Easily misdiagnosed complex Klippel-Trenaunay syndrome: A case report

BACKGROUND Klippel-Trenaunay syndrome(KTS) is a congenital vascular malformation with a complicated etiology. It is sporadic and clinically rare in occurrence. The typical characteristics are capillary malformation(also known as port-wine stain),varicose veins and malformations, and bony and/or soft tissue hypertrophy with or without lymphatic malformation, which are known as the “classic clinical triad”. Herein, a rare case of KTS characterized by crossed-bilateral limb hypertrophy accompanied by intermittent hematochezia and hematuria is reported.CASE SUMMARY We described a 37-year-old female with KTS. She was admitted to our hospital owing to the gradual enlargement of the left lower extremity along with intermittent hematochezia and hematuria. The patient was diagnosed to have hemorrhoid bleeding by other hospitals and treated with conventional hemostatic drugs, but continued to have intermittent gastrointestinal bleeding and hematuria. Therefore, she visited our hospital to seek further treatment. During hospitalization, relevant imaging and laboratory examinations and colonoscopy were performed. In combination with the patient’s history and relevant examinations, we considered that the patient had a complex form of KTS. We recommended a combined diagnosis and treatment from the vascular, interventional,anorectal, and other departments, although she declined any further treatment for financial reasons.CONCLUSION The clinical manifestations of KTS are extensive and diverse and chiefly include the typical triad. However, Vascular malformations of KTS can also involve several parts and systems such as digestive and urogenital systems. Therefore, the atypical manifestations and rare complications necessitate the clinician’s attention and are not to be ignored.

Massive pulmonary embolism in Klippel-Trenaunay syndrome after leg raising:A case report

BACKGROUND Klippel-Trenaunay syndrome(KTS)is a rare congenital disorder characterized by a combination of capillary malformations,soft-tissue or bone hypertrophy,and varicose veins or venous malformations.The syndrome predisposes patients to hypercoagulable states,including venous thromboembolism and pulmonary embolism(PE).CASE SUMMARY A 12-year-old girl with KTS was scheduled excision of verrucous hyperkeratosis in the left foot and posterior aspect of the left leg and left thigh and excision of a cutaneous hemangioma in the right buttock.After induction,the surgeon elevated the patient’s leg for sterilization,whereupon she experienced a massive PE and refractory cardiac arrest.Extracorporeal membrane oxygenation(ECMO)was performed after prolonged resuscitation,and she had a return of spontaneous circulation.After this episode,the patient was discharged without any neurologic complications.CONCLUSION The mechanism of PE,a lethal disease,involves a preexisting deep vein thrombosis that is mechanically dislodged by compression or changing positions and travels to the pulmonary artery.Therefore,patients predisposed to PE should be prescribed prophylactic anticoagulants.If the patient has unstable vital signs,resuscitation should be started immediately,and extracorporeal cardiopulmonary resuscitation should be considered in settings with existing ECMO protocols,expertise,and equipment.Awareness of PE in patients with KTS while leg raising for sterilization is critical.

Klippel-Trenaunay syndrome with gastrointestinal bleeding,splenic hemangiomas and left inferior vena cava

Klippel-Trenaunay syndrome is a congenital vascular anomaly characterized by a triad of varicose veins,cutaneous capillary malformation,and hypertrophy of bone and(or)soft tissue.Gastrointestinal vascular malformations in Klippel-Trenaunay syndrome may present with gastrointestinal bleeding.The majority of patients with spleenic hemangiomatosis and/or left inferior vena cava are asymptomatic.We herein report a case admitted to the gastroenterology clinic with life-threatening hematochezia and symptomatic iron deficiency anemia.Due to the asymptomatic mild intermittent hematochezia,splenic hemangiomas and left inferior vena cava,the patient did not seek any help for gastrointestinal bleeding until his admittance to our department for evaluation of massive gastrointestinal bleeding.He was referred to angiography because of his serious pathogenetic condition and inefficiency of medical therapy.The method showed that hemostasis was successfully achieved in the hemorrhage site by embolism of corresponding vessels.Further endoscopy revealed vascular malformations starting from the stomach to the descending colon.On the other hand,computed tomography revealed splenic hemangiomas and left inferior vena cava.To the best of our knowledge,this is the first Klippel-Trenaunay syndrome case presenting with gastrointestinal bleeding,splenic hemangiomas and left inferior vena cava.The literature on the evaluation and management of this case is reviewed.

CT下肢静脉造影在Klippel-Trenaunay Syndrome诊断中的应用价值

目的探讨CT静脉造影(CTV)在Klippel-Trenaunay Syndrome(KTS)中的诊断价值。方法选取53例疑似KTS患者资料纳入分析,分别行超声和CTV检查,比较两种检查结果,使用к统计确定一致性水平。结果在53例患者中,50例(94%)两种检查结果一致。2例经超声诊断为血栓形成后综合征,CTV诊断为KTS,1例CTV诊断为KTS,而超声诊断为Klippel-Trenaunay-Weber综合征。关于KTS,CTV和超声检查之间的к一致性水平为0.878。结论CTV能准确而全方位地显示可疑KTS患者的静脉系统。

Prenatal ultrasonographic findings in Klippel-Trenaunay syndrome:A case report

BACKGROUND Klippel-Trenaunay syndrome(KTS)is a rare congenital disorder.A detailed prenatal ultrasound examination plays an important role in the diagnosis of KTS and the subsequent counseling and follow-up of the patient.CASE SUMMARY A 25-year-old woman attended our department for a regular examination.The whole of the right lower extremity and right buttock were observed to be markedly thicker compared to the left one at 18 wk of gestation.However,the lengths of the right femur,tibia and fibula were in the normal range.No marked edema and fluid/cystic spaces were detected in the lower limbs.There were no other organ abnormalities.The vasculature in the right limb was visibly dilated,with much higher intensive blood flow signals.No congenital embryonic veins were visible in both limbs.The right lower limb exhibited much more hypertrophy compared to the left limb two weeks later.Amniocentesis and genetic tests showed normal results with 46 XX.Despite the normal karyotype,the family opted to terminate the pregnancy.The post-mortem examination confirmed asymmetric hypertrophy of the right limb in the fetus and revealed a large area of marked dark-purple superficial capillary malformations occupying the skin of the right lower extremity.The enlargement of veins and soft tissue hypertrophy were also seen on postnatal X-ray and Magnetic Resonance Imaging.Autopsy revealed severe congestion in the right lower limb.A final diagnosis of KTS was made.CONCLUSION KTS may be diagnosed prenatally based on the typical features observed during ultrasound examination.

Pregnancy and Klippel-Trenaunay Syndrome—A Case Report

Klippel-Trenaunay Syndrome (KTS) is a rare triad of congenital vascular malformations involving extensive Port wine stains, soft tissue or bone hypertrophy and underlying venous and/or lymphatic malformation affecting limb, pelvicor abdominal organs. Pregnancy is known to exacerbate KTS complications and can put women at increased obstetrical risk due to deep venous thrombosis and other thromboembolic events. We report a case of a pregnant woman with KTS with the personal antecedent of two episodes of pulmonary thromboembolism.

Klippel-Trenaunay Syndrome: A Rare Cause of Vaginal Bleeding in the Prepubescent Girl

Klippel-Trénaunay syndrome (KTS) is an uncommon congenital disorder with unknown etiology that consists of mixed vascular malformations. Visceral organs may also be involved leading to a variety of manifestations. Although seemingly uncommon, genital tract involvement can occur and be a source of significant morbidity. We hereby describe a case of KTS of a 7-year-old female patient presenting with genital bleeding, large venous and capillary malformations and soft tissue hypertrophy of right limb. Patient was treated conservatively and asked to follow-up regularly. KTS should be kept on mind as a cause of vaginal bleeding in preteen girls especially those with suggestive clinical features. Management of this complex condition is challenging because of its progressive nature and wide range of disease severity.

Endovascular Treatment and Selective Image Guided Partial Resection of Epidural Spinal Vascular Malformation in Klippel-Trenaunay Syndrome: Case Report

Background: Klippel-Trenaunay-Weber syndrome is a rare congenital condition that may involve the central nervous system with extensive vascular malformations, and soft-tissue hypertrophy of the affected limb. Methods: A 51-year-old patient underwent previous procedures including decompressive laminectomy and endovascular embolization using Onyx and a self-expandable stent. However, recanalization of the malformation was observed, his symptoms progressed, and the decision was made to undergo selective surgical resection with intraoperative image guidance using Stealth system paired with the O-arm. Results: Adequate decompression of the affected spinal cord and cervical roots were obtained, and the patient’s symptoms improved. Conclusion: Since the typical anatomic landmarks were obliterated by the extensive vascular malformation and previous surgery, intraoperative image guidance proved to be very beneficial. This case reports on the usage of spinal navigation to efficiently dissect out the affected nerve roots and avoid vascular injury by referencing the Onyx and stent.

Klippel Trenaunay Syndrome with Angiokeratoma Circumscriptum Naeviforme and Bilateral Congenital Anorchia: A Rare Association

Klippel-Trenaunay syndrome (KTS) is not a common congenital vascular abnormality. A trio of capillary malformation, venous varicosities, and bony or soft-tissue hypertrophy define this syndrome. Significant morbidities associated with this illness include bleeding, deep vein thrombosis, and embolic consequences. Angiokeratoma circumscriptum naeviforme (ACN) is indeed a congenital variant of angiokeratoma that appears as a hyperkeratotic plaque on the lower extremity. Bilateral congenital anorchia (BCA) is the total lack of testicular tissue in a male with a normal phenotype and karyotype. KTS has been linked to ACN. Here we presented an 8-year-old male child who came with a swollen left thigh and the right side of his face with overlying blackish nodules on his left thigh and scrotum. The patient was diagnosed as KTS with angiokeratoma circumscriptum naeviforme and bilateral congenital anorchia based on his history, imaging studies and the typical clinical features of the disease.

Hepatocardiorenal syndrome in liver cirrhosis:Recognition of a new entity?

Emerging evidence and perspectives have pointed towards the heart playing an important role in hepatorenal syndrome(HRS),outside of conventional understanding that liver cirrhosis is traditionally considered the sole origin of a cascade of pathophysiological mechanisms directly affecting the kidneys in this context.In the absence of established heart disease,cirrhotic cardiomyopathy may occur more frequently in those with liver cirrhosis and kidney disease.It is a specific form of cardiac dysfunction characterized by blunted contractile responsiveness to stress stimuli and altered diastolic relaxation with electrophysiological abnormalities.Despite the clinical description of these potential cardiac-related complications of the liver,the role of the heart has traditionally been an overlooked aspect of circulatory dysfunction in HRS.Yet from a physiological sense,temporality(prior onset)of cardiorenal interactions in HRS and positive effects stemming from portosystemic shunting demonstrated an important role of the heart in the development and progression of kidney dysfunction in cirrhotic patients.In this review,we discuss current concepts surrounding how the heart may influence the development and progression of HRS,and the role of systemic inflammation and endothelial dysfunction causing circulatory dysfunction within this setting.The temporality of heart and kidney dysfunction in HRS will be discussed.For a subgroup of patients who receive portosystemic shunting,the dynamics of cardiorenal interactions following treatment is reviewed.Continued research to determine the unknowns in this topic is anticipated,hopefully to further clarify the intricacies surrounding the liver-heart-kidney connection and improve strategies for management.

Tricuspid mass-curious case of Li-Fraumeni syndrome: A case report

BACKGROUND Li-Fraumeni syndrome(LFS)is a rare autosomal dominant cancer-predisposing syndrome,which can manifest as a polymorphic spectrum of malignancies.LFS is associated with an early onset in life,with the majority of cases occurring prior to the age of 46.Notwithstanding the infrequency of primary cardiac tumors,it behooves clinicians to remain vigilant in considering the differential diagnosis of such tumors in LFS patients who present with a cardiac mass.This is due to the markedly elevated risk for malignancy in this particular population,far surpassing that of the general populace.CASE SUMMARY Herein,we present a case of a 30-year-old female with LFS who was found to have a tricuspid valve leaflet mass.CONCLUSION This case exemplifies valuable learning points in the diagnostic approach for this exceptionally rare patient population.

Protective mechanism of quercetin in alleviating sepsis-related acute respiratory distress syndrome based on network pharmacology and in vitro experiments

BACKGROUND:Sepsis-related acute respiratory distress syndrome(ARDS)has a high mortality rate,and no effective treatment is available currently.Quercetin is a natural plant product with many pharmacological activities,such as antioxidative,anti-apoptotic,and anti-inflammatory effects.This study aimed to elucidate the protective mechanism of quercetin against sepsis-related ARDS.METHODS:In this study,network pharmacology and in vitro experiments were used to investigate the underlying mechanisms of quercetin against sepsis-related ARDS.Core targets and signaling pathways of quercetin against sepsis-related ARDS were screened and were verified by in vitro experiments.RESULTS:A total of 4,230 targets of quercetin,360 disease targets of sepsis-related ARDS,and 211 intersection targets were obtained via database screening.Among the 211 intersection targets,interleukin-6(IL-6),tumor necrosis factor(TNF),albumin(ALB),AKT serine/threonine kinase 1(AKT1),and interleukin-1β(IL-1β)were identified as the core targets.A Gene Ontology(GO)enrichment analysis revealed 894 genes involved in the inflammatory response,apoptosis regulation,and response to hypoxia.Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analysis identified 106 pathways.After eliminating and generalizing,the hypoxia-inducible factor-1(HIF-1),TNF,nuclear factor-κB(NF-κB),and nucleotide-binding and oligomerization domain(NOD)-like receptor signaling pathways were identified.Molecular docking revealed that quercetin had good binding activity with the core targets.Moreover,quercetin blocked the HIF-1,TNF,NF-κB,and NODlike receptor signaling pathways in lipopolysaccharide(LPS)-induced murine alveolar macrophage(MH-S)cells.It also suppressed the inflammatory response,oxidative reactions,and cell apoptosis.CONCLUSION:Quercetin ameliorates sepsis-related ARDS by binding to its core targets and blocking the HIF-1,TNF,NF-κB,and NOD-like receptor signaling pathways to reduce inflammation,cell apoptosis,and oxidative stress.

Immunoglobulin G-mediated food intolerance and metabolic syndrome influence the occurrence of reflux esophagitis in Helicobacter pylori-infected patients

BACKGROUND Reflux esophagitis has an increasing prevalence and complex and diverse symptoms.Identifying its risk factors is crucial to understanding the etiology,prevention,and management of the disease.The occurrence of reflux esophagitis may be associated with food reactions,Helicobacter pylori(H.pylori)infection,and metabolic syndromes.AIM To investigate the risk factors for reflux esophagitis and analyze the effects of immunoglobulin(Ig)G-mediated food intolerance,H.pylori infection,and metabolic syndrome on reflux esophagitis.METHODS Outpatients attending the Second Medical Center of the PLA General Hospital between 2017 and 2021 were retrospectively enrolled.The patients’basic information,test results,gastroscopy results,H.pylori test results,and IgG-mediated food intolerance results were collected.Multivariate logistic regression analysis was used to analyze risk factors for reflux esophagitis.Statistical mediation analysis was used to evaluate the effects of IgG-mediated food intolerance and metabolic syndrome on H.pylori infection affecting reflux esophagitis.RESULTS A total of 7954 outpatients were included;the prevalence of reflux esophagitis,IgG-mediated food intolerance,H.pylori infection,and metabolic syndrome were 20.84%,61.77%,35.91%,and 60.15%,respectively.Multivariate analysis showed that the independent risk factors for reflux esophagitis included IgG-mediated food intolerance(OR=1.688,95%CI:1.497-1.903,P<0.00001)and metabolic syndrome(OR=1.165,95%CI:1.030-1.317,P=0.01484),and the independent protective factor for reflux esophagitis was H.pylori infection(OR=0.400,95%CI:0.351-0.456,P<0.00001).IgG-mediated food intolerance had a partially positive mediating effect on H.pylori infection as it was associated with reduced occurrence of reflux esophagitis(P=0.0200).Metabolic syndrome had a partially negative mediating effect on H.pylori infection and reduced the occurrence of reflux esophagitis(P=0.0220).CONCLUSION Patients with IgG-mediated food intolerance and metabolic syndrome were at higher risk of developing reflux esophagitis,while patients with H.pylori infection were at lower risk.IgG-mediated food intolerance reduced the risk of reflux esophagitis pathogenesis in patients with H.pylori infection;however,metabolic syndrome increased the risk of patients with H.pylori infection developing reflux esophagitis.

Body composition and metabolic syndrome in patients with type 1 diabetes

BACKGROUND In recent years,the prevalence of obesity and metabolic syndrome in type 1 diabetes(T1DM)patients has gradually increased.Insulin resistance in T1DM deserves attention.It is necessary to clarify the relationship between body composition,metabolic syndrome and insulin resistance in T1DM to guide clinical treatment and intervention.AIM To assess body composition(BC)in T1DM patients and evaluate the relationship between BC,metabolic syndrome(MS),and insulin resistance in these indi-viduals.METHODS A total of 101 subjects with T1DM,aged 10 years or older,and with a disease duration of over 1 year were included.Bioelectrical impedance analysis using the Tsinghua-Tongfang BC Analyzer BCA-1B was employed to measure various BC parameters.Clinical and laboratory data were collected,and insulin resistance was calculated using the estimated glucose disposal rate(eGDR).RESULTS MS was diagnosed in 16/101 patients(15.84%),overweight in 16/101 patients(15.84%),obesity in 4/101(3.96%),hypertension in 34/101(33.66%%)and dyslip-idemia in 16/101 patients(15.84%).Visceral fat index(VFI)and trunk fat mass were significantly and negatively correlated with eGDR(both P<0.001).Female patients exhibited higher body fat percentage and visceral fat ratio compared to male patients.Binary logistic regression analysis revealed that significant factors for MS included eGDR[P=0.017,odds ratio(OR)=0.109],VFI(P=0.030,OR=3.529),and a family history of diabetes(P=0.004,OR=0.228).Significant factors for hypertension included eGDR(P<0.001,OR=0.488)and skeletal muscle mass(P=0.003,OR=1.111).Significant factors for dyslipidemia included trunk fat mass(P=0.033,OR=1.202)and eGDR(P=0.037,OR=0.708).CONCLUSION Visceral fat was found to be a superior predictor of MS compared to conventional measures such as body mass index and waist-to-hip ratio in Chinese individuals with T1DM.BC analysis,specifically identifying visceral fat(trunk fat),may play an important role in identifying the increased risk of MS in non-obese patients with T1DM.

Incidence and risk factors of depression in patients with metabolic syndrome

BACKGROUND Many studies have explored the relationship between depression and metabolic syndrome(MetS),especially in older people.China has entered an aging society.However,there are still few studies on the elderly in Chinese communities.AIM To investigate the incidence and risk factors of depression in MetS patients in China's Mainland and to construct a predictive model.METHODS Data from four waves of the China Health and Retirement Longitudinal Study were selected,and middle-aged and elderly patients with MetS(n=2533)were included based on the first wave.According to the center for epidemiological survey-depression scale(CESD),participants with MetS were divided into depression(n=938)and non-depression groups(n=1595),and factors related to depression were screened out.Subsequently,the 2-,4-,and 7-year follow-up data were analyzed,and a prediction model for depression in MetS patients was constructed.RESULTS The prevalence of depression in middle-aged and elderly patients with MetS was 37.02%.The prevalence of depression at the 2-,4-,and 7-year follow-up was 29.55%,34.53%,and 38.15%,respectively.The prediction model,constructed using baseline CESD and Physical Self-Maintenance Scale scores,average sleep duration,number of chronic diseases,age,and weight had a good predictive effect on the risk of depression in MetS patients at the 2-year follow-up(area under the curve=0.775,95%confidence interval:0.750-0.800,P<0.001),with a sensitivity of 68%and a specificity of 74%.CONCLUSION The prevalence of depression in middle-aged and elderly patients with MetS has increased over time.The early identification of and intervention for depressive symptoms requires greater attention in MetS patients.

Immune cell signatures and causal association with irritable bowel syndrome:A mendelian randomization study

BACKGROUND The mucosal barrier's immune-brain interactions,pivotal for neural development and function,are increasingly recognized for their potential causal and therapeutic relevance to irritable bowel syndrome(IBS).Prior studies linking immune inflammation with IBS have been inconsistent.To further elucidate this relationship,we conducted a Mendelian randomization(MR)analysis of 731 immune cell markers to dissect the influence of various immune phenotypes on IBS.Our goal was to deepen our understanding of the disrupted brain-gut axis in IBS and to identify novel therapeutic targets.AIM To leverage publicly available data to perform MR analysis on 731 immune cell markers and explore their impact on IBS.We aimed to uncover immunophenotypic associations with IBS that could inform future drug development and therapeutic strategies.METHODS We performed a comprehensive two-sample MR analysis to evaluate the causal relationship between immune cell markers and IBS.By utilizing genetic data from public databases,we examined the causal associations between 731 immune cell markers,encompassing median fluorescence intensity,relative cell abundance,absolute cell count,and morphological parameters,with IBS susceptibility.Sensitivity analyses were conducted to validate our findings and address potential heterogeneity and pleiotropy.RESULTS Bidirectional false discovery rate correction indicated no significant influence of IBS on immunophenotypes.However,our analysis revealed a causal impact of IBS on 30 out of 731 immune phenotypes(P<0.05).Nine immune phenotypes demonstrated a protective effect against IBS[inverse variance weighting(IVW)<0.05,odd ratio(OR)<1],while 21 others were associated with an increased risk of IBS onset(IVW≥0.05,OR≥1).CONCLUSION Our findings underscore a substantial genetic correlation between immune cell phenotypes and IBS,providing valuable insights into the pathophysiology of the condition.These results pave the way for the development of more precise biomarkers and targeted therapies for IBS.Furthermore,this research enriches our comprehension of immune cell roles in IBS pathogenesis,offering a foundation for more effective,personalized treatment approaches.These advancements hold promise for improving IBS patient quality of life and reducing the disease burden on individuals and their families.

Causal role of immune cells in obstructive sleep apnea hypopnea syndrome:Mendelian randomization study

BACKGROUND Despite being one of the most prevalent sleep disorders,obstructive sleep apnea hypoventilation syndrome(OSAHS)has limited information on its immunologic foundation.The immunological underpinnings of certain major psychiatric diseases have been uncovered in recent years thanks to the extensive use of genome-wide association studies(GWAS)and genotyping techniques using highdensity genetic markers(e.g.,SNP or CNVs).But this tactic hasn't yet been applied to OSAHS.Using a Mendelian randomization analysis,we analyzed the causal link between immune cells and the illness in order to comprehend the immunological bases of OSAHS.AIM To investigate the immune cells'association with OSAHS via genetic methods,guiding future clinical research.METHODS A comprehensive two-sample mendelian randomization study was conducted to investigate the causal relationship between immune cell characteristics and OSAHS.Summary statistics for each immune cell feature were obtained from the GWAS catalog.Information on 731 immune cell properties,such as morphologic parameters,median fluorescence intensity,absolute cellular,and relative cellular,was compiled using publicly available genetic databases.The results'robustness,heterogeneity,and horizontal pleiotropy were confirmed using extensive sensitivity examination.RESULTS Following false discovery rate(FDR)correction,no statistically significant effect of OSAHS on immunophenotypes was observed.However,two lymphocyte subsets were found to have a significant association with the risk of OSAHS:Basophil%CD33dim HLA DR-CD66b-(OR=1.03,95%CI=1.01-1.03,P<0.001);CD38 on IgD+CD24-B cell(OR=1.04,95%CI=1.02-1.04,P=0.019).CONCLUSION This study shows a strong link between immune cells and OSAHS through a gene approach,thus offering direction for potential future medical research.

Metabolic syndrome’s new therapy:Supplement the gut microbiome

This letter to the editor discusses the publication on gut microbiome supple-mentation as therapy for metabolic syndrome.Gut microbiome dysbiosis disrupts intestinal bacterial homeostasis and is related to chronic inflammation,insulin resistance,cardiovascular diseases,type 2 diabetes mellitus,and obesity.Previous research has found that increasing the abundance of beneficial microbiota in the gut modulates metabolic syndrome by reducing chronic inflammation and insulin resistance.Prebiotics,probiotics,synbiotics,and postbiotics are often used as supplements to increase the number of beneficial microbes and thus the produc-tion of short-chain fatty acids,which have positive effects on the gut microbiome and metabolic syndrome.In this review article,the author summarizes the available supplements to increase the abundance of beneficial gut microbiota and reduce the abundance of harmful microbiota in patients with metabolic disorders.Our group is also researching the role of the gut microbiota in chronic liver disease.This article will be of great help to our research.At the end of the letter,the mechanism of the gut microbiota in chronic liver disease is discussed.

Chitin-glucan improves important pathophysiological features of irritable bowel syndrome

BACKGROUND Irritable bowel syndrome(IBS)is one of the most frequent and debilitating conditions leading to gastroenterological referrals.However,recommended treatments remain limited,yielding only limited therapeutic gains.Chitin-glucan(CG)is a novel dietary prebiotic classically used in humans at a dosage of 1.5-3.0 g/d and is considered a safe food ingredient by the European Food Safety Authority.To provide an alternative approach to managing patients with IBS,we performed preclinical molecular,cellular,and animal studies to evaluate the role of chitin-glucan in the main pathophysiological mechanisms involved in IBS.AIM To evaluate the roles of CG in visceral analgesia,intestinal inflammation,barrier function,and to develop computational molecular models.METHODS Visceral pain was recorded through colorectal distension(CRD)in a model of long-lasting colon hypersensitivity induced by an intra-rectal administration of TNBS[15 milligrams(mg)/kilogram(kg)]in 33 Sprague-Dawley rats.Intracolonic pressure was regularly assessed during the 9 wk-experiment(weeks 0,3,5,and 7)in animals receiving CG(n=14)at a human equivalent dose(HED)of 1.5 g/d or 3.0 g/d and compared to negative control(tap water,n=11)and positive control(phloroglucinol at 1.5 g/d HED,n=8)groups.The anti-inflammatory effect of CG was evaluated using clinical and histological scores in 30 C57bl6 male mice with colitis induced by dextran sodium sulfate(DSS)administered in their drinking water during 14 d.HT-29 cells under basal conditions and after stimulation with lipopolysaccharide(LPS)were treated with CG to evaluate changes in pathways related to analgesia μ-opioid receptor(MOR),cannabinoid receptor 2(CB2),peroxisome proliferator-activated receptor alpha,inflammation[interleukin(IL)-10,IL-1b,and IL-8]and barrier function[mucin 2-5AC,claudin-2,zonula occludens(ZO)-1,ZO-2]using the real-time PCR method.Molecular modelling of CG,LPS,lipoteichoic acid(LTA),and phospholipomannan(PLM)was developed,and the ability of CG to chelate microbial pathogenic lipids was evaluated by docking and molecular dynamics simulations.Data were expressed as the mean±SEM.RESULTS Daily CG orally-administered to rats or mice was well tolerated without including diarrhea,visceral hypersensitivity,or inflammation,as evaluated at histological and molecular levels.In a model of CRD,CG at a dosage of 3 g/d HED significantly decreased visceral pain perception by 14%after 2 wk of administration(P<0.01)and reduced inflammation intensity by 50%,resulting in complete regeneration of the colonic mucosa in mice with DSS-induced colitis.To better reproduce the characteristics of visceral pain in patients with IBS,we then measured the therapeutic impact of CG in rats with TNBS-induced inflammation to long-lasting visceral hypersensitivity.CG at a dosage of 1.5 g/d HED decreased visceral pain perception by 20%five weeks after colitis induction(P<0.01).When the CG dosage was increased to 3.0 g/d HED,this analgesic effect surpassed that of the spasmolytic agent phloroglucinol,manifesting more rapidly within 3 wk and leading to a 50%inhibition of pain perception(P<0.0001).The underlying molecular mechanisms contributing to these analgesic and anti-inflammatory effects of CG involved,at least in part,a significant induction of MOR,CB2 receptor,and IL-10,as well as a significant decrease in pro-inflammatory cytokines IL-1b and IL-8.CG also significantly upregulated barrier-related genes including muc5AC,claudin-2,and ZO-2.Molecular modelling of CG revealed a new property of the molecule as a chelator of microbial pathogenic lipids,sequestering gram-negative LPS and gram-positive LTA bacterial toxins,as well as PLM in fungi at the lowesr energy conformations.CONCLUSION CG decreased visceral perception and intestinal inflammation through master gene regulation and direct binding of microbial products,suggesting that CG may constitute a new therapeutic strategy for patients with IBS or IBSlike symptoms.