The Place of Stress and Emotions in the Irritable Bowel Syndrome

Safety and feasibility of early drinking water after general anesthesia recovery in patients undergoing daytime surgery

BACKGROUND

Patients who are recovering from general anesthesia commonly exhibit symptoms such as dry lips, throat irritation, and thirst, prompting a desire to drink water in the post-anesthesia care unit (PACU). In this study, we aimed to evaluate the therapeutic effects and any potential complications of administering varying quantities of water to such patients. The primary objectives are to assess the safety and feasibility of early water intake after general anesthesia, specifically in the context of daytime surgery.

METHODS

A total of 200 nongastrointestinal patients who underwent outpatient surgery were randomly assigned to four groups: Group A (drinking < 1 ml/kg), Group B (drinking 1-2 ml/kg), Group C (drinking > 2 ml/kg), and Group D (no water intake). We monitored changes in the assessment parameters before and after water consumption, as well as the incidence of post-drinking nausea and vomiting, and compared these outcomes among the four groups.

RESULTS

Water intake led to a significant reduction in thirst, oropharyngeal discomfort, and pain scores and a notable increase in the gastric antrum motility index (MI), exhibiting statistical significance compared to the values before drinking (p < 0.05). Remarkably, higher water consumption correlated with enhanced gastrointestinal peristalsis. There was a significant difference in the antral MI among groups B, C, and A (p < 0.05). The occurrence of nausea and vomiting did not significantly differ among groups A, B, C, and D (p > 0.05). Early water consumption enhanced patient satisfaction with medical care, significantly varying from Group D (p < 0.05).

CONCLUSION

Non-gastrointestinal surgical patients who passed pre-drinking water assessments post GA(general anesthesia)recovery could safely ingest moderate amounts of water in the PACU. Early water intake is both safe and feasible, effectively fostering swift postoperative recovery.

Unmet needs of drugs for irritable bowel syndrome and inflammatory bowel diseases: interest of vagus nerve stimulation and hypnosis

The gut and the brain communicate bidirectionally through the autonomic nervous system. The vagus nerve is a key component of this gut-brain axis, and has numerous properties such as anti-inflammatory, antinociceptive, anti-depressive effects. A perturbation of this gut-brain communication is involved in the pathogeny of functional digestive disorders, such as irritable bowel syndrome, and inflammatory bowel diseases. Stress plays a role in the pathogeny of these diseases, which are biopsychosocial models. There are presently unmet needs of pharmacological treatments of these chronic debilitating diseases. Treatments are not devoid of side effects, cost-effective, do not cure the diseases, can lose effects over time, thus explaining the poor satisfaction of patients, their lack of compliance, and their interest for non-drug therapies. The gut-brain axis can be targeted for therapeutic purposes in irritable bowel syndrome and inflammatory bowel disease through non-drug therapies, such as hypnosis and vagus nerve stimulation, opening up possibilities for responding to patient expectations.

The gut-brain axis in Parkinson's disease

There is a bi-directional communication between the gut, including the microbiota, and the brain through the autonomic nervous system. Accumulating evidence has suggested a bidirectional link between gastrointestinal inflammation and neurodegeneration, in accordance with the concept of the gut-rain axis. An abnormal microbiota-gut-brain interaction contributes to the pathogeny of Parkinson's disease. This supports the hypothesis that Parkinson's disease originates in the gut to spread to the central nervous system, in particular through the vagus nerve. Targeting the gut-to-brain axis with vagus nerve stimulation, fecal microbiota transplantation, gut-selective antibiotics, as well as drugs targeting the leaky gut might be of interest in the management of Parkinson's disease.

Rectal sensitivity and associated factors in patients with different subtypes of functional defecation disorder

OBJECTIVE

To investigate rectal sensitivity and associated factors in patients with different subtypes of functional defecation disorder (FDD).

METHODS

We segregated individuals diagnosed with FDD into two groups based on their defecation patterns: those with dyssynergic defecation and those with inadequate defecatory propulsion. We gathered general information through questionnaires and assessed rectal sensitivity using anorectal manometry. The rectal sensitivity performances of the two groups were compared; the factors related to rectal sensitivity were analyzed to determine the factors associated with rectal sensitivity, and the effect of biofeedback therapy on rectal sensitivity was clarified.

RESULTS

Rectal sensitivity in different subtypes of FDD decreased, and the difference between the two groups was not statistically significant ( P  > 0.05). There were no statistically significant differences in the first constant sensation volume, defecatory desire volume, and maximum tolerable volume between the different subtypes of FDD ( P  > 0.05). Multi-factor binary logistic regression analysis showed that age, constipation symptom score, and diabetes were all independent risk factors for decreased rectal sensitivity ( P  < 0.05). There were no statistically significant differences between the prior- and post-biofeedback therapy in the first constant sensation volume, defecatory desire volume, and maximum tolerable volume ( P  > 0.05).

CONCLUSION

Rectal sensitivity in different subtypes of FDD decreased. Age, constipation symptom score, and diabetes were independent risk factors for decreased rectal sensitivity. Short-term biofeedback therapy did not improve rectal hyposensitivity in patients with FDD.

Communication of gut microbiota and brain via immune and neuroendocrine signaling

The gastrointestinal tract of the human is inhabited by about 5 × 10¹³ bacteria (of about 1,000 species) as well as archaea, fungi, and viruses. Gut microbiota is known to influence the host organism, but the host may also affect the functioning of the microbiota. This bidirectional cooperation occurs in three main inter-organ signaling: immune, neural, and endocrine. Immune communication relies mostly on the cytokines released by the immune cells into circulation. Also, pathogen-associated or damage-associated molecular patterns (PAMPs or DAMPs) may enter circulation and affect the functioning of the internal organs and gut microbiota. Neural communication relies mostly on the direct anatomical connections made by the vagus nerve, or indirect connections via the enteric nervous system. The third pathway, endocrine communication, is the broadest one and includes the hypothalamic-pituitary-adrenal axis. This review focuses on presenting the latest data on the role of the gut microbiota in inter-organ communication with particular emphasis on the role of neurotransmitters (catecholamines, serotonin, gamma-aminobutyric acid), intestinal peptides (cholecystokinin, peptide YY, and glucagon-like peptide 1), and bacterial metabolites (short-chain fatty acids).

[The regulatory role of gut microbiota in inflammation in depression and anxiety]

Numerous studies have identified the important role of the gut microbiota in maintaining of the CNS normal functioning and in the pathogenesis of mental disorders as one of the systems regulating the bidirectional communication between the gut and the brain. The microbiota has been found to be involved in the modulation of inflammation as well as in the development and function of the immune and nervous systems. It is assumed that in multicellular organisms, the nervous and immune systems have evolved together with the microbiota, being in interaction with it, in order to optimize the body's ability to adapt to a wide range of environmental stresses in order to maintain the constancy of its homeostasis. Normally, microbes live in stable communities, while under conditions of even mild or chronic social stress, significant shifts in the composition of the microbiota occur, which lead to the development of dysbiosis associated with changes in microbiota metabolites, which can lead to the formation of physiology and behavior characteristic of stress and depression. Microbes influence the activation of peripheral immune cells that regulate the response to neuroinflammation, brain damage, autoimmune responses, and neurogenesis. The review provides a brief overview of the normal gut microbiota, describes the factors influencing the state of the microbiota, and also discusses recent discoveries concerning the regulatory effect of the gut microbiota on CNS functions, the immune system, and inflammation in the pathogenesis of depression and anxiety.

Clinical significance and related factors of rectal hyposensitivity in patients with functional defecation disorder

Background

Rectal hyposensitivity (RH) is not uncommon in patients with functional defecation disorder (FDD). FDD patients with RH are usually unsatisfied with their treatment.

Aims

The aim of this study was to find the significance of RH in patients with FDD and the related factors of RH.

Methods

Patients with FDD first completed clinical questionnaires regarding constipation symptoms, mental state, and quality of life. Then anorectal physiologic tests (anorectal manometry and balloon expulsion test) were performed. Rectal sensory testing (assessing rectal response to balloon distension using anorectal manometry) was applied to obtain three sensory thresholds. Patients were separated into three groups (non-RH, borderline RH, and RH) based on the London Classification. The associations between RH and clinical symptoms, mental state, quality of life, and rectal/anal motility were investigated.

Results

Of 331 included patients with FDD, 87 patients (26.3%) had at least one abnormally elevated rectal sensory threshold and 50 patients (15.1%) were diagnosed with RH. Patients with RH were older and mostly men. Defecation symptoms were more severe (p = 0.013), and hard stool (p < 0.001) and manual maneuver (p = 0.003) were more frequently seen in the RH group. No difference in rectal/anal pressure was found among the three groups. Elevated defecatory desire volume (DDV) existed in all patients with RH. With the number of elevated sensory thresholds increasing, defecation symptoms got more severe (r = 0.35, p = 0.001). Gender (male) (6.78 [3.07-15.00], p < 0.001) and hard stool (5.92 [2.28-15.33], p < 0.001) were main related factors of RH.

Conclusion

Rectal hyposensitivity plays an important role in the occurrence of FDD and is associated with defecation symptom severity. Older male FDD patients with hard stool are prone to suffer from RH and need more care.

Reviewing the role of gut microbiota in the pathogenesis of depression and exploring new therapeutic options

The relationship between gut microbiota (GM) and mental health is one of the focuses of psychobiology research. In recent years, the microbial-gut-brain axis (MGBA) concept has gradually formed about this bidirectional communication between gut and brain. But how the GM is involved in regulating brain function and how they affect emotional disorders these mechanisms are tenuous and limited to animal research, and often controversial. Therefore, in this review, we attempt to summarize and categorize the latest advances in current research on the mechanisms of GM and depression to provide valid information for future diagnoses and therapy of mental disorders. Finally, we introduced some antidepressant regimens that can help restore gut dysbiosis, including classic antidepressants, Chinese materia medica (CMM), diet, and exogenous strains. These studies provide further insight into GM's role and potential pathways in emotion-related diseases, which holds essential possible clinical outcomes for people with depression or related psychiatric disorders. Future research should focus on clarifying the causal role of GM in disease and developing microbial targets, applying these findings to the prevention and treatment of depression.

Functional Abdominal Cramping Pain: Expert Practical Guidance

Functional abdominal cramping pain (FACP) is a common complaint, which may present either on its own or in association with a functional gastrointestinal disorder. It is likely caused by a variety of, probably partly unknown, etiologies. Effective management of FACP can be challenging owing to the lack of usable diagnostic tools and the availability of a diverse range of treatment approaches. Practical guidance for their selection and use is limited. The objective of this article is to present a working definition of FACP based on expert consensus, and to propose practical strategies for the diagnosis and management of this condition for physicians, pharmacists, and patients. A panel of experts on functional gastrointestinal disorders was convened to participate in workshop activities aimed at defining FACP and agreeing upon a recommended sequence of diagnostic criteria and management recommendations. The key principles forming the foundation of the definition of FACP and suggested management algorithms include the primacy of cramping pain as the distinguishing symptom; the importance of recognizing and acting upon alarm signals of potential structural disease; the recognition of known causes that might be addressed through lifestyle adjustment; and the central role of antispasmodics in the treatment of FACP. The proposed algorithm is intended to assist physicians in reaching a meaningful diagnostic endpoint based on patient-reported symptoms of FACP. We also discuss how this algorithm may be adapted for use by pharmacists and patients.

Association between impaired healing after orthognathic surgery and irritable bowel syndrome: A case report and literature review

Introduction

In the disease irritable bowel syndrome (IBS), gastrointestinal function is worsened even though no organic abnormalities are observed in the gastrointestinal mucosa. We report the case of an orthognathic surgery patient with suspected irritable bowel syndrome.

Case

In September 2017, a 15-year-old Japanese female was referred to us with dental crowding, malocclusion, and mandibular protrusion. In June 2019, a disagreement with classmates led to abdominal pain, diarrhea, and hemorrhage; in August 2019, a preoperative blood test showed sudden anemia, and her surgery was thus postponed. Subsequent upper and lower gastrointestinal endoscopy revealed no organic abnormality, and no definitive diagnosis was made. In March 2020, after an improvement in anemia was observed, a segmental Le Fort I osteotomy and bilateral sagittal split ramus osteotomy (BSSRO) were performed under general anesthesia. On the third post-operative day, due to the mucosal dehiscence adjacent to the suture part, the titanium plate was exposed, and irrigation of the wound with normal saline solution and oral hygiene instruction was continued daily for 2 weeks. Two years and eight months have passed since the surgery, and the healing of the oral mucosa and bone has been uneventful.

Discussion

The relationship between IBS and post-operative impaired healing associated with the fragility of the oral mucosa is unknown. However, psychological stress has been reported as a cause of IBS and to be related to oral microorganisms.

Conclusion

Reducing risk factors for IBS and maintaining proper perioperative oral hygiene is essential in managing similar cases.

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Irritable bowel syndrome (IBS) is a functional gastrointestinal disease with recurrent abdominal pain.

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It is difficult to diagnose IBS since the clinical symptoms are confusing.

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IBS and psychological stress affect post-surgical healing.

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Reducing risk factors for IBS and maintaining proper perioperative oral hygiene is essential in the management.

Irritable bowel syndrome in adults: Prevalence and risk factors

Introduction

The prevalence of irritable bowel syndrome (IBS) ranges from 7 to 18% over the world. We aimed to assess the prevalence and risk factors of irritable bowel syndrome in adults.

Methodology

We conducted a cross-sectional study of IBS prevalence and risk factors from March to May 2022 at KRL Hospital Islamabad. 300 people were given Pre-validated Performa's. Our research adheres to the principles outlined in the Helsinki Declaration. The PSS was used to measures how much stress a person has felt in the past month.

The higher the score, the more stressed the person appears to be. A variety of mental health disorders can be evaluated using this method. Data on dietary and lifestyle factors associated with IBS for the last 12 months was also collected from the participants.

Results

The majority of patients, 70%, were classed as Grade 1 and 146 (48.66%) reported abdominal pain associated with defecation. 162 (54%) individuals reported high levels of tea consumed, 81 (27%) consumed coffee and 57 (19%) reported carbonated drinks consumed. 139 individuals reported having Vigorous-Intensity activity, out of which 69 (49.64%) spend 60 min of vigorous activity in a day.

Conclusion

Screening patients for IBS on a regular basis is critical, especially in the younger demographic. If a patient experiences any symptoms of IBS, they should contact their doctor immediately. Consider the care of patients with chronic gastrointestinal complaints, particularly in women and those at greater risk of developing the illness.

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Perceived Stress Scale (PSS) measures how much stress a person has felt in the past month.

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The Chalder Fatigue Scale (CFS) is used to measure fatigue.

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We recommend the younger population to be screened for IBS on a regular basis.

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Persistent gastrointestinal symptoms, especially women and those at high risk of the condition, it is critical to take this into account.

Cold Exposure Induces Intestinal Barrier Damage and Endoplasmic Reticulum Stress in the Colon via the SIRT1/Nrf2 Signaling Pathway

Ambient air temperature is a key factor affecting human health. Long-term exposure to a cold environment can cause various diseases, while the impact on the intestine, the organ which has the largest contact area with the external environment, cannot be ignored. In this study, we investigated the effect of chronic cold exposure on the colon and its preliminary mechanism of action. Mice were exposed to 4°C for 3 hours a day for 10 days. We found that cold exposure damaged the morphology and structure of the colon, destroyed the tight junctions of the colonic epithelial tissue, and promoted inflammation of the colon. At the same time, cold exposure also activated the unfolded protein response (UPR) in the colon and promoted apoptosis in intestinal epithelial cells. Chronic cold exposure induced oxidative stress in vivo, but also significantly enhanced the response of the Nrf2 pathway that promotes an anti-oxidant effect. Furthermore, we demonstrated that chronic cold exposure promoted p65 acetylation to aggravate the inflammatory response by inhibiting SIRT1. Similar results were observed following SIRT1 knock-down by shRNA in Caco-2 cells treated with Thapsigargin (Tg). Knock-down of SIRT1 promoted nuclear localization of Nrf2, and increased the level of Nrf2 acetylation. Taken together, our study indicates that cold exposure may aggravate endoplasmic reticulum stress and damage epithelial tight junctions in the colon by inhibiting SIRT1, which promotes nuclear localization of Nrf2 and induces an anti-oxidant response to maintain intestinal homeostasis. These findings suggest that SIRT1 is a potential target for regulating intestinal health under cold exposure conditions.

Contribution of Amygdala Histone Acetylation in Early Life Stress-Induced Visceral Hypersensitivity and Emotional Comorbidity

Patients with irritable bowel syndrome (IBS) experience not only enhanced visceral pain but also emotional comorbidities, such as anxiety and depression. Early life stress (ELS) is a high-risk for the development of IBS. Literatures have reported an important epigenetic modulation in sustaining extrinsic phenotypes. The amygdala is closely related to the regulation of visceral functions and emotional experiences. In this study, we hypothesized that ELS-induced reprogramming inappropriate adaptation of histone acetylation modification in the amygdala may result in visceral hypersensitivity and anxiety-like behaviors in ELS rats. To test this hypothesis, the model of ELS rats was established by neonatal colorectal dilatation (CRD). Visceral hypersensitivity was assessed based on the electromyography response of the abdominal external oblique muscle to CRD. Emotional comorbidities were examined using the elevated plus maze test, open field test, and sucrose preference test. Trichostatin A (TSA) and C646 were microinjected into the central amygdala (CeA) individually to investigate the effects of different levels of histone acetylation modification on visceral hypersensitivity and emotion. We found neonatal CRD resulted in visceral hypersensitivity and anxiety-like behaviors after adulthood. Inhibiting histone deacetylases (HDACs) in the CeA by TSA enhanced visceral sensitivity but did not affect anxiety-like behaviors, whereas inhibiting HAT by C646 attenuated visceral hypersensitivity in ELS rats. Interestingly, CeA treatment with TSA induced visceral sensitivity and anxiety-like behaviors in the control rats. Western blot showed that the expressions of acetylated 9 residue of Histone 3 (H3K9) and protein kinase C zeta type (PKMζ) were higher in the ELS rats compared to those of the controls. The administration of the PKMζ inhibitor ZIP into the CeA attenuated visceral hypersensitivity of ELS rats. Furthermore, the expression of amygdala PKMζ was enhanced by TSA treatment in control rats. Finally, western blot and immunofluorescence results indicated the decrease of HDAC1 and HDAC2 expressions, but not HDAC3 expression, contributed to the enhancement of histone acetylation in ELS rats. Our results support our hypothesis that amygdala-enhanced histone acetylation induced by stress in early life results in visceral hypersensitivity and anxiety-like behaviors in ELS rats, and reversing the abnormal epigenetic mechanisms may be crucial to relieve chronic symptoms in ELS rats.

Effect of a Combination of Magnesium, B Vitamins, Rhodiola, and Green Tea (L-Theanine) on Chronically Stressed Healthy Individuals-A Randomized, Placebo-Controlled Study

The effect of a combination of magnesium, vitamins B6, B9, B12, rhodiola and green tea/L-theanine (Mg-Teadiola) on stress was evaluated in chronically stressed, otherwise healthy individuals. Effects on stress-related quality-of-life parameters (sleep and perception of pain) were also explored. Adults with stress for ≥1 month, scoring ≥14 points on the Depression Anxiety Stress Scale (DASS)-42 questionnaire, were randomized (1:1) to receive oral Mg-Teadiola (n = 49) or a placebo (n = 51), for 28 days, with a follow-up assessment on Day 56 (NCT04391452). The primary endpoint was the change in the DASS-42 stress score from baseline to Day 28 with Mg-Teadiola versus placebo. The DASS-42 stress scores significantly decreased from baseline to Day 28 with Mg-Teadiola versus placebo (effect size, 0.29; 95% CI [0.01, 0.57]; p = 0.04). Similar reductions were observed on Day 14 (p = 0.006) and Day 56 (p = 0.02). A significant reduction in sensitivity to cold pain (p = 0.01) and a trend for lower sensitivity to warm pain was observed (p = 0.06) on Day 28. Improvements in daytime dysfunction due to sleepiness (Pittsburgh Sleep Quality Index-7 component score) were reported on Day 28, and were significant on Day 56 (p < 0.001). Mg-Teadiola is effective in managing stress in otherwise healthy individuals. Its beneficial effects on sleep and pain perception need further investigation.

The Prevalence of Irritable Bowel Syndrome Among Chinese University Students: A Systematic Review and Meta-Analysis

Background

Irritable bowel syndrome (IBS) has become a common public health issue among university students, impairing their physical and mental health. This meta-analysis aimed to examine the pooled prevalence of IBS and its associated factors among Chinese university students.

Methods

Databases of PubMed, EMBASE, MEDLINE (via EBSCO), CINAHL (via EBSCO), Wan Fang, CNKI and Weipu (via VIP) were systematically searched from inception date to May 31, 2021. Meta-analysis was performed using random-effects models. Meta-regression and subgroup analysis were used to detect the potential source of heterogeneity.

Key Results

A total of 22 cross-sectional studies (14 were in Chinese and 8 were in English) with 33,166 Chinese university students were included. The pooled prevalence of IBS was estimated as 11.89% (95% CI = 8.06%, 16.35%). The prevalence was 10.50% (95% CI = 6.80%, 15.87%) in Rome II criteria, 12.00% (95% CI = 8.23%, 17.17%) in Rome III criteria, and 3.66% (95% CI = 2.01%, 6.60%) in Rome IV criteria. The highest prevalence of IBS was 17.66% (95% CI = 7.37%, 36.64%) in North China, and the lowest was 3.18% (95% CI = 1.28%, 7.68%) in South China. Subgroup analyses indicated that gender, major, anxiety and depression symptoms, drinking and smoking behaviors were significantly associated with the prevalence of IBS. Meta-regression analyses suggested that region influenced prevalence estimates for IBS.

Conclusions and Inferences

This meta-analysis illustrated that IBS is very common in Chinese university students. Regular screening, effective prevention, and appropriate treatments should be implemented to reduce the risk of IBS in this population. More future studies should be conducted in Northeastern and Southwestern parts of China.

Anatomical Evidence for the Neural Connection from the Emotional Brain to Autonomic Innervation in the Anterior Chamber Structures of the Eye

OBJECTIVE

Previous studies have shown that the autonomic nervous system (ANS), which can be affected by emotions, is important in the occurrence or progression of glaucoma. The autonomic innervation distributed in the anterior chamber (AC) structures might play an efferent role in the neural regulation of intraocular pressure (IOP). This study aimed to investigate the anatomic neural connection from the emotional brain to autonomic innervation in the AC.

METHODS

A retrograde trans-multisynaptic pseudorabies virus encoded with an enhanced green fluorescent protein (PRV531) and non-trans-synaptic tracer FAST Dil were injected into the right eye of mice, respectively. Fluorescent localization in the emotional brain and preganglionic nuclei was studied. Five and a half days after PRV531 injection into the right AC, fluorescent signals were observed in several emotional brain regions, including the amygdala, agranular insular cortex, lateral septal nuclei, periaqueductal gray, and hypothalamus. Autonomic preganglionic nuclei, including Edinger-Westphal nucleus, superior salivatory nucleus, and intermediolateral nucleus, were labeled using PRV531.

RESULTS

The sensory trigeminal nuclei were not labeled using PRV531. The fluorescence signals in the nuclei mentioned above showed bilateral distribution, primarily on the ipsilateral side. Seven days after injecting FAST Dil into the AC, we observed no FAST Dil-labeled neurons in the central nervous system.

CONCLUSION

Our results indicate a neural connection from the emotional brain to autonomic innervation in the AC, which provides anatomical support for the emotional influence of IOP via the ANS.

Efficacy of psychological interventions for irritable bowel syndrome: A protocol for systematic review and meta-analysis

BACKGROUND

Guidelines for the management of irritable bowel syndrome (IBS) recommend that psychological therapies should be considered, but their relative efficacy is unknown. We performed a protocol for systematic review and meta-analysis to try to resolve this uncertainty.

METHODS

Two individual researchers conducted the platform searches on Ovid Medline In-Process & Other Non-Indexed Citations, Ovid MEDLINE, Ovid EMBASE, Ovid PsycINFO, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus from inception to February 2022. Systematic review and meta-analysis of the data will be performed in STATA13.0 software according to the preferred reporting items for systematic reviews and meta-analyses protocols guidelines. Two authors independently performed the literature searching, data extraction, and quality evaluation. Risk of bias was assessed using the Cochrane Risk of Bias Tool for randomized controlled trials.

RESULTS

A synthesis of current evidence of psychological interventions for IBS will be provided in this study.

CONCLUSION

This result will provide a comprehensive analysis and synthesis to inform practitioners and policy makers about the effectiveness of psychological interventions for patients with IBS.

Patients with ankylosing spondylitis have high risk of irritable bowel syndrome. A long-term nationwide population-based cohort study

OBJECTIVE

Ankylosing spondylitis (AS) is a chronic inflammatory disease, might carry a high risk of irritable bowel syndrome (IBS) due to abnormal gut microbiota or inflammatory reaction.

METHODS

We conducted a 14-year retrospective cohort study based on Taiwan's National Health Insurance Research Database (NHIRD). A total of 4007 patients with newly diagnosed AS (outpatient visits≧3 times, or hospitalization≧1 time) and 988,084 non-AS comparisons were enrolled during 2000-2012. To ensure baseline comparability, the propensity score was matched by age, gender, comorbidities, and other possible confounders. The outcome was the incidence of IBS, followed up to the end of 2013. Cox proportional hazard model calculated adjusted hazard ratio (aHR) and the cumulative incidence of both groups was analyzed by the Kaplan-Meier method.

RESULT

After propensity score matching, baseline demographic characteristics were comparable between AS patients and the comparison group. The crude HR for IBS in the AS group was significantly higher 2.41 (95%C.I. =1.84-3.16) than comparison group. After adjusting for possible confounders, adjusted HR was 2.50 (95%C.I.=1.91-3.29). The cumulative incidence of IBS in AS was significantly higher than non-AS comparisons during the 14-year follow-up (P<0.001).

CONCLUSION

This nationwide population-based cohort study showed that patients with AS have higher risks of IBS than those of the non-AS comparison group.

Impending Mental Health Issues During Coronavirus Disease 2019 - Time for Personalized Nutrition Based on the Gut Microbiota to Tide Over the Crisis?

Coronavirus disease 2019 (COVID-19) is a major pandemic facing the world today caused by SARS-CoV-2 which has implications on our mental health as well. The uncertain future, fear of job loss, lockdown and negative news all around have taken a heavy toll on the mental health of individuals from across the world. Stress and anxiety can affect the COVID-19 patients even more. Recent study suggests COVID-19 infection may lead to post-traumatic stress disorder (PTSD). Certain prebiotics and probiotics have been shown to have anxiolytic effect through gut microbiota modulation. Incidentally, preliminary report also suggests a differential microbial profile in COVID-19 patients as compared to healthy individuals. Gut microbiota's role in anxiety and depression is well studied. The importance of the "gut-brain" axis has been implicated in overall mental health. It is known that diet, environmental factors and genetics play an important role in shaping gut microbiota. Trials may be initiated to study if personalized diet and supplementation based on individual's gut microbiome profile may improve the general mental well-being of people prone to anxiety during this pandemic. Also, COVID-19 patients may be provided personalized nutritional therapy based on their gut microbiota profile to see if PTSD and anxiety symptoms can be alleviated.

Activation of CRF1 receptors expressed in brainstem autonomic nuclei stimulates colonic enteric neurons and secreto-motor function in male rats

BACKGROUND

Hypothalamic corticotropin-releasing factor (CRF) receptor 1 (CRF1 ) plays a role in acute stress-related stimulation of colonic motor function. Less is known on CRF1 signaling in the brainstem.

METHODS

We investigate CRF1 expression in the brainstem and the colonic response to 4th ventricle (4V) injection of CRF and urocortin (Ucn) 2 (3 µg/rat) in chronically cannulated male rats.

KEY RESULTS

Transcripts of CRF1 wild-type 1a and splice variants 1c, 1e, 1f, 1o along with three novel variants 1a-2 (desK-110 in exon 5), 1p (-exon 7), and 1q (exon 5 extension) were identified in the pons and medulla. The area postrema, nucleus tractus solitarius, dorsal motor nucleus of the vagus, locus coeruleus, and Barrington's nucleus isolated by laser capture microdissection expressed 1a, 1a-2, and 1p but not 1q. Compared to 4V vehicle, 4V CRF induced fecal pellet output (FPO) and diarrhea that were blocked by the CRF antagonist, astressin-B. CRF2 agonist, Ucn2 had no effect on basal or CRF-induced FPO. CRF actions were correlated with the induction of c-Fos immunoreactivity in myenteric neurons of the proximal and distal colon (pC, dC) and submucosal neurons of dC. c-Fos immunoreactivity occurred in 39% and 37% of myenteric cholinergic and 7% and 58% of nitrergic neurons in the pC and dC, respectively.

CONCLUSIONS & INFERENCES

CRF1a and its splice variants are expressed in brainstem nuclei, and activation of CRF1 signaling at the level of the brainstem stimulates colonic secretory-motor function through activation of colonic enteric neurons.

Diseases, Disorders, and Comorbidities of Interoception

Interoception, the sense of the body's internal physiological state, underpins homeostatic reflexes, motivational states, and sensations contributing to emotional experiences. The continuous nature of interoceptive processing, coupled to behavior, is implicated in the neurobiological construction of the sense of self. Aberrant integration and control of interoceptive signals, originating in the brain and/or the periphery, can perturb the whole system. Interoceptive abnormalities are implicated in the pathophysiology of psychiatric disorders and in the symptomatic expression of developmental, neurodegenerative, and neurological disorders. Moreover, interoceptive mechanisms appear central to somatic disorders of brain-body interactions, including functional digestive disorders, chronic pain, and comorbid conditions. The present article provides an overview of disorders of interoception and suggests future directions for better understanding, diagnosis, and management of these disorders.

Are Anxious and Depressive Symptoms Associated with Gastrointestinal Symptoms in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL)?

Psychological distress is common among non-Hispanic/Latino adults with gastrointestinal (GI) symptoms. Heartburn and acid regurgitation symptom prevalence, and their relationship with anxious and depressive symptoms, was examined in 16,415 Hispanic Community Health Study/Study of Latinos participants aged 18-74 from 4 US cities (Bronx, NY; Chicago, IL; Miami, FL; San Diego, CA). Complex survey logistic regression models were used to test relations between GI, anxious, and depressive symptoms. 10.1% (95% confidence interval [CI] = 9.4, 10.8) and 8.9% (95% CI = 8.3, 9.5) of the overall sample (estimates are weighted and adjusted for age and body mass index) respectively self-reported heartburn and acid regurgitation at least several times/week within the past year. Adults who reported GI symptoms several times/week or more also self-reported higher psychological distress compared to adults who reported GI symptoms less frequently. For one standard deviation higher in anxious symptoms (5.6 units), GI prevalence odds were respectively 1.14 (95% CI = 1.10, 1.17) and 1.14 (95% CI = 1.09, 1.18) for heartburn and acid regurgitation. GI prevalence odds (heartburn = 1.14, 95% CI = 1.11, 1.18; acid regurgitation = 1.15, 95% CI = 1.10, 1.18) were similar for one standard deviation higher in depressive symptoms (5.9 units). Demographic, health, and clinical characteristics did not significantly attenuate relationships between GI and psychological distress symptoms. Psychological distress is related to GI symptoms in US Hispanics/Latinos.

Effects of Medium Chain Fatty Acids on Intestinal Health of Monogastric Animals

Medium-chain fatty acids (MCFAs) are the main form of Medium Chain Triglycerides (MCTs) utilized by monogastric animals. MCFAs can be directly absorbed and supply rapid energy to promote the renewal and repair of intestinal epithelial cells, maintain the integrity of intestinal mucosal barrier function, and reduce inflammation and stress. In our review, we pay more attention to the role of MCFAs on intestinal microbiota and mucosa immunity to explore MCFA's positive effect. It was found that MCFAs and their esterified forms can decrease pathogens while increasing probiotics. In addition, being recognized via specific receptors, MCFAs are capable of alleviating inflammation to a certain extent by regulating inflammation and immune-related pathways. MCFAs may also have a certain value to relieve intestinal allergy and inflammatory bowel disease (IBD). Unknown mechanism of various MCFA characteristics still causes dilemmas in the application, thus MCFAs are used generally in limited dosages and combined with short-chain organic acids (SOAs) to attain ideal results. We hope that further studies will provide guidance for the practical use of MCFAs in animal feed.

Therapeutic Potential of Vagus Nerve Stimulation for Inflammatory Bowel Diseases

The vagus nerve is a mixed nerve, comprising 80% afferent fibers and 20% efferent fibers. It allows a bidirectional communication between the central nervous system and the digestive tract. It has a dual anti-inflammatory properties via activation of the hypothalamic pituitary adrenal axis, by its afferents, but also through a vago-vagal inflammatory reflex involving an afferent (vagal) and an efferent (vagal) arm, called the cholinergic anti-inflammatory pathway. Indeed, the release of acetylcholine at the end of its efferent fibers is able to inhibit the release of tumor necrosis factor (TNF) alpha by macrophages via an interneuron of the enteric nervous system synapsing between the efferent vagal endings and the macrophages and releasing acetylcholine. The vagus nerve also synapses with the splenic sympathetic nerve to inhibit the release of TNF-alpha by splenic macrophages. It can also activate the spinal sympathetic system after central integration of its afferents. This anti-TNF-alpha effect of the vagus nerve can be used in the treatment of chronic inflammatory bowel diseases, represented by Crohn’s disease and ulcerative colitis where this cytokine plays a key role. Bioelectronic medicine, via vagus nerve stimulation, may have an interest in this non-drug therapeutic approach as an alternative to conventional anti-TNF-alpha drugs, which are not devoid of side effects feared by patients.

Non-responsive celiac disease may coincide with additional food intolerance/malabsorption, including histamine intolerance

BACKGROUND AND PILOT STUDY

Celiac disease (CD) or gluten malabsorption is a well-defined autoimmune disorder characterized by mucosal gastrointestinal reaction to ingested gluten proteins. The necessary treatment for CD is a gluten-free diet. However, up to 30% of celiac patients experience persistent or recurring abdominal complaints despite following an exact gluten-free diet. This condition was named refractory, non-responsive celiac disease. Other food ingredients, such as carbohydrates and biogenic amines, also influence and impair digestion, and may cause these abdominal symptoms. In this retrospective pilot study, we have reported on 20 non-responsive, celiac disease patients, with persistent abdominal complaints, for longer than 6 months. These patients were evaluated for extra food intolerance/malabsorption, including fructose malabsorption, histamine-, lactose intolerance, and Helicobacter pylori (H.p.) infection.

RESULTS AND CONCLUSIONS

The results demonstrate that 18 of the 20 refractory, non-responsive celiac disease patients presented various, additional food intolerance/malabsorption and/or H.p. infection. Seven NRCD patients demonstrated lactose intolerance, 7 showed fructose malabsorption, 11 had additional histamine intolerance and 6 had signs of H.p. infection or combinations thereof. If present, then eradication of H.p. was performed. Histamine intolerance, was found in more than 50% of patients, and it seems to play an important role in non-responsive celiac disease. A registered dietician continued to help with, and to improve, the patients' gluten-free diet. Furthermore, additional food intolerance/malabsorption considerations were included in the individual, dietary recommendations.

The HPA axis dysregulation in severe mental illness: Can we shift the blame to gut microbiota?

Accumulating evidence indicates that patients with severe mental disorders, including major depression, bipolar disorder and schizophrenia present with various alterations of the gut microbiota and increased intestinal permeability. In addition, the hypothalamic-pituitary-adrenal (HPA) axis dysregulation and subclinical inflammation have been reported in this group of patients. Although it has been found that the HPA axis dysregulation appears as a consequence of psychosocial stress, especially traumatic life events, the exact mechanisms of this observation remain unclear. Animal model studies have unraveled several mechanisms linking the gut microbiota with the HPA axis dysfunction. Indeed, the gut microbiota can activate the HPA axis through several mediators that cross the blood-brain barrier and include microbial antigens, cytokines and prostaglandins. There is also evidence that various microbial species can affect ileal corticosterone production that may impact the activity of the HPA axis. However, some metabolites released by various microbes, e.g., short-chain fatty acids, can attenuate the HPA axis response. Moreover, several bacteria release neurotransmitters that can directly interact with vagal afferents. It has been postulated that the HPA axis activation can impact the gut microbiota and intestinal permeability. In this article, we discuss various mechanisms linking the gut microbiota with the HPA axis activity and summarize current evidence for a cross-talk between the gut-brain axis and the HPA axis from studies of patients with mood and psychotic disorders. Finally, we show potential clinical implications that can arise from future studies investigating the HPA axis activity with respect to the gut microbiota in severe mental disorders.

Cohort Profile: The Christchurch IBS cOhort to investigate Mechanisms FOr gut Relief and improved Transit (COMFORT)

BACKGROUND AND AIMS

This cross-sectional observational case-control study was initiated in July 2016 with the aim of increasing an understanding of the underlying disease mechanisms in functional gastrointestinal disorders (FGIDs) including irritable bowel syndrome (IBS), functional diarrhoea (FD), and functional constipation (FC). Specific areas of interest include the effect of food, microbiome, host and microbial genetics, metabolome, and psychological variables on unexplained chronic gastrointestinal (GI) symptoms.

METHODS

This study recruited consecutive patients who were attending one of two endoscopy centres in Christchurch, New Zealand, for colonoscopy and a subgroup of participants from the general public who did not undergo colonoscopy. Participants with known GI disease other than an FGID were excluded. Those with symptoms were recruited as cases, whilst those without symptoms were recruited as controls. In the days prior to preparation for colonoscopy, or an agreeable time for those not undergoing colonoscopy, demographic, symptom, psychological, dietary, and health data were collected in addition to biological samples (breath, faeces, blood, and urine). Colonic biopsies were taken at the time of colonoscopy from participants in the colonoscopy subgroup.

RESULTS

Between July 2016 and December 2018, 349 participants were recruited, 315 of whom completed the study, 220 participants were from the colonoscopy subgroup, and 95 from the non-colonoscopy subgroup. This included 129 controls and 186 cases (57 IBS-diarrhoea predominant, 30 IBS-constipation predominant, 41 IBS-mixed, 42 FC, and 16 FD). The mean age of FGID cases was 53.4 years and controls 54.4 years. Cases (149/186, 80.1%) and controls (57/72, 55.8%) were predominantly female. Education levels were similar across the cohort. Smoking and alcohol rates were also similar. Biological samples were collected as planned from participants.

CONCLUSIONS

The COMFORT cohort is a unique clinical cohort of FGID cases and controls with a wide range of demographic, dietary, clinical, psychological, and health data in addition to biological samples. Future research will aim to use a systems biology approach to establish the potential role of diet, host-microbiome interactions, and other factors in the pathogenesis of FGIDs.

Burnout, but not job strain, is associated with irritable bowel syndrome in working adults

OBJECTIVE

Although stress is an important component of irritable bowel syndrome (IBS) pathophysiology, the possibility that work-related stress is implicated in the pathophysiology of IBS has not been widely studied. This study aimed to examine whether job strain (a combination of high job demands and low control at work) and/or burnout, the outcome of a gradual depletion of energetic resources resulting from chronic exposure to work-related stress, are associated with IBS.

METHODS

Fifty-five patients fulfilling the Rome III criteria for IBS and 214 matched healthy controls (HC) participated in this cross-sectional study. All participants completed a job strain measure, the Shirom - Melamed Burnout Measure (SMBM), and dietary and health questionnaires.

RESULTS

There was no significant difference in the prevalence of job strain between IBS patients and HC (25.5% vs. 23.0%, respectively). Job strain was not associated with increased IBS prevalence (adjusted OR = 1.99, 95% CI: 0.54-7.33). In contrast, the mean burnout score in the IBS group was significantly higher than in HC (2.9 ± 1.1 vs. 2.1 ± 0.8, p < .001). Burnout was associated with a 2.41-fold elevated prevalence of IBS (95% CI: 1.16-5.02), after adjusting for potential confounding variables including job strain. Moreover, the odds of having IBS increased in patients with a high burnout level (adjusted OR = 3.3, 95% CI:1.09-10.03).

CONCLUSION

Burnout, but not job strain, is associated with the prevalence of IBS in working adults.

Interoceptive Abilities in Inflammatory Bowel Diseases and Irritable Bowel Syndrome

Alexithymia is usually described by three main dimensions difficulty identifying feelings (DIF), difficulty describing feelings (DDF), and externally oriented thinking (EOT). The most commonly used questionnaire investigating alexithymia, the Toronto Alexithymia Scale (TAS-20), supports this three-factor structure. One important assumption is that alexithymia severity is associated to vulnerability to somatic diseases, among them gastrointestinal disorders. However, the association between alexithymia and gastrointestinal disorders is not systematic, thus questioning the role of alexithymia as a vulnerability factor for those illnesses. A recent factor analysis suggested another four-factor structure for the TAS-20: difficulties in awareness of feelings (DAF), difficulties in interoceptive abilities (DIA), externally oriented thinking (EOT), and poor affective sharing (PAS). We assume that DIA and DAF might be more relevant to investigate the association between alexithymia and gastrointestinal disorders. The rationale is that DIA and DAF reflect impairments in emotion regulation that could contribute to an inappropriate autonomic and HPA axis homeostasis in irritable bowel syndrome (IBS), ulcerative colitis (UC), or Crohn's disease (CD). The aim of this study was to investigate whether DIA and DAF are associated with the presence of IBS, UC or CD, while checking for anxiety, depression, parasympathetic (vagus nerve) activity and cortisol levels. We recruited control participants (n=26), and patients in remission who were diagnosed with IBS (n=24), UC (n=18), or CD (n=21). Participants completed questionnaires to assess anxiety, depression, and alexithymia. A blood sample and an electrocardiogram were used to measure the level of cortisol and parasympathetic activity, respectively. Logistic regressions with the four-factor structure of the TAS-20 revealed that DIA was a significant predictor of IBS (W(1)=6.27, p=.01). Conversely, DIA and DAF were not significant predictors in CD and UC patients. However, low cortisol level was a significant predictor of UC (W(1)=4.67, p=.035). Additional logistic regressions based on the original 3-factor structure of TAS-20 (DIF, DDF, and EOT) showed that only DDF was a significant predictor of CD [W(1)=6.16, p < .001]. The present study suggests that DIA is an important dimension for assessing potential risk for gastrointestinal diseases, in particular for IBS.

Microbiota-gut-brain axis and its affect inflammatory bowel disease: Pathophysiological concepts and insights for clinicians

Despite the bi-directional interaction between gut microbiota and the brain not being fully understood, there is increasing evidence arising from animal and human studies that show how this intricate relationship may facilitate inflammatory bowel disease (IBD) pathogenesis, with consequent important implications on the possibility to improve the clinical outcomes of the diseases themselves, by acting on the different components of this system, mainly by modifying the microbiota. With the emergence of precision medicine, strategies in which patients with IBD might be categorized other than for standard gut symptom complexes could offer the opportunity to tailor therapies to individual patients. The aim of this narrative review is to elaborate on the concept of the gut-brain-microbiota axis and its clinical significance regarding IBD on the basis of recent scientific literature, and finally to focus on pharmacological therapies that could allow us to favorably modify the function of this complex system.

Autonomic nervous system and inflammation interaction in endometriosis-associated pain

Endometriosis is a chronic inflammatory disease. Pain is the most common symptom in endometriosis. Endometriosis-associated pain is caused by inflammation, and is related to aberrant innervation. Although the specific mechanism between endometriosis-associated pain and the interaction of aberrant innervation and inflammation remains unclear, many studies have confirmed certain correlations between them. In addition, we found that some chronic inflammatory autoimmune diseases (AIDs) such as inflammatory bowel disease (IBD) and rheumatoid arthritis (RA) share similar characteristics: the changes in dysregulation of inflammatory factors as well as the function and innervation of the autonomic nervous system (ANS). The mechanisms underlying the interaction between the ANS and inflammation have provided new advances among these disorders. Therefore, the purpose of this review is to compare the changes in inflammation and ANS in endometriosis, IBD, and RA; and to explore the role and possible mechanism of sympathetic and parasympathetic nerves in endometriosis-associated inflammation by referring to IBD and RA studies to provide some reference for further endometriosis research and treatment.

The Evolving Role of Gut Microbiota in the Management of Irritable Bowel Syndrome: An Overview of the Current Knowledge

The intestinal microbiota is one of the most rapidly evolving areas in biology and medicine. Extensive research in the last decade has escalated our understanding of the role of the microbiota in the pathogenesis of several intestinal and extra-intestinal disorders. Marked by high prevalence, substantial morbidity, and enormous costs, irritable bowel syndrome (IBS) is an important chronic gastrointestinal disorder that is widely encountered by gastroenterologists. Despite advances in our understanding of its pathophysiology, curative interventions have yet to be discovered, and therapeutic approaches remain symptom-driven. Recently, accumulating evidence has enlightened the possible impact of an imbalanced gut microbiome in the pathogenesis of IBS. In fact, several studies have documented altered microbiota in patients, while others have shown that IBS severity was associated with a distinct microbiota signature. These findings may pave the way for the use of microbiota manipulation strategies as an attractive option for IBS management, and may have an essential role in efforts to reduce the societal and economic effects of this ever-growing disorder. In this review, we have outlined the results of the latest research on the association between microbiota and IBS and their implications for the clinical management of affected patients.

Relationship of Cannabis Use Disorder and Irritable Bowel Syndrome (IBS): An Analysis of 6.8 Million Hospitalizations in the United States

Background: Irritable bowel syndrome (IBS) is a chronic multifactorial gastrointestinal condition that substantially affects the quality of life. Research have suggested an increasing trend in cannabis use to alleviate IBS-related psychiatric symptoms. Objectives: We aim to investigate the association of psychiatric comorbidities and cannabis use disorders (CUD) in hospitalized IBS patients. Methods: We analyzed 31,272 IBS hospitalizations in patients (aged 15-54 years) from the Nationwide Inpatient Sample (NIS). We utilized logistic regression to evaluate the adjusted odds ratio (aOR) of CUD and psychiatric comorbidities. Results: Anxiety (26.3%) and depressive (24.8%) disorders were prevalent and increased the odds for IBS-hospitalization by 2.5 and 1.8 times respectively. Tobacco use disorder was most prevalent (24.5%) followed by CUD (3.7%). After controlling for demographics, psychiatric and medical comorbidities, and other substance use disorders, CUD had higher odds for IBS hospitalizations (aOR 1.407, 95% CI 1.32-1.50). IBS hospitalizations with CUD increased by 32.8% from 2010 to 2014. CUD patients were younger (15-24 years, aOR 5.4, 95% CI 4.27-6.77), males (aOR 1.8, 95% CI 1.59-2.09) and African Americans (aOR 2.8, 95% CI 1.45-2.23) and from low-income families (aOR 1.9, 95% CI 1.58-2.39). Conclusions: We found that patients with CUD have 40.7% higher odds for IBS-hospitalizations with a rising trend of CUD and related psychiatric comorbidities which may further worsen IBS and health quality of life. With limited evidence of efficacy and safety of cannabis in IBS, larger, randomized controlled studies are required to examine its therapeutic efficacy.

What impact do Rome IV criteria have on patients with IBS in China?

Background: The Rome criteria for functional gastrointestinal diseases (FGIDs) have been updated from Rome III to Rome IV. This study aimed to investigate the impact of the update on patients with irritable bowel syndrome (IBS) in China.Methods: A previous database including consecutive patients with FGIDs (according to Rome III criteria) from gastrointestinal department of a tertiary hospital in China was re-analyzed. Demographic information, clinical symptoms, psychological status (Zung self-rating scale), and sleep quality (Pittsburgh sleep quality index) were compared between patients with Rome III and Rome IV IBS.Results: Of the 946 patients with FGIDs, only 58 (6.1%) were diagnosed with Rome IV IBS [less than 292 (30.9%) under Rome III criteria] with a surge of the number of unspecified functional bowel disorders (U-FBD). All patients with IBS were divided into three groups: group A [meeting both Rome III and IV criteria, accounting for 43 (4.6%) of patients with FGIDs], group B [meeting only Rome III criteria, 249 (26.3%)], and group C [meeting only Rome IV criteria,15 (1.6%)]. Significant differences in frequency and severity of symptoms, subtypes, and sleep quality among groups (all p < .05) were found. Patients with Rome III IBS having sleep disorder tended to be more serious than those without. On the contrary, it was not the case under Rome IV criteria.Conclusions: Number of IBS patients was greatly reduced accompanied by a surge in U-FBD. Besides, the updated criteria also had great impacts on clinical parameters, sleep quality and psychological state of IBS patients.HighlightsRome IV criteria removed the description of abdominal discomfort for IBS.The updated Rome criteria had great impacts on IBS patients in our database.Our study analyzed the characteristics of IBS patients who fulfilled both criteria.Alterations in the Rome criteria also led to changes in the disease spectrum of FBD.

Gut Microbial Dysbiosis in the Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis of Case-Control Studies

BACKGROUND

Irritable bowel syndrome (IBS) is the most common functional digestive condition in the industrialized world. The gut microbiota plays a key role in disease pathogenesis.

OBJECTIVE

A systematic review and meta-analysis on case-control studies was conducted to determine whether there is gut microbial dysbiosis in participants with IBS in comparison with healthy controls and, if so, whether the dysbiosis pattern differs among IBS subtypes and geographic regions.

METHODS

This review was conducted and reported according to the MOOSE (Meta-Analysis of Observational Studies in Epidemiology) 2000 and PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) 2009 guidelines. Research articles published up to May 9, 2018 were identified through MEDLINE (PubMed), Cochrane Central Register of Controlled Trials (Cochrane Library), ClinicalTrials.gov, EMBASE, and Web of Science. Study quality was assessed using the Newcastle-Ottawa Scale. Case-control studies of participants with IBS who had undergone quantitative gut microbial stool analysis were included. The primary exposure measure of interest is log₁₀ bacterial counts per gram of stool. Meta-analyses were performed to estimate the mean difference (MD) in gut microbiota between participants with IBS and healthy controls using the random-effects model with inverse variance in Revman 5.3 and R 3.5.1. Publication bias was assessed with funnel plots and Egger's test. Between-study heterogeneity was analyzed using Higgins I² statistic with 95% CIs.

RESULTS

There were 6,333 unique articles identified; 52 qualified for full-text screening. Of these, 23 studies were included for analysis (n=1,340 participants from North America, Europe, and Asia). Overall, the studies were moderate in quality. Comparing participants with IBS to healthy controls, lower fecal Lactobacillus (MD= -0.57 log₁₀ colony-forming unit [CFU]/g; P<0.01) and Bifidobacterium (MD= -1.04 log₁₀CFU/g; P<0.01), higher Escherichia coli (MD=0.60 log₁₀CFU/g; P<0.01), and marginally higher Enterobacter (MD=0.74 log₁₀CFU/g; P=0.05). No difference was found between participants with IBS and healthy controls in fecal Bacteroides and Enterococcus (P=0.18 and 0.68, respectively). Publication bias was not observed except in Bifidobacterium (P=0.015). Subgroup analyses on participants with diarrhea-predominant and constipation-predominant IBS showed consistent results with the primary results. A subgroup analysis of Chinese studies was consistent with the primary results, except for fecal Bacteroides, which was increased in participants with IBS vs healthy controls (MD=0.29; 95% CI 0.13 to 0.46; P<0.01). Although substantial heterogeneity was detected (I²>75%) in most comparisons, the direction of the effect estimates is relatively consistent across studies.

CONCLUSIONS

IBS is characterized by gut microbial dysbiosis. Prospective, large-scale studies are needed to delineate how gut microbial profiles can be used to guide targeted therapies in this challenging patient population.

Vagus Nerve Stimulation at the Interface of Brain-Gut Interactions

The vagus nerve, a key component of the cross-communication between the gut and the brain, is a major element of homeostasis sensing the "milieu intérieur" and boosting the nervous and endocrine responses to maintain the gastrointestinal health status. This nerve has anti-inflammatory properties regulating the gut through the activation of the hypothalamic-pituitary-adrenal axis and the release of cortisol and through a vagovagal reflex, which has an anti-tumor necrosis factor (TNF) effect called the cholinergic anti-inflammatory pathway. Stimulating this nerve is an interesting tool as a nondrug therapy for the treatment of gastrointestinal diseases in which brain-gut communication is dysfunctional, such as inflammatory bowel disorders and others. This review presents the rationale of vagal gastrointestinal physiology and diseases and the most recent advances in vagus nerve stimulation. It also highlights the main issues to be addressed in the future to improve this bioelectronic therapy for gastrointestinal disorders.

Predictors of Health-related Quality of Life in Irritable Bowel Syndrome Patients Compared With Healthy Individuals

BACKGROUND

Irritable bowel syndrome (IBS) reduces health-related quality of life (HRQOL). It is unclear how having IBS modifies the impact of gastrointestinal (GI), psychosocial, and somatic symptom variables on HRQOL compared with healthy controls (HCs).

AIMS

(1) Determine psychosocial, somatic, and physical status variables most predictive of HRQOL in IBS and HCs and (2) determine if IBS status modifies relationships between predictive factors and HRQOL.

METHODS

IBS patients and HCs completed validated questionnaires measuring GI symptoms, psychosocial/somatic variables, and physical [physical component score (PCS)] and mental [mental component score (MCS)] HRQOL via the Short-Form-36. Associations between these variables and HRQOL were evaluated with multiple linear regressions. Variables were standardized to determine the strongest predictors of HRQOL. Statistical significance level was 0.01.

RESULTS

Mean HRQOL was higher in 417 HCs versus 290 IBS subjects (PCS: 55.6 vs. 48.6, P<0.001; MCS: 53.7 vs. 44.8, P<0.001). The GI symptom measures were negatively associated with PCS in IBS, but only usual severity was associated with MCS (P<0.01). In all subjects, psychosocial and somatic measures were associated with MCS and not PCS excluding GI symptom anxiety, which correlated with both (P<0.01). The strongest predictor of MCS was perceived stress in IBS and depression symptoms in HCs. GI symptom anxiety was the strongest predictor of PCS in both. Greater perceived stress and somatic symptom severity and less mindfulness was linked to larger reductions in HRQOL for IBS compared with HCs (P<0.01).

CONCLUSIONS

GI symptom severity and anxiety correlate with PCS, whereas psychosocial/somatic measures parallel MCS. However, HRQOL is comparable in IBS and HCs when perceived stress, somatic symptom severity, and mindfulness are at optimal levels. These findings may have important implications in the management of IBS.

Wired for Threat: Clinical Features of Nervous System Dysregulation in 80 Children

BACKGROUND

The negative effect of perceived stress on health has become a cultural epidemic. Despite many health implications, the clinical impact of stress on the nervous system is not well understood. This case series describes the symptom profiles of 80 children with nervous system dysregulation attributed to maladaptive neuroendocrine responses to stress.

METHODS

We reviewed of 80 children with nervous system dysregulation identified from a single, tertiary care pediatric neurology clinic. Included patients were between five and 17 years of age, with unexplained medical symptoms lasting three months or longer affecting at least four of six neurological domains: (1) somatization, (2) executive function, (3) autonomic function, (4) digestion, (5) sleep, and (6) emotional regulation. Medical symptoms, diagnoses, and detailed social histories were collected.

RESULTS

Of 80 children, 57 were female (71%), 57 were Caucasian (71%), with median age of 14 years. Symptoms had a mean duration of 32 months, and included: 100% somatic symptoms, 100% emotional dysregulation, 92.5% disrupted sleep, 82.5% autonomic dysregulation, 75% executive dysfunction, and 66% digestive problems. Overall, 94% reported chronic or traumatic stressors; adverse childhood experiences were present in 65%.

CONCLUSIONS

Perceived stress impacts many functions of the neuroendocrine system through experience-dependent plasticity, resulting in a constellation of symptoms and functional impairments we describe as nervous system dysregulation. The pathophysiology of these symptoms involves dysregulation of subcortical, hormonal, and autonomic circuits, which remain largely untested. Recognition and understanding of maladaptive neurophysiology in stress-related symptoms has important implications for diagnosis, treatment, and advances in health research.

trans-Resveratrol Ameliorates Stress-Induced Irritable Bowel Syndrome-Like Behaviors by Regulation of Brain-Gut Axis

Background: Irritable bowel syndrome (IBS) is a functional disorder characterized by abdominal pain and abnormalities in defecation associated with psychiatric disorders such as depression and anxiety due to the dysfunction of brain-gut axis. This study aims to determine whether trans-Resveratrol affects chronic-acute combined stress (CACS)-induced IBS-like symptoms including depression, anxiety and intestinal dysfunction. Methods: ICR male mice were exposed to the CACS for 3 weeks. trans-Resveratrol were administrated daily (2.5, 5, and 10 mg/kg, i.g.) 30 min before CACS. Behavioral tests were performed to evaluate the treatment effects of trans-Resveratrol on IBS. Hippocampus tissues were collected and processed Golgi staining and immuno-blot analysis. Ileum and colon tissues were collected and processed Hematoxylin and Eosin staining and immuno-blot analysis. Results: Administration with trans-Resveratrol before CACS for 3 weeks significantly reversed CACS-induced depression- and anxiety-like behaviors and intestinal dysfunction in mice, which implied a crucial role of trans-Resveratrol in treatment of IBS-like disorder. Furthermore, trans-Resveratrol improved hippocampal neuronal remodeling, protected ileal and colonic epithelial barrier structure against CACS insults. The further study suggested that trans-Resveratrol normalized phosphodiesterases 4A (PDE4A) expression and CREB-BDNF signaling that were disturbed by CACS. The increased pCREB and BDNF expression in the hippocampus were found, while decreased pCREB and BDNF levels were observed after treatment with trans-Resveratrol. Conclusions: The dual effects of trans-Resveratrol on stress-induced psychiatric and intestinal dysfunction may be related to normalization of PDE4A expression and subsequent pCREB-BDNF signaling in the hippocampus, ileum and colon.

Stereotaxic Exposure of the Central Nucleus of the Amygdala to Corticosterone Increases Colonic Permeability and Reduces Nerve-Mediated Active Ion Transport in Rats

Background: Irritable bowel syndrome (IBS) is characterized by visceral pain and abnormal bowel habits that are worsened during stress. Evidence also suggests altered intestinal barrier function in IBS. Previously, we demonstrated that stereotaxic application of the stress hormone corticosterone (CORT) onto the central nucleus of the amygdala (CeA) induces colonic hyperalgesia and anxiety-like behavior in a rat model, however the effect on intestinal permeability and mucosal function remain to be evaluated. Methods: Male Fischer 344 rats underwent bilateral stereotaxic implantation of CORT or inert cholesterol (CHOL)-containing micropellets (30 μg) onto the dorsal margin of the CeA. Seven days later, colonic tissue was isolated to assess tissue permeability in modified Ussing chambers via transepithelial electrical resistance (TEER) and macromolecular flux of horseradish peroxidase (HRP). Secretory responses to electrical field stimulation (EFS) of submucosal enteric nerves as well as activation with forskolin were used to assess movements of ions across the isolated colonic tissues. In a separate cohort, colonic histology, and mast cell infiltration was assessed. Key Results: Compared to CHOL-implanted controls, we determined that exposing the CeA to elevated levels of CORT significantly increased macromolecular flux across the colonic epithelial layer without changing TEER. Nerve-mediated but not cAMP-mediated active transport was inhibited in response to elevated amygdala CORT. There were no histological changes or increases in mast cell infiltration within colonic tissue from CORT treated animals. Conclusion and Inferences: These observations support a novel role for the CeA as a modulator of nerve-mediated colonic epithelial function.

The Vagus Nerve in the Neuro-Immune Axis: Implications in the Pathology of the Gastrointestinal Tract

The vagus nerve (VN) is the longest nerve of the organism and a major component of the parasympathetic nervous system which constitutes the autonomic nervous system (ANS), with the sympathetic nervous system. There is classically an equilibrium between the sympathetic and parasympathetic nervous systems which is responsible for the maintenance of homeostasis. An imbalance of the ANS is observed in various pathologic conditions. The VN, a mixed nerve with 4/5 afferent and 1/5 efferent fibers, is a key component of the neuro-immune and brain-gut axes through a bidirectional communication between the brain and the gastrointestinal (GI) tract. A dual anti-inflammatory role of the VN is observed using either vagal afferents, targeting the hypothalamic–pituitary–adrenal axis, or vagal efferents, targeting the cholinergic anti-inflammatory pathway. The sympathetic nervous system and the VN act in synergy, through the splenic nerve, to inhibit the release of tumor necrosis factor-alpha (TNFα) by macrophages of the peripheral tissues and the spleen. Because of its anti-inflammatory effect, the VN is a therapeutic target in the treatment of chronic inflammatory disorders where TNFα is a key component. In this review, we will focus on the anti-inflammatory role of the VN in inflammatory bowel diseases (IBD). The anti-inflammatory properties of the VN could be targeted pharmacologically, with enteral nutrition, by VN stimulation (VNS), with complementary medicines or by physical exercise. VNS is one of the alternative treatments for drug resistant epilepsy and depression and one might think that VNS could be used as a non-drug therapy to treat inflammatory disorders of the GI tract, such as IBD, irritable bowel syndrome, and postoperative ileus, which are all characterized by a blunted autonomic balance with a decreased vagal tone.