Gastrointestinal motility disorders in inflammatory bowel diseases

Enteric neuronal Piezo1 maintains mechanical and immunological homeostasis by sensing force

The gastrointestinal (GI) tract experiences a myriad of mechanical forces while orchestrating digestion and barrier immunity. A central conductor of these processes, the enteric nervous system (ENS), detects luminal pressure to regulate peristalsis independently of extrinsic input from the central and peripheral nervous systems. However, how the ∼500 million enteric neurons that reside in the GI tract sense and respond to force remains unknown. Herein, we establish that the mechanosensor Piezo1 is functionally expressed in cholinergic enteric neurons. Optogenetic stimulation of Piezo1+ cholinergic enteric neurons drives colonic motility, while Piezo1 deficiency reduces cholinergic neuronal activity and slows peristalsis. Additionally, Piezo1 deficiency in cholinergic enteric neurons abolishes exercise-induced acceleration of GI motility. Finally, we uncover that enteric neuronal Piezo1 function is required for motility alterations in colitis and acts to prevent aberrant inflammation and tissue damage. This work uncovers how the ENS senses and responds to mechanical force.

How do probiotics alleviate constipation? A narrative review of mechanisms

Constipation is a common gastrointestinal condition, which may occur at any age and affects countless people. The search for new treatments for constipation is ongoing as current drug treatments fail to provide fully satisfactory results. In recent years, probiotics have attracted much attention because of their demonstrated therapeutic efficacy and fewer side effects than pharmaceutical products. Many studies attempted to answer the question of how probiotics can alleviate constipation. It has been shown that different probiotic strains can alleviate constipation by different mechanisms. The mechanisms on probiotics in relieving constipation were associated with various aspects, including regulation of the gut microbiota composition, the level of short-chain fatty acids, aquaporin expression levels, neurotransmitters and hormone levels, inflammation, the intestinal environmental metabolic status, neurotrophic factor levels and the body's antioxidant levels. This paper summarizes the perception of the mechanisms on probiotics in relieving constipation and provides some suggestions on new research directions.

Segmental Regulation of Intestinal Motility by Colitis and the Adaptive Immune System in the Mouse Ileum and Colon

Gastrointestinal motility disturbances are a hallmark of inflammatory bowel disease (IBD); however, their mechanisms remain unclear. This study used a dextran sulfate sodium-induced colitis mouse model, deficient in mature B and T lymphocytes, to assess intestinal motility and the role of the adaptive immune system in health and IBD. In healthy mice, the absence of adaptive lymphocytes reduced acetylcholine (ACh) sensitivity in the ileum. During colitis, it decreases motility by reducing the intensity and frequency of spontaneous contractions while increasing cholinergic responsiveness. In the proximal colon, adaptive immunity deficiency led to increased contractility and reduced ACh sensitivity in homeostasis, whereas colitis reduced contractile capacity. In the mid colon, immune-deficient mice had reduced ACh sensitivity in homeostasis and exacerbated contractile responses during colitis. In the distal colon, adaptive immunity loss reduced contractility in health and cholinergic responsiveness during colitis. These motility alterations were associated with altered acetylcholinesterase and M2/M3 muscarinic receptor expression. Notably, adaptive lymphocyte deficiency resulted in reduced tissue damage and lower tumor necrosis factor-α expression in the colon during colitis, paralleling intestinal motility changes. Overall, the adaptive immune system critically regulates motility and inflammation across different intestinal segments in IBD.

Intestinal organ chips for disease modelling and personalized medicine

Alterations in intestinal structure, mechanics and physiology underlie acute and chronic intestinal conditions, many of which are influenced by dysregulation of microbiome, peristalsis, stroma or immune responses. Studying human intestinal physiology or pathophysiology is difficult in preclinical animal models because their microbiomes and immune systems differ from those of humans. Although advances in organoid culture partially overcome this challenge, intestinal organoids still lack crucial features that are necessary to study functions central to intestinal health and disease, such as digestion or fluid flow, as well as contributions from long-term effects of living microbiome, peristalsis and immune cells. Here, we review developments in organ-on-a-chip (organ chip) microfluidic culture models of the human intestine that are lined by epithelial cells and interfaced with other tissues (such as stroma or endothelium), which can experience both fluid flow and peristalsis-like motions. Organ chips offer powerful ways to model intestinal physiology and disease states for various human populations and individual patients, and can be used to gain new insight into underlying molecular and biophysical mechanisms of disease. They can also be used as preclinical tools to discover new drugs and then validate their therapeutic efficacy and safety in the same human-relevant model.

Integrated serum pharmacochemistry, 16S rDNA sequencing, and metabolomics to reveal the material basis and mechanism of Shouhui Tongbian capsule against diphenoxylate-induced slow transit constipation in rats

BACKGROUND

Slow transit constipation (STC) is highly prevalent and has rising incidence. Shouhui Tongbian capsule (SHTB) is a traditional Chinese Medicine formula with extensive and highly efficacious usage in STC treatment, however, its mechanism of action, especially the regulation of microbiome and lipid metabolites, remains unclear.

METHODS

After quality control of SHTB using LC‒MS to obtain its material basis, we tried to elucidate the cohesive modulatory network of SHTB against STC using hyphenated methods from microbiomics, lipidomics, mass spectrometry imaging (MSI) and molecular methods.

RESULTS

SHTB could repair intestinal barrier damage, reduce systemic inflammation and increase intestinal motility in a diphenoxylate-induced STC rat model. Based on 16S rDNA sequencing results, SHTB rehabilitated the abnormal changes in Alloprevotella, Coprococcus, Marvinbryantia, etc., which were associated with STC symptoms. Meanwhile, microbial functional prediction showed that lipid metabolism was improved with SHTB administration. The differential lipids, including fatty acids, lysophosphatidylcholine, phosphatidylcholine, sphingomyelin triglyceride and ceramide, that are closely related to STC disease and SHTB efficacy. Furthermore, SHTB significantly reversed the abnormal expression of these key target enzymes in colon samples, including CTP-phosphocholine cytidylyltransferase, CTP-phosphoethanolamine cytidylyltransferase, phosphatidic acid phosphatase, acid sphingomyelinase etc. CONCLUSIONS: Combined analysis demonstrated that SHTB reducing lipid accumulation and recovery of intestinal microbial homeostasis was the critical mechanism by which SHTB treats STC.

Metabolomics and gut microbiota analysis reveal the differential efficacy of areca nut and charred areca nut in treating constipation

Background

Areca nut (AN) is a traditional Chinese herbal medicine used for centuries to treat gastrointestinal (GI) disorders. Charred AN (CAN) is a processed product of AN with similar therapeutic effects. This study aimed to investigate the therapeutic mechanisms of AN and CAN for constipation via metabolomics and gut microbiota analysis.

Methods

In this study, the rats were randomly divided into 5 groups (n = 6): control, constipation model, positive drug, AN treatment, and CAN treatment groups. Constipation was induced by intragastric administration of loperamide hydrochloride, followed by 14-day treatment with mosapride, AN, or CAN. The efficacy difference between AN and CAN was assessed by evaluating the weight gain, fecal water content, GI transit rate, colonic histopathology, serum levels of GI hormones, gut microbiota, and fecal metabolites.

Results

The results demonstrated that both AN and CAN could alleviate loperamide-induced constipation. Furthermore, they significantly elevated the serum levels of motilin, vasoactive intestinal peptide, substance P, and acetylcholine. 16S rRNA analysis revealed that AN regulated the relative abundance of Bacillus, UCG-005, norank_f_Muribaculaceae, Candidatus_Saccharimonas, and Ruminococcus, whereas CAN modulate the relative abundance of Lactobacillus, Bacillus, norank_f_Muribaculaceae, Ruminococcus, unclassified_f_Oscillospiraceae, and unclassified_f_Prevotellaceae. Moreover, the metabolic profile of AN- and CAN-treated rats was also different, where AN treatment involved pathways of citrate cycle (TCA) and tyrosine, alanine, aspartate, and glutamate metabolisms. Whereas CAN treatment involved pathways of steroid and primary bile acid biosynthesis, as well as pyrimidine and purine metabolisms. Spearman correlation analysis indicated a close relationship between gut microbiota and fecal metabolites.

Conclusion

In summary, this study revealed that AN may protect GI mucosa, enhance GI motility, and alleviate constipation symptoms by regulating the relative abundance of specific gut microbiota (Bacillus, UCG-005, norank_f_Muribaculaceae, Candidatus_Saccharimonas, Ruminococcus) as well as citrate cycle or tyrosine, alanine, aspartate, and glutamate metabolic pathways. Furthermore, CAN was observed to promote gastric emptying and intestinal propulsion, thereby alleviating constipation, by modulating the relative abundance of specific gut microbiota (Lactobacillus, Bacillus, norank_f_Muribaculaceae, Ruminococcus, unclassified_f_Oscillospiraceae, unclassified_f_Prevotellaceae) as well as steroid and primary bile acid biosynthesis, as well as pyrimidine and purine metabolic pathways.

Comparison of Pelvic Floor Dysfunction in Women with Ulcerative Colitis and Healthy Population

Background

The possibility of pelvic floor dysfunction (PFD) occurrence seems to be higher in patients with inflammatory bowel disease (IBD) due to the presence of functional gastrointestinal disorders in these patients. Hence, this study aimed to evaluate the association of ulcerative colitis (UC) in women with PFD and its comparison with the healthy (without IBD) population.

Methods

The present study was conducted on 150 women with UC and 150 without-IBD individuals. Pelvic Floor Distress Inventory (PFDI-20) was used to evaluate the pelvic floor function.

Results

The results of this study revealed that UC had a significant role in increasing not only the PFD score (Beta=3.04; P<0.001) but also the score of each sub-scale of Pelvic Organ Prolapse Distress Inventory (POPDI) (Beta=6.61; P<0.001), Colo-Rectal-Anal Distress Inventory (CRADI) (Beta=9.37; P<0.001), and Urinary Distress Inventory (UDI) (Beta=5.56; P=0.015). In addition, aging, increased body mass index (BMI) and menopause had significant role in increasing POPDI, UDI, and PFDI scores, respectively (P<0.05).

Conclusion

The percentage of PFD in women with UC was significantly higher than its percentage in women without IBD. This dysfunction was more visible in the two sub-scales of POPDI and CRADI. In addition to having UC, aging, BMI, and menopause played a significant role in increasing PFD.

Gut Epithelial Barrier Function is Impacted by Hyperglycemia and Secondary Bile Acids in Vitro: Possible Rescuing Effects of Specific Pectins

Gut epithelial barrier disruption is commonly observed in Western diseases like diabetes and inflammatory bowel disease (IBD). Enhanced epithelial permeability triggers inflammatory responses and gut microbiota dysbiosis. Reduced bacterial diversity in IBD affects gut microbiota metabolism, altering microbial products such as secondary bile acids (BAs), which potentially play a role in gut barrier regulation and immunity. Dietary fibers such as pectin may substitute effects of these BAs. The study examines transepithelial electrical resistance of gut epithelial T84 cells and the gene expression of tight junctions after exposure to (un)sulfated secondary BAs. This is compared to the impact of the dietary fiber pectin with different degrees of methylation (DM) and blockiness (DB), with disruption induced by calcium ionophore A23187 under both normal and hyperglycemic conditions. Unsulfated lithocholic acid (LCA) and deoxycholic acid (DCA) show a stronger rescuing effect, particularly evident under 20 mM glucose levels. DM19 with high DB (HB) and DM43HB pectin exhibit rescuing effects under both glucose conditions. Notably, DM19HB and DM43HB display higher rescue effects under 20 mM glucose compared to 5 mM glucose. The study demonstrates that specific pectins such as DM19HB and DM43HB may serve as alternatives for preventing barrier disruption in the case of disturbed DCA metabolism.

Comparative Assessment of the Anti-Helicobacter pylori Activity and Gastroprotective Effects of Three Herbal Formulas for Functional Dyspepsia In Vitro

Helicobacter pylori has been implicated in various gastrointestinal disorders, including functional dyspepsia. This study aimed to compare the anti-H. pylori activity and gastroprotective effects of three typical herbal formulas used for gastrointestinal disorders in Korea: Shihosogan-tang (ST), Yijung-tang (YT), and Pyeongwi-san (PS). Firstly, we assessed the total phenolic and flavonoid contents, as well as the antioxidative capacity. Additionally, we evaluated the antibacterial effect on H. pylori using an ammonia assay, minimum inhibitory concentration (MIC) test, and the disk agar diffusion method. Furthermore, we examined alterations in the gene expression of tight junction proteins, pro-inflammatory cytokines, and cellular vacuolation using an AGS cell model infected with H. pylori. While ST exhibited a higher total phenolic content, superior free radical scavenging, and inhibition of H. pylori compared to YT and PS, YT more evidently inhibited gastric cellular morphological changes such as vacuolation. All formulations significantly ameliorated changes in inflammatory and gastric inflammation-related genes and cellular morphological alterations induced by H. pylori infection. Overall, the present in vitro study suggests that all three herbal formulas possess potential for ameliorating gastrointestinal disorders, with ST relatively excelling in inhibiting H. pylori infection and inflammation, while YT potentially shows greater efficacy in directly protecting the gastric mucosa.

Colitis-Induced Small Intestinal Hypomotility Is Dependent on Enteroendocrine Cell Loss in Mice

BACKGROUND & AIMS

The abdominal discomfort experienced by patients with colitis may be attributable in part to the presence of small intestinal dysmotility, yet mechanisms linking colonic inflammation with small-bowel motility remain largely unexplored. We hypothesize that colitis results in small intestinal hypomotility owing to a loss of enteroendocrine cells (EECs) within the small intestine that can be rescued using serotonergic-modulating agents.

METHODS

Male C57BL/6J mice, as well as mice that overexpress (EECOVER) or lack (EECDEL) NeuroD1+ enteroendocrine cells, were exposed to dextran sulfate sodium (DSS) colitis (2.5% or 5% for 7 days) and small intestinal motility was assessed by 70-kilodalton fluorescein isothiocyanate-dextran fluorescence transit. EEC number and differentiation were evaluated by immunohistochemistry, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling staining, and quantitative reverse-transcriptase polymerase chain reaction. Mice were treated with the 5-hydroxytryptamine receptor 4 agonist prucalopride (5 mg/kg orally, daily) to restore serotonin signaling.

RESULTS

DSS-induced colitis was associated with a significant small-bowel hypomotility that developed in the absence of significant inflammation in the small intestine and was associated with a significant reduction in EEC density. EEC loss occurred in conjunction with alterations in the expression of key serotonin synthesis and transporter genes, including Tph1, Ddc, and Slc6a4. Importantly, mice overexpressing EECs revealed improved small intestinal motility, whereas mice lacking EECs had worse intestinal motility when exposed to DSS. Finally, treatment of DSS-exposed mice with the 5-hydroxytryptamine receptor 4 agonist prucalopride restored small intestinal motility and attenuated colitis.

CONCLUSIONS

Experimental DSS colitis induces significant small-bowel dysmotility in mice owing to enteroendocrine loss that can be reversed by genetic modulation of EEC or administering serotonin analogs, suggesting novel therapeutic approaches for patients with symptomatic colitis.

Exploring the Interconnections of Functional Gut Disorders and Inflammatory Bowel Disease: A Narrative Review Article

This review reveals details of the interaction between disorders of gut-brain interaction (DGBI) and inflammatory bowel disease (IBD) by providing an in-depth review of that relationship. The review provides a nuanced understanding of this multifaceted dynamic by spanning shared symptomatology, the impact of inflammation on functional aspects, and addressing diagnostic challenges, psychological influences, treatment strategies, and emerging research directions. By synthesizing current knowledge and identifying gaps in understanding, this article aims to contribute to the evolving discourse surrounding the interplay between IBD and DGBI, offering valuable insights for clinicians, researchers, and healthcare professionals navigating the complexities of gastrointestinal health.

The Prokineticin System in Inflammatory Bowel Diseases: A Clinical and Preclinical Overview

Inflammatory bowel disease (IBD) includes Crohn's disease (CD) and ulcerative colitis (UC), which are characterized by chronic inflammation of the gastrointestinal (GI) tract. IBDs clinical manifestations are heterogeneous and characterized by a chronic relapsing-remitting course. Typical gastrointestinal signs and symptoms include diarrhea, GI bleeding, weight loss, and abdominal pain. Moreover, the presence of pain often manifests in the remitting disease phase. As a result, patients report a further reduction in life quality. Despite the scientific advances implemented in the last two decades and the therapies aimed at inducing or maintaining IBDs in a remissive condition, to date, their pathophysiology still remains unknown. In this scenario, the importance of identifying a common and effective therapeutic target for both digestive symptoms and pain remains a priority. Recent clinical and preclinical studies have reported the prokineticin system (PKS) as an emerging therapeutic target for IBDs. PKS alterations are likely to play a role in IBDs at multiple levels, such as in intestinal motility, local inflammation, ulceration processes, localized abdominal and visceral pain, as well as central nervous system sensitization, leading to the development of chronic and widespread pain. This narrative review summarized the evidence about the involvement of the PKS in IBD and discussed its potential as a druggable target.

Major Indole Alkaloids in Evodia Rutaecarpa: The Latest Insights and Review of Their Impact on Gastrointestinal Diseases

Evodia rutaecarpa, the near-ripe fruit of Euodia rutaecarpa (Juss.) Benth, Euodia rutaecarpa (Juss.) Benth. var. officinalis (Dode) Huang, or Euodia rutaecarpa (Juss.) Benth. var. bodinieri (Dode) Huang, is a famous herbal medicine with several biological activities and therapeutic values, which has been applied for abdominalgia, abdominal distension, vomiting, and diarrhea as a complementary and alternative therapy in clinic. Indole alkaloids, particularly evodiamine (EVO), rutaecarpine (RUT), and dedhydroevodiamine (DHE), are received rising attention as the major bioactivity compounds in Evodia rutaecarpa. Therefore, this review summarizes the physicochemical properties, pharmacological activities, pharmacokinetics, and therapeutic effects on gastrointestinal diseases of these three indole alkaloids with original literature collected by PubMed, Web of Science Core Collection, and CNKI up to June 2023. Despite sharing the same parent nucleus, EVO, RUT, and DHE have different structural and chemical properties, which result in different advantages of biological effects. In their wide range of pharmacological activities, the anti-migratory activity of RUT is less effective than that of EVO, and the neuroprotection of DHE is significant. Additionally, although DHE has a higher bioavailability, EVO and RUT display better permeabilities within blood-brain barrier. These three indole alkaloids can alleviate gastrointestinal inflammatory in particular, and EVO also has outstanding anti-cancer effect, although clinical trials are still required to further support their therapeutic potential.

Anorectal Function and Clinical Characteristics Associated with Faecal Incontinence in Patients with Crohn's Disease

BACKGROUND AND AIMS

Faecal incontinence is an important complaint reported by patients with Crohn's disease [CD] and it is associated with several disease-related mechanisms, including anorectal functional disorders. This study aimed to assess the anorectal function and clinical characteristics to identify parameters associated with faecal incontinence in CD patients.

METHODS

This is a cross-sectional study of 104 patients with CD, aged 18 years or older, from a referral centre between August 2019 and May 2021. Patients responded to a specific questionnaire, and underwent medical record review, proctological examination and anorectal functional assessment with anorectal manometry.

RESULTS

Of the 104 patients, 49% were incontinent. Patients with incontinence had a lower mean resting pressure [43.5 vs 53.1 mmHg; p = 0.038], lower mean squeeze pressure [62.1 vs 94.1 mmHg; p = 0.036] and lower maximum rectal capacity [140 vs 180 mL; p < 0.001]. Faecal incontinence was also associated with disease activity [p < 0.001], loose stools [p = 0.02], perianal disease [p = 0.006], previous anoperineal surgery [p = 0.048] and number of anorectal surgeries [p = 0.036].

CONCLUSIONS

This is the largest reported study describing manometric findings of Crohn's disease patients with and without faecal incontinence. Our results identified an association between faecal incontinence and functional disorders, in addition to clinical features in these patients. Functional assessment with anorectal manometry may help choose the best treatment for faecal incontinence in patients with CD.

Therapeutic role of Wuda granule in gastrointestinal motility disorder through promoting gastrointestinal motility and decreasing inflammatory level

Introduction: Previous studies indicated that Wuda Granule (WDG) has been applied in the treatment of gastrointestinal motility disorder (GMD), but the effect and underlying mechanisms is yet to be elucidated. This study aimed to explore the mechanism and pharmacological effect of WDG for GMD via network analysis, verification of animal experiments and clinical experiments. Methods: The chemical components of WDG were identified from the Traditional Chinese Medicine Systems Pharmacology Database (TCMSP, http://lsp.nwu.edu.cn/index.php), and the Encyclopedia of Traditional Chinese Medicine (ETCM, http://www.tcmip.cn/ETCM/index.php/Home/Index/) according to oral bioavailability (OB) ≥ 20% and drug-likeness (DL) ≥ 0.10. The targets of WDG compounds were retrieved from the Swiss Target Prediction database (http://www.swisstargetprediction.ch/) and targets related to GMD were retrieved from GeneCards database (https://www.genecards.org/). Network analysis were performed to screen the key active compounds of WDG and its hub targets. Then the pharmacological effect of WDG were verified via vivo experiments in rats and clinical experiments. Results: The results showed that 117 effective active compounds of WDG were screened and 494 targets of WDG compounds targeting GMD were selected. These targets were involved in the biological process of inflammatory regulation and the regulation of gastrointestinal motility. The mechanism was mainly involved in the regulation of PI3K-Akt signaling pathway and Rap1 signaling pathway. In addition, molecular docking analysis suggested that eight key active compounds of WDG may be mainly responsible for the effect of WDG on GMD by targeting HARS, AKT, and PIK3CA, respectively. Animal experiments and clinical trials both suggested that WDG could exert therapeutical effect on GMD via inhibiting inflammation and promoting gastrointestinal motility, it could also improve digestive function of patients with laparoscopic colorectal cancer after surgery. Conclusion: This study was the first to demonstrate that WDG improved GMD mainly via inhibiting inflammatory level and promoting gastrointestinal motility, providing new insights for the understanding of WDG for GMD, inspiration for future research and reference for clinical strategy in terms of the treatment of GMD.

Inflammatory Bowel Disease and Neurodegenerative Diseases

A growing body of evidence has demonstrated an intricate association between inflammatory bowel disease (IBD) and neurodegenerative conditions, expanding beyond previous foci of comorbidities between IBD and mood disorders. These new discoveries stem from an improved understanding of the gut-microbiome-brain axis: specifically, the ability of the intestinal microbiota to modulate inflammation and regulate neuromodulatory compounds. Clinical retrospective studies incorporating large sample sizes and population-based cohorts have demonstrated and confirmed the relevance of IBD and chronic neurodegeneration in clinical medicine. In this review, we expound upon the current knowledge on the gut-microbiome-brain axis, highlighting several plausible mechanisms linking IBD with neurodegeneration. We also summarize the known associations between IBD with Parkinson disease, Alzheimer disease, vascular dementia and ischemic stroke, and multiple sclerosis in a clinical context. Finally, we discuss the implications of an improved understanding of the gut-microbiome-brain axis in preventing, diagnosing, and managing neurodegeneration among IBD and non-IBD patients.

Body Surface Gastrointestinal Potential Mapping: A Simulation Framework to Evaluate Source Separation Algorithms. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023;2023:1-4. [PMID: 38083102 DOI: 10.1109/embc40787.2023.10340911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Gastrointestinal (GI) potential mapping could be useful for evaluating GI motility disorders. Such disorders are found in inflammatory bowel diseases, such as Crohn's disease, or GI functional disorders. GI potential mapping data originate from a mixture of several GI electrophysiological sources (termed ExG) and other noise sources, including the electrocardiogram (ECG) and respiration. Denoising and/or source separation techniques are required, however, with real measurements, no ground truth is available. In this paper we propose a framework for the simulation of body surface GI potential mapping data. The framework is an electrostatic model, based on fecgsyn toolbox, using dipoles as electrical sources for the heart, stomach, small bowel and colon, and an array of surface electrodes. It is shown to generate realistic ExG waveforms, which are then used to compare several ECG and respiration cancellation techniques, based on, fast independent component analysis (FastICA) and pseudo-periodic component analysis (PiCA). The best performance was obtained with PiCA with a median root mean squared error of 0.005.

Macrophages regulate gastrointestinal motility through complement component 1q

Peristaltic movement of the intestine propels food down the length of the gastrointestinal tract to promote nutrient absorption. Interactions between intestinal macrophages and the enteric nervous system regulate gastrointestinal motility, yet we have an incomplete understanding of the molecular mediators of this crosstalk. Here, we identify complement component 1q (C1q) as a macrophage product that regulates gut motility. Macrophages were the predominant source of C1q in the mouse intestine and most extraintestinal tissues. Although C1q mediates the complement-mediated killing of bacteria in the bloodstream, we found that C1q was not essential for the immune defense of the intestine. Instead, C1q-expressing macrophages were located in the intestinal submucosal and myenteric plexuses where they were closely associated with enteric neurons and expressed surface markers characteristic of nerve-adjacent macrophages in other tissues. Mice with a macrophage-specific deletion of C1qa showed changes in enteric neuronal gene expression, increased neurogenic activity of peristalsis, and accelerated intestinal transit. Our findings identify C1q as a key regulator of gastrointestinal motility and provide enhanced insight into the crosstalk between macrophages and the enteric nervous system.

Endoscopic Disease Activity and Biologic Therapy Are Independent Predictors of Suboptimal Bowel Preparation in Patients with Inflammatory Bowel Disease Undergoing Colonoscopy

BACKGROUND AND AIMS

Optimal bowel preparation (BP) is critical for endoscopic assessment of inflammation and dysplasia in patients with inflammatory bowel disease (IBD). Comorbidities and patient-related factors have been associated with suboptimal BP (SOBP) in the general population. We sought to identify disease-specific characteristics that may impact the quality of BP in patients with IBD.

METHODS

We conducted a retrospective analysis of adult IBD patients who underwent outpatient colonoscopies between January 2014 and September 2020 at a large academic medical center. Quality of BP was documented using the Boston Bowel Preparation Scale (BBPS) or the Aronchick scale and dichotomized into "suboptimal" (BBPS 0-5 or Aronchick "fair," "poor," unsatisfactory") and "optimal" (BBPS 6-9 or Aronchick "excellent," "good"). IBD-specific and other factors associated with SOBP were evaluated using logistic regression analyses.

RESULTS

Among a total of 395 IBD patients [54% males, mean age 40 years, 63% with Crohn's disease (CD), 35% with ulcerative colitis (UC)], 24.8% had SOBP. On multivariable analysis, moderate-to-severe endoscopic disease vs mild or inactive disease was associated with a higher odds of SOBP [adjusted OR 2.7(95% CI 1.52-4.94)], whereas baseline biologic use was associated with a lower odds of SOBP [aOR 0.24(0.09-0.65)] among the overall IBD cohort. Additionally, age > 65 years [aOR 2.99(1.19-7.54)] and single-dose vs split-dose BP [aOR 2.37(1.43-3.95)] were predictors of SOBP. In the subgroup analysis by IBD type, moderate-to-severe endoscopic disease predicted SOBP among both CD and UC cohorts.

CONCLUSION

Endoscopic disease activity was predictive of SOBP, and biologic therapy was protective against SOBP among IBD patients.

The role of colonic motility in low anterior resection syndrome

Low anterior resection syndrome (LARS) describes the symptoms and experiences of bowel dysfunction experienced by patients after rectal cancer surgery. LARS is a complex and multifactorial syndrome exacerbated by factors such as low anastomotic height, defunctioning of the colon and neorectum, and radiotherapy. There has recently been growing awareness and understanding regarding the role of colonic motility as a contributing mechanism for LARS. It is well established that rectosigmoid motility serves an important role in coordinating rectal filling and maintaining continence. Resection of the rectosigmoid may therefore contribute to LARS through altered distal colonic and neorectal motility. This review evaluates the role of colonic motility within the broader pathophysiology of LARS and outlines future directions of research needed to enable targeted therapy for specific LARS phenotypes.

Esculentoside A Alleviates Intestinal Dysmotility in Ulcerative Colitis by Regulating H2S/CSE and NO/nNOS Systems

Background

Ulcerative colitis (UC) is a type of inflammatory bowel disease (IBD) that commonly affects the health of many individuals. Esculentoside A (EsA), a saponin extracted from the roots of Phytolacca esculenta, has antioxidative and anti-inflammatory effects against various diseases. Nonetheless, its role in UC is undetermined. Hence, in this study, we examined the therapeutic effects of EsA in UC.

Methods

Primary intestinal neuronal cells (in vitro) were treated with lipopolysaccharide (LPS) to induce inflammatory injury. An in vivo UC rat model was created by the administration of dextran sulfate sodium (DSS) to rats, which were subsequently treated with different doses of EsA. The effects of EsA on intestinal motility, histological score, inflammatory response, hydrogen sulfide (H₂S)/cystathionine γ-lyase (CSE) system, NO/neuronal nitric oxide synthase (nNOS) system, and LPS-induced primary intestinal neuronal cell viability loss, proliferation inhibition, and apoptosis were detected.

Results

In vitro, EsA treatment increased the number of DSS-inhibited bowel movements and body weight, improved the histological score of colitis, and inhibited the inflammatory response by reducing IL-6 and TNF-α levels in rats. More importantly, EsA reduced the NO and H₂S levels in serum and CSE, CBS, and nNOS expressions in the colon tissue. In vivo, EsA treatment eased the viability loss, proliferation inhibition, and apoptosis of LPS-stimulated primary intestinal neuronal cells, as well as inhibited the expressions of IL-6, TNF-α, CSE, CBS, and nNOS in cells.

Conclusion

EsA improved intestinal motility and suppressed inflammatory response in DSS-induced UC, which may be mediated by H₂S/CSE and NO/nNOS systems.

Aggregative trans-eQTL analysis detects trait-specific target gene sets in whole blood

Large scale genetic association studies have identified many trait-associated variants and understanding the role of these variants in the downstream regulation of gene-expressions can uncover important mediating biological mechanisms. Here we propose ARCHIE, a summary statistic based sparse canonical correlation analysis method to identify sets of gene-expressions trans-regulated by sets of known trait-related genetic variants. Simulation studies show that compared to standard methods, ARCHIE is better suited to identify "core"-like genes through which effects of many other genes may be mediated and can capture disease-specific patterns of genetic associations. By applying ARCHIE to publicly available summary statistics from the eQTLGen consortium, we identify gene sets which have significant evidence of trans-association with groups of known genetic variants across 29 complex traits. Around half (50.7%) of the selected genes do not have any strong trans-associations and are not detected by standard methods. We provide further evidence for causal basis of the target genes through a series of follow-up analyses. These results show ARCHIE is a powerful tool for identifying sets of genes whose trans-regulation may be related to specific complex traits.

Microscopic colitis in older adults: impact, diagnosis, and management

Microscopic colitis (comprising lymphocytic and collagenous colitis, albeit an incomplete variant is gaining recognition as well) is a chronic, immune-mediated inflammatory state of the lower gastrointestinal tract (colon). The diagnosis requires diagnostic colonoscopy with characteristic histopathological findings. They have a propensity to present in senior populations (above 60 years of age), particularly women - who are approximately 2.5-3 times more likely to develop microscopic colitis. Preexisting other immune-inflammatory diseases are also shown to predispose patients for the development of microscopic colitis. The classic presentation is profuse watery diarrhea, often during the night or early morning hours. Fecal incontinence and abdominal pain are frequent as well. Thus, the disease impacts patients' quality of life and well-being. The first described cases date back to the seventies and eighties of the twentieth century, thereby they can be considered fairly recently discovered disease states. Our understanding of the disease and its pathophysiology is still incomplete. Although there is a lack of unified recommendation for treatment, most clinicians prefer the use of budesonide, and most published guidelines regard this locally acting glucocorticoid as the therapy of choice. In our article, we aimed for a brief, noncomprehensive overview of the clinical significance, diagnosis, and management of microscopic colitis.

Bifidobacterium lactis TY-S01 Prevents Loperamide-Induced Constipation by Modulating Gut Microbiota and Its Metabolites in Mice

Probiotics have received widespread attention as a healthy ingredient. The preventive effect of Bifidobacterium lactis TY-S01 on loperamide-induced constipation in mice was investigated in this study. TY-S01 accelerated the peristalsis of intestine, maintained the humidity of faeces, and prevented the destruction of gut barrier. TY-S01 also maintained the 5-HT, MTL and SP at normal levels in constipated mice. Simultaneously, TY-S01 up-regulated the mRNA expressions of 5-HT4R, SERT, and MUC-2, while down-regulated the mRNA expressions of pro-inflammatory genes remarkably. The levels of short-chain fatty acids in the feces of constipated mice were also increased because of the intervention with TY-S01. Moreover, TY-S01 prevented gut microbiological dysbiosis in constipated mice. Spearman’s correlation analysis revealed that there was an obvious association between metabolic biomarkers and gut microbiota. In summary, TY-S01 regulated gut microbiota and the production of intestinal metabolites to prevent loperamide-induced constipation.

Magnolol and honokiol target TRPC4 to regulate extracellular calcium influx and relax intestinal smooth muscle

ETHNOPHARMACOLOGICAL RELEVANCE

Magnolia officinalis Cortex (M. officinalis) is a classical traditional Chinese medicine (TCM) widely used to treat digestive system diseases. It effectively regulates gastrointestinal motility to improve abdominal pain, abdominal distension and other symptoms. Magnolol (MAG) and honokiol (HON) are the main pharmacodynamic components responsible for the gastrointestinal activity of M. officinalis.

AIM OF THE STUDY

The transient receptor potential (TRP) family is highly expressed in the gastrointestinal tract and participates in the regulation of gastrointestinal motility, visceral hypersensitivity, visceral secretion and other physiological activities. In this study, the calcium-lowering mechanisms of MAG and HON contributing to the smooth muscle relaxation associated with TRP are discussed.

MATERIALS AND METHODS

The relaxation smooth muscle effects of MAG and HON were tested by the isolated intestine tone tests. A synthetic MAG probe (MAG-P) was used to target fishing for their possible target. The distribution of MAG on the smooth muscle was identified by a molecular tracer based on chemical biology. Ca²⁺ imaging and dual-luciferase reporter assays were used to determine the effects on the target proteins. Finally, the calcium-mediating effects of MAG and HON on smooth muscle cells and TRPC4-knockdown cells were compared to verify the potential mechanism.

RESULTS

After confirming the smooth muscle relaxation in the small intestine induced by MAG and HON, the relaxation effect was identified mainly due to the downregulation of intracellular calcium by controlling external calcium influx. Although MAG and HON inhibited both TRPV4 and TRPC4 channels to reduce calcium levels, the inhibitory effect on TRPC4 channels is an important mechanism of their smooth muscle relaxation effect, since TRPC4 is widely expressed in the small intestinal smooth muscle cells.

CONCLUSIONS

The inhibition of MAG and HON on TRPC4 channels contributes to the relaxation of intestinal smooth muscle.

A novel method for measuring bowel motility and velocity with dynamic magnetic resonance imaging in two and three dimensions

Increasingly, dynamic magnetic resonance imaging (MRI) has potential as a noninvasive and accessible tool for diagnosing and monitoring gastrointestinal motility in healthy and diseased bowel. However, current MRI methods of measuring bowel motility have limitations: requiring bowel preparation or long acquisition times; providing mainly surrogate measures of motion; and estimating bowel-wall movement in just two dimensions. In this proof-of-concept study we apply a method that provides a quantitative measure of motion within the bowel, in both two and three dimensions, using existing, vendor-implemented MRI pulse sequences with minimal bowel preparation. This method uses a minimised cost function to fit linear vectors in the spatial and temporal domains. It is sensitised to the spatial scale of the bowel and aims to address issues relating to the low signal-to-noise in high-temporal resolution dynamic MRI scans, previously compensated for by performing thick-slice (10-mm) two-dimensional (2D) coronal scans. We applied both 2D and three-dimensional (3D) scanning protocols in two healthy volunteers. For 2D scanning, analysis yielded bi-modal velocity peaks, with a mean antegrade motion of 5.5 mm/s and an additional peak at ~9 mm/s corresponding to longitudinal peristalsis, as supported by intraoperative data from the literature. Furthermore, 3D scans indicated a mean forward motion of 4.7 mm/s, and degrees of antegrade and retrograde motion were also established. These measures show promise for the noninvasive assessment of bowel motility, and have the potential to be tuned to particular regions of interest and behaviours within the bowel.

Wear and Tear of the Intestinal Visceral Musculature by Intrinsic and Extrinsic Factors

BACKGROUND

The gut visceral musculature plays essential roles in not only moving substances through the lumen but also maintaining the function and physiology of the gut. Although the development of the visceral musculature has been studied in multiple model organisms, how it degenerates is poorly understood.

RESULTS

Here, we employ the Drosophila midgut as a model to demonstrate that the visceral musculature is disrupted by intrinsic and extrinsic factors, such as aging, feeding, chemical-induced tissue damage, and oncogenic transformation in the epithelium. Notably, we define four prominent visceral musculature disruption phenotypes, which we refer as 'sprout', 'discontinuity', 'furcation', and 'crossover' of the longitudinal muscle. Given that the occurrence of these phenotypes is increased during aging and under various stresses, we propose that these phenotypes can be used as quantitative readouts of deterioration of the visceral musculature. Intriguingly, administration of a tissue-damaging chemical dextran sulfate sodium (DSS) induced similar visceral musculature disruption phenotypes in zebrafish larvae, indicating that ingestion of a tissue-damaging chemical can disrupt the visceral musculature in a vertebrate as well.

CONCLUSIONS

Our study provides insights into the deterioration of the gut visceral musculature and lays a groundwork for investigating the underlying mechanisms in Drosophila as well as other animals. This article is protected by copyright. All rights reserved.

[Functional Gastrointestinal Disorders in Patients with Inflammatory Bowel Disease]

With emerging more effective drugs, the therapeutic goal of inflammatory bowel disease (IBD) has progressed from clinical remission to mucosal healing. Although the inflammation could be controlled more effectively than before, symptoms such as abdominal pain and bowel habit change is still bothersome to some IBD patients. Recently, these "refractory functional gastrointestinal symptoms" in quiescent IBD patients has been paid more attention. The pathophysiology could be multifactorial with genetics, change in gut motility associated with post inflammatory condition, increased permeability, impaired colorectal function, visceral hypersensitivity and gut microbiota. Because both IBD and functional gastrointestinal disease (FGID) could share similar symptoms and some pathophysiology, it is sometimes challenging to distinguish them exactly. However, to reduce the risk of overtreatment or insufficient control of inflammation, exact diagnosis of functional disease or symptoms in quiescent IBD patients is important. Because there is limited randomized controlled trials or prospective study currently, most of the therapeutic approach in IBD patients are empirical or referred to those of functional gastrointestinal disorders. However, approaches based on pathophysiological mechanisms could give appropriate therapies for both IBD and FGIDs.

Microscopic colitis: controversies in clinical symptoms and autoimmune comorbidities

BACKGROUND

Microscopic colitides are chronic immune-inflammatory bowel diseases. The typical presentation is chronic, watery diarrhoea. Inflammation mostly cannot be visualized via macroscopic inspection. The diagnosis thus requires histologic sampling. The clinical picture can vary. New investigations can prove valuable in setting up recommendations.

PATIENTS

A total of 103 patients with microscopic colitis (MC) [28 lymphocytic colitis (LC) 27.2%, 75 collagenous colitis (CC) 72.8%] in the Clinical Centre of the University of Debrecen (tertiary care centre) were included, diagnosed between 1993 and 2020. We aimed for a retrospective analysis characterizing Hungarian MC patients. We sought to compare two subgroups of patients (with either LC or CC). Our investigation focussed on dominant alteration of stool habits, autoimmune and allergic comorbidities. Autoimmune diseases were diagnosed in 39% (40) of the patients, allergic diseases in 26.2% (27) of patients and 22.2% of tested patients had alimentary hypersensitivity to certain foods (18 cases out of 81 tested).

RESULTS

Age of diagnosis was younger in LC (44.5 years, SD: 5.3 vs. 51.9 years, SD: 12.8, difference= 7.4 years p = .0151). Autoimmune diseases were equally frequent in the two groups (LC: 10 patients 36%, CC: 30 patients, 40%, difference: 4%, p = .7124). Food-linked hypersensitivities were more common in CC (LC: 1 patient, CC: 17 patients). Difference in allergic diseases (asthma, rhinitis, urticaria) did not differ between groups (LC: 6 patients, 21%; CC: 21 patients, 28%, difference: 7% p = .4739). One-third of the patients did not complain about chronic diarrhoea. These patients had chronic constipation as the main symptom (34 patients, 33%).

CONCLUSION

Pre-existing autoimmune and allergic diseases were common in patients with MC. Chronic watery diarrhoea is not experienced in many cases. The absence of certain symptoms should not be used to rule out the condition.

Ileocolic Intussusception in a Woman: A Case Report and Literature Review

BACKGROUND Intussusception is a rare pathological entity in adults and remains a diagnostic challenge for clinicians, as it shares many clinical signs and symptoms with other morbid conditions (including appendicitis, abdominal hernias, colic, volvulus, and Meckel diverticulum). High clinical suspicion and use of appropriate imaging techniques are essential for early diagnosis and treatment of intussusception. Surgical intervention is the treatment of choice in cases of sustained and persistent invagination. CASE REPORT We present the case of a 65-year-old woman with a medical history of Crohn's disease, diabetes mellitus type II, hypertension, and rheumatoid arthritis. She was hospitalized for diarrhea, fatigue, and anemia. Computerized tomography of the abdomen and a colonoscopy revealed telescoping of the ileum, ileocecal valve, and part of the ascending colon inside the terminal segment of the ascending colon. The antegrade ileocolic intussusception was treated by performing a right hemicolectomy. The pathologic examination of the excised intestine showed mucosal lesions compatible with Crohn's disease, an inflammatory fibroid polyp at the terminal section of the ileum, and a low-grade appendiceal mucinous neoplasm. CONCLUSIONS Regardless of the etiology, when the normal motility of the intestine is altered, it can lead to invagination. Although intussusception is rare, it must always be part of the differential diagnosis for a patient presenting with constant abdominal pain.

Dietary synbiotic ameliorates constipation through the modulation of gut microbiota and its metabolic function

The purpose of this study is to investigate the mitigatory effect of a novel synbiotic (SBT) on constipation from the perspective of gut microbiome and metabolome. Here, intake of SBT effectively attenuated diphenoxylate-induced constipation, recuperated colonic epithelial integrity and increased serum levels of gastrointestinal excitatory neurotransmitters (P substance, vasoactive intestinal peptide, motilin, gastrin and serotonin). 16S rRNA sequencing showed that SBT intake rehabilitated the composition and functionality of gut microbiota. Relative abundances of short-chain fatty acids (SCFAs)-producing bacteria including Lactobacillus, Faecalibaculum and Bifidobacterium were elevated by administration of SBT. The gas chromatography-mass spectrometry analysis confirmed that fecal concentrations of propionate and butyrate were significantly increased in the rats intervened with SBT. In addition, SBT ingestion reduced the relative levels of opportunistic pathogens, such as Oscillibacter, Parasutterella and Parabacteroides. Microbial functional prediction showed that the relative abundances of lipopolysaccharide (LPS) biosynthesis and arachidonic acid metabolism were downregulated with SBT administration, which were in accordance with the serum metabolomics results. Furthermore, serum levels of LPS, tumour necrosis factor alpha and interleukin 6 were significantly decreased, indicating that SBT supplementation suppressed inflammatory responses. Therefore, this study demonstrated that consumption of SBT ameliorated constipation possibly by regulating gut microbiota, promoting the SCFAs production and inhibiting inflammatory responses in rats. Our study also indicated that SBT may provide a novel alternative strategy for the treatment of constipation clinically in future.

Identification of the Molecular Basis of Nanocurcumin-Induced Telocyte Preservation within the Colon of Ulcerative Colitis Rat Model

Background

Telocytes (TCs) are a distinct type of interstitial cells that play a vital role in the pathogenesis of ulcerative colitis and colonic tissue hemostasis. The aim of this study was to examine the effect of nanocurcumin (NC) on the morphometric and immunohistochemical characterization of TCs in the ulcerative colitis (UC) rat model.

Methods

Forty rats were randomly divided into control, NC, UC, and UC+NC groups. At the end of the experiment, the colon was dissected and prepared for histopathological and immunohistochemical assessment. Tissue homogenates were prepared for real-time PCR assessment of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and transforming growth factor-beta (TGF-β) gene expression. Our results revealed extensive mucosal damage with inflammatory cell infiltration, significant reduction of CD34, and vimentin immunostained TCs in the colon of the UC group with significant elevation of expression of IL-6, TNF-α, and TGF-β. The UC+NC-treated group revealed significant elevation of TC count compared to the UC group besides, a significant reduction of the three gene expression.

Conclusion

NC successfully targeted the colonic tissue, improved the mucosal lesion, preserve TCs distribution, and count through its anti-inflammatory and fibrinolytic properties.

Quantified small bowel motility in patients with ulcerative colitis and gastrointestinal symptoms: a pilot study

BACKGROUND

Gastrointestinal (GI) symptoms are common in patients with ulcerative colitis (UC), even when the disease is in remission, possibly due to abnormalities in GI motility. Small bowel motility can be assessed globally and in specific intestinal regions during magnetic resonance enterography (MRE) using a displacement mapping technique.

PURPOSE

To investigate whether small bowel motility in MRE differs between patients with UC and controls, and if altered motility correlates with GI symptoms.

MATERIAL AND METHODS

In 2016-2018, patients who were admitted for MRE, regardless of clinical indication, were consecutively invited to the study. Healthy volunteers were recruited. The participants completed a questionnaire regarding GI symptoms and relevant clinical data were reviewed in the medical records. The dynamic imaging series obtained during MRE were sent for motility mapping and a motility index (MI) was calculated in jejunum, ileum and terminal ileum in all participants.

RESULTS

In total, 224 patients and healthy volunteers were enrolled in the study. Fifteen were diagnosed with UC and 22 were considered healthy controls. In UC, the prevalence of GI symptoms was higher than in controls (P < 0.001), both in remission and in active disease. There was no correlation between GI symptoms and small bowel motility in UC. Jejunal motility was lower in UC than in controls (P = 0.049).

CONCLUSION

Jejunal motility is decreased in UC compared with healthy controls, but there is no relationship between small bowel motility and GI symptoms in UC.

Pharmacologycal activity of peperina (Minthostachys verticillata) on gastrointestinal tract

ETHNOPHARMACOLOGICAL RELEVANCE

Minthostachys verticillata (Griseb.) Epling (Lamiaceae), known as Peperina is a medicinal native plant, with a traditional use as a digestive, antispasmodic and antidiarrheic.

AIM OF THE STUDY

Despite its folkloric use, no scientific evaluation of this plant related to the gastrointestinal inflammatory process has been carried out to date. The present study aims to assess the effects of M. verticillata on gastrointestinal system in experimental models.

MATERIALS AND METHODS

M. verticillata (250 and 500 mg/kg) was orally tested in a colitis model induced by acetic acid. Colon weight/length ratio, oxidative stress (oxidized and reduced glutathione), histological changes using Alcian blue and hematoxylin & eosin staining and expression of IL1β, TNFα, iNOS, COX-2 were evaluated. The effect of the extract in three additional in vivo models were studied: intestinal motility and diarrhea induced by ricin oil, and visceral pain induced by intracolonic administration of capsaicin. Finally, the activity on concentration response curves of acetylcholine, calcium chloride, potassium and serotonin were achieved in isolated rat jejunum.

RESULTS

In the colitis model, M. verticillata induced a significant reduction in the colon weight/length ratio, oxidative stress and expression levels of IL-1β, iNOS and COX-2. Also, the extract diminished the severity of microscopic tissue damage and showed protective effect on goblet cells. Intestinal motility, diarrhea, visceral pain-related behaviors and referred hyperalgesia were significantly reduced when the animals were treated with the extract. Furthermore, in isolated jejunum, M. verticillata significantly reduced the contraction induced by serotonin and acetylcholine. Likewise, the extract non-competitively inhibited the response-concentration induced by CaCl2 and inhibited both low and high K+-induced contractions.

CONCLUSIONS

This is the first study to validate traditional use of M. verticillata for digestive disorders and demonstrated that its aqueous extract could represent a promising strategy in targeting the multifactorial pathophysiology of inflammatory bowel disease.

Cognitive dysfunction in ulcerative colitis patients in remission and its comparison with patients with irritable bowel syndrome and healthy controls

BACKGROUND

There is a paucity of research concerning cognitive impairments in Inflammatory bowel disease - ulcerative colitis (IBD-UC) and irritable bowel syndrome (IBS). Studies on cognitive dysfunction in patients with IBD-UC have either been small or have shown conflicting results. This study is conducted to examine the evidence of cognitive dysfunction in IBD-UC patients in remission and compare the evident cognitive deficit with IBS patients and healthy controls.

METHODS

This single-centre cross-sectional observational study enrolled a total of 90 participants, 29 in ulcerative colitis (UC) in remission group, 31 in IBS group and 30 in healthy control group. Assessment of cognition with the help of cognitive function tests mini-mental state examination (MMSE), Montreal Cognitive Assessment (MoCA) test and p300 was performed in all participants.

RESULTS

A statistically significant number of the participants in IBD-UC in remission group had MMSE and MoCA score below the lower limit of normal, in comparison to the healthy control and IBS groups. The mean peak latency of the p300 wave was statistically significantly increased in people in the IBD-UC group, in comparison to the healthy control and IBS groups.

CONCLUSION

Patients with IBD-UC in remission show impairments in cognitive functioning compared to the IBS and healthy control groups as assessed on cognitive function testing on MMSE, MoCA and mean peak latency of the p300 wave. This impairment in cognitive function is unlikely to be due to premorbid levels of intellectual functioning and is likely to have impact on health-related quality of life.

Fecal Incontinence in Inflammatory Bowel Disease

BACKGROUND

Fecal incontinence (FI) is frequently reported in inflammatory bowel disease (IBD).

METHODS

We retrospectively reviewed data from the Study of a Prospective Adult Research Cohort with IBD registry.

RESULTS

Three hundred forty-seven patients had Crohn disease and 145 had ulcerative colitis. 14.2% of patients reported FI. FI was associated with active disease. FI was not associated with disease location, phenotype, or perianal involvement. Greater than 50 years of age or 15 years of disease increased the odds of FI and remission decreased the odds of FI.

CONCLUSIONS

Further research into the mechanism of FI in IBD is needed.

Effect of roxithromycin on contractile activity of gastrointestinal smooth muscles in colitic rats

OBJECTIVES

Roxithromycin, a macrolide antibiotic, has been shown to ameliorate acetic acid induced colitis in rats by suppressing inflammation and oxidative stress. The aim of this study was to evaluate the effect of roxithromycin on small intestinal transit and cholinergic responsiveness of the colonic smooth muscles of colitic rats.

METHODS

Colitis was induced in rats by acetic acid and the small intestinal transit was determined by measuring the distance traversed by charcoal meal from the gastro-duodenal junction in 1 h. The test drug roxithromycin, reference drug mesalazine and anti-inflammatory drug diclofenac were administered orally before inducing colitis and their effect on intestinal transit was compared with colitic control group. The effect on cholinergic responsiveness of colonic smooth muscles was evaluated in vitro by plotting a dose-response curve using different concentrations of acetylcholine. The concentration producing 50% of maximal response (EC₅₀) was calculated for all the treatment groups.

RESULTS

The small intestinal transit was enhanced in colitic rats as compared to normal rats (86.00 ± 1.36 vs. 57.00 ± 1.34 cm; p<0.001). Like mesalazine, roxithromycin normalized intestinal transit while diclofenac was ineffective. The results of in vitro experiment show that colitis increased cholinergic responsiveness of the colonic smooth muscles that was not affected by roxithromycin and mesalazine while diclofenac significantly decreased it.

CONCLUSIONS

This study shows that like mesalazine, roxithromycin affords protection in colitis mainly by normalizing propulsive movement of the small intestine than by affecting cholinergic responsiveness of the colonic smooth muscles.

Developing an advanced gut on chip model enabling the study of epithelial cell/fibroblast interactions

Organoids are widely used as a model system to study gut pathophysiology; however, they fail to fully reproduce the complex, multi-component structure of the intestinal wall. We present here a new gut on chip model that allows the co-culture of primary epithelial and stromal cells. The device has the topography and dimensions of the mouse gut and is based on a 3D collagen I scaffold. The scaffold is coated with a thin layer of laminin to mimic the basement membrane. To maintain the scaffold structure while preserving its cytocompatibility, the collagen scaffold was rigidified by threose-based post-polymerization treatment. This treatment being cytocompatible enabled the incorporation of primary intestinal fibroblasts inside the scaffold, reproducing the gut stromal compartment. We observed that mouse organoids, when deposited into crypts, opened up and epithelialized the scaffold, generating a polarized epithelial monolayer. Proper segregation of dividing and differentiated cells along the crypt-villus axis was achieved under these conditions. Finally, we show that the application of fluid shear stress allows the long-term culture of this intestinal epithelium. Our device represents a new biomimetic tool that captures key features of the gut complexity and could be used to study gut pathophysiology.

The contribution of gut bacterial metabolites in the human immune signaling pathway of non-communicable diseases

The interaction disorder between gut microbiota and its host has been documented in different non-communicable diseases (NCDs) such as metabolic syndrome, neurodegenerative disease, and autoimmune disease. The majority of these altered interactions arise through metabolic cross-talk between gut microbiota and host immune system, inducing a low-grade chronic inflammation that characterizes all NCDs. In this review, we discuss the contribution of bacterial metabolites to immune signaling pathways involved in NCDs. We then review recent advances that aid to rationally design microbial therapeutics. A deeper understanding of these intersections between host and gut microbiota metabolism using metabolomics-based system biology platform promises to reveal the fundamental mechanisms that drive metabolic predispositions to disease and suggest new avenues to use microbial therapeutic opportunities for NCDs treatment and prevention. Abbreviations: NCDs: non-communicable disease, IBD: inflammatory bowel disease, IL: interleukin, T2D: type 2 diabetes, SCFAs: short-chain fatty acids, HDAC: histone deacetylases, GPCR: G-protein coupled receptors, 5-HT: 5-hydroxytryptamine receptor signaling, DCs: dendritic cells, IECs: intestinal epithelial cells, T-reg: T regulatory cell, NF-κB: nuclear factor κB, TNF-α: tumor necrosis factor alpha, Th: T helper cell, CNS: central nervous system, ECs: enterochromaffin cells, NSAIDs: non-steroidal anti-inflammatory drugs, AhR: aryl hydrocarbon receptor, IDO: indoleamine 2,3-dioxygenase, QUIN: quinolinic acid, PC: phosphatidylcholine, TMA: trimethylamine, TMAO: trimethylamine N-oxide, CVD: cardiovascular disease, NASH: nonalcoholic steatohepatitis, BAs: bile acids, FXR: farnesoid X receptor, CDCA: chenodeoxycholic acid, DCA: deoxycholic acid, LCA: lithocholic acid, UDCA: ursodeoxycholic acid, CB: cannabinoid receptor, COBRA: constraint-based reconstruction and analysis.

An automated sensitive approach for measuring whole gut transit time

BACKGROUND

Commonly used methods to measure whole gut transit time in rodents have yet to combine high sensitivity, objectivity, and automation. We have developed a novel method using oral gavage of non-toxic fluorescent dye particles and their detection by fluorescence imaging to enable unbiased automated detection of gut transit time simultaneously in 8 cages.

METHODS

Naïve mice (n = 20) were gavaged with a non-caloric viscous suspension of 4.4% fluorescent dye in 3 groups on 2 occasions. Each group was imaged in 8 cages at 5-minute intervals using blue LEDs for illumination and a Sony full-frame mirrorless camera with a green band-pass emission filter. Custom MATLAB code counted the number of fluorescent boli per cage post hoc and provided graphical and spreadsheet output. Boli counts across a wide range of parameters were compared to blind assessments by an experimenter.

RESULTS

Fluorescent boli were detected with high sensitivity, while unstained boli were readily rejected. All cages showed no fluorescent boli for the first ~20 frames (100 minutes), after which many cages gradually show a rise to 1-6 fluorescent boli. The mean time to first fluorescent bolus in each session was 264 ± 141 and 223 ± 81 minutes post-gavage, with no within subject consistency. There was high correlation between automated scores and that of experimenter (r = .95 ± .02), being robust to parameter changes.

CONCLUSIONS AND INFERENCES

This novel approach provides a reliable, automatic, and low-cost method of measuring gastrointestinal transit time in mice.

Functional gastrointestinal disorders in inflammatory bowel disease: Time for a paradigm shift?

Recent advances in biological therapies have revolutionalised and redefined treatment targets in inflammatory bowel disease (IBD). There is now a stronger emphasis on achieving the more stringent therapeutic goals of mucosal and histological healing, rather than clinical remission alone. Consequently, the treatment of refractory “functional” gastrointestinal symptoms, often attributed as the aftermath of previous inflammation, has recently become more prominent in quiescent disease. With further expected advances in anti-inflammatory treatments on the horizon, the burden of such symptoms in quiescent disease, which have been relatively neglected, is set to become an even bigger problem. In this article, we highlight the current state of research and understanding in this field, including recent developments and clinical practice guidelines on the diagnosis and management of functional gastrointestinal symptoms, such as irritable bowel syndrome and functional anorectal and pelvic floor disorders, in patients with quiescent IBD. These disorders are not only highly prevalent in these patients, they are often misdiagnosed, and are difficult to treat, with very few evidence-based therapies. Moreover, they are associated with substantial impairment in quality-of-life, considerable morbidity, and psychological distress. There is therefore an urgent need for a change in emphasis towards earlier recognition, positive diagnosis, and targeted treatment for patients with ongoing functional gastrointestinal symptoms in the absence of active IBD. This article also highlights the need for further research to develop much needed evidence-based therapies.

Abnormal gut motility in inflammatory bowel disease: an update

BACKGROUND

There is substantial evidence linking disturbed gastrointestinal motility to inflammation. Thus, it is not surprising that abnormalities of gastrointestinal motility play a role in inflammatory bowel disease (IBD), affecting patient outcomes. We performed a review of the literature to investigate the relationship between abnormal gut motility and IBD.

METHODS

With an extensive literature search, we retrieved the pertinent articles linking disturbed gut motility to IBD in various anatomical districts.

RESULTS

The evidence in the literature suggests that abnormal gastrointestinal motility plays a role in the clinical setting of IBD and may confuse the clinical picture.

CONCLUSIONS

Abnormal gut motility may be important in the clinical setting of IBD. However, additional data obtained with modern techniques (e.g., magnetic resonance imaging) are needed to individuate in a more precise manner gastrointestinal motor dysfunctions, to understand the nature of clinical manifestations and properly tailor the treatment of patients.

Drug Screen Identifies Leflunomide for Treatment of Inflammatory Bowel Disease Caused by TTC7A Deficiency

BACKGROUND & AIMS

Mutations in the tetratricopeptide repeat domain 7A gene (TTC7A) cause intestinal epithelial and immune defects. Patients can become immune deficient and develop apoptotic enterocolitis, multiple intestinal atresia, and recurrent intestinal stenosis. The intestinal disease in patients with TTC7A deficiency is severe and untreatable, and it recurs despite resection or allogeneic hematopoietic stem cell transplant. We screened drugs for those that prevent apoptosis of in cells with TTC7A deficiency and tested their effects in an animal model of the disease.

METHODS

We developed a high-throughput screen to identify compounds approved by the US Food and Drug Administration that reduce activity of caspases 3 and 7 in TTC7A-knockout (TTC7A-KO) HAP1 (human haploid) cells and reduce the susceptibility to apoptosis. We validated the effects of identified agents in HeLa cells that stably express TTC7A with point mutations found in patients. Signaling pathways in cells were analyzed by immunoblots. We tested the effects of identified agents in zebrafish with disruption of ttc7a, which develop intestinal defects, and colonoids derived from biopsy samples of patients with and without mutations in TTC7A. We performed real-time imaging of intestinal peristalsis in zebrafish and histologic analyses of intestinal tissues from patients and zebrafish. Colonoids were analyzed by immunofluorescence and for ion transport.

RESULTS

TTC7A-KO HAP1 cells have abnormal morphology and undergo apoptosis, due to increased levels of active caspases 3 and 7. We identified drugs that increased cell viability; leflunomide (used to treat patients with inflammatory conditions) reduced caspase 3 and 7 activity in cells by 96%. TTC7A-KO cells contained cleaved caspase 3 and had reduced levels of phosphorylated AKT and X-linked inhibitor of apoptosis (XIAP); incubation of these cells with leflunomide increased levels of phosphorylated AKT and XIAP and reduced levels of cleaved caspase 3. Administration of leflunomide to ttc7a^-/- zebrafish increased gut motility, reduced intestinal tract narrowing, increased intestinal cell survival, increased sizes of intestinal luminal spaces, and restored villi and goblet cell morphology. Exposure of patient-derived colonoids to leflunomide increased cell survival, polarity, and transport function.

CONCLUSIONS

In a drug screen, we identified leflunomide as an agent that reduces apoptosis and activates AKT signaling in TTC7A-KO cells. In zebrafish with disruption of ttc7a, leflunomide restores gut motility, reduces intestinal tract narrowing, and increases intestinal cell survival. This drug might be repurposed for treatment of TTC7A deficiency.

Effect of N-palmitoylethanolamine-oxazoline on comorbid neuropsychiatric disturbance associated with inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic disorder characterized by inflammation of the gastrointestinal (GI) tract, and it is associated with different neurological disorders. Recent evidence has demonstrated that the gut-brain-axis has a central function in the perpetuation of IBS, and for this reason, it can be considered a possible therapeutic target. N-Palmitoylethanolamine-oxazoline (PEA-OXA) possesses anti-inflammatory and potent neuroprotective effects. Although recent studies have explained the neuroprotective properties of PEA-OXA, nothing is known about its effects on the gut-brain axis during colitis. The aim of this study is to explore the mechanism and the effect of PEA-OXA on the gut-brain axis in rats subjected to experimental colitis induced by oral administration of dextran sulfate sodium (DSS). Daily oral administration of PEA-OXA (10 mg/kg daily o.s.) was able to decrease the body weight loss, macroscopic damage, colon length, histological alteration, and inflammation after DSS induction. Additionally, PEA-OXA administration enhanced neurotrophic growth factor release and decreased the astroglial and microglial activation induced by DSS. Moreover, PEA-OXA restored intestinal permeability and tight junctions (TJs) as well as reduced apoptosis in the colon and brain. In our work, we demonstrated, for the first time, the action of PEA-OXA on the gut-brain axis in a model of DSS-induced colitis and its implication on the "secondary" effects associated with colonic disturbance.

Tight junctions in the development of asthma, chronic rhinosinusitis, atopic dermatitis, eosinophilic esophagitis, and inflammatory bowel diseases

This review focuses on recent developments related to asthma, chronic rhinosinusitis, atopic dermatitis (AD), eosinophilic esophagitis, and inflammatory bowel diseases (IBD), with a particular focus on tight junctions (TJs) and their role in the pathogenetic mechanisms of these diseases. Lung, skin, and intestinal surfaces are lined by epithelial cells that interact with environmental factors and immune cells. Therefore, together with the cellular immune system, the epithelium performs a pivotal role as the first line physical barrier against external antigens. Paracellular space is almost exclusively sealed by TJs and is maintained by complex protein-protein interactions. Thus, TJ dysfunction increases paracellular permeability, resulting in enhanced flux across TJs. Epithelial TJ dysfunction also causes immune cell activation and contributes to the pathogenesis of chronic lung, skin, and intestinal inflammation. Characterization of TJ protein alteration is one of the key factors for enhancing our understanding of allergic diseases as well as IBDs. Furthermore, TJ-based epithelial disturbance can promote immune cell behaviors, such as those in dendritic cells, Th2 cells, Th17 cells, and innate lymphoid cells (ILCs), thereby offering new insights into TJ-based targets. The purpose of this review is to illustrate how TJ dysfunction can lead to the disruption of the immune homeostasis in barrier tissues and subsequent inflammation. This review also highlights the various TJ barrier dysfunctions across different organ sites, which would help to develop future drugs to target allergic diseases and IBD.

Colonic dysmotility associated with high-fat diet-induced obesity: Role of enteric glia

The present study was designed to examine the role of enteric glial cells (EGCs) in colonic neuromuscular dysfunctions in a mouse model of high-fat diet (HFD)-induced obesity. C57BL/6J mice were fed with HFD or standard diet (SD) for 1, 2, or 8 weeks. Colonic interleukin (IL)-1β, IL-6, and malondialdehyde (MDA) levels were measured. Expression of occludin in colonic tissues was examined by western blot. Substance P (SP), S100β, GFAP, and phosphorylated mitogen-activated protein kinase 1 (pERK) were assessed in whole mount specimens of colonic plexus by immunohistochemistry. Colonic tachykininergic contractions, elicited by electrical stimulation or exogenous SP, were recorded in the presence or absence of fluorocitrate (FC). To mimic exposure to HFD, cultured EGCs were incubated with palmitate (PA) and/or lipopolysaccharide (LPS). SP and IL-1β levels were assayed in the culture medium by ELISA. HFD mice displayed an increase in colonic IL-1β and MDA, and a reduction of occludin at week 2. These changes occurred to a greater extent at week 8. In vitro electrically evoked tachykininergic contractions were enhanced in HFD mice after 2 or 8 weeks, and they were blunted by FC. Colonic IL-6 levels as well as substance P and S100β density in myenteric ganglia of HFD mice were increased at week 8, but not at week 1 or 2. In cultured EGCs, co-incubation with palmitate plus LPS led to a significant increase in both SP and IL-1β release. HFD-induced obesity is characterized by a hyperactivation of EGCs and is involved in the development of enteric motor disorders through an increase in tachykininergic activity and release of pro-inflammatory mediators.

Melatonin controls microbiota in colitis by goblet cell differentiation and antimicrobial peptide production through Toll-like receptor 4 signalling

Microbial dysbiosis has long been postulated to be associated with the pathogenesis of inflammatory bowel disease (IBD). Although evidence supporting the anti-colitic effects of melatonin have been accumulating, it is not clear how melatonin affects the microbiota. Herein, we investigated the effects of melatonin on the microbiome in colitis and identified involvement of Toll-like receptor (TLR) 4 signalling in the effects. Melatonin improved dextran sulfate sodium (DSS)-induced colitis and reverted microbial dysbiosis in wild-type (WT) mice but not in TLR4 knockout (KO) mice. Induction of goblet cells was observed with melatonin administration, which was accompanied by suppression of Il1b and Il17a and induction of melatonin receptor and Reg3β, an antimicrobial peptide (AMP) against Gram-negative bacteria. In vitro, melatonin treatment of HT-29 intestinal epithelial cells promotes mucin and wound healing and inhibits growth of Escherichia coli. Herein, we showed that melatonin significantly increases goblet cells, Reg3β, and the ratio of Firmicutes to Bacteriodetes by suppressing Gram-negative bacteria through TLR4 signalling. Our study suggests that sensing of bacteria through TLR4 and regulation of bacteria through altered goblet cells and AMPs is involved in the anti-colitic effects of melatonin. Melatonin may have use in therapeutics for IBD.

Systematic review: Pelvic floor muscle training for functional bowel symptoms in inflammatory bowel disease

BACKGROUND AND AIM

Large bowel functional symptoms are common in patients with inflammatory bowel disease (IBD) who are in disease remission. The efficacy of pelvic floor muscle training for symptoms of evacuation difficulty or fecal incontinence is well established in patients without organic bowel disease but is unknown in these patients. This study aimed to systematically evaluate the published evidence in this group of patients.

METHODS

A systematic review was conducted of articles evaluating pelvic floor muscle training, with or without biofeedback, to improve bowel function in patients with quiescent IBD, including those with an ileoanal pouch. The outcome of interest was improved bowel function measured by bowel diary, patient report, or validated questionnaire in randomized controlled studies, cohort studies, or case series.

RESULTS

Two randomized controlled trials, four retrospective case series, and one prospective study met eligibility criteria. Pelvic floor muscle training for patients with quiescent IBD improved symptoms in 51 of 76 (68%) patients with evacuation difficulty and 20 of 25 (80%) patients with fecal incontinence. Pelvic floor muscle training for patients with an ileoanal pouch, prior to stoma closure, did not appear to reduce the risk or severity of fecal incontinence following stoma closure. Studies were limited by small numbers, study design, methodological quality, and lack of long-term follow-up.

CONCLUSION

Pelvic floor muscle training appears to be of therapeutic value in some patients with quiescent IBD and evacuation difficulty or fecal incontinence. The effectiveness of this approach warrants further investigation.

Mechanosensation of cyclical force by PIEZO1 is essential for innate immunity

Direct recognition of invading pathogens by innate immune cells is a critical driver of the inflammatory response. However, cells of the innate immune system can also sense their local microenvironment and respond to physiological fluctuations in temperature, pH, oxygen and nutrient availability, which are altered during inflammation. Although cells of the immune system experience force and pressure throughout their life cycle, little is known about how these mechanical processes regulate the immune response. Here we show that cyclical hydrostatic pressure, similar to that experienced by immune cells in the lung, initiates an inflammatory response via the mechanically activated ion channel PIEZO1. Mice lacking PIEZO1 in innate immune cells showed ablated pulmonary inflammation in the context of bacterial infection or fibrotic autoinflammation. Our results reveal an environmental sensory axis that stimulates innate immune cells to mount an inflammatory response, and demonstrate a physiological role for PIEZO1 and mechanosensation in immunity.