Functional bowel symptoms in quiescent inflammatory bowel diseases: role of epithelial barrier disruption and low-grade inflammation

Fecal gut microbiota and amino acids as noninvasive diagnostic biomarkers of Pediatric inflammatory bowel disease

BACKGROUND AND AIMS

Fecal calprotectin (FCP) has limited specificity as diagnostic biomarker of pediatric inflammatory bowel disease (IBD), leading to unnecessary invasive endoscopies. This study aimed to develop and validate a fecal microbiota and amino acid (AA)-based diagnostic model.

METHODS

Fecal samples from a discovery cohort (de novo IBD and healthy controls [HC]) were used to develop the diagnostic model. This model was applied in a validation cohort (de novo IBD and controls with gastrointestinal symptoms [CGI]). Microbiota and AAs were analyzed using interspace profiling and liquid chromatography-mass spectrometry techniques, respectively. Machine learning techniques were used to build the diagnostic model.

RESULTS

In the discovery cohort (58 IBD, 59 hC), two microbial species (Escherichia coli and Alistipes finegoldii) and four AAs (leucine, ornithine, taurine, and alpha-aminoadipic acid [AAD]) combined allowed for discrimination between both subgroups (AUC 0.94, 95% CI [0.89, 0.98]). In the validation cohort (43 IBD, 38 CGI), this panel of six markers could differentiate patients with IBD from CGI with an AUC of 0.84, 95% CI [0.67, 0.95]). Leucine showed the best diagnostic performance (AUC 0.89, 95% CI [0.81, 0.95]).

CONCLUSIONS

Leucine might serve as adjuvant noninvasive biomarker in the diagnostic work-up of pediatric IBD. Future research should investigate whether the combination of leucine with FCP could improve specificity and may help tailor the course of diagnostics.

2025 Seoul Consensus on Clinical Practice Guidelines for Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a chronic, disabling, and functional bowel disorder that significantly affects social functioning and reduces quality of life and increases social costs. The Korean Society of Neurogastroenterology and Motility published clinical practice guidelines on the management of IBS based on a systematic review of the literature in 2017, and planned to revise these guidelines in light of new evidence on the pathophysiology, diagnosis, and management of IBS. The current revised version of the guidelines is consistent with the previous version and targets adults diagnosed with or suspected of having IBS. These guidelines were developed using a combination of de novo and adaptation methods, with analyses of existing guidelines and discussions within the committee, leading to the identification of key clinical questions. Finally, the guidelines consisted of 22 recommendations, including 3 concerning the definition and risk factors of IBS, 4 regarding diagnostic modalities and strategies, 2 regarding general management, and 13 regarding medical treatment. For each statement, the advantages, disadvantages, and precautions were thoroughly detailed. The modified Delphi method was used to achieve expert consensus to adopt the core recommendations of the guidelines. These guidelines serve as a reference for clinicians (including primary care physicians, general healthcare providers, medical students, residents, and other healthcare professionals) and patients, helping them to make informed decisions regarding IBS management.

Rome Foundation Working Team Report on overlap in disorders of gut-brain interaction

In patients with disorders of gut-brain interaction (DGBI), overlapping non-gastrointestinal conditions such as fibromyalgia, headaches, gynaecological and urological conditions, sleep disturbances and fatigue are common, as is overlap among DGBI in different regions of the gastrointestinal tract. These overlaps strongly influence patient management and outcome. Shared pathophysiology could explain this scenario, but details are not fully understood. This overlap has been shown to be of great relevance for DGBI. In addition, symptoms considered to be caused by a DGBI could have a detectable organic cause, and in patients with a diagnosed organic gastrointestinal disease, symptoms not clearly explained by the pathology defining this organic disease are common. Thus, the aims of this Rome Foundation Working Team Report were to review the literature on overlapping conditions among patients with paediatric and adult DGBI and, based on the available epidemiological and clinical evidence, make recommendations for the current diagnostic and therapeutic approach, and for future research. Specifically, we focused on other DGBI in the same or different gastrointestinal anatomical region(s), DGBI overlap with organic bowel diseases in remission, and DGBI overlap with non-gastrointestinal, non-structural conditions.

Ganoderic Acid Ameliorates Ulcerative Colitis by Improving Intestinal Barrier Function via Gut Microbiota Modulation

Ulcerative colitis (UC) is a chronic and recurrent gastrointestinal disease that affects millions of humans worldwide and imposes a huge social and economic burden. It is necessary to find safe and efficient drugs for preventing and treating UC. The aim of this study was to determine whether ganoderic acid (GA), the main bioactive components of Ganoderma lucidum, has preventive and therapeutic effect on UC in a dextran sulfate sodium (DSS)-induced UC mouse model. Our experimental results showed that GA significantly ameliorated the body weight loss and disease activity index (DAI) of UC mice. GA significantly restored 11% of the colon length and 69% of the spleen index compared to UC mice. GA significantly decreased the intestinal inflammatory response and improved the barrier function of the intestine by upregulating the tight junction proteins Zonula occludens-1 (ZO-1), occludin and claudin-1. A co-housing experiment showed that gut microbiota accounted for the therapeutic activity of GA on UC, which was confirmed by fecal microbiota transplantation from GA-treated mice to the UC mice. Furthermore, 16S rDNA high-throughput sequencing of fecal bacteria showed that GA significantly enriched the abundance of Lactobacillus, Oscillospira, Odoribacter and Ruminococcus, which were positively correlated with colon length. Furthermore, this study found the functional metabolites, including Indole-3-acetaldehyde (IAAld), Glutamine (Gln) and Glutathione (GSH), reduced barrier damage in the Caco-2 cell model. In conclusion, this study suggests that GA could ameliorate UC by improving intestinal barrier function via modulating gut microbiota and associated metabolites.

Why Symptoms Linger in Quiescent Crohn's Disease: Investigating the Impact of Sulfidogenic Microbes and Sulfur Metabolic Pathways

INTRODUCTION

Even in the absence of inflammation, persistent symptoms in patients with Crohn's disease (CD) are prevalent and worsen quality of life. We previously demonstrated enrichment in sulfidogenic microbes in quiescent Crohn's disease patients with (qCD + S) vs without persistent GI symptoms (qCD-S). Thus, we hypothesized that sulfur metabolic pathways would be enriched in stool while differentially abundant microbes would be associated with important sulfur metabolic pathways in qCD + S.

METHODS

We performed a multicenter observational study nested within SPARC IBD. Quiescent inflammation was defined by fecal calprotectin level < 150 mcg/g. Persistent symptoms were defined by CD-PRO2. Active CD (aCD) and non-IBD diarrhea-predominant irritable bowel syndrome (IBS-D) were included as controls.

RESULTS

Thirty-nine patients with qCD + S, 274 qCD-S, 21 aCD, and 40 IBS-D underwent paired shotgun metagenomic sequencing and untargeted metabolomic profiling. The fecal metabolome in qCD + S was significantly different relative to qCD-S and IBS-D but not aCD. Patients with qCD + S were enriched in sulfur-containing amino acid pathways, including cysteine and methionine, as well as serine, glycine, and threonine. Glutathione and nicotinate/nicotinamide pathways were also enriched in qCD + S relative to qCD-S, suggestive of mitochondrial dysfunction, a downstream target of H2S signaling. Multi-omic integration demonstrated that enriched microbes in qCD + S were associated with important sulfur metabolic pathways. Bacterial sulfur metabolic genes, including CTH, isfD, sarD, and asrC, were dysregulated in qCD + S. Finally, sulfur metabolites with and without sulfidogenic microbes showed good accuracy in predicting the presence of qCD + S.

DISCUSSION

Microbial-derived sulfur pathways and downstream mitochondrial function are perturbed in qCD + S, which implicate H2S signaling in the pathogenesis of this condition. Future studies will determine whether targeting H2S pathways results in improved quality of life in qCD + S.

The Impact of Hangeshashinto on Symptoms and Gut Microbiota in Diarrhea-type Irritable Bowel Syndrome: A Retrospective Analysis

Objectives

Effective treatments for diarrhea-type irritable bowel syndrome (IBS-D) are limited. Hangeshashinto (HST), an anti-inflammatory Kampo medicine, may offer benefits but its efficacy for IBS-D requires further investigation. This study evaluated IBS-D symptom improvement and gut microbiota changes following HST administration.

Methods

This was a multicenter retrospective study with a prospective analysis of microbiota conducted at five affiliated institutions. Patients diagnosed with IBS-D based on the ROME IV criteria between April 2019 and December 2023, who received HST 7.5 g/day for 2-3 weeks were included. The outcome measures were improvement rates in overall symptoms, stool frequency, stool consistency, and abdominal pain. Intestinal microbiota was analyzed using 16S rRNA gene sequencing from fecal samples of 20 patients before and after HST treatment.

Results

One hundred patients (42 males/58 females, mean age: 69.5±11.8 years) were analyzed. The overall improvement rate of HST was 82.0%. Those of males and females were 81.0% and 82.8% (p=0.816). By age, those of patients aged ≥75 and aged <75 years were 82.9% and 81.5% (p=0.869). The improvement rates of stool frequency, stool consistency, and abdominal pain were 59.0%, 51.0%, and 62.0%, respectively. The stool frequency per week before and after HST was 21.7±18.2 vs. 14.0±12.6 (p<0.001). Significant differences in gut microbiota β diversity were observed, although α diversity was not significantly changed. Bacteroides (p=0.003) and Ruminococcus (p=0.010) decreased significantly, while Megasphaera (p=0.030) and Subdoligranulum (p=0.002) increased.

Conclusions

HST may improve IBS-D symptoms by altering microbiota composition.

Recent advances in clinical practice: mastering the challenge-managing IBS symptoms in IBD

Many patients with IBD report persisting symptoms, despite resolution of the inflammatory process. Although by definition, a diagnosis of IBS cannot be made, the prevalence of 'IBS in IBD' surpasses the rate of IBS in the global population by fivefold. Because IBS-like symptoms are associated with a decreased quality of life and increased healthcare utilisation in IBD, diagnosis and treatment are necessary. In this review, we summarise the current knowledge on IBS-like symptoms in IBD. A pathophysiological common ground is present, which includes genetic susceptibility, environmental triggers, gut microbial dysbiosis, increased intestinal permeability, visceral hypersensitivity and involvement of brain-gut interaction. When symptoms persist after resolution of inflammation, other GI diseases should be excluded based on the chief complaint, considering any possible psychological co-morbidity early in the diagnostic work-up. Subsequent treatment should be initiated that is evidence-based and often multimodal, including classical and non-classical pharmacological agents as well as lifestyle and microbiota-based approaches, spanning the breadth of the gut, brain and its interaction. Treatment goals in this substantial part of the IBD population should be adapted to not only focus on treating the inflammation but taking care of the patient.

Effect of the arabinogalactan from Ixeris chinensis (Thunb.) Nakai. attenuates DSS-induced colitis and accompanying depression-like behavior

An arabinogalactan (ICPA) was extracted from the medicinal and edible plant Ixeris chinensis (Thunb.) Nakai., and ICPA exhibited excellent immunomodulatory activity. In this research, the impact of ICPA on DSS-induced ulcerative colitis was investigated. The results indicated that ICPA ameliorated the symptoms of colitis mice including loss of body weight, decrease of disease activity index, shortness of colon length and reduction of spleen index that caused by DSS. After treatment with ICPA, inflammatory cell infiltration and crypt loss were alleviated, and the number of goblet epithelial cells was enriched. ICPA inhibited the overproduction of TNF-α, IL-1β, and NLRP3, and promoted the secretion of IL-10 in colon tissues. Meanwhile, the intestinal barrier integrity was restored through increasing the expression of ZO-1 and occludin. ICPA could also regulate the structure of gut microbiota through elevating the abundance of Turicibacter and Bifidobacterium, and decreasing the ratio of Bacteroidetes/Firmicutes. In addition, ICPA improved the depression-like behavior of UC mice, and reduced the expression of proteins NLRP3, GFAP, and Iba-1 in brain tissues. These results suggested ICPA had an alleviative effect on UC and accompanied depression-like behavior, and could be developed as a dietary supplement for the prevention and treatment of UC.

Anti-CdtB and anti-vinculin antibodies to diagnose irritable bowel syndrome in inflammatory bowel disease patients

BACKGROUND

Despite adequate treatment, a subgroup of patients with inflammatory bowel disease (IBD), including Crohn`s disease and ulcerative colitis, have persistent gastrointestinal symptoms that are not always related to mucosal damage. Recently, two autoantibodies, anti-CdtB and anti-vinculin, were validated as post-infectious IBS (PI-IBS) markers, however there is limited evidence of its diagnostic role in IBD population.

METHODS

Patients with more than 3 bowel movements/day and indication of colonoscopy were enrolled. Samples were collected at the time of colonoscopy for assessment of serum levels of anti-CdtB and anti-vinculin antibodies.

RESULTS

A total of 160 subjects were included in 4 groups: active IBD (n = 44); quiescent IBD and chronic diarrhea IBD-IBS (n = 25); predominant-diarrhea IBS (n = 45) and controls (n = 46). The mean value of the optical density for anti-CdtB was 1.2 ± 0.65 in group 1, 1.27 ± 0.64 in group 2, 1.49 ± 0.47 in the group 3 and 1.6 ± 0.68 in group 4, p = 0.012. For anti-vinculin, optical densities were: 1.34 ± 0.78 in group 1, 1.46 ± 0.92 in group 2, 1.31 ± 0.79 in group 3 and 1.41 ± 0.86 for controls (p = 0.875). Using a cut-off of 1.56 for anti-CdtB, the positivity between groups was n = 10 (22.7%) in group 1, n = 9 (34.6%) in group 2, 19 (43.2%) in group 3, 21 (45.7%) in group 4 (p = 0.106). The positivity of anti-vinculin using a cut-off of 1.6 was n = 18 (40.9%) in group 1, n = 11 (42.3%), n = 15 (34.1%), n = 22 (47.8%) (p = 0.622).

CONCLUSIONS

Our findings show that anti-CdtB and anti-vinculin could not identify IBD-IBS patients or discriminate IBS-D from healthy controls.

Multisample lipidomic profiles of irritable bowel syndrome and irritable bowel syndrome-like symptoms in patients with inflammatory bowel disease: new insight into the recognition of the same symptoms in different diseases

BACKGROUND

Overlapping clinical manifestations of irritable bowel syndrome (IBS) and IBS-like symptoms in patients with inflammatory bowel disease (IBD-IBS) present challenges in diagnosis and management. Both conditions are associated with alterations in metabolites, but few studies have described the lipid profiles. Our aim was to pinpoint specific lipids that contribute to the pathogenesis of IBS and IBD-IBS by analyzing multiple biologic samples.

METHODS

Diarrhea-predominant IBS (IBS-D) patients (n = 39), ulcerative colitis in remission with IBS-like symptoms patients (UCR-IBS) (n = 21), and healthy volunteers (n = 35) were recruited. IBS-D patients meet the Rome IV diagnostic criteria, and UCR-IBS patients matched mayo scores ≤ two points and Rome IV diagnostic criteria. Serum, feces, and mucosa were collected for further analysis. Lipid extraction was carried out by ultra-performance liquid chromatography-high resolution mass spectrometry (UPLC-HRMS).

RESULTS

Lipidomics of mucosa and serum samples significantly differed among the three groups. Feces showed the most altered lipid species, and the enrichment analysis of 347 differentially abundant metabolites via KEGG pathway analysis revealed that alpha-linolenic acid metabolism was significantly altered in the two groups (P < 0.01). The ratio of omega-6/omega-3 fatty acid were imbalance in serum samples.

CONCLUSIONS

This study revealed a comprehensive lipid composition pattern between IBS-D patients and UCR-IBS patients. We found several distinctive lipids involved in alpha-linolenic acid metabolism, reflecting an imbalance in the omega-6/omega-3 fatty acid ratio. Compared to mucosa and serum samples, fecal samples might have more advantages in lipidomics studies due to the convenience of sample collection and effectiveness in reflecting metabolic information.

Monocyte CD36 Expression Predicts Disease Activity in Patients With Crohn's Disease

Background: Crohn's disease (CD) is a chronic intestinal inflammatory disease associated with genetic, environmental, and other unknown factors. Cluster of differentiation 36 (CD36) plays an important role in cancer, inflammation, and metabolic diseases. Although CD36 has recently been implicated in various diseases, its role in CD is still unclear. Methods: Blood samples were collected from patients with CD and healthy volunteers. Peripheral blood mononuclear cells (PBMCs) were isolated by density gradient centrifugation over Ficoll-Paque and labeled with monoclonal antibodies (CD14-APC and CD36-PE). Flow cytometer CytoFlex is used for analysis. Results: Twenty-nine patients with CD in remission, 42 patients with active CD, and 23 healthy volunteers were included in the study. Our results showed that the frequency of the CD14+CD36+ monocyte subset was increased in PBMCs from patients with active CD compared with patients in remission and healthy controls. However, CD36 on monocytes was lower in CD compared with the healthy controls. CD36 expression was decreased in patients with active CD compared with that of patients with CD in remission and healthy control subjects, but no difference was found between patients with CD in remission and healthy controls. Interestingly, we found negative correlations of CD36 with HBI, SES-CD, C-reactive protein, and neutrophil-to-lymphocyte ratio. Conclusions: These data indicate that monocyte CD36 associates with disease activity in CD and might be a potential biomarker for assessing the activity of CD.

Review article: The role of the gut-brain axis in inflammatory bowel disease and its therapeutic implications

BACKGROUND

Treatments targeting the gut-brain axis (GBA) are effective at reducing symptom burden in irritable bowel syndrome (IBS). The prevalence of common mental disorders and IBS-type symptom reporting is significantly higher in inflammatory bowel disease (IBD) than would be expected, suggesting potential GBA effects in this setting. Manipulation of the GBA may offer novel treatment strategies in selected patients with IBD. We present a narrative review of the bi-directional effects of the GBA in IBD and explore the potential for GBA-targeted therapies in this setting.

METHODS

We searched MEDLINE, EMBASE, EMBASE Classic, PsychINFO, and the Cochrane Central Register of Controlled Trials for relevant articles published by March 2024.

RESULTS

The bi-directional relationship between psychological well-being and adverse longitudinal disease activity outcomes, and the high prevalence of IBS-type symptom reporting highlight the presence of GBA-mediated effects in IBD. Treatments targeting gut-brain interactions including brain-gut behavioural treatments, neuromodulators, and dietary interventions appear to be useful adjunctive treatments in a subset of patients.

CONCLUSIONS

Psychological morbidity is prevalent in patients with IBD. The relationship between longitudinal disease activity outcomes, IBS-type symptom reporting, and poor psychological health is mediated via the GBA. Proactive management of psychological health should be integrated into routine care. Further clinical trials of GBA-targeted therapies, conducted in selected groups of patients with co-existent common mental disorders, or those who report IBS-type symptoms, are required to inform effective integrated models of care in the future.

Mechanisms of Action of Exclusive Enteral Nutrition and Other Nutritional Therapies in Crohn's Disease

BACKGROUND AND OBJECTIVES

Crohn's disease (CD) is an inflammatory bowel disease (IBD) characterized by transmural inflammation and intestinal fibrosis involving mostly the small intestine and colon. The pathogenic mechanisms of CD remain incompletely understood and cures are unavailable. Current medical therapies are aimed at inducing prolonged remission. Most of the medical therapies such as corticosteroids have substantial adverse effects. Consequently, many dietary therapies have been explored for the management of CD. Up to now, exclusive enteral nutrition (EEN) has been considered the only established dietary treatment for IBD, especially CD. In this article, we aim to give a concise review about the current therapeutic options and challenges in the management of CD and aim to compare the efficacy of EEN with other dietary therapies and update on the possible mechanisms of the benefits of EEN and other nutritional therapies.

METHODS

We searched the literature up to August 2024 through PubMed, Web of Science, and other sources using search terms such as EEN, nutritional therapy, IBD, Crohn's disease, ulcerative colitis. Clinical studies in patients and preclinical studies in rodent models of IBD were included in the summary of the therapeutic benefits.

RESULTS AND CONCLUSIONS

EEN involves oral or nasogastric tube feeding of a complete liquid diet with exclusion of normal foods for a defined period (usually 6 to 8 weeks). EEN treatment is demonstrated to have anti-inflammatory and healing effects in CD through various potential pathways, including altering gut bacteria and their metabolites, restoring the barrier function, direct anti-inflammatory action, and indirect anti-inflammatory action by eliminating mechanical stress in the bowel. However, efficacy of other nutritional therapies is not well established in CD, and mechanisms of action are largely unknown.

Why Symptoms Linger in Quiescent Crohn's Disease: Investigating the Impact of Sulfidogenic Microbes and Sulfur Metabolic Pathways

Introduction

Even in the absence of inflammation, persistent symptoms in patients with Crohn's disease (CD) are prevalent and worsen quality of life. We previously demonstrated enrichment in sulfidogenic microbes in quiescent Crohn's disease patients with ( qCD+S ) vs. without persistent GI symptoms ( qCD-S ). Thus, we hypothesized that sulfur metabolic pathways would be enriched in stool while differentially abundant microbes would be associated with important sulfur-metabolic pathways in qCD+S.

Methods

We performed a multi-center observational study nested within SPARC IBD. Quiescent inflammation was defined by fecal calprotectin level <150 mcg/g. Persistent symptoms were defined by CD-PRO2. Active CD ( aCD ) and non-IBD diarrhea-predominant irritable bowel syndrome ( IBS-D ) were included as controls.

Results

Thirty-nine patients with qCD+S, 274 qCD-S, 21 aCD, and 40 IBS-D underwent paired shotgun metagenomic sequencing and untargeted metabolomic profiling. The fecal metabolome in qCD+S was significantly different relative to qCD-S and IBS-D but not aCD. Patients with qCD+S were enriched in sulfur-containing amino acid pathways, including cysteine and methionine, as well as serine, glycine, and threonine. Glutathione and nicotinate/nicotinamide pathways were also enriched in qCD+S relative to qCD-S, suggestive of mitochondrial dysfunction, a downstream target of H 2 S signaling. Multi-omic integration demonstrated that enriched microbes in qCD+S were associated with important sulfur-metabolic pathways. Bacterial sulfur-metabolic genes, including CTH , isfD , sarD , and asrC , were dysregulated in qCD+S. Finally, sulfur metabolites with and without sulfidogenic microbes showed good accuracy in predicting presence of qCD+S.

Discussion

Microbial-derived sulfur pathways and downstream mitochondrial function are perturbed in qCD+S, which implicate H 2 S signaling in the pathogenesis of this condition. Future studies will determine whether targeting H 2 S pathways results in improved quality of life in qCD+S.

Key Messages

What is Already Known Even in the absence of inflammation, persistent gastrointestinal symptoms are common in Crohn's disease.The microbiome is altered in quiescent Crohn's disease patients with persistent symptoms, but the functional significance of these changes is unknown. What is New Here Sulfur metabolites and sulfur metabolic pathways were enriched in stool in quiescent Crohn's disease patients with persistent symptoms.Multi-omic integration showed enriched microbes were associated with important sulfur metabolic pathways in quiescent Crohn's disease patients with persistent symptoms. How Can This Study Help Patient Care Strategies to decrease sulfidogenic microbes and associated sulfur metabolic pathways could represent a novel strategy to improve quality of life in quiescent Crohn's disease with persistent GI symptoms.

Gender-specific insights into the irritable bowel syndrome pathophysiology. Focus on gut dysbiosis and permeability

Irritable bowel syndrome (IBS) is the most common functional gastrointestinal disorder involving the brain-gut interaction. IBS is characterized by persistent abdominal pain and changes in bowel habits. IBS exerts significant impacts on quality of life and imposes huge economic costs. Global epidemiological data reveal variations in IBS prevalence, both globally and between genders, necessitating comprehensive studies to uncover potential societal and cultural influences. While the exact pathophysiology of IBS remains incompletely understood, the mechanism involves a dysregulation of the brain-gut axis, leading to disturbed intestinal motility, local inflammation, altered intestinal permeability, visceral sensitivity, and gut microbiota composition. We reviewed several gender-related pathophysiological aspects of IBS pathophysiology, by focusing on gut dysbiosis and intestinal permeability. This perspective paves the way to personalized and multidimensional clinical management of individuals with IBS.

Reinforcement of the intestinal mucosal barrier via mucus-penetrating PEGylated bacteria

The breakdown of the gut's mucosal barrier that prevents the infiltration of microorganisms, inflammatory cytokines and toxins into bodily tissues can lead to inflammatory bowel disease and to metabolic and autoimmune diseases. Here we show that the intestinal mucosal barrier can be reinforced via the oral administration of commensal bacteria coated with poly(ethylene glycol) (PEG) to facilitate their penetration into mucus. In mice with intestinal homoeostatic imbalance, mucus-penetrating PEGylated bacteria preferentially localized in mucus at the lower gastrointestinal tract, inhibited the invasion of pathogenic bacteria, maintained homoeostasis of the gut microbiota, stimulated the secretion of mucus and the expression of tight junctions, and prevented the mice from developing colitis and diabetes. Orally delivered PEGylated bacteria may help prevent and treat gastrointestinal disorders.

Gingerenone A Attenuates Ulcerative Colitis via Targeting IL-17RA to Inhibit Inflammation and Restore Intestinal Barrier Function

Ulcerative colitis (UC) is a complicated and recurrent intestinal disease. Currently available drugs for UC treatment are scarce, therefore, novel therapeutic drugs for the UC are urgently to be developed. Gingerenone A (GA) is a phenolic compound known for its anti-inflammatory effect, but its effect on UC remains unknown. Here, it is shown that GA protects mice against UC, which is closely associated with inhibiting intestinal mucosal inflammation and enhancing intestinal barrier integrity in vivo and in vitro. Of note, RNA sequencing analysis demonstrates an evident correlation with IL-17 signaling pathway after GA treatment, and this effect is further corroborated by Western blot. Mechanistically, GA directly interacts with IL-17RA protein through pull-down, surface plasmon resonance analysis and molecular dynamics simulation. Importantly, lentivirus-mediated IL-17RA/Act1 knock-down or GA co-treatment with brodalumab/ixekizumab significantly impairs the protective effects of GA against DSS-induced inflammation and barrier dysfunction, suggesting a critical role of IL-17RA signaling for GA-mediated protection against UC. Overall, these results indicate that GA is an effective agent against UC mainly through the direct binding of IL-17RA to inhibit inflammatory signaling activation.

Circadian rhythm disruption-mediated downregulation of Bmal1 exacerbates DSS-induced colitis by impairing intestinal barrier

Background

Circadian rhythm disruption (CRD) is thought to increase the risk of inflammatory bowel disease. The deletion of Bmal1, a core transcription factor, leads to a complete loss of the circadian rhythm and exacerbates the severity of dextran sodium sulfate (DSS)-induced colitis in mice. However, the underlying mechanisms by which CRD and Bmal1 mediate IBD are still unclear.

Methods

We used a CRD mouse model, a mouse colitis model, and an in vitro model of colonic epithelial cell monolayers. We also knocked down and overexpressed Bmal1 in Caco-2 cells by transfecting lentivirus in vitro. The collected colon tissue and treated cells were assessed and analyzed using immunohistochemistry, immunofluorescence staining, quantitative reverse transcription-polymerase chain reaction, western blot, flow cytometry, transmission electron microscopy, and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling staining.

Results

We found that CRD mice with downregulated Bmal1 expression were more sensitive to DSS-induced colitis and had more severely impaired intestinal barrier function than wild-type mice. Bmal1-/- mice exhibited more severe colitis, accompanied by decreased tight junction protein levels and increased apoptosis of intestinal epithelial cells compared with wild-type mice, which were alleviated by using the autophagy agonist rapamycin. Bmal1 overexpression attenuated Lipopolysaccharide-induced apoptosis of intestinal epithelial cells and impaired intestinal epithelial cells barrier function in vitro, while inhibition of autophagy reversed this protective effect.

Conclusion

This study suggests that CRD leads to the downregulation of Bmal1 expression in the colon, which may exacerbate DSS-induced colitis in mice, and that Bmal1 may serve as a novel target for treating inflammatory bowel disease.

IL-22 promotes occludin expression by activating autophagy and treats ulcerative colitis

IL-22 serves a protective function in the intestinal barrier. These protective properties of IL-22 may offer a potential treatment for ulcerative colitis (UC). However, the exact mechanisms of action remain unclear. Autophagy plays an important protective role in stabilizing the intestinal barrier. We aimed to explore the role of autophagy in the IL-22-mediated-protective effects in UC. Dextran sulfate sodium (DSS) was administrated via drinking water over 7 days to induce acute UC in BALB/c mice. Treatments with IL-22 (0.25 μg/10 g bodyweight) were started by intraperitoneal injection on days 1, 3, and 5. Weight, disease activity index, histological score, and myeloperoxidase (MPO) activity were used to evaluate the severity of colitis. The expressions of occludin and autophagy-related proteins LC3BII/I were measured by western blot analysis. The lipopolysaccharide-induced HT-29 cell model was used to explore the mechanism. In vivo, IL-22 significantly alleviated DSS-induced clinical manifestations, reduced histological injury, and inhibited MPO activity. IL-22 upregulated the expression of occludin and the LC3B II/I ratio in the colon. In vitro, IL-22 significantly lowered TNF-α levels and enhanced the expression of occludin and the LC3B II/I ratio. Importantly, inhibiting autophagy in vitro by 3-Methyladenine (3-MA) attenuated the occludin protective effects of IL-22. In summary, our findings demonstrate that IL-22 ameliorates DSS-induced ulcerative colitis, which may be attributable to activating autophagy and then promoting occludin expression.

Chronic Visceral Pain: New Peripheral Mechanistic Insights and Resulting Treatments

Chronic visceral pain is one of the most common reasons for patients with gastrointestinal disorders, such as inflammatory bowel disease or disorders of brain-gut interaction, to seek medical attention. It represents a substantial burden to patients and is associated with anxiety, depression, reductions in quality of life, and impaired social functioning, as well as increased direct and indirect health care costs to society. Unfortunately, the diagnosis and treatment of chronic visceral pain is difficult, in part because our understanding of the underlying pathophysiologic basis is incomplete. In this review, we highlight recent advances in peripheral pain signaling and specific physiologic and pathophysiologic preclinical mechanisms that result in the sensitization of peripheral pain pathways. We focus on preclinical mechanisms that have been translated into treatment approaches and summarize the current evidence base for directing treatment toward these mechanisms of chronic visceral pain derived from clinical trials. The effective management of chronic visceral pain remains of critical importance for the quality of life of suffers. A deeper understanding of peripheral pain mechanisms is necessary and may provide the basis for novel therapeutic interventions.

Current understanding of the interplay between extracellular matrix remodelling and gut permeability in health and disease

The intestinal wall represents an interactive network regulated by the intestinal epithelium, extracellular matrix (ECM) and mesenchymal compartment. Under healthy physiological conditions, the epithelium undergoes constant renewal and forms an integral and selective barrier. Following damage, the healthy epithelium is restored via a series of signalling pathways that result in remodelling of the scaffolding tissue through finely-regulated proteolysis of the ECM by proteases such as matrix metalloproteinases (MMPs). However, chronic inflammation of the gastrointestinal tract, as occurs in Inflammatory Bowel Disease (IBD), is associated with prolonged disruption of the epithelial barrier and persistent damage to the intestinal mucosa. Increased barrier permeability exhibits distinctive signatures of inflammatory, immunological and ECM components, accompanied by increased ECM proteolytic activity. This narrative review aims to bring together the current knowledge of the interplay between gut barrier, immune and ECM features in health and disease, discussing the role of barrier permeability as a discriminant between homoeostasis and IBD.

Anti-inflammatory probiotics HF05 and HF06 synergistically alleviate ulcerative colitis and secondary liver injury

Given the limited efficacy and adverse effects associated with conventional drugs, probiotics are emerging as a promising therapeutic strategy for mitigating the chronic nature of ulcerative colitis (UC) and its consequential secondary liver injury (SLI). Limosilactobacillus fermentum HF06 and Lactiplatibacillus plantarum HF05 are strains we screened with excellent anti-inflammatory and probiotic properties in vitro. In this study, the intervention of HF06 and HF05 in combination (MIXL) was found to be more effective in alleviating intestinal inflammation and secondary liver injury in UC mice compared to supplementing with the two strains individually. Results demonstrated that MIXL effectively attenuated colon shortening and weight loss, downregulated the expression of pro-inflammatory cytokines TNF-α, IL-1β, and IL-6 mRNA in the intestines, mitigated SLI, and augmented the enzymatic activities of SOD, CAT, and GSH-Px in the liver. MIXL enhances the intestinal barrier in UC mice, regulates the structure and composition of the gut microbiota, promotes the abundance of Lactobacillus, and suppresses the abundance of bacteria associated with inflammation and liver injury, including Clostridium_Sensu_Stricto_1, Escherichia, Shigella, Enterococcus, Corynebacterium, Desulfovibrio, and norank_f__Oscillospiraceae. This study demonstrated the synergistic effect of HF06 and HF05, providing a reliable foundation for the alleviation of UC.

Electroacupuncture Improving Intestinal Barrier Function in Rats with Irritable Bowel Syndrome Through Regulating Aquaporins

BACKGROUND

Intestinal mucosal barrier dysfunction plays a crucial role in the pathogenesis of irritable bowel syndrome with diarrhea (IBS-D). In order to explore the mechanism of electroacupuncture (EA) treatment on intestinal mucosal barrier, this study observed the effect of EA on aquaporins (AQPs), tight junctions (TJs), NF-κB pathway and the gut microbiota in IBS-D rats.

METHODS

The IBS-D model was established by acetic acid enema combined with chronic restraint method. The effects of EA on the treatment of IBS-D were examined by the abdominal withdrawal reflex score, Bristol's fecal character score, fecal water content, small intestine propulsion rate and HE staining. AQPs, TJs and inflammation-related molecular mechanisms were explored. The fecal samples were applied for 16S rRNA sequencing to assess the effect of EA intervention to the intestinal bacterial abundance.

RESULTS

EA reduced intestinal sensitization, restored intestinal motility and improved inflammatory cell infiltration. Furthermore, EA improved intestinal inflammation and flora environment significantly, inhibited NF-κB signaling and inflammatory factors (IL-1β and TNF-α). It can also increase the gene and protein expression of AQPs (AQP1, AQP3, and AQP8) and the gene levels of TJs (ZO-1 and Occludin).

CONCLUSION

EA has an inhibitory effect on the NF-κB signaling pathway, and regulates the proteins of AQP1, AQP3, AQP8, and TJs to restore the balance of water metabolism and intestinal permeability in IBS-D, which also restored the function of the intestinal mucosa by regulating the intestinal flora.

The epithelium takes the stage in asthma and inflammatory bowel diseases

The epithelium is a dynamic barrier and the damage to this epithelial layer governs a variety of complex mechanisms involving not only epithelial cells but all resident tissue constituents, including immune and stroma cells. Traditionally, diseases characterized by a damaged epithelium have been considered "immunological diseases," and research efforts aimed at preventing and treating these diseases have primarily focused on immuno-centric therapeutic strategies, that often fail to halt or reverse the natural progression of the disease. In this review, we intend to focus on specific mechanisms driven by the epithelium that ensure barrier function. We will bring asthma and Inflammatory Bowel Diseases into the spotlight, as we believe that these two diseases serve as pertinent examples of epithelium derived pathologies. Finally, we will argue how targeting the epithelium is emerging as a novel therapeutic strategy that holds promise for addressing these chronic diseases.

Impact of bread diet on intestinal dysbiosis and irritable bowel syndrome symptoms in quiescent ulcerative colitis: A pilot study

Gut microbiota may be involved in the presence of irritable bowel syndrome (IBS)-like symptomatology in ulcerative colitis (UC) patients in remission. Bread is an important source of dietary fiber, and a potential prebiotic. To assess the effect of a bread baked using traditional elaboration, in comparison with using modern elaboration procedures, in changing the gut microbiota and relieving IBS-like symptoms in patients with quiescent ulcerative colitis. Thirty-one UC patients in remission with IBS-like symptoms were randomly assigned to a dietary intervention with 200 g/d of either treatment or control bread for 8 weeks. Clinical symptomatology was tested using questionnaires and inflammatory parameters. Changes in fecal microbiota composition were assessed by high-throughput sequencing of the 16S rRNA gene. A decrease in IBS-like symptomatology was observed after both the treatment and control bread interventions as reductions in IBS-Symptom Severity Score values (p-value < 0.001) and presence of abdominal pain (p-value < 0.001). The treatment bread suggestively reduced the Firmicutes/Bacteroidetes ratio (p-value = 0.058). In addition, the Firmicutes/Bacteroidetes ratio seemed to be associated with improving IBS-like symptoms as suggested by a slight decrease in patient without abdominal pain (p-value = 0.059). No statistically significant differential abundances were found at any taxonomic level. The intake of a bread baked using traditional elaboration decreased the Firmicutes/Bacteroidetes ratio, which seemed to be associated with improving IBS-like symptoms in quiescent ulcerative colitis patients. These findings suggest that the traditional bread elaboration has a potential prebiotic effect improving gut health (ClinicalTrials.gov ID number of study: NCT05656391).

Effects of polyphenolic maqui (Aristotelia chilensis) extract on the inhibition of NLRP3 inflammasome and activation of mast cells in a mouse model of Crohn's disease-like colitis

Introduction

Crohn's disease (CD) involves activation of mast cells (MC) and NF-кB in parallel with the PPAR-α/NLRP3 inflammasome/IL-1β pathway in the inflamed colon. Whether polyphenols from maqui (Aristotelia chilensis) represent a natural alternative treatment for CD is unclear. Therefore, we used an animal model of 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced CD-like colitis to investigate protective effects of maqui extract through monitoring NLRP3 inflammasome and MC activation in colon tissue.

Methods

Maqui extract was administered via orogastric route to mice after (post-Treatment group) or prior (pre-Treatment group) to TNBS-induction. Colon pathology was characterized by histoarchitectural imaging, disease activity index (DAI), and assessing NF-кB, p-NF-кB, PPAR-α/NLRP3 expression and IL-1β levels.

Results

Compared to mice treated with TNBS alone administration of anthocyanin-rich maqui extract improved the DAI, colon histoarchitecture and reduced both colon wet-weight and transmural inflammation. Induction with TNBS significantly increased colonic NLPR3 inflammasome activation, while co-treatment with maqui extract (either post- or pre-Treatment) significantly downregulated NLRP3, ASC and caspase-1 levels, which manifested as reduced colonic IL-1β levels. Supplemented maqui extract marginally diminished NF-кB activity in epithelial cells but reached statistical significance in immune cells (as judged by decreased NF-кB phosphorylation). PPAR-α signaling was largely unaffected by Maqui whereas MC infiltration into the colon mucosa and submucosa decreased and their level of degranulation was suppressed.

Conclusion

These outcomes show the post- and pre- Treatment effect of a polyphenolic extract rich in anthocyanins from maqui the acute phase of TNBS- induced CD-like colitis is linked to suppression of the NLRP3 inflammasome and reduced MC responses. These data indicate that maqui extract represents a potential nutraceutical for the treatment of inflammatory bowel disease (IBD).

Deciphering internal and external factors influencing intestinal junctional complexes

The intestinal barrier, an indispensable guardian of gastrointestinal health, mediates the intricate exchange between internal and external environments. Anchored by evolutionarily conserved junctional complexes, this barrier meticulously regulates paracellular permeability in essentially all living organisms. Disruptions in intestinal junctional complexes, prevalent in inflammatory bowel diseases and irritable bowel syndrome, compromise barrier integrity and often lead to the notorious "leaky gut" syndrome. Critical to the maintenance of the intestinal barrier is a finely orchestrated network of intrinsic and extrinsic factors that modulate the expression, composition, and functionality of junctional complexes. This review navigates through the composition of key junctional complex components and the common methods used to assess intestinal permeability. It also explores the critical intracellular signaling pathways that modulate these junctional components. Lastly, we delve into the complex dynamics between the junctional complexes, microbial communities, and environmental chemicals in shaping the intestinal barrier function. Comprehending this intricate interplay holds paramount importance in unraveling the pathophysiology of gastrointestinal disorders. Furthermore, it lays the foundation for the development of precise therapeutic interventions targeting barrier dysfunction.

Different therapies of Chinese herbal medicine for diarrhea-predominant irritable bowel syndrome: A network meta-analysis of double-blinded, placebo-controlled trials

ETHNOPHARMACOLOGICAL RELEVANCE

Shuganjianpi Therapy (SGJP), Jianpi Therapy (JP), Shugan Therapy (SG), Jianpiwenshen Therapy (JPWS), and Shuganjianpiwenshen Therapy (SGJPWS), consisting of formulas from Chinese herbal medicine (CHM), have been tremendously applied to irritable bowel syndrome (IBS). However, it remains uncertain when exploring the preferable option among different CHM therapies for diarrhea-predominant irritable bowel syndrome (IBS-D).

AIM OF THE STUDY

To compare and rank the efficacy and safety of different CHM therapies for IBS-D.

MATERIALS AND METHODS

We searched randomized, double-blinded, placebo-controlled trials through mainstream databases from their inception to October 31, 2022. Eligible randomized controlled trials (RCTs) applied one of the CHM therapies as the experimental group and placebo as the control group. Two authors independently extracted data into a form and evaluated the quality of the retrieved articles by the Cochrane Risk of Bias Tool. At least one of the following outcomes was assessed: Serotonin, Neuropeptide Y (NPY), Incidence of Adverse Events (AE), and Irritable Bowel Syndrome-Severity Scoring System (IBS-SSS) with its subscales of Severity of Abdominal Pain (SAP), Frequency of Abdominal Pain (FAP), Severity of Abdominal Distension (SAD), Dissatisfaction with Bowel Habits (DBH), and Interference with Quality of Life (IQOL). A Bayesian network meta-analysis on a random-effect model was conducted using R 4.2.2 software.

RESULTS

1367 records were retrieved from databases in an initial search. Fourteen studies involving six interventions with 2248 participants were identified. Provided pairwise comparisons, the surface under the cumulative ranking curve (SUCRA) ranking, and cluster analysis, JPWS was the best option for ameliorating clinical symptoms simultaneously, which included IBS-SSS, SAP, FAP, SAD, DBH, and IQOL. As for AE, JPWS contributed to fewer adverse events than others as well. In respect of serum indicators, we noticed the dominance of SGJP in regulating both serotonin and NPY.

CONCLUSIONS

JPWS and SGJP were the most prominent CHM therapies for IBS-D in terms of clinical symptoms, including abdominal pain, distension, bowel habits, and improvement of quality of life. The effect of JP and SG for IBS-D required further investigation. As a potential candidate, SGJP may well treat IBS-D by mediating dysmotility, visceral hypersensitivity, and the gut-brain axis with an increase of NPY and a reduction of serotonin. For safety, JPWS was ideal for the fewest adverse events in the treatment of IBS-D. On account of a small sample size and possible geographical publication bias, more double-blinded and placebo-controlled trials with larger samples worldwide would be necessary for strengthening current evidence.

Mast Cell Disorders of the Gastrointestinal Tract: Clarity out of Chaos

Pathologists are increasingly asked to evaluate mast cell infiltrates in the gastrointestinal tract when there is clinical concern for systemic mastocytosis or a variety of functional disorders, including irritable bowel syndrome and mast cell activation syndrome. Neoplastic mast cells have established quantitative, morphologic, and immunohistochemical features that facilitate their identification in gastrointestinal mucosal biopsies. Specific qualitative and quantitative findings are lacking for inflammatory mast cell-mediated disorders. This review covers histopathologic features of mast cell disorders that affect the gastrointestinal tract and offers practical guidance for their assessment in mucosal biopsies.

The Microbiome in Quiescent Crohn's Disease With Persistent Symptoms Show Disruptions in Microbial Sulfur and Tryptophan Pathways

Background and Aims

Even in the absence of inflammation, persistent symptoms in Crohn's disease (CD) are prevalent and worsen quality of life. Amongst patients without inflammation (quiescent CD), we hypothesized that microbial community structure and function, including tryptophan metabolism, would differ between patients with persistent symptoms (qCD + S) and without persistent symptoms (qCD-S).

Methods

We performed a multicenter observational study nested within the Study of a Prospective Adult Research Cohort with Inflammatory Bowel Disease. Quiescent inflammation was defined by fecal calprotectin level <150 mcg/g. Persistent symptoms were defined by Crohn's Disease Patient-Reported Outcome-2. Active CD, diarrhea-predominant irritable bowel syndrome, and healthy controls were included as controls. Stool samples underwent whole-genome shotgun metagenomic sequencing.

Results

Thirty-nine patients with qCD + S, 274 qCD-S, 21 active CD, 40 diarrhea-predominant irritable bowel syndrome, and 50 healthy controls were included for analysis. Patients with qCD + S had a less-diverse microbiome. Furthermore, patients with qCD + S showed significant enrichment of bacterial species that are normal inhabitants of the oral microbiome (eg Rothia dentocariosa, Fusobacterium nucleatum) and sulfidogenic microbes (eg Prevotella copri, Bilophila spp.). Depletion of important butyrate and indole producers (eg Eubacterium rectale, Faecalibacterium prausnitzii) was also noted in qCD + S. Potential metagenome-related functional changes in cysteine and methionine metabolism, ATP transport, and redox reactions were disturbed in qCD + S, also suggestive of altered sulfur metabolism. Finally, qCD + S showed significant reductions in bacterial tnaA genes, which mediate tryptophan metabolism to indole, and significant tnaA allelic variation compared with qCD-S.

Conclusion

The microbiome in qCD + S showed significant differences in sulfidogenesis, butyrate producers, and typically oral microbes compared to qCD-S and active CD. These results suggest that inflammation may lead to durable microbiome alterations which may mediate persistent symptoms through testable mechanisms.

Endoscopic laser endomicroscopy and "leaky gut" in patients with functional gastrointestinal symptoms and food intolerance

BACKGROUND

Intestinal epithelial barrier dysfunction ("leaky gut syndrome", LGS) is thought to play a major role in the pathogenesis of disorders of the gut brain axis. Endoscopic confocal laser endomicroscopy (eCLE) is an objective measure to test duodenal permeability. We applied this technique in patients with functional gastrointestinal symptoms and food intolerance to characterize the proportion of patients with LGS.

MATERIAL AND METHODS

In an observational study, we evaluated 85 patients with functional gastrointestinal symptoms and food intolerance. Gastrointestinal symptoms were classified according to Rom IV into functional abdominal pain (FAP), irritable bowel syndrome (IBS), irritable bowel syndrome diarrhea dominant (IBS-D), irritable bowel syndrome constipation dominant (IBS-C), irritable bowel syndrome with mixed stool (IBS-M), functional abdominal bloating (FAB), functional diarrhea (FD) and unclassified (NC). During eCLE, spontaneous transfer of intravenously applied fluorescein into duodenal lumen (LGS) and following duodenal food challenge (DFC) were analyzed. Blood analysis comprised parameters of mast cell function, histology of duodenal mucosal biopsies analysis of mucosal inflammation, intraepithelial lymphocytes (IELs) as well as number, distribution and morphology of mast cells.

RESULTS

24 patients (9 IBS, 9 FAP, 3 FAB, 1 FD, 2 NC), showed LGS, 50 patients (14 IBS-D, 4 IBS-C, 3 IBS-M, 23 FAP, 3 FAB, 3 NC) had no LGS but responded to DFC and 11 patients (6 NC, 3 FAP, 1 FAB, 1 FD) had no LGS and no response to DFC. The proportion of subgroups with/or without spontaneous leakage of fluorescein (+LGS/-LGS) were IBS-LGS/IBS+LGS 67%/33%, FAP-LGS/FAP+LGS 72%/28%,FAB-LGS/FAB+LGS 50%/50%, NC-LGS/NC+LGS 60%/40%. Subgroup analysis revealed no significant differences for all parameters tested.

CONCLUSION

As a proof of concept, the results of our study indicate that eCLE is a clinical useful tool to evaluate patients with disorders of the gut brain axis and those suspicious of LGS. However, the clinical significance of LGS remains unclear. The study should be an incentive to perform a randomized study including healthy controls.

Lifestyle Factors Associated with Abdominal Pain in Quiescent Inflammatory Bowel Disease

BACKGROUND

Lifestyle factors, including diet, exercise, substance use, and sexual activity, have been shown to influence risk of inflammation and complications in inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC). Little is known about their potential role in abdominal pain generation in IBD.

AIMS

We performed this study to evaluate for relationships between lifestyle factors and abdominal pain in quiescent IBD (QP-IBD).

METHODS

We performed a retrospective analysis utilizing data from our institution's IBD Natural History Registry (January 1, 2017-December 31, 2022). Endoscopic evaluation, concurrent laboratory studies and surveys were completed by participants. Demographic and clinical data were also abstracted.

RESULTS

We identified 177 consecutive patients with quiescent disease (105 females:72 males; 121 with CD:56 with UC) for participation in this study, 93 (52.5%) had QP-IBD. Compared to patients with quiescent IBD without pain (QNP-IBD, patients with QP-IBD exhibited no significant differences in IBD type, location, severity or complication rate. Patients with QP-IBD were more likely to have anxiety/depression (55.9% vs. 32.1%, p = 0.002) and to use antidepressants/anxiolytics (49.5% vs. 21.4%, p < 0.001). They were also less likely to engage in exercise at least three times per week (39.8% vs. 54.8%, p = 0.05) or participate in sexual activity at least monthly (53.8% vs. 69.1%, p = 0.04). On logistic regression analysis, antidepressant and/or anxiolytic use was independently associated with QP-IBD [2.72(1.32-5.62)], while monthly sexual activity was inversely associated [0.48(0.24-0.96)].

CONCLUSION

Lifestyle factors, including the lack of sexual activity and exercise, are significantly associated with QP-IBD. Further study is warranted to clarify the relationships between these factors and the development of abdominal pain in quiescent IBD.

Genotype Prevalence of Lactose Deficiency, Vitamin D Deficiency, and the Vitamin D Receptor in a Chilean Inflammatory Bowel Disease Cohort: Insights from an Observational Study

Lactose intolerance (LI) and vitamin D deficiency (VDD) have been linked to inflammatory bowel disease (IBD). We conducted an observational study in 192 Chilean IBD patients to investigate the prevalence of a specific gene variant (LCT-13910 CC genotype) associated with LI and the prevalence of VDD/Vitamin D Receptor (VDR) gene variants. Blood samples were analyzed using Illumina's Infinium Global Screening Array. The LCT-13910 CC genotype was found in 61% of IBD patients, similar to Chilean Hispanic controls and lower than Chilean Amerindian controls. The frequency of the LCT-13910-C allele in Chilean IBD patients (0.79) was comparable to the general population and higher than Europeans (0.49). Regarding VDR and VDD variants, in our study, the rs12785878-GG variant was associated with an increased risk of IBD (OR = 2.64, CI = 1.61-4.32; p-value = 0.001). Sixty-one percent of the Chilean IBD cohort have a genetic predisposition to lactose malabsorption, and a significant proportion exhibit genetic variants associated with VDD/VDR. Screening for LI and VDD is crucial in this Latin American IBD population.

Impact of Baseline Disease Activity and Trial Duration on Efficacy of Biologics in Active Crohn's Disease: Meta-analysis

BACKGROUND

Timings of assessment of efficacy and criteria used to define Crohn's disease (CD) activity at baseline may affect therapeutic gain of active drug over placebo in induction of remission trials in CD, but these issues have not been assessed systematically. We examined these issues in a meta-analysis.

METHODS

We searched the literature to June 2022 for randomized controlled trials of biologics vs placebo in active CD. We extracted clinical remission and response rates according to criteria used to define CD activity and time point of assessment, pooling them in a meta-analysis for all patients according to previous biologic exposure. We calculated the number needed to treat (NNT), with a 95% confidence interval (CI) to assess therapeutic gain of active drug over placebo according to these characteristics of trial design.

RESULTS

We identified 20 induction of remission trials (6754 patients). Rates of clinical remission were highest (42.6% with active drug vs 21.0% with placebo) and NNT lowest (5; 95% CI, 3-7.5) in trials using clinical and endoscopic activity to define active CD. Rates of remission were lower (26.5% with active drug, vs 18.6% with placebo) and NNT highest (12; 95% CI, 6-61) in trials using clinical activity alone. Results were similar according to previous biologic exposure. Time point of assessment seemed to have less of an effect, although the NNT was lowest in trials assessing remission rates at 9 to 12 weeks (NNT = 5.5; 95% CI, 4-8). Again, results were similar according to previous biologic exposure.

CONCLUSIONS

Both the criteria used to define CD activity at study entry and the time point used to confirm efficacy may be important in maximizing therapeutic gain of active drug over placebo.

Update in diagnosis and management of irritable bowel syndrome

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder characterized by a lack of structural or biochemical abnormalities. The current diagnosis of IBS is based on the Rome IV criteria, and it is recommended to approach IBS patients using a multidimensional clinical profile (MDCP). The pathophysiology of IBS is multifactorial and involves motility disorders, genetic factors, immune responses, visceral hypersensitivity, brain-gut dysregulation, and altered intestinal microbiota. The management of IBS includes both nonpharmacologic and pharmacologic therapies. Nonpharmacologic therapy options include physical activity, low fermentable oligosaccharides, disaccharides, monosaccharides, and polyol diet, as well as cognitive behavioral therapy. Pharmacologic therapy options include probiotics, antidepressants, antispasmodics, and new agents. In clinical practice, a multidisciplinary strategy, including nonpharmacologic or/and pharmacologic treatment for IBS, is emphasized. Therefore, clinicians should carefully consider the underlying pathophysiology before selecting an appropriate therapeutic option for the treatment of IBS. In other words, individualized treatment plans are necessary for managing IBS.

Visceral hypersensitivity induced by mild traumatic brain injury via the corticotropin-releasing hormone receptor: An animal model

BACKGROUND

Mild blast-induced traumatic brain injury (bTBI) induces various gut symptoms resembling human irritable bowel syndrome (IBS) as one of mental and behavioral disorders. However, the underlying mechanisms remain unclear. We investigated whether the extremely localized brain impact extracranially induced by laser-induced shock wave (LISW) evoked IBS-like phenomenon including visceral hypersensitivity and intestinal hyperpermeability in rats.

METHODS

The rats were subjected to LISW on the scalp to shock the entire brain. Visceral hypersensitivity was evaluated by the threshold pressure of abdominal withdrawal reflex (AWR) using a colorectal distension test. Permeability was evaluated by the concentration of penetrating FITC-dextran from intestine and the mRNA expression levels of tight junction family proteins. Involvement of corticotropin-releasing factor receptor (CRFR) 1 and 2 was examined by evaluating mRNA expression and modulating CRFR function with agonist, recombinant CRF (10 μg/kg), and antagonist, astressin (33 μg/kg). High-throughput sequencing of the gut microbiota was performed by MiSeqIII instrument and QIIME tool.

KEY RESULTS

The thresholds of the AWR were significantly lowered after LISW. Permeability was increased in small intestine by LISW along with decreased expression of tight junction ZO-1. LISW significantly increased CRFR1 expression and decreased CRFR2 expression. Visceral hypersensitivity was significantly aggravated by CRFR agonist and suppressed by CRFR antagonist. The α- and β-diversity of the fecal microbiota was altered after LISW.

CONCLUSIONS AND INFERENCES

LISW provoked visceral hypersensitivity, small intestinal hyperpermeability, altered expression of CRFRs and changes in the microbiota, suggesting that genuine bTBI caused by LISW can induce a pathophysiology comparable to that of human IBS.

Celery soluble dietary fiber antagonizes flavonoids ameliorative effect on dextran-sodium-sulfate-induced colitis in mice

INTRODUCTION

Dietary fiber and flavonoids are promising drugs reported in the treatment of inflammatory bowel disease (IBD). However, it is unclear the interaction between dietary fiber and flavonoids in gut health.

OBJECTIVE

The therapeutic effect of celery, kale, and red chicory powders on colitis mice using non-group feeding cages was investigated. Further, the efficacy of whole celery, celery soluble dietary fiber (CSDF), celery insoluble dietary fiber (CIDF), celery flavonoids (CF), CSDF + CF and CIDF + CF in IBD mice model was assessed to dissect protective effect to attribute to which component(s) in such complex matrix.

METHODS

3% Dextran sulfate sodium salt (DSS) was used to induce mice colitis model. Multiple molecular biological methods were employed to evaluate the severity of mice colitis and the gut microbial composition of mice.

RESULTS

Administration of kale and red chicory significantly restored body weight, DAI score, and colon length in colonic mice, and celery showed the weakest effects. Administration of either CSDF or CF markedly improved the histological damage, increased colonic mucus expression, and reduced colonic MPO/iNOS activities, and IL-6/IL-1β levels. However, CSDF + CF showed weaker improvement than CF or SDF in most physical and biochemical signs. Furthermore, CSDF and CF decreased intestinal g_Escherichia-Shihella and g_Clostridium_sensu_stricto_1 induced by DSS administration. Interestingly, celery flavonoid promoted g_Akkermansia proliferation both in vivo and in vitro, and which can be inhibited by CSDF.

CONCLUSIONS

This study revealed for the first time that CSDF can suppress the protective effect of CF on intestinal health by inhibiting g_Akkermansia, and clarified that the decreased efficacy of celery whole food on colitis was mediated by an antagonism between CSDF and CF. Moreover, this study presents for the first time that interaction between soluble dietary fiber and flavonoids in vivo can ameliorate the efficacy of dietary fiber or flavonoids when administered alone suggestive for an antagonistic effect.

Dietary intake of phytochemicals in association with irritable bowel syndrome in adults

BACKGROUND & AIM

There is limited data regarding the association between phytochemical-rich diets and irritable bowel syndrome (IBS). The current study aimed to cross-sectionally evaluate the association of dietary phytochemical index (DPI) with the odds and severity of IBS.

METHODS

In this study, which included 3362 Iranian healthcare staffs, a dish-based semi-quantitative food frequency questionnaire (DS-FFQ) was utilized to collect dietary information. The DPI was defined as the daily percentage of calories consumed from phytochemical-rich foods. The IBS assessment was performed using a revised Iranian version of the Rome III questionnaire. We applied the restricted cubic spline (RCS) to detect the possible non-linear dependency of the relationship between DPI and the odds of IBS.

RESULTS

The mean age, Body Mass Index (BMI), and DPI scores of the participants were 36.29 ± 7.8 years, 24.90 ± 3.8 kg/m2, and 16.07 ± 9.01, respectively. After adjusting for possible confounders, no significant association was observed between DPI and odds of IBS in the whole study population or in gender- and BMI-stratified analyses. We found a significant inverse association between DPI and IBS severity in the study population (OR: 0.70; 95% CI: 0.51-0.98). Concerning gender, such an association was only found in women (OR: 0.65; 95% CI: 0.44-0.96). However, there was no significant relationship between DPI and IBS severity in BMI subgroups. In addition, we found no meaningful relationship between DPI and IBS subtypes. The RCS model showed that there is no non-linear relationship between DPI classification and IBS (non-linear test, χ2 = 1.14, Pnon-linearity = 0.513).

CONCLUSIONS

Higher phytochemical intake was associated with reduced IBS severity, particularly in women. Further prospective studies are required to confirm these findings.

Mechanism by which oleracein E alleviates TNBS-induced ulcerative colitis

OBJECTIVE

This study aimed to investigate the effect of oleracein E (OE) in improving 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced ulcerative colitis (UC).

METHODS

Lipopolysaccharide (LPS) was used to induce a UC cell model, and TNBS was used to induce a UC rat model. ELISA was performed to assess the levels of inflammatory factors (IL-1β, TNF-α, and IL-6). Moreover, the activities of catalase (CAT), myeloperoxidase (MPO), and malonaldehyde (MDA) were detected by kits. Western blotting was performed to assess related proteins of the Nrf2/HO-1 signaling pathway, tight junction protein (ZO-1, Occludin, and claudin-2) expression levels, and apoptosis-related proteins (Bcl2, Bax, and cleaved caspase 3). Flow cytometry was used to analyze ROS levels. The morphology of colon tissues and the apoptosis of cells were detected by HE and TUNEL staining, respectively.

RESULTS

OE significantly increased the activity of CAT and decreased the activity of MPO in LPS-induced Caco-2 cells and TNBS-induced UC rats. However, the levels of IL-1β, IL-6, and TNF-α were markedly reduced both in vivo and in vitro. In addition, OE significantly increased the levels of Nrf2/HO-1 signaling pathway-related proteins and tight junction proteins and inhibited cell apoptosis. HE staining showed that OE significantly decreased the severity of acute TNBS-induced colitis in rats.

CONCLUSION

OE may exert a regulatory effect on ameliorating intestinal barrier injury and reducing inflammation and oxidative stress levels by activating the Nrf2/HO-1 pathway.

The Efficacy and Safety of Single-Strain Probiotic Formulations Containing Bifidobacterium lactis or Bacillus coagulans in Adult Patients with Irritable Bowel Syndrome-A Randomized Double-Blind Placebo-Controlled Three-Arm Interventional Trial

Probiotics offer a potential new therapeutic approach for irritable bowel syndrome (IBS), but current results are still controversial. The aim of this study was to assess the efficacy and safety of single-strain probiotic formulations in adult IBS patients and to compare the effects of Bifidobacterium lactis NORDBIOTIC™ BI040 (DSM 33812/34614) and Bacillus coagulans NORDBIOTIC™ BC300 (DSM 33836) in a prospective three-arm interventional randomized double-blind placebo-controlled clinical trial. The study included 123 IBS subjects diagnosed according to the Rome IV criteria. The primary outcomes were changes in symptom severity and symptom improvement as assessed using the IBS Severity Scoring System (IBS-SSS) after 4, 8, and 12 weeks of intervention and after 4 weeks of follow-up. Secondary outcomes included the assessment of individual IBS symptoms and the occurrence of adverse events. During the 12-week intervention, IBS-SSS scores significantly decreased (p-values < 0.001) in the study groups but differences between the interventional and placebo groups did not reach statistical significance. However, at the 16th week of follow-up, a significant improvement in the total IBS-SSS score in comparison to the placebo group (20.5%) was found in 43.8% and 52.9% of the Bifidobacterium lactis (p = 0.038, OR 3.0, [95% CI 1.1-8.6]) and the Bacillus coagulans (p = 0.005, OR 4.6 [95% CI 1.5-12.2]) groups, respectively. Bifidobacterium lactis had a beneficial effect on the intensity and frequency of pain, whereas Bacillus coagulans decreased the bowel dissatisfaction. Both strains increased the percentage of patients with normal stool consistency, but only Bifidobacterium lactis induced a decrease in the number of patients with constipation after 6 weeks of supplementation. Both probiotic strains were well tolerated, without differences in the occurrence of adverse events between groups. In conclusion, single-strain supplementation was safe and efficient in IBS patients but showed a different range of effects. Bifidobacterium lactis BI040 primarily reduced the frequency and intensity of pain, while Bacillus coagulans BC300 increased bowel satisfaction [ClinicalTrials.gov NCT05064930].

A multi-mineral intervention to counter pro-inflammatory activity and to improve the barrier in human colon organoids

Introduction: Ulcerative colitis is a chronic inflammatory condition, and continuous inflammatory stimulus may lead to barrier dysfunction. The goal of this study was to assess barrier proteomic expression by a red algae-derived multi-mineral intervention in the absence or presence of pro-inflammatory insult. Methods: Human colon organoids were maintained in a control culture medium alone or exposed to lipopolysaccharide with a combination of three pro-inflammatory cytokines [tumor necrosis factor-α, interleukin-1β and interferon-γ (LPS-cytokines)] to mimic the environment in the inflamed colon. Untreated organoids and those exposed to LPS-cytokines were concomitantly treated for 14 days with a multi-mineral product (Aquamin®) that has previously been shown to improve barrier structure/function. The colon organoids were subjected to proteomic analysis to obtain a broad view of the protein changes induced by the two interventions alone and in combination. In parallel, confocal fluorescence microscopy, tissue cohesion and transepithelial electrical resistance (TEER) measurements were used to assess barrier structure/function. Results: The LPS-cytokine mix altered the expression of multiple proteins that influence innate immunity and promote inflammation. Several of these were significantly decreased with Aquamin® alone but only a modest decrease in a subset of these proteins was detected by Aquamin® in the presence of LPS-cytokines. Among these, a subset of inflammation-related proteins including fibrinogen-β and -γ chains (FGB and FGG), phospholipase A2 (PLA2G2A) and SPARC was significantly downregulated in the presence of Aquamin® (alone and in combination with LPS-cytokines); another subset of proteins with anti-inflammatory, antioxidant or anti-microbial activity was upregulated by Aquamin® treatment. When provided alone, Aquamin® strongly upregulated proteins that contribute to barrier formation and tissue strength. Concomitant treatment with LPS-cytokines did not inhibit barrier formation in response to Aquamin®. Confocal microscopy also displayed increased expression of desmoglein-2 (DSG2) and cadherin-17 (CDH17) with Aquamin®, either alone or in the presence of the pro-inflammatory stimulus. Increased cohesion and TEER with Aquamin® (alone or in the presence of LPS-cytokines) indicates improved barrier function. Conclusion: Taken together, these findings suggest that multi-mineral intervention (Aquamin®) may provide a novel approach to combating inflammation in the colon by improving barrier structure/function as well as by directly altering the expression of certain pro-inflammatory proteins.

Network pharmacology and molecular docking reveal the immunomodulatory mechanism of rhubarb peony decoction for the treatment of ulcerative colitis and irritable bowel syndrome

Background: Ulcerative colitis (UC) and irritable bowel syndrome (IBS) share various similarities in clinical symptoms, pathogenesis, and treatment. UC concurrent IBS tends toward more severe symptoms and worse prognosis, and promising feasible therapies for the overlapping symptoms remains a challenge. Rhubarb peony decoction (RPD) is a well-known traditional Chinese medicine that has been widely applied in treating UC. RPD may exert extensive therapeutic effects on both IBS and UC. However, the common mechanism of its treatment remains unclear. We aimed to assess the potential pharmacological mechanism of RPD in the treatment of overlapping IBS and UC. Methods: The active components and targets of RPD were retrieved from ETCM, TCMSP, BATMAN-TCM, and TCM databases. The disease targets were screened by searching the DrugBank, OMIM, TTD, and PharmGKB databases. PPI network analysis was performed and visualized via the STRING platform and Cytoscape software. GO and KEGG enrichment analyses of the hub genes of RPD were predicted to elucidate the potential molecular mechanism. Subsequently, molecular docking was carried out to verify the combination of active compounds with core targets. Results: By integrating all targets of RPD and disease, a total of 31 bioactive ingredients were identified including quercetin, kaempferol, aloe-emodin, beta-sitosterol, and (+)-catechin, etc. JUN, TP53, MAPK1, RELA, MYC, and ESR1 were explored as potential therapeutic targets among 126 common drug-disease-related targets. They were enriched in the AGE-RAGE signaling pathway in diabetic complications, as well as the NF-kappa B signaling pathway and MAPK signaling pathway. Additionally, some active ingredients were identified as candidates for binding to the hub targets via molecular docking, further suggesting their anti-inflammatory and antioxidative properties. Conclusion: RPD may exert the overall treatment effect for UC and IBS overlap syndrome via the biological mechanism of "multi-ingredients, multi-targets, and multi-pathways" on inflammation, oxidative stress, immune, oncogenicity, and gut microbiota dysbiosis.

The Fecal Microbiome in Quiescent Crohn's Disease with Persistent Gastrointestinal Symptoms Show Enrichment of Oral Microbes But Depletion of Butyrate and Indole Producers

Background and Aims

Even in the absence of inflammation, persistent symptoms in Crohn's disease (CD) are prevalent and negatively impact quality of life. We aimed to determine whether quiescent CD patients with persistent symptoms ( qCD+symptoms ) have changes in microbial structure and functional potential compared to those without symptoms ( qCD-symptoms ).

Methods

We performed a prospective multi-center observational study nested within the SPARC IBD study. CD patients were included if they had evidence of quiescent disease as defined by fecal calprotectin level < 150 mcg/g. Persistent symptoms were defined by the CD-PRO2 questionnaire. Active CD ( aCD ), diarrhea-predominant irritable bowel syndrome ( IBS-D ), and healthy controls ( HC ) were included as controls. Stool samples underwent whole genome shotgun metagenomic sequencing.

Results

A total of 424 patients were analyzed, including 39 qCD+symptoms, 274 qCD-symptoms, 21 aCD, 40 IBS-D, and 50 HC. Patients with qCD+symptoms had a less diverse microbiome, including significant reductions in Shannon diversity ( P <.001) and significant differences in microbial community structure ( P <.0001), compared with qCD-symptoms, IBS-D, and HC. Further, patients with qCD+symptoms showed significant enrichment of bacterial species that are normal inhabitants of the oral microbiome, including Klebsiella pneumoniae (q=.003) as well as depletion of important butyrate and indole producers, such as Eubacterium rectale (q=.001), Lachnospiraceae spp . (q<.0001), and Faecalibacterium prausnitzii (q<.0001), compared with qCD-symptoms. Finally, qCD+symptoms showed significant reductions in bacterial tnaA genes, which mediate tryptophan metabolism, as well as significant tnaA allelic variation, compared with qCD-symptoms.

Conclusion

The microbiome in patients with qCD+symptoms show significant changes in diversity, community profile, and composition compared with qCD-symptoms. Future studies will focus on the functional significance of these changes.

What You Need to Know

Background: Persistent symptoms in quiescent Crohn's disease (CD) are prevalent and lead to worse outcomes. While changes in the microbial community have been implicated, the mechanisms by which altered microbiota may lead to qCD+symptoms remain unclear.Findings: Quiescent CD patients with persistent symptoms demonstrated significant differences in microbial diversity and composition compared to those without persistent symptoms. Specifically, quiescent CD patients with persistent symptoms were enriched in bacterial species that are normal inhabitants of the oral microbiome but depleted in important butyrate and indole producers compared to those without persistent symptoms.Implications for Patient Care: Alterations in the gut microbiome may be a potential mediator of persistent symptoms in quiescent CD. Future studies will determine whether targeting these microbial changes may improve symptoms in quiescent CD.

Effect of Bifidobacterium bifidum G9-1 on the Intestinal Environment and Diarrhea-Predominant Irritable Bowel Syndrome (IBS-D)-like Symptoms in Patients with Quiescent Crohn's Disease: A Prospective Pilot Study

Diarrhea-predominant irritable bowel syndrome (IBS-D)-like symptoms are distressing for patients with quiescent Crohn's disease (qCD) and worsen their quality of life. In the present study, we assessed the effect of the probiotic Bifidobacterium bifidum G9-1 (BBG9-1) on the intestinal environment and clinical features in patients with qCD. Eleven patients with qCD, who met the Rome III diagnostic criteria for IBS-D, received BBG9-1 (24 mg) orally three times daily for 4 weeks. Indices of the intestinal environment (fecal calprotectin level and gut microbiome) and clinical features (CD/IBS-related symptoms, quality of life and stool irregularities) were evaluated before and after treatment. Treatment with BBG9-1 tended to reduce the IBS severity index in the studied patients (p = 0.07). Among gastrointestinal symptoms, abdominal pain and dyspepsia tended to be improved by the BBG9-1 treatment (p = 0.07 and p = 0.07, respectively), and IBD-related QOL showed a significant improvement (p = 0.007). With regard to mental status, the patient anxiety score was significantly lower at the endpoint of BBG9-1 treatment than at the baseline (p = 0.03). Although BBG9-1 treatment did not affect the fecal calprotectin level, it suppressed the serum MCP-1 level significantly and increased the abundance of intestinal Bacteroides in the study patients. The probiotic BBG9-1 is able to improve IBD-related QOL with a reduction of anxiety score in patients with quiescent CD and IBS-D-like symptoms.

Pterostilbene and Probiotic Complex in Chemoprevention of Putative Precursor Lesions for Colorectal Cancer in an Experimental Model of Intestinal Carcinogenesis with 1,2-Dimethylhydrazine

Dietary supplementation with pterostilbene (PS) and/or a probiotic (PRO) may ameliorate the intestinal microbiota in disease conditions. This study aims to evaluate PS and PRO for the chemoprevention of putative precursor lesions for colorectal cancer (CRC) in an experimental model of intestinal carcinogenesis with 1,2-dimethylhydrazine (1,2-DMH). Sixty male Wistar rats were equally divided into five groups: Sham, 1,2-DMH, 1,2-DMH + PS, 1,2-DMH + PRO, and 1,2-DMH + PS + PRO. PRO (5 × 107/mL) was offered in water, and PS (300 ppm) was provided in the diet ad libitum. 1,2-DMH (20 mg/kg/week) was administered for 15 consecutive weeks. In the 25th week, proctocolectomy was conducted. PRO alone and PRO combined with PS were the best intervention strategies to improve experimental 1,2-DMH-induced CRC regarding several parameters of carcinogenesis. Our findings may contribute to the development of novel preventive strategies for CRC and may help to identify novel modulators of colon carcinogenesis.

Metformin alleviates liver fibrosis in mice by enriching Lactobacillus sp. MF-1 in the gut microbiota

BACKGROUND

Liver fibrosis is associated with gut dysbiosis. Metformin administration has emerged as a promising method for the treatment of organ fibrosis. We aimed to investigate whether metformin ameliorates liver fibrosis by enhancing the gut microbiota in mice with carbon tetrachloride (CCl₄)-induced liver fibrosis and the underlying mechanism.

MATERIALS AND METHODS

A liver fibrosis mouse model was established, and the therapeutic effects of metformin were observed. We administered antibiotic treatment and performed fecal microbiota transplantation (FMT), and 16S rRNA-based microbiome analysis to evaluate the effects of the gut microbiome on metformin-treated liver fibrosis. We isolated the bacterial strain preferably enriched by metformin and assessed its antifibrotic effects.

RESULTS

Metformin treatment repaired the gut integrity of the CCl₄-treated mice. It reduced the number of bacteria in colon tissues and reduced the portal vein lipopolysaccharide (LPS) levels. The FMT performed on the metformin-treated CCl₄ mice alleviated their liver fibrosis and reduced their portal vein LPS levels. The markedly changed gut microbiota was screened out from the feces and named Lactobacillus sp. MF-1 (L. sp. MF-1). In the CCl₄-treated mice, daily gavage of L. sp. MF-1 maintained gut integrity, inhibited bacterial translocation, and reduced liver fibrosis. Mechanistically, metformin or L. sp. MF-1 inhibited the apoptosis of intestinal epithelial cells and restored CD3⁺ intestinal intraepithelial lymphocytes in the ileum and CD4⁺Foxp3⁺ lamina propria lymphocytes in the colon.

CONCLUSIONS

Metformin and its enriched L. sp. MF-1 can reinforce the intestinal barrier to alleviate liver fibrosis by restoring immune function.

Distinct blood protein profiles associated with the risk of short-term and mid/long-term clinical relapse in patients with Crohn's disease stopping infliximab: when the remission state hides different types of residual disease activity

OBJECTIVE

Despite being in sustained and stable remission, patients with Crohn's disease (CD) stopping anti-tumour necrosis factor α (TNFα) show a high rate of relapse (~50% within 2 years). Characterising non-invasively the biological profiles of those patients is needed to better guide the decision of anti-TNFα withdrawal.

DESIGN

Ninety-two immune-related proteins were measured by proximity extension assay in serum of patients with CD (n=102) in sustained steroid-free remission and stopping anti-TNFα (infliximab). As previously shown, a stratification based on time to clinical relapse was used to characterise the distinct biological profiles of relapsers (short-term relapsers: <6 months vs mid/long-term relapsers: >6 months). Associations between protein levels and time to clinical relapse were determined by univariable Cox model.

RESULTS

The risk (HR) of mid/long-term clinical relapse was specifically associated with a high serum level of proteins mainly expressed in lymphocytes (LAG3, SH2B3, SIT1; HR: 2.2-4.5; p<0.05), a low serum level of anti-inflammatory effectors (IL-10, HSD11B1; HR: 0.2-0.3; p<0.05) and cellular junction proteins (CDSN, CNTNAP2, CXADR, ITGA11; HR: 0.4; p<0.05). The risk of short-term clinical relapse was specifically associated with a high serum level of pro-inflammatory effectors (IL-6, IL12RB1; HR: 3.5-3.6; p<0.05) and a low or high serum level of proteins mainly expressed in antigen presenting cells (CLEC4A, CLEC4C, CLEC7A, LAMP3; HR: 0.4-4.1; p<0.05).

CONCLUSION

We identified distinct blood protein profiles associated with the risk of short-term and mid/long-term clinical relapse in patients with CD stopping infliximab. These findings constitute an advance for the development of non-invasive biomarkers guiding the decision of anti-TNFα withdrawal.

Iohexol is an intestinal permeability marker in broilers under coccidiosis challenge

Intestinal integrity losses have been identified as a main driver for poor performance in broilers. The oral administration of markers such as iohexol is a major asset for measuring intestinal permeability (IP) alterations. The aim of the current study was to evaluate oral iohexol administration and serum levels as a quantitative measure for IP in Ross 308 broilers and to identify possible associations with histologic measurements. A total of 40, day-old broiler chickens were randomly divided into 4 groups of 10 broilers and a coccidiosis model was used to induce IP. Three challenge groups received a mixture of different field strains and concentrations of Eimeria acervulina and Eimeria maxima at d 16, and 1 group operated as an uninfected control group. On d 20, 5 birds per group were orally administered the permeability marker iohexol at a dose of 64.7 mg/kg body weight and blood was taken 60 min after the oral gavage. On d 21 these 5 birds per group were euthanized. On d 21, 5 other birds per group were given iohexol where after blood was taken. These birds were euthanized on d 22. During necropsy, birds were scored for coccidiosis lesions and a duodenal segment was taken for histology. The Eimeria challenge had a significant impact on the villus length, crypt depth, villus-to-crypt ratio and CD3⁺ T-lymphocytes area percentage. Challenged birds had a significant higher concentration of serum iohexol on both sampling days, as compared to the uninfected controls. A significant correlation could be found between the serum iohexol concentration and the histologic parameters (villus length, crypt depth and villus-to-crypt ratio) on the first sampling day. This suggests that iohexol may be used as a gut permeability marker in broilers under Eimeria challenge.