Structural Remodeling of the Human Colonic Mesenchyme in Inflammatory Bowel Disease.

Intestinal mesenchymal cells play essential roles in epithelial homeostasis, matrix remodeling, immunity, and inflammation. But the extent of heterogeneity within the colonic mesenchyme in these processes remains unknown. Using unbiased single-cell profiling of over 16,500 colonic mesenchymal cells, we reveal four subsets of fibroblasts expressing divergent transcriptional regulators and functional pathways, in addition to pericytes and myofibroblasts. We identified a niche population located in proximity to epithelial crypts expressing SOX6, F3 (CD142), and WNT genes essential for colonic epithelial stem cell function. In colitis, we observed dysregulation of this niche and emergence of an activated mesenchymal population. This subset expressed TNF superfamily member 14 (TNFSF14), fibroblastic reticular cell-associated genes, IL-33, and Lysyl oxidases. Further, it induced factors that impaired epithelial proliferation and maturation and contributed to oxidative stress and disease severity in vivo. Our work defines how the colonic mesenchyme remodels to fuel inflammation and barrier dysfunction in IBD.

Cytokine Networks in the Pathophysiology of Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract. Cytokine-targeted therapies have transformed the treatment of IBD, providing control of symptoms and longer relapse-free periods. However, many patients fail to respond, highlighting the need for therapies tailored to the underlying cell and molecular disease drivers. Here we discuss the progression of IBD from the perspective of remodeling of cytokine networks. We place well-established and under-studied cytokine modules in the context of cellular interactions, their dynamic regulation in early and late stages of disease (i.e., fibrosis), and their current and potential use in the clinic. Examining how particular cytokine networks drive distinct features and phases of IBD will shed light on the etiology of IBD and provide a basis for more effective treatments.

Ocular endothelial dysfunction in pediatric inflammatory bowel disease.

OBJECTIVES: To assess ocular microvasculature changes using optical coherence tomography angiography (OCTA) in pediatric patients with inflammatory bowel disease (IBD). METHODS: Patients (aged 6-18 years) with IBD were recruited between September 2021 and May 2023. All eligible participants underwent comprehensive clinical assessment and laboratory investigation. Patients with functional gastrointestinal disorders served as the controls. This study assessed specific IBD phenotypes, disease duration, clinical and endoscopic activity indices, laboratory markers, and medication histories. OCTA was utilized to evaluate ocular microvasculature changes in both groups. RESULTS: A total of 63 children (mean age 12.9 ± 3.3 years) were enrolled, comprising 38 in the IBD group (16 ulcerative colitis, 22 Crohn's disease, and 25 in the control group). Most patients in the IBD group were in remission or had mild-to-moderate disease activity at enrollment. Analysis of the OCTA results revealed significant differences in the choroidal luminal area and total choroidal area between the IBD and control groups. CONCLUSIONS: The study identified distinct ocular microvasculature changes in pediatric IBD patients through OCTA, suggestive of potential systemic endothelial dysfunction. These findings underscore the utility of OCTA in evaluating microvascular alterations associated with pediatric IBD, offering insights into potential systemic complications linked to inflammation in IBD patients.

Evaluation of QRS duration and presence of fragmented QRS in patients with inflammatory bowel disease.

Background: Inflammatory Bowel Disease (IBD) is mostly characterized by gastrointestinal tract involvement, however can also be accompanied with cardiac manifestations. QRS prolongation and the presence of QRS fragmentation (fQRS) have been previously evaluated in many chronic inflammatory diseases, as an independent predictor of cardiac events. In this study, we aimed to evaluate the QRS duration and fQRS in patients with IBD. Methods: The presented study was designed as a single-center retrospective cohort study. The study population consisted of 217 patients with IBD and 195 healthy controls. QRS duration and presence of fQRS were evaluated using a 12-lead electrocardiogram. These parameters were compared between groups. Results: QRS duration was demonstrated to be higher in the IBD group compared to the control group (92 (86-98) vs. 82 (75-90), p<0.001). The presence of fQRS was significantly higher in the IBD group (n=101 (47%) vs n=59 (30%), p=0.006). In addition, a positive correlation was demonstrated between QRS duration and disease duration (Spearman's Rho= 0.4, p<0.001). Notably, disease and QRS duration were significantly higher in the fQRS (+) group (102 (56.5-154) vs. 55 (24.3-118.3), <0.001; 94 (86-100) vs. 92 (84-96), 0.016; respectively). Conclusion: Our results demonstrated that QRS prolongation and the presence of fQRS (+) were more common in IBD patients, and associated with longer disease duration. These findings may indicate subclinical cardiac involvement in IBD. Therefore, IBD patients, especially those with long-standing disease, should be followed more closely in terms of cardiac manifestations.

Acetylcholine ameliorates colitis by promoting IL-10 secretion of monocytic myeloid-derived suppressor cells through the nAChR/ERK pathway.

The alteration of the enteric nervous system (ENS) and its role in neuroimmune modulation remain obscure in the pathogenesis of inflammatory bowel diseases (IBDs). Here, by using the xCell tool and the latest immunolabeling-enabled three-dimensional (3D) imaging of solvent-cleared organs technique, we found severe pathological damage of the entire ENS and decreased expression of choline acetyltransferase (ChAT) in IBD patients. As a result, acetylcholine (ACh), a major neurotransmitter of the nervous system synthesized by ChAT, was greatly reduced in colon tissues of both IBD patients and colitis mice. Importantly, administration of ACh via enema remarkably ameliorated colitis, which was proved to be directly dependent on monocytic myeloid-derived suppressor cells (M-MDSCs). Furthermore, ACh was demonstrated to promote interleukin-10 secretion of M-MDSCs and suppress the inflammation through activating the nAChR/ERK pathway. The present data reveal that the cholinergic signaling pathway in the ENS is impaired during colitis and uncover an ACh-MDSCs neuroimmune regulatory pathway, which may offer promising therapeutic strategies for IBDs.

Exploring Electrical Neuromodulation as an Alternative Therapeutic Approach in Inflammatory Bowel Diseases.

Background and Objectives: This review systematically evaluates the potential of electrical neuromodulation techniques-vagus nerve stimulation (VNS), sacral nerve stimulation (SNS), and tibial nerve stimulation (TNS)-as alternative treatments for inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's Disease (CD). It aims to synthesize current evidence on the efficacy and safety of these modalities, addressing the significant burden of IBD on patient quality of life and the limitations of existing pharmacological therapies. Materials and Methods: We conducted a comprehensive analysis of studies from PubMed, focusing on research published between 1978 and 2024. The review included animal models and clinical trials investigating the mechanisms, effectiveness, and safety of VNS, SNS, and TNS in IBD management. Special attention was given to the modulation of inflammatory responses and its impact on gastrointestinal motility and functional gastrointestinal disorders associated with IBD. Results: Preliminary findings suggest that VNS, SNS, and TNS can significantly reduce inflammatory markers and improve symptoms in IBD patients. These techniques also show potential in treating related gastrointestinal disorders during IBD remission phases. However, the specific mechanisms underlying these benefits remain to be fully elucidated, and there is considerable variability in treatment parameters. Conclusions: Electrical neuromodulation holds promise as a novel therapeutic avenue for IBD, offering an alternative to patients who do not respond to traditional treatments or experience adverse effects. The review highlights the need for further rigorous studies to optimize stimulation parameters, understand long-term outcomes, and integrate neuromodulation effectively into IBD treatment protocols.

High Perceived Stress is Associated With Increased Risk of Ulcerative Colitis Clinical Flares.

BACKGROUND & AIMS: Although perceived stress (PS) has been associated with symptomatic flares in inflammatory bowel disease, clinical and physiological measures associated with perceived stress and flare are not known. The aim of this study was to identify physiological factors associated with perceived stress in ulcerative colitis (UC) subjects, and their relationship with flare. METHODS: Patients with UC in clinical remission (Simple Colitis Clinical Activity Index [SCCAI] score <5) underwent clinical and behavioral assessments, morning salivary cortisol measurements, autonomic nervous system activity testing (heart rate variability, electrodermal activity) at baseline with patient-reported SCCAI every 2 weeks over 1 to 2 years and fecal calprotectin at time of flare. Clinical flares (SCCAI ≥5) and biochemical flares (SCCAI ≥5 with fecal calprotectin ≥250 µg/g) were evaluated. RESULTS: One hundred ten patients with UC were enrolled, with mean follow-up of 65.6 weeks. Patients with UC with higher and lower PS were determined. Although the high PS group had 3.6 times higher odds of a clinical flare than the low PS group, no significant differences in biochemical flares were observed between the low and high PS groups. The high vs low PS group differed in tonic sympathetic arousal as indexed by significantly greater baseline electrodermal activity (4.3 vs 3.4 microsiemens; P = .026) in the high PS group, but not in terms of heart rate variability and morning cortisol levels. Increased fecal calprotectin was associated with cardioautonomic measures, suggesting lower parasympathetic activity. CONCLUSIONS: Increased PS assessed at baseline is associated with tonic sympathetic arousal and greater odds of clinical flares in patients with UC.

Neuroinflammation as an etiological trigger for depression comorbid with inflammatory bowel disease.

Patients with inflammatory bowel disease (IBD) suffer from depression at higher rates than the general population. An etiological trigger of depressive symptoms is theorised to be inflammation within the central nervous system. It is believed that heightened intestinal inflammation and dysfunction of the enteric nervous system (ENS) contribute to impaired intestinal permeability, which facilitates the translocation of intestinal enterotoxins into the blood circulation. Consequently, these may compromise the immunological and physiological functioning of distant non-intestinal tissues such as the brain. In vivo models of colitis provide evidence of increased blood-brain barrier permeability and enhanced central nervous system (CNS) immune activity triggered by intestinal enterotoxins and blood-borne inflammatory mediators. Understanding the immunological, physiological, and structural changes associated with IBD and neuroinflammation may aid in the development of more tailored and suitable pharmaceutical treatment for IBD-associated depression.

A Multicenter Study of Patient Acceptability of the IBD Disk Tool and Patient-Reported Disabilities.

BACKGROUND: IBD, both Crohn's disease and ulcerative colitis, is associated with significant functional disability. Gastrointestinal symptoms alone are not the sole purpose of the interaction between patients and providers. In order to ascertain patients' disabilities, we utilized the recently developed IBD Disk to help determine their functional concerns and initiate relevant conversation. We aimed to ascertain patient acceptability and their major disabilities. PATIENTS AND METHODS: In this multicenter study, IBD patients at their outpatient visit were given the paper version of the IBD Disk. Patients were asked to score their level of disability for each item of the IBD Disk. The completed scores were then shared with their healthcare provider to act as a focus of discussion during the consultation. Patients and clinicians were also asked to provide informal qualitative feedback as to the benefits of the IBD Disk and areas for improvement. RESULTS: A total of 377 (female 60%) patients completed the questionnaires over the study period. Patient acceptability scored on a 0-10 Likert scale was excellent. All patients scored all domains of disability. Sleep, energy, and joint pain were the highest scoring domains of the IBD Disk, scoring higher than digestive symptoms. Clinicians and patients agreed that the IBD Disk allowed for ease of communication about disability symptoms and relevance to their day-to-day functioning. CONCLUSION: The IBD Disk is a novel easy-to-use tool to assess the functional disability of patients. We next plan to utilize it in the form of an electronic app internationally and in relation to treatment commencement and escalation.

Mucosal Integrity Testing Can Detect Differences in the Rectums of Patients with Inflammatory Bowel Disease Compared to Controls: A Pilot Study.

BACKGROUND: While the pathogenesis of inflammatory bowel disease (IBD) is incompletely understood, disruption of epithelial integrity is suspected to play a prominent role in disease initiation and progression. Currently, there is no convenient way to measure this in vivo. AIMS: Our aim is to determine whether a mucosal integrity (MI) testing device that has been used to measure MI in the esophagus can also be used to measure barrier function in the colon during colonoscopy. METHODS: Mucosal integrity testing was measured in patients with IBD (n = 17) and controls (n = 7) during colonoscopy. During the procedure, an MI catheter was passed down the working channel of the colonoscope and placed along the mucosal wall to measure MI in the rectum, left, transverse, and right colon. In patients with IBD, MI measurements and biopsies were taken in areas which appeared inflamed when present. We then determined if there was a significant difference in MI between patients with IBD and controls. RESULTS: MI was significantly higher in the rectum of patients with IBD (CD and UC combined) versus control colons [767 (618-991) vs. 531 (418-604) ohms, P < 0.01]. There were no significant differences in MI among patients with IBD versus controls in the right, transverse, or left colon. Within the IBD group, there were no significant differences in MI between inflamed versus non-inflamed rectums. There was no correlation between quality of life scores or endoscopic severity with MI, though this study was likely underpowered to detect these differences. CONCLUSION: Rectal MI is significantly higher in patients with IBD versus controls. Future studies are needed to determine how this information can be used clinically.

Inflammatory Bowel Disease Patients Who Respond to Treatment with Anti-tumor Necrosis Factor Agents Demonstrate Improvement in Pre-treatment Frailty.

BACKGROUND: Frailty may be a risk factor for complications in inflammatory bowel diseases (IBD) patients. We examined the impact of treatment on IBD patients who were frail prior to treatment and identified predictors of post-treatment change in frailty. METHODS: In an electronic health record-based cohort of IBD patients initiating anti-tumor necrosis factor (TNF)-α agents, we applied a validated claims-based frailty index to determine frailty in the 1 year prior to and after treatment initiation. We characterized treatment non-response using a composite outcome of IBD-related hospitalization, surgery, change in therapy, or initiation of systemic steroids. We constructed multivariable logistic regression models to identify determinants of post-treatment frailty. RESULTS: The 1210 patients initiating anti-TNF therapy had a median age of 30 years; 20% were ≥ 50 years. In the first year after anti-TNF initiation, 40% were non-responders. Many more treatment non-responders were frail in the year following treatment compared with treatment responders (27% vs 7%, p < 0.001). Pre-treatment frailty (OR 2.01, 95% CI 1.35-3.00) and prior IBD-related hospitalization (OR 1.63, 95% CI 1.15-2.30) were independently predictive of higher likelihood of post-treatment frailty. Therapy response was associated with a lower likelihood (OR 0.24, 95% CI 0.16-0.34) of post-treatment frailty. Nearly 85% of patients who were frail prior to treatment demonstrated improvement in frailty following treatment CONCLUSIONS: Response to anti-TNF therapy is an important determinant of post-treatment frailty in patients with IBD. Our findings suggest that effectively treating inflammatory states in older patients with IBD may improve frailty.

Irritable bowel syndrome in inflammatory bowel disease. Synergy in alterations of the gut-brain axis? / Síndrome de intestino irritable en la enfermedad inflamatoria intestinal. ¿Sinergia en las alteraciones del eje cerebro-intestino?

The presence of digestive symptoms associated with irritable bowel syndrome (IBS) in patients with inflammatory bowel disease (IBD) in remission is a topic of growing interest. Although there is heterogeneity in clinical studies regarding the use of IBD remission criteria and the diagnosis of IBS, the available data indicate that the IBD-IBS overlap would affect up to one third of patients in remission, and they agree on the finding of a negative impact on the mental health and quality of life of the individuals who suffer from it. The pathophysiological bases that would explain this potential overlap are not completely elucidated; however, an alteration in the gut-brain axis associated with an increase in intestinal permeability, neuroimmune activation and dysbiosis would be common to both conditions. The hypothesis of a new clinical entity or syndrome of "Irritable Inflammatory Bowel Disease" or "Post-inflammatory IBS" is the subject of intense investigation. The clinical approach is based on certifying the remission of IBD activity and ruling out other non-inflammatory causes of potentially treatable persistent functional digestive symptoms. In the case of symptoms associated with IBS and in the absence of sufficient evidence, comprehensive and personalized management of the clinical picture (dietary, pharmacological and psychotherapeutic measures) should be carried out, similar to a genuine IBS.

Inflammatory bowel disease and Parkinson's disease: common pathophysiological links.

Inflammatory bowel disease and Parkinson's disease are chronic progressive disorders that mainly affect different organs: the gut and brain, respectively. Accumulating evidence has suggested a bidirectional link between gastrointestinal inflammation and neurodegeneration, in accordance with the concept of the 'gut-brain axis'. Moreover, recent population-based studies have shown that inflammatory bowel disease might increase the risk of Parkinson's disease. Although the precise mechanisms underlying gut-brain interactions remain elusive, some of the latest findings have begun to explain the link. Several genetic loci are shared between both disorders with a similar direction of effect on the risk of both diseases. The most interesting example is LRRK2 (leucine-rich repeat kinase 2), initially identified as a causal gene in Parkinson's disease, and recently also implicated in Crohn's disease. In this review, we highlight recent findings on the link between these seemingly unrelated diseases with shared genetic susceptibility. We discuss supporting and conflicting data obtained from epidemiological and genetic studies along with remaining questions and concerns. In addition, we discuss possible biological links including the gut-brain axis, microbiota, autoimmunity, mitochondrial function and autophagy.

Role of perivascular nerve and sensory neurotransmitter dysfunction in inflammatory bowel disease.

Inflammatory bowel disease (IBD) is associated with both impaired intestinal blood flow and increased risk of cardiovascular disease, but the functional role of perivascular nerves that control vasomotor function of mesenteric arteries (MAs) perfusing the intestine during IBD is unknown. Because perivascular sensory nerves and their transmitters calcitonin gene-related peptide (CGRP) and substance P (SP) are important mediators of both vasodilation and inflammatory responses, our objective was to identify IBD-related deficits in perivascular sensory nerve function and vascular neurotransmitter signaling. In MAs from an interleukin-10 knockout (IL-10-/-) mouse model, IBD significantly impairs electrical field stimulation (EFS)-mediated sensory vasodilation and inhibition of sympathetic vasoconstriction, despite decreased sympathetic nerve density and vasoconstriction. The MA content and EFS-mediated release of both CGRP and SP are decreased with IBD, but IBD has unique effects on each transmitter. CGRP nerve density, receptor expression, hyperpolarization, and vasodilation are preserved with IBD. In contrast, SP nerve density and receptor expression are increased, and SP hyperpolarization and vasodilation are impaired with IBD. A key finding is that blockade of SP receptors restores EFS-mediated sensory vasodilation and enhanced CGRP-mediated vasodilation in MAs from IBD but not Control mice. Together, these data suggest that an aberrant role for the perivascular sensory neurotransmitter SP and its downstream signaling in MAs underlies vascular dysfunction with IBD. We propose that with IBD, SP signaling impedes CGRP-mediated sensory vasodilation, contributing to impaired blood flow. Thus, substance P and NK1 receptors may represent an important target for treating vascular dysfunction in IBD.NEW & NOTEWORTHY Our study is the first to show that IBD causes profound impairment of sensory vasodilation and inhibition of sympathetic vasoconstriction in mesenteric arteries. This occurs alongside decreased SP-containing nerve density and increased expression of NK1 receptors for SP. In contrast, CGRP dilation, nerve density, and receptor expression are unchanged. Blocking NK1 receptors restores sensory vasodilation in MAs and increases CGRP-mediated vasodilation, indicating that SP interference with CGRP signaling may underlie impaired sensory vasodilation with IBD.

Tryptophan-kynurenine metabolism: a link between the gut and brain for depression in inflammatory bowel disease.

Inflammatory bowel disease (IBD), which mainly includes ulcerative colitis (UC) and Crohn's disease (CD), is a group of chronic bowel diseases that are characterized by abdominal pain, diarrhea, and bloody stools. IBD is strongly associated with depression, and its patients have a higher incidence of depression than the general population. Depression also adversely affects the quality of life and disease prognosis of patients with IBD. The tryptophan-kynurenine metabolic pathway degrades more than 90% of tryptophan (TRP) throughout the body, with indoleamine 2,3-dioxygenase (IDO), the key metabolic enzyme, being activated in the inflammatory environment. A series of metabolites of the pathway are neurologically active, among which kynerunic acid (KYNA) and quinolinic acid (QUIN) are molecules of great interest in recent studies on the mechanisms of inflammation-induced depression. In this review, the relationship between depression in IBD and the tryptophan-kynurenine metabolic pathway is overviewed in the light of recent publications.

Daily physical activity patterns in children and adolescents with inflammatory bowel disease.

BACKGROUND: The aim of this study was to assess PA patterns among children and adolescents with inflammatory bowel disease (IBD). METHODS: Sixty participants with IBD (42 Crohn's disease [CD], 10 ulcerative colitis [UC], and 8 IBD-unclassified [IBD-U], 30 male patients) in remission (n = 45) or with mild disease (n = 15) were compared with 60 healthy age- and sex-matched controls. Each participant wore a triaxial accelerometer during 4 consecutive days for objective daily PA quantification. RESULTS: Overall, there was no significant difference in daily PA patterns between patients with IBD and healthy controls, with 31.7% of patients with IBD and 38.3% of healthy controls fulfilling the recommendation of 60 min of moderate-to-vigorous physical activity (MVPA) daily (NS). Male patients with IBD spent significantly less time in MVPA compared with matched healthy controls (mean difference, 16.2 min day-1; p < 0.05). No difference was observed for female patients with IBD. No difference in sedentary pattern between male patients with IBD and controls was found. CONCLUSIONS: Children and adolescents with inactive or mildly active IBD have similar PA patterns compared with healthy controls, except for male patients who have reduced moderate-to-vigorous PA. By far, most patients with IBD do not fulfill the MVPA recommendations for health benefits. IMPACT: There is few data on PA patterns in pediatric patients with IBD. Methodological issues to assess PA limit the strengths of these studies. Pediatric IBD patients with inactive or mildly active IBD have similar physical activity patterns compared with healthy controls, except for male patients who have reduced moderate-to-vigorous PA. Most patients with IBD do not fulfill the MVPA recommendations for health benefits.

Factors Associated with Inflammatory Bowel Disease Flare During Pregnancy Among Women with Preconception Remission.

BACKGROUND: The factors associated with inflammatory bowel diseases (IBD) relapse throughout gestation in those with preconception remission remain unknown. AIMS: We aimed to investigate disease and pregnancy course among IBD women with quiescent disease at conception. METHODS: Women with IBD attending a multidisciplinary clinic for preconception, antenatal and postnatal treatment were prospectively recruited during 2011-2018. RESULTS: Overall, 298 women with IBD with quiescent disease at the time of conception constituted the study cohort. Of these, 112 (37.6%) women experienced disease flare during pregnancy. The risk of disease relapse was higher in those with ulcerative colitis (UC) as compared to those with Crohn's disease (CD) (48.1% vs. 31.8%, P = 0.005). The proportion of women with prior IBD-related gastrointestinal surgery was lower in those who experienced disease flare up (13.4% vs. 26.3%, P = 0.009). The use of biologic therapy at the time of conception was associated with lower rates of disease relapse (25.0% vs. 43.9%, P = 0.001). In multivariate analysis, use of conventional medications or no treatment (aOR [95% CI]: 2.0 (1.12, 3.57), P = 0.02) and lack of prior history of IBD-related surgery (aOR [95% CI]: 3.13 (1.37, 7.14), P = 0.007) were independently positively associated with disease relapse. Rates of hospitalization during pregnancy (21.4% vs. 2.2%, P < 0.001) and preterm delivery (22.3% vs. 9.1%, P = 0.002) were higher, and birthweight was lower (median 2987 vs. 3153 grams, P = 0.05) in those with disease flare as compared to those who maintained remission. CONCLUSION: Prior IBD-related surgery and biologic therapy were found as independent protective factors against relapse during pregnancy among women with quiescent disease at conception.

LncRNA: A Potential Research Direction in Intestinal Barrier Function.

Long non-coding RNAs (lncRNAs) are transcripts longer than 200 nucleotides and play important roles in a variety of diseases. LncRNAs are involved in many biologic processes including cell differentiation, development, and apoptosis. The intestinal barrier is considered one of the most important protective barriers in humans. Severe damage or dysfunction of the intestinal barrier may be associated with the occurrence and development of many diseases, such as inflammatory bowel disease and ulcerative colitis. LncRNAs have been found to be associated with intestinal barrier function in some studies, which are at an early stage. In this review, we introduce the roles of LncRNAs in the intestinal barrier and investigate the possibility of lncRNAs as a research field in the intestinal barrier.

Sleep Characteristics and Rest-Activity Rhythms Are Associated with Gastrointestinal Symptoms Among Adults with Inflammatory Bowel Disease.

BACKGROUND: Sleep disturbance is common in inflammatory bowel disease (IBD) and is associated with poorer quality of life and increased disease activity; however, sleep is a multidimensional process, and little is known about specific sleep characteristics and rest-activity rhythms (RARs) in this population. AIMS: The purposes were to (1) describe sleep characteristics and RARs; (2) compare sleep characteristics and RARs and GI symptoms by disease activity; and (3) describe associations between sleep characteristics, RARs, and GI symptoms among adults with IBD. METHODS: We conducted a cross-sectional study of adults with IBD. We measured sleep characteristics and RARs (continuous wrist actigraphy); GI symptoms (PROMIS-GI); and disease activity (physicians' global assessment). We conducted cosinor and nonparametric analyses to compute RAR variables and bivariate analyses to address the aims. RESULTS: The sample included 37 participants [age M = 38 years (SD = 13.8) and 21 (56.8%) female], of whom 23 (60.6%) were in remission. Sleep efficiency [M = 82.91% (SD 5.35)] and wake after sleep onset (WASO) [M = 42.26 min (SD 18.57)] were not associated with disease activity. Inter-daily stability of the RAR was associated with heartburn/reflux (r = - .491, p = .005) and gas/bloating (r = - .469, p = .008). Intra-daily variability of the RAR was associated with heartburn/reflux (r = .421, p = .018). CONCLUSIONS: People with IBD may have disrupted RARs, which are associated with GI symptoms. Research is needed to improve understanding of these associations and to develop interventions to improve these characteristics in adults with IBD.

Gut mycobiome: The probable determinative role of fungi in IBD patients.

Inflammatory bowel disease (IBD) is a multi-factorial autoimmune disorder that its causative agents are unknown. The gut microbiota comprises of bacteria, viruses, fungi and protozoa that its role in IBD has remained controversially. Bacteria constitute more than 99% of the gut microbiota composition, and the main core of the gut microbiota is composed from Bacteroidetes and Firmicutes. The gut microbiota plays an important role in training, development and haemostasis of the immune responses during the life. Fungi compose a very small portion of gut microbiota, but play determinative roles in homeostasis of the gut bacterial composition and the mucosal immune responses. An interkingdom correlation between bacteria and fungi has been suggested. For example, the presence of Salmonella enterica serovar Typhimurium reduces the viability and colonisation of C albicans. Alterations in the composition and function of the gut microbiota, which is known as dysbiosis, are a usual event in patients who suffer from IBD. Although the main reason for this alteration is not clear, the interaction between gut bacteria and gut fungi seems to be an important subject in IBD patients. This review covers new findings on the interaction between fungi and bacteria and the role of fungi in the pathophysiology of IBD.