate the prevalence of disorders of gut-brain interaction (DGBI) and life stress in college students, and explore risk factors of DGBI in college students and the role of life stress.

METHODS

A total of 2,578 college students filled up validated questionnaires assessing GI symptoms, lifestyle, and life stress. Participants were diagnosed as DGBI based on the Rome III criteria. Multivariate ordinal logistic regression analysis and mediation effect model were employed to explore potential risk factors of DGBI and the mediating role of life stress and lifestyle in DGBI.

RESULTS

A total of 437 of 2,578 (17.0%) college students were diagnosed with DGBI. College students with DGBI had higher levels of life stress, including eight specific categories. Females (1.709 [1.437, 2.033]), staying up late (1.519 [1.300, 1.776]), and life stress (1.008 [1.006, 1.010]) were risk factors for DGBI, while postgraduates (0.751 [0.578, 0.976]) and regular diet (0.751 [0.685, 0.947]) were protective factors. Males and poor family economic were associated with a higher risk of DGBI after controlling stress, while an association between grade and DGBI was mediated by stress, regular diet, and sleep habits.

CONCLUSION

DGBI was common among college students. Life stress and lifestyle were associated with DGBI and mediated partial association between grade and DGBI in college students. More attention should be paid to undergraduates.

Alleviating depressive-like behavior in DSS-induced colitis mice: Exploring naringin and poncirin from Poncirus trifoliata extracts

Patients with inflammatory bowel diseases (IBDs), including ulcerative colitis (UC) and Crohn's disease (CD), often have concomitant mental disorders such as depression and anxiety. Therefore, a bidirectional approach involving the gut and brain axes is necessary for the prevention and treatment thereof. In this study, we explored the potential of Poncirus trifoliata extract (PT), traditionally known for its neuroprotective effects against gastrointestinal diseases, as a natural treatment agent for IBD in a dextran sulfate sodium (DSS)-induced colitis model. Oral administration of PT ameliorated weight loss and inflammatory responses in mice with DSS-induced colitis. Furthermore, PT treatment effectively restored the colon length and ameliorated enterocyte death by inhibiting DSS-induced reactive oxygen species (ROS)-mediated necroptosis. The main bioactive components of PT, poncirin and naringin, confirmed using ultra-performance liquid chromatography-quadrupole time-of-flight (UPLC-qTOF), can be utilized to regulate necroptosis. The antidepressant-like effects of PT were confirmed using open field test (OFT) and tail suspension test (TST). PT treatment also restored vascular endothelial cell integrity in the hippocampus. In the Cornu Ammonis 1 (CA1) and dentate gyrus (DG) regions of the hippocampus, PT controlled the neuroinflammatory responses of proliferated microglia. In conclusion, PT, which contains high levels of poncirin and naringin, has potential as a bidirectional therapeutic agent that can simultaneously improve IBD-associated intestinal and mental disorders.

Research Progress of Central and Peripheral Corticotropin-Releasing Hormone in Irritable Bowel Syndrome with Comorbid Dysthymic Disorders

Irritable bowel syndrome (IBS) is considered a stress disorder characterized by psychological and gastrointestinal dysfunction. IBS patients not only suffer from intestinal symptoms such as abdominal pain, diarrhea, or constipation but also, experience dysthymic disorders such as anxiety and depression. Studies have found that corticotropin-releasing hormone plays a key role in IBS with comorbid dysthymic disorders. Next, we will summarize the effects of corticotropin-releasing hormone from the central nervous system and periphery on IBS with comorbid dysthymic disorders and relevant treatments based on published literatures in recent years.

The central executive network moderates the relationship between posttraumatic stress symptom severity and gastrointestinal related issues

Although most adults experience at least one traumatic event in their lifetime, a smaller proportion will go on to be clinically diagnosed with post-traumatic stress disorder (PTSD). Persons diagnosed with PTSD have a greater likelihood of developing gastrointestinal (GI) disorders. However, the extent to which subclinical levels of post-traumatic stress (PTS) correspond with the incidence of GI issues in a normative sample is unclear. Resting state fMRI, medical history, psychological survey, and anthropometric data were acquired from the Enhanced Nathan Kline Institute-Rockland Sample (n = 378; age range 18-85.6 years). The primary aim of this study was to test the main effect of subclinical PTS symptom severity on the number of endorsed GI issues. The secondary aim was to test the moderating effect of high versus low resting state functional connectivity (rsFC) of the central executive network (CEN) on the relationship between PTS symptom severity and GI issues. Trauma Symptom Checklist-40 (TSC-40) scores were positively associated with the number of endorsed GI issues (b = -0.038, SE = .009, p < .001). The interaction between TSC-40 scores and rsFC within the CEN was significant on GI issues after controlling for sociodemographic and cardiometabolic variables (b = -0.031, SE = .016, p < .05), such that above average rsFC within the CEN buffered the effect of TSC-40 scores on GI issues. Our findings of higher rsFC within the CEN moderating the magnitude of coincidence in PTS and GI symptom severity may reflect the mitigating role of executive control processes in the putative stress signaling mechanisms that contribute to gut dysbiosis.

Biobehavioral approach to distinguishing panic symptoms from medical illness

Panic disorder is a common psychiatric diagnosis characterized by acute, distressing somatic symptoms that mimic medically-relevant symptoms. As a result, individuals with panic disorder overutilize personal and healthcare resources in an attempt to diagnose and treat physical symptoms that are often medically benign. A biobehavioral perspective on these symptoms is needed that integrates psychological and medical knowledge to avoid costly treatments and prolonged suffering. This narrative review examines six common somatic symptoms of panic attacks (non-cardiac chest pain, palpitations, dyspnea, dizziness, abdominal distress, and paresthesia), identified in the literature as the most severe, prevalent, or critical for differential diagnosis in somatic illness, including long COVID. We review somatic illnesses that are commonly comorbid or produce panic-like symptoms, their relevant risk factors, characteristics that assist in distinguishing them from panic, and treatment approaches that are typical for these conditions. Additionally, this review discusses key factors, including cultural considerations, to assist healthcare professionals in differentiating benign from medically relevant symptoms in panic sufferers.

Faecal incontinence with concurrent disorders of gut-brain interaction: A worse outcome

BACKGROUND

Faecal incontinence is a common debilitating condition associated with poor quality of life that generates substantial economic strain on healthcare systems.

OBJECTIVES

We aimed to evaluate, in a tertiary referral population presenting with faecal incontinence, the impact of suffering additional disorders of gut-brain interaction (DGBI) on symptom severity, anxiety, depression and quality of life.

METHODS

Design: Retrospective cohort study.

SETTING

Tertiary referral Neurogastroenterology centre.

PATIENTS

All patients presenting with faecal incontinence from 2007 to 2020 were included.

MAIN OUTCOME MEASURES

The results from structured medical and surgical questionnaires including Rome III Integrative Questionnaire, Faecal Incontinence Severity Index, Hospital Anxiety and Depression Scale, SF-36, and anorectal physiology were analysed using Stata version 17. Patients were categorised into 3 groups: 0-1 additional DGBI, 2 DGBIs, and 3+ DGBI. Statistical significance was defined as p < 0.05 (two-tailed).

KEY RESULTS

Faecal incontinence patients (n = 249; mean age 63.4 ± 12.6 years; 93.6% female, 48.1% urge subtype) met diagnostic criteria for mean 2.2 additional DGBI each, mostly affecting bowel (n = 231, 42.4%) and anorectal (n = 150, 27.5%) regions. A greater number of DGBIs was associated with higher faecal incontinence symptom severity (p < 0.001), higher anxiety (p = 0.002) and depression (p = 0.003), and worse quality of life in areas of mental health (p = 0.037) and social effect (p < 0.001). Patients with a greater number of concurrent DGBI demonstrated a greater family history of gastrointestinal problems (p = 0.004). There were no associations found between a greater amount of DGBIs and anorectal physiology.

CONCLUSIONS AND INFERENCES

A greater number of additional DGBIs in faecal incontinence patients was associated with worse faecal incontinence symptoms, higher anxiety and depression scores, and worse quality of life but was unrelated to physiology. This highlights the need to proactively search for comorbid DGBI in patients presenting with faecal incontinence.

Effects of corticotropin-releasing hormone on gastric electrical activity and sensorimotor function in healthy volunteers: a double-blinded crossover study

Biopsychosocial factors are associated with disorders of gut-brain interaction (DGBI) and exacerbate gastrointestinal symptoms. The mechanisms underlying pathophysiological alterations of stress remain unclear. Corticotropin-releasing hormone (CRH) is a central regulator of the hormonal stress response and has diverse impact on different organ systems. The aim of the present study was to investigate the effects of peripheral CRH infusion on meal-related gastrointestinal symptoms, gastric electrical activity, and gastric sensorimotor function in healthy volunteers (HVs). In a randomized, double-blinded, placebo-controlled, crossover study, we evaluated the effects of CRH on gastric motility and sensitivity. HVs were randomized to receive either peripheral-administered CRH (100 µg bolus + 1 µg/kg/h) or placebo (saline), followed by at least a 7-day washout period and assignment to the opposite treatment. Tests encompassed saliva samples, gastric-emptying (GE) testing, body surface gastric mapping (BSGM, Gastric Alimetry; Alimetry) to assess gastric myoelectrical activity with real-time symptom profiling, and a gastric barostat study to assess gastric sensitivity to distention and accommodation. Twenty HVs [13 women, mean age 29.2 ± 5.3 yr, body mass index (BMI) 23.3 ± 3.8 kg/m2] completed GE tests, of which 18 also underwent BSGM measurements during the GE tests. The GE half-time decreased significantly after CRH exposure (65.2 ± 17.4 vs. 78.8 ± 24.5 min, P = 0.02) with significantly increased gastric amplitude [49.7 (34.7-55.6) vs. 31.7 (25.7-51.0) µV, P < 0.01], saliva cortisol levels, and postprandial symptom severity. Eleven HVs also underwent gastric barostat studies on a separate day. However, the thresholds for discomfort during isobaric distensions, gastric compliance, and accommodation did not differ between CRH and placebo.NEW & NOTEWORTHY In healthy volunteers, peripheral corticotropin-releasing hormone (CRH) infusion accelerates gastric-emptying rate and increases postprandial gastric response, accompanied by a rise in symptoms, but does not alter gastric sensitivity or meal-induced accommodation. These findings underscore a significant link between stress and dyspeptic symptoms, with CRH playing a pivotal role in mediating these effects.

Role of CRH in colitis and colitis-associated cancer: a combinative result of central and peripheral effects?

Corticotropin-releasing factor family peptides (CRF peptides) comprise corticotropin releasing hormone (CRH), urocortin (UCN1), UCN2 and UCN3. CRH is first isolated in the brain and later with UCNs found in many peripheral cells/tissues including the colon. CRH and UCNs function via the two types of receptors, CRF1 and CRF2, with CRH mainly acting on CRF1, UCN1 on both CRF1 &CRF2 and UCN2-3 on CRF2. Compiling evidence shows that CRH participates in inflammation and cancers via both indirect central effects related to stress response and direct peripheral influence. CRH, as a stress-response mediator, plays a significant central role in promoting the development of colitis involving colon motility, immunity and gut flora, while a few anti-colitis results of central CRH are also reported. Moreover, CRH is found to directly influence the motility and immune/inflammatory cells in the colon. Likewise, CRH is believed to be greatly related to tumorigenesis of many kinds of cancers including colon cancer via the central action during chronic stress while the peripheral effects on colitis-associated-colon cancer (CAC) are also proved. We and others observe that CRH/CRF1 plays a significant peripheral role in the development of colitis and CAC in that CRF1 deficiency dramatically suppresses the colon inflammation and CAC. However, up to date, there still exist not many relevant experimental data on this topic, and there seems to be no absolute clearcut between the central and direct peripheral effects of CRH in colitis and colon cancer. Taken together, CRH, as a critical factor in stress and immunity, may participate in colitis and CAC as a centrally active molecule; meanwhile, CRH has direct peripheral effects regulating the development of colitis and CAC, both of which will be summarized in this review.

Microbial and Metabolite Signatures of Stress Reactivity in Ulcerative Colitis Patients in Clinical Remission Predict Clinical Flare Risk

BACKGROUND

Stress reactivity (SR) is associated with increased risk of flares in ulcerative colitis (UC) patients. Because both preclinical and clinical data support that stress can influence gut microbiome composition and function, we investigated whether microbiome profiles of SR exist in UC.

METHODS

Ninety-one UC subjects in clinical and biochemical remission were classified into high and low SR groups by questionnaires. Baseline and longitudinal characterization of the intestinal microbiome was performed by 16S rRNA gene sequencing and fecal and plasma global untargeted metabolomics. Microbe, fecal metabolite, and plasma metabolite abundances were analyzed separately to create random forest classifiers for high SR and biomarker-derived SR scores.

RESULTS

High SR reactivity was characterized by altered abundance of fecal microbes, primarily in the Ruminococcaceae and Lachnospiraceae families; fecal metabolites including reduced levels of monoacylglycerols (endocannabinoid-related) and bile acids; and plasma metabolites including increased 4-ethyl phenyl sulfate, 1-arachidonoylglycerol (endocannabinoid), and sphingomyelin. Classifiers generated from baseline microbe, fecal metabolite, and plasma metabolite abundance distinguished high vs low SR with area under the receiver operating characteristic curve of 0.81, 0.83, and 0.91, respectively. Stress reactivity scores derived from these classifiers were significantly associated with flare risk during 6 to 24 months of follow-up, with odds ratios of 3.8, 4.1, and 4.9. Clinical flare and intestinal inflammation did not alter fecal microbial abundances but attenuated fecal and plasma metabolite differences between high and low SR.

CONCLUSIONS

High SR in UC is characterized by microbial signatures that predict clinical flare risk, suggesting that the microbiome may contribute to stress-induced UC flares.

Evaluation of a Multimodal Stress Management and Comprehensive Lifestyle Modification Program on Quality of Life and Gastrointestinal Symptoms in Patients with Crohn's Disease: A Randomized Controlled Pilot Trial with 9-Month Follow-Up

INTRODUCTION

Stress and lifestyle factors impact the course of Crohn's disease (CD). Our primary objective was to assess whether patients with CD benefit from a mind-body-medicine stress management and lifestyle modification (MBM) program.

METHODS

This 9-month two-arm pilot trial was conducted in Bamberg, Germany (2020-2021). Patients (18-75 years) with mild to moderate activity of CD and stable medication were enrolled and randomly assigned to either a 10-week MBM program (intervention group, IG) or a single 90-min education session (waiting list control group, CG). Primary endpoints were quality of life (IBDQ) and disease activity (HBI). Secondary endpoints were emotional distress, core self-evaluation, and inflammatory biomarkers 3 and 9 months after baseline assessment.

RESULTS

We analyzed data from 37 patients (IG: n = 19, mean ± SD age 49.6 ± 13.1 years, 68% female; CG: 18, 46.8 ± 11.4, 67% female). Immediately after the intervention, 79% (IG) and 44% (CG) experienced a clinically relevant improvement (IBDQ score ≥16 points). This was similar after 9 months (63% vs. 44%). There was no difference in disease activity (3 months: p = 0.082, 95% CI -1.3 to 2.6; 9 months: p = 0.251, 95% CI -1.2 to 2.5). Secondary outcomes indicated improvements in emotional distress, core self-evaluation, erythrocyte sedimentation rate after three and in emotional distress, T-cell profiling in the blood, and fecal lactoferrin and calprotectin group after 9 months in the IG.

CONCLUSION

Our study suggested benefits of a multimodal stress management and lifestyle modification program for patients with CD. Larger trials are needed to determine if the program can supplement or at least partially replace pharmacological treatment approaches.

Appraising the causal association between Crohn's disease and breast cancer: a Mendelian randomization study

Background

Previous research has indicated that there may be a link between Crohn's disease (CD) and breast cancer (BC), but the causality remains unclear. This study aimed to investigate the causal association between CD and BC using Mendelian randomization (MR) analysis.

Methods

The summary data for CD (5,956 cases/14,927 controls) was obtained from the International Inflammatory Bowel Disease Genetics Consortium (IIBDGC). And the summary data for BC (122,977 cases/105,974 controls) was extracted from the Breast Cancer Association Consortium (BCAC). Based on the estrogen receptor status, the cases were classified into two subtypes: estrogen receptor-positive (ER+) BC and estrogen receptor-negative (ER-) BC. We used the inverse variance weighted method as the primary approach for two-sample MR. MR-PRESSO method was used to rule out outliers. Heterogeneity and pleiotropy tests were carried out to improve the accuracy of results. Additionally, multivariable MR was conducted by adjusting for possible confounders to ensure the stability of the results.

Results

The two-sample MR indicated that CD increased the risks of overall (OR: 1.020; 95% CI: 1.010-1.031; p=0.000106), ER+ (OR: 1.019; 95%CI: 1.006-1.034; p=0.006) and ER- BC (OR: 1.019; 95%CI: 1.000-1.037; p=0.046) after removal of outliers by MR-PRESSO. This result was reliable in the sensitivity analysis, including Cochran's Q and MR-Egger regression. In multivariate MR analyses, after adjusting for smoking and drinking separately or concurrently, the positive association between CD and the risks of overall and ER+ BC remained, but it disappeared in ER- BC. Furthermore, reverse MR analysis suggested that BC did not have a significant impact on CD risk.

Conclusion

Our findings provide evidence for a possible positive association between CD and the risk of BC. However, further studies are needed to fully understand the underlying mechanisms and establish a stronger causal relationship.

Gastrointestinal Disorders and Atopic Dermatitis in Infants in the First Year of Life According to ROME IV Criteria-A Possible Association with the Mode of Delivery and Early Life Nutrition

Background: Functional gastrointestinal disorders are very common condition. The aim of this study is to evaluate the implications of the mode of pregnancy termination and early infant feeding on the incidence of gastrointestinal disorders and atopic dermatitis at birth and 3, 6, and 12 months of age. Methods: This study included 82 pregnant women and their newborns born at term. All newborns were examined at birth and 3, 6, and 12 months of age according to the ROME IV criteria. Results: In children born after cesarean section, the incidence of regurgitation was significantly higher. In children fed mostly or exclusively with formula, dry skin with allergic features was observed more often compared to breastfed children, but this relation was statistically significant only at the age of 12 months. The use of antibiotic therapy increased the risk of allergic skin lesions by almost seven times at 3 months of life. Gastrointestinal disorders in the form of regurgitation, colic, and constipation occur within the period of up to 12 months of the child's life and may be related to the mode of the termination of pregnancy via cesarean section and the use of artificial feeding or antibiotic therapy. The occurrence of atopic dermatitis in infants at 12 months of life is correlated with the mode of the termination of pregnancy after cesarean section. Conclusions: One of the risk factors for the occurrence of atopic dermatitis and gastrointestinal disorders in the period up to 12 months of the child's life may be a cesarean section and the use of formula feeding or antibiotic therapy.

From the Gut to the Brain: The Role of Enteric Glial Cells and Their Involvement in the Pathogenesis of Parkinson's Disease

The brain-gut axis has been identified as an important contributor to the physiopathology of Parkinson's disease. In this pathology, inflammation is thought to be driven by the damage caused by aggregation of α-synuclein in the brain. Interestingly, the Braak's theory proposes that α-synuclein misfolding may originate in the gut and spread in a "prion-like" manner through the vagus nerve into the central nervous system. In the enteric nervous system, enteric glial cells are the most abundant cellular component. Several studies have evaluated their role in Parkinson's disease. Using samples obtained from patients, cell cultures, or animal models, the studies with specific antibodies to label enteric glial cells (GFAP, Sox-10, and S100β) seem to indicate that activation and reactive gliosis are associated to the neurodegeneration produced by Parkinson's disease in the enteric nervous system. Of interest, Toll-like receptors, which are expressed on enteric glial cells, participate in the triggering of immune/inflammatory responses, in the maintenance of intestinal barrier integrity and in the configuration of gut microbiota; thus, these receptors might contribute to Parkinson's disease. External factors like stress also seem to be relevant in its pathogenesis. Some authors have studied ways to reverse changes in EGCs with interventions such as administration of Tryptophan-2,3-dioxygenase inhibitors, nutraceuticals, or physical exercise. Some researchers point out that beyond being activated during the disease, enteric glial cells may contribute to the development of synucleinopathies. Thus, it is still necessary to further study these cells and their role in Parkinson's disease.

Determining Risk Factors for Functional Gastrointestinal Disorder among Muslim University Students in Indonesia

Functional gastrointestinal disorders (FGIDs) are disorders of the gastrointestinal tract without a clear structural or biochemical cause. FGIDs can interfere with a person's daily life. Several psychological conditions can cause FGIDs as psychosomatic disorders. Five factors are thought to affect a person's FGID condition, namely Generalized Anxiety Disorder (GAD), life satisfaction, perceived stress, perceived social support, and religiosity. This study aims to analyze the determinants of FGID conditions and the role of religiosity as a moderator variable. This study used a quantitative approach with correlation methods. A total of 383 Indonesian Muslim students participated as respondents in this study. The instruments used in this study were the life satisfaction scale, perceived stress-10 scale, perceived social support multidimensional scale, GAD-7, Duke University Religion Index, and FGID scale. Research data were collected online from research respondents. Furthermore, the research data analysis technique used was partial structural equation modeling (PLS-SEM). The results of this study indicate that GAD, life satisfaction, and perceived stress are determinants of FGID conditions in Indonesian Muslim students. The results also show that religiosity acts as a moderator variable in the influence of GAD conditions on a person's FGID condition.

Pre-treatment expectations and their influence on subjective symptom change in Crohn's disease

BACKGROUND

Treatment expectations reportedly shape treatment outcomes, but have not been studied in the context of multimodal therapy in Crohn's disease (CD). Therefore, the current study investigated the role of treatment expectations for subjective symptom changes in CD patients who have undergone an integrative multimodal therapy program.

METHODS

Validated questionnaires were completed at the start of the treatment program and post intervention. Pre-treatment expectations and experienced symptom change were assessed with the Generic Rating Scale for Previous Treatment Experiences, Treatment Expectations, and Treatment Effects (GEEE); stress levels were quantified with the Perceived Stress Scale (PSS-10) and disease specific quality of life was quantified with the disease-specific Inflammatory Bowel Disease Questionnaire (IBDQ). We performed multiple linear and Bayesian regression to determine how expectations related to symptom change.

RESULTS

N = 71 CD patients (66.2% female) were included. Stronger expectations regarding symptom improvement (b = 0.422, t = 3.70, p < .001) were associated with higher experienced symptom improvement. Additionally, Bayesian analysis provided strong evidence for including improvement expectations as a predictor of improvement experience (BFinclusion = 13.78).

CONCLUSIONS

In line with research in other disorders, we found that positive treatment expectations were associated with experienced symptom improvement. In contrast, we found no indication that an experience of symptom worsening was associated with positive or negative baseline treatment expectations. Induction of positive expectations might be a potential avenue for improving treatment outcomes in CD therapy.

Evaluation of the Effects of Instant Cascara Beverage on the Brain-Gut Axis of Healthy Male and Female Rats

Instant cascara (IC) is a sustainable beverage obtained from dried coffee cherry pulp, rich in nutrients and bioactive compounds. The present research aimed to determine the effects of IC on general health and brain-gut axis parameters of healthy female and male rats. Wistar rats were exposed to IC (10 mg/mL) in their drinking water for 3 weeks. Body weight and solid and liquid intakes were monitored as indicators of food safety. Gastrointestinal transit was radiographically evaluated one day (acute) and 3 weeks (chronic) after the start of IC exposure. Locomotor activity, anxiety, and anhedonia of the animals after 3 weeks of treatment was also studied. Overall, compared to water-exposed animals, IC significantly increased food intake in males (p < 0.0001) and liquid intake in females (p < 0.05) without changes in body weight in either case. IC did not significantly modify gastrointestinal motility parameters after its acute or repeated intake and did not cause any significant behavioral alterations in males or females (p > 0.05). In conclusion, repeated intake of IC at the studied concentration did not negatively affect brain-gut axis functions of healthy male and female rats. Anxiety behavior, diarrhea, constipation, abnormal weight modifications, or other typical effects of toxicity were not observed in animals treated with the new powdered beverage, suggesting its food safety under the studied conditions.

Noninvasive Transcutaneous Auricular Vagal Nerve Stimulation Improves Gastric Slow Waves Impaired by Cold Stress in Healthy Subjects

BACKGROUND/AIMS

Stress is known to inhibit gastric motility. The aim of this study was to investigate the effects and autonomic mechanisms of transcutaneous auricular vagal nerve stimulation (taVNS) on cold stress (CS)-induced impairment in gastric motility that are relevant to the brain-gut interactions in healthy volunteers.

MATERIALS AND METHODS

Healthy volunteers (eight women; age 28.2 ± 1.8 years) were studied in four randomized sessions (control, CS, CS + taVNS, and CS + sham-electrical stimulation [sham-ES]). Each session was composed of 30 minutes in the fasting state and 30 minutes after a standard test meal. CS was induced during minutes 10 to 30 after the meal, whereas taVNS or sham-ES was performed during minutes 0 to 30 after the meal. The electrogastrogram and electrocardiogram were recorded for assessing gastric slow waves and autonomic functions, respectively.

RESULTS

First, CS decreased the percentage of normal gastric slow waves (59.7% ± 9.8% vs 85.4% ± 4.5%, p < 0.001 vs control); this impairment was dramatically improved by taVNS (75.5% ± 6.3% vs 58.4% ± 12.5%, p < 0.001 vs sham-ES). Second, CS increased the symptom score (22.0 ± 12.1 vs 39.3 ± 11.5, p = 0.001 vs control); taVNS, but not sham-ES, reduced the symptom score (26.0 ± 12.2 vs 38.3 ± 21.6, p = 0.026 vs sham-ES). Third, CS decreased vagal activity assessed from the spectral analysis of heart rate variability (0.21 ± 0.10 vs 0.26 ± 0.11, p < 0.05 vs control) and increased the sympathovagal ratio (4.89 ± 1.94 vs 3.74 ± 1.32, p = 0.048 vs control); taVNS normalized CS-induced suppression in vagal activity (0.27 ± 0.13 vs 0.22 ± 0.10, p = 0.049 vs sham-ES; p > 0.05 vs control) and CS-induced increase in the sympathovagal ratio (3.28 ± 1.61 vs 4.28 ± 2.10, p = 0.042 vs sham-ES; p > 0.05 vs control).

CONCLUSION

The noninvasive taVNS improves the CS-induced impairment in gastric pace-making activity, possibly by reversing the detrimental effect of CS on autonomic functions. taVNS may have a therapeutic potential for stress-induced gastric dysmotility.

Sinisan ameliorates colonic injury induced by water immersion restraint stress by enhancing intestinal barrier function and the gut microbiota structure

CONTEXT

Sinisan (SNS) has been used to treat psychosomatic diseases of the digestive system. But little is known about how SNS affects water immersion restraint stress (WIRS).

OBJECTIVE

To study the effects of SNS on colonic tissue injury in the WIRS model.

MATERIALS AND METHODS

Forty-eight Kunming (KM) mice were randomized into 6 groups (n = 8): The control and WIRS groups receiving deionized water; the SNS low-dose (SL, 3.12 g/kg/d), SNS middle-dose (SM, 6.24 g/kg/d), SNS high-dose (SH, 12.48 g/kg/d), and diazepam (DZ, 5 mg/kg/d) groups; each with two daily administrations for 5 consecutive days. The 5 treatment groups were subjected to WIRS for 24 h on day 6. The effects of SNS on colon tissue injury caused by WIRS were assessed by changes in colon histology, inflammatory cytokines, brain-gut peptides, and tight junction (TJ) proteins levels. 16S rRNA gene sequencing was used to detect the regulation of the gut microbiota.

RESULTS

SNS pretreatment significantly reduced TNF-α (0.75- to 0.81-fold), IL-6 (0.77-fold), and IFN-γ (0.69-fold) levels; and increased TJ proteins levels, such as ZO-1 (4.06- to 5.27-fold), claudin-1 (3.33- to 5.14-fold), and occludin (6.46- to 11.82-fold). However, there was no significant difference between the levels of substance P (SP) and vasoactive intestinal peptide (VIP) in the control and WIRS groups. SNS regulated the composition of gut microbiota in WIRS mice.

CONCLUSION

The positive effects of SNS on WIRS could provide a theoretical basis to treat stress-related gastrointestinal disorders.

Distinct Alterations in Central Pain Processing of Visceral and Somatic Pain in Quiescent Ulcerative Colitis Compared to Irritable Bowel Syndrome and Health

BACKGROUND AND AIMS

Despite relevance to pain chronicity, disease burden, and treatment, mechanisms of pain perception for different types of acute pain remain incompletely understood in patients with inflammatory bowel disease [IBD]. Building on experimental research across pain modalities, we herein addressed behavioural and neural correlates of visceral versus somatic pain processing in women with quiescent ulcerative colitis [UC] compared to irritable bowel syndrome [IBS] as a patient control group and healthy women [HC].

METHODS

Thresholds for visceral and somatic pain were assessed with rectal distensions and cutaneous thermal pain, respectively. Using functional magnetic resonance imaging, neural and behavioural responses to individually calibrated and intensity-matched painful stimuli from both modalities were compared.

RESULTS

Pain thresholds were comparable across groups, but visceral thresholds correlated with gastrointestinal symptom severity and chronic stress burden exclusively within UC. Upon experience of visceral and somatic pain, both control groups demonstrated enhanced visceral pain-induced neural activation and greater perceived pain intensity, whereas UC patients failed to differentiate between pain modalities at both behavioural and neural levels.

CONCLUSIONS

When confronted with acute pain from multiple bodily sites, UC patients' responses are distinctly altered. Their failure to prioritise pain arising from the viscera may reflect a lack of adaptive behavioural flexibility, possibly resulting from long-lasting central effects of repeated intestinal inflammatory insults persisting during remission. The role of psychological factors, particularly chronic stress, in visceral sensitivity and disease-specific alterations in the response to acute pain call for dedicated mechanistic research as a basis for tailoring interventions for intestinal and extraintestinal pain symptoms in IBD.

The burden of early life stress in chronic inflammatory bowel diseases

The aim of this study was to evaluate the prevalence of early life stress (ELS) in a population with inflammatory bowel diseases (IBD) and to estimate its burden on mental, physical, and digestive health. Ninety-three participants with IBD were asked to anonymously complete questionnaires (Childhood Trauma Questionnaire-Short Form, Early Life Event Scale, Perceived Stress Scale, Hospital Anxiety and Depression Scale, Ways of Coping Checklist, Gastro-Intestinal Quality of Life Index questionnaire, and ad hoc questions about symptoms). The prevalence of patients with IBD who were exposed to at least one childhood abuse was 53%. Mental health and quality of life were significantly poorer in patients with IBD who were exposed to early abuse than in those who were not. Patients exposed to ELS had also more digestive perturbations and fatigue. These results suggest that early abuse should be considered a component of IBD care.

Nocebo effects in visceral pain: concept and design of the experimental randomized-controlled pain study 'NoVis'

The role of psychological factors in the pathophysiology and treatment of chronic visceral pain in disorders of gut-brain interactions (DGBI) is increasingly appreciated. Placebo research has underscored that expectations arising from the psychosocial treatment context and from prior experiences shape treatment responses. However, effects of negative expectations, i.e., nocebo effects, as they are likely crucial elements of DGBI patients' clinical reality, have thus far only rarely been investigated in the context of visceral pain, with untapped potential for improved prevention and treatment. The experimental randomized-controlled pain study "NoVis," carried out within the Collaborative Research Center (CRC) 289 ("Treatment Expectation"), aims to close gaps regarding the generation and persistence of nocebo effects in healthy volunteers. It is designed to elucidate effects of negative expectations in a multiple-threat paradigm with intensity-matched rectal distensions and cutaneous thermal stimuli, allowing to test nocebo effects in the visceral and somatic pain modalities. Negative expectations are experimentally induced by elements of doctor-patient communication (i.e., instruction) and/or by surreptitious amplification of symptom intensity (i.e., experience/learning) within a treatment context. Accordingly, the repeated measures between-subject design contains the between-group factors "treatment instruction" (negative vs. control) and "treatment experience" (negative vs. control), with volunteers randomized into four experimental groups undergoing several pain stimulation phases (repeated factor). This allows to compare the efficacy of instruction vs. experience, and more importantly, their combined effects on the magnitude of negative expectations and their impact on pain responses, which we expect will be greatest for the visceral modality. After a Baseline, short-term effects are assessed during a test phase accomplished on study day 1 (Test-1 Phase). To explore the persistence of effects, a second test phase is accomplished 1 week later (Test-2 Phase). Effects of negative expectations within and across pain modalities are assessed at the subjective and objective levels, with a focus on psychophysiological and neuroendocrine measures related to stress, fear, and anxiety. Since nocebo effects can play a considerable role in the generation, maintenance, or worsening of chronic visceral pain, and may even constitute risk factors for treatment failure, knowledge from experimental nocebo research has potential to improve treatment outcomes in DGBI and other clinical conditions associated with chronic visceral pain.

Review of microbiota gut brain axis and innate immunity in inflammatory and infective diseases

The microbiota gut brain (MGB) axis has been shown to play a significant role in the regulation of inflammatory and infective diseases. Exploring the structure and communication mode of MGB axis is crucial for understanding its role in diseases, and studying the signaling pathways and regulatory methods of MGB axis regulation in diseases is also of profound significance for future clinical research. This article reviews the composition, communication mechanism of MGB axis and its role in inflammatory and infective diseases, including Parkinson's disease (PD), Alzheimer's disease (AD), multiple sclerosis (MS), autism spectrum disorder (ASD), depression, psoriasis, irritable bowel syndrome (IBS), and inflammatory bowel diseases (IBD). In addition, our investigation delved into the regulatory functions of the inflammasome, IFN-I, NF-κB, and PARK7/DJ-1 innate immune signaling pathway in the context of inflammatory and infective diseases. Ultimately, we discussed the efficacy of various interventions, including fecal microbiota transplantation (FMT), antibiotics, probiotics, prebiotics, synbiotics, and postbiotics, in the management of inflammatory and infective diseases. Understanding the role and mechanism of the MGB axis might make positive effects in the treatment of inflammatory and infective diseases.

Functional Gastrointestinal Disorders

Functional gastrointestinal disorders (FGIDs) are an extremely common set of more than 50 disorders characterized by persistent and recurring gastrointestinal symptoms. Most of these patients can be diagnosed and managed by primary care physicians. Treatment includes patient education and reassurance, eliminating triggers, dietary modification, and pharmacologic management. Primary care physicians should consider referral to gastroenterologists when patients exhibit red flag symptoms such as blood in stool, abnormal laboratory findings, involuntary weight loss, age of presentation greater than 50 years, or certain concerning family history.

Causal association between psycho-psychological factors, such as stress, anxiety, depression, and irritable bowel syndrome: Mendelian randomization

BACKGROUND

Pathogenesis, diagnosis, and treatment of irritable bowel syndrome (IBS) have been reported to be challenging hotspots in clinical practice. Previous observational studies have found that stress, anxiety, depression, and other mental and psychological diseases are closely associated with IBS. This study aimed to further explore the causal relationships of these associations through Mendelian randomization (MR).

METHODS

The data needed for MR were obtained from publicly published genome-wide association databases. We performed a bidirectional, 2-sample MR analysis using instrumental variables (IV) associated with stress, anxiety, and depression, and other mental and psychological factors as exposures and IBS as the outcome. A reverse MR analysis with IBS as exposure and stress, anxiety, depression, and other mental and psychological factors as the outcomes was also performed. The inverse variance weighting (IVW) method was adopted as the main method of MR, and the causal effect between stress, anxiety, depression, and other mental and psychological factors and IBS was evaluated as the main result of the study. In addition, a series of sensitivity analyses was conducted to comprehensively evaluate the causal relationship between them.

RESULTS

Stress, anxiety, depression, and other mental and psychological factors were the underlying etiologies for IBS (odds ratio [OR] = 1.06, 95% confidence interval [CI]: 1.03-1.08), and they were positively correlated. Univariate analysis further supported the above conclusions (Depression, [OR = 1.31, 95% CI: 1.05-1.63, P = .016], Anxiety, [OR = 1.53, 95% CI: 1.16-2.03, P = .003]). However, in reverse MR analysis, we found that IBS did not affect stress, anxiety, depression, or other mental and psychological factors and that there was no causal relationship between IBS and stress, anxiety, depression, or other mental and psychological factors (P > .05).

CONCLUSION

This study demonstrates that mental and psychological factors are the underlying etiologies for IBS. These findings may provide important information for physicians regarding the clinical treatment of IBS.

"Mens Sana in Cute Sana"-A State of the Art of Mutual Etiopathogenetic Influence and Relevant Pathophysiological Pathways between Skin and Mental Disorders: An Integrated Approach to Contemporary Psychopathological Scenarios

The negative socioeconomic impact of mental health disorders and skin diseases has increased in part due to the conflict between Russia and Ukraine, which has been a fertile ground for the emergence of psychopathologies. It is firmly established that there is a direct thread of etiopathogenetic communication between skin diseases and neuropsychiatric disorders, and the literature has tried to reveal the pathophysiological mechanisms governing such bidirectionality. This paper discusses this complex network of molecular pathways that are targeted by conventional and biological pharmacological agents that appear to impact two pathological spheres that previously seemed to have little connection. This molecular discussion is supplemented with a literature review, from a clinical viewpoint, regarding skin-brain etiopathogenetic bidirectionality. We focus on post-traumatic stress disorder (PTSD), which can be considered for all intents and purposes a systemic inflammatory disease that also affects the skin. A brief overview is also provided on the diagnostic-therapeutic and follow-up potential of oxidative and inflammatory markers potentially involved in the pathophysiological mechanisms treated. The aim is to clarify how these mechanisms may be useful in defining different stress-coping strategies and thus individual phenotypes of stress sensitivity/resistance in order to promote personalized medicine in the field of psychodermatology.

Effects of Unconventional Work and Shift Work on the Human Gut Microbiota and the Potential of Probiotics to Restore Dysbiosis

The work environment is a factor that can significantly influence the composition and functionality of the gut microbiota of workers, in many cases leading to gut dysbiosis that will result in serious health problems. The aim of this paper was to provide a compilation of the different studies that have examined the influence of jobs with unconventional work schedules and environments on the gut microbiota of workers performing such work. As a possible solution, probiotic supplements, via modulation of the gut microbiota, can moderate the effects of sleep disturbance on the immune system, as well as restore the dysbiosis produced. Rotating shift work has been found to be associated with an increase in the risk of various metabolic diseases, such as obesity, metabolic syndrome, and type 2 diabetes. Sleep disturbance or lack of sleep due to night work is also associated with metabolic diseases. In addition, sleep disturbance induces a stress response, both physiologically and psychologically, and disrupts the healthy functioning of the gut microbiota, thus triggering an inflammatory state. Other workers, including military, healthcare, or metallurgy workers, as well as livestock farmers or long-travel seamen, work in environments and schedules that can significantly affect their gut microbiota.

Neurodegenerative and Neurodevelopmental Diseases and the Gut-Brain Axis: The Potential of Therapeutic Targeting of the Microbiome

The human gut microbiome contains the largest number of bacteria in the body and has the potential to greatly influence metabolism, not only locally but also systemically. There is an established link between a healthy, balanced, and diverse microbiome and overall health. When the gut microbiome becomes unbalanced (dysbiosis) through dietary changes, medication use, lifestyle choices, environmental factors, and ageing, this has a profound effect on our health and is linked to many diseases, including lifestyle diseases, metabolic diseases, inflammatory diseases, and neurological diseases. While this link in humans is largely an association of dysbiosis with disease, in animal models, a causative link can be demonstrated. The link between the gut and the brain is particularly important in maintaining brain health, with a strong association between dysbiosis in the gut and neurodegenerative and neurodevelopmental diseases. This link suggests not only that the gut microbiota composition can be used to make an early diagnosis of neurodegenerative and neurodevelopmental diseases but also that modifying the gut microbiome to influence the microbiome-gut-brain axis might present a therapeutic target for diseases that have proved intractable, with the aim of altering the trajectory of neurodegenerative and neurodevelopmental diseases such as Alzheimer's disease, Parkinson's disease, multiple sclerosis, autism spectrum disorder, and attention-deficit hyperactivity disorder, among others. There is also a microbiome-gut-brain link to other potentially reversible neurological diseases, such as migraine, post-operative cognitive dysfunction, and long COVID, which might be considered models of therapy for neurodegenerative disease. The role of traditional methods in altering the microbiome, as well as newer, more novel treatments such as faecal microbiome transplants and photobiomodulation, are discussed.

Connecting dots in disorders of gut-brain interaction: the interplay of stress and sex hormones in shaping visceral pain

Visceral pain and stress are tightly intertwined bodily and emotional phenomena, which enable a flexible adaptation to environmental challenges by activating a response repertoire to restore homeostasis along the gut-brain axis. However, visceral pain and stress can persist widely independent of the initial cause, acquiring independent disease values and posing major health burdens as predominant features in disorders of gut-brain interaction (DGBI). Epidemiological data consistently documents an increased prevalence for women to suffer from chronic visceral pain, possibly shaped by sex hormones and modulated by stress and its biological and psychosocial correlates. Yet, mechanisms underlying the complex interactions between altered visceroception, stress and sex remain widely elusive, especially in clinical populations with DGBI. We herein selectively review mechanisms of interactions between stress and sex in the complex pathophysiology of DGBI. A particular emphasis is laid on visceral pain, in which stress constitutes a major risk factor as well as mediator, and sex-related differences are particularly pronounced. Building on the neurobiology of stress and mechanisms of gut-brain interactions, we highlight putative target mechanisms via which visceral pain and stress may converge with sex effects into a triad. Accommodating a global demographic shift, we propose a lifespan perspective in future research, which may enable a more fine-tuned evaluation of this complex interplay exerting distinct challenges during vulnerable developmental phases. This viewpoint may advance our understanding of pathophysiological processes and can ultimately inspire novel tailored prevention strategies and therapeutic approaches in the treatment of chronic visceral pain and DGBI across the lifespan.