The Mucosal Antibacterial Response Profile and Fecal Microbiota Composition Are Linked to the Disease Course in Patients with Newly Diagnosed Ulcerative Colitis

Factors Associated With Abdominal Pain in Patients With Active and Quiescent Ulcerative Colitis: A Multicohort Study

BACKGROUND

Abdominal pain can be an overlooked symptom in patients with ulcerative colitis (UC).

AIMS

The aim of this study was to investigate the prevalence and factors associated with abdominal pain in active and quiescent UC.

METHODS

Three study cohorts of adult UC patients were used. Cross-sectional cohorts I and II included 130 (46 active) and 288 (156 active) patients. Longitudinal cohort III included 83 patients with active disease at diagnosis that reached deep remission during follow-up. The Gastrointestinal Symptom Rating Scale was used to assess abdominal pain and other validated questionnaires to assess psychological distress, fatigue and quality of life (QoL).

RESULTS

In the two cross-sectional cohorts, 63% and 58% of the active vs. 54% and 33% of the quiescent UC patients reported abdominal pain (both p ≤ 0.02). In the longitudinal cohort, 71% had abdominal pain at diagnosis vs. 46% when in remission (p < 0.001). In multivariable models, symptoms of anxiety were associated with higher abdominal pain levels in both cross-sectional cohorts (OR 1.75 [IQR 1.11-2.76] and OR 1.99 [1.45-2.73]), whereas in cohort II, active disease (OR 2.68 [1.61-4.45]) and female sex (OR 2.03 [1.21-3.41]) were also associated with pain. QoL was negatively correlated with higher levels of abdominal pain, both in active and quiescent disease.

CONCLUSIONS

Abdominal pain in UC is prevalent and associated with lower QoL in both active and quiescent disease. Associated factors are active disease, female sex and psychological symptoms, especially anxiety. We suggest considering a holistic approach when treating UC patients with abdominal pain.

Dysbiosis in inflammatory bowel diseases: egg, not chicken

There is agreement that inflammatory bowel diseases are, both in terms of species composition and function, associated with an altered intestinal microbiome. This is usually described by the term "dysbiosis," but this is a vague definition lacking quantitative precision. In this brief narrative review, the evidence concerning the primary or secondary role of this dysbiotic state is critically evaluated. Among others, the following facts argue against a primary etiological impact: 1) There is no specific dysbiotic microbiome in IBD, 2) the presence or absence of mucosal inflammation has a profound impact on the composition of the microbiome, 3) dysbiosis is not specific for IBD but linked to many unrelated diseases, 4) antibiotics, probiotics, and microbiome transfer have a very limited therapeutic effect, 5) the microbiome in concordant twins is similar to disease-discordant twins, and 6) the microbiome in relatives of IBD patients later developing IBD is altered, but these individuals already display subclinical inflammation.

Acute severe ulcerative colitis management: unanswered questions and latest insights

Acute severe ulcerative colitis (ASUC) is a distinctive ulcerative colitis flare presentation characterised by the presence of systemic inflammation as well as bloody diarrhoea, and occurs at least once in 25% of patients with ulcerative colitis during their disease course. Each episode carries a risk of complications, need for colectomy, and mortality. Little is known about ASUC pathogenesis, although impaired host-microbiota crosstalk involving pathobionts is suspected. In this Review, we discuss unanswered questions and results from the latest research on the medical-first-line, second-line, and potential third-line therapies-and surgical management of ASUC. We detail promising options for management, such as the use of enteral nutrition in combination with intravenous steroids, the ability to predict early failure of first-line or second-line therapies, and the emerging role of JAK inhibitors. An optimal framework to personalise therapy on the basis of multiomics tools is yet to be developed.

The practice of fecal microbiota transplantation in inflammatory bowel disease

Current evidence posits a central role for gut microbiota and the metabolome in the pathogenesis and progression of inflammatory bowel disease (IBD). Fecal microbiota transplantation (FMT) has been established as a means to manipulate this microbiome safely and sustainably. Several aspects of the technical improvement including pretreatment with antibiotics, use of frozen stool samples as well as short donor-to-recipient time are proposed to improve its response rates. Its efficacy in ulcerative colitis has been proven in clinical trials while data is emerging for Crohn's disease. This review describes briefly the biology behind FMT, the available evidence for its use in IBD, and the host, recipient and procedural factors which determine the clinical outcomes.

Prognostic modelling in IBD

In the ideal world prognostication or predicting disease course in any chronic condition would allow the clinician to anticipate disease behaviour, providing crucial information for the patient and data regarding best use of resources. Prognostication also allows an understanding of likely response to treatment and the risk of adverse effects of a treatment leading to withdrawal in any individual patient. Therefore, the ability to predict outcomes from the onset of disease is the key step to developing precision personalised medicine, which is the design of medical care to optimise efficiency or therapeutic benefit based on careful profiling of patients. An important corollary is to prevent unnecessary healthcare costs. This paper outlines currently available predictors of disease outcome in IBD and looks to the future which will involve the use of artificial intelligence to interrogate big data derived from various important 'omes' to tease out a more holistic approach to IBD.

Gut microbiota-derived 12-ketolithocholic acid suppresses the IL-17A secretion from colonic group 3 innate lymphoid cells to prevent the acute exacerbation of ulcerative colitis

Intestinal microbiota dysbiosis and metabolic disruption are well-known as the primary triggers of ulcerative colitis (UC). However, their role in regulating the group 3 innate lymphoid cells (ILC3s), which are essential for intestinal health, remains unexplored during the development of disease severity. Here, our results showed that the microbiota structure of patients with severe UC (SUCs) differed from those with mild UC (MiUCs), moderate UC (MoUCs), and healthy controls (HCs). Microbes producing secondary bile acids (SBAs) and SBAs decreased with the aggravation of UC, and a strong positive correlation existed between them. Next, fecal microbiota transfer was used to reproduce the human-derived microbiota in mice and decipher the microbiota-mediated inflammatory modulation during an increase in disease severity. Mice receiving SUC-derived microbiota exhibited enhancive inflammation, a lowered percentage of ILC3s, and the down-regulated expressions of bile acid receptors, including vitamin D receptor (VDR) and pregnane X receptor (PXR), in the colon. Similar to clinical results, SBA-producing microbes, deoxycholic acids (DCA), and 12-ketolithocholic acids (12-KLCA) were diminished in the intestine of these recipients. Finally, we compared the therapeutic potential of DCA and 12-KLCA in preventing colitis and the regulatory mechanisms mediated by ILC3s. 12-KLCA but not DCA represented a strong anti-inflammatory effect associated with the higher expression of VDR and the lower secretion of IL-17A from colonic ILC3s. Collectively, these findings provide new signatures for monitoring the acute deterioration of UC by targeting gut microbiota and bile acid metabolism and demonstrate the therapeutic and preventive potential of a novel microbiota-derived metabolite, 12-KLCA.

Characterisation of gut microbiota composition in patients with axial spondyloarthritis and its modulation by TNF inhibitor treatment

OBJECTIVE

To assess whether gut microbiota composition is associated with patient characteristics and may have predictive value on the response to TNF inhibitor (TNFi) treatment in axial spondyloarthritis (AxSpA).

METHODS

The study involved 61 patients fulfilling the Assessment of SpondyloArthritis International Society classification criteria for AxSpA. All patients had active disease despite non-steroidal anti-inflammatory drugs intake and were eligible for treatment with a TNFi. At baseline, the mean Ankylosing Spondylitis Disease Activity Score was 2.9±1 and mean C reactive protein (CRP) level 9.7±11.4 mg/L. Bacterial 16S ribosomal RNA gene sequencing was performed on stool samples collected at baseline (month 0 (M0)) and 3 months after TNFi initiation (month 3 (M3)). Alpha and beta diversity metrics were calculated on the relative abundance of core operational taxonomic units (OTUs).

RESULTS

The HLA-B27 status affected at least in part the global composition of faecal microbiota at M0 as well as the abundance/prevalence of several anaerobic bacteria in the families Oscillospiraceae, Lachnospiraceae and Bifidobacteriaceae. In contrast, smoking affected the global composition of faecal microbiota at both M0 and M3. The prevalence/abundance of seven bacterial OTUs at M0 was associated with response to TNFi treatment. One of the candidates, present only in non-responders, is the genus Sutterella, and the other six candidates are in the class Clostridia.

CONCLUSIONS

Several SpA patients' characteristics modulate the composition of gut microbiota as did TNFi treatment. Moreover, the abundance/prevalence of seven OTUs at baseline may be used as a novel non-invasive index that predicts the response to TNFi with greater accuracy than HLA-B27 status, CRP level and measures of disease activity.

Salivary bactericidal/permeability-increasing protein: A novel inflammatory marker associated with periodontitis

OBJECTIVES

The present case-control study aims to investigate the salivary levels of bactericidal/permeability-increasing protein (BPI) and interleukin-1beta (IL-1ß) in systemically healthy individuals with periodontitis and periodontally healthy for the evaluation of BPI's relation with periodontal inflammation and clinical diagnosis of periodontitis.

MATERIALS AND METHODS

A total of 100 participants were enrolled in this study and divided into periodontitis (P group) (n = 50) and periodontally healthy (H group) (n = 50) groups based on their full-mouth periodontal examination results including plaque index, probing pocket depth, gingival index, bleeding on probing, and clinical attachment level. Unstimulated whole saliva was collected. Salivary BPI and IL-1β levels were determined using an enzyme-linked immunosorbent assay. Receiver operating characteristic (ROC) curves were created to determine the diagnostic value of BPI.

RESULTS

The levels of BPI and IL-1ß in saliva were significantly higher in the P group than in the H group (p<0.001). Moreover, salivary BPI and IL-1ß levels correlated significantly with all clinical periodontal parameters (all p<0.001). Interestingly, there was a strong positive correlation between salivary levels of BPI and IL-1ß (r=0.544, p<0.001). In addition, the results of the ROC curve analysis showed that BPI had a high diagnostic potential to distinguish periodontitis from healthy controls with an area under the curve value of 0.94% (p<0.000).

CONCLUSION

The significantly higher salivary levels of BPI in periodontitis patients together with strong positive correlations between all periodontal parameters and salivary IL-1ß levels suggest that BPI may be involved in the inflammatory process of periodontal disease.

CLINICAL RELEVANCE

The present study for the first time report that salivary BPI levels may serve as a potential biomarker of inflammation in periodontal disease.

TRIAL REGISTRATION NUMBER

Thai Clinical Trials.gov (TCTR20211222008) (22 December 2021).

Relationship between clinical features and intestinal microbiota in Chinese patients with ulcerative colitis

BACKGROUND

Dysbacteriosis may be a crucial environmental factor for ulcerative colitis (UC). Further study is required on microbiota alterations in the gastrointestinal tract of patients with UC for better clinical management and treatment.

AIM

To analyze the relationship between different clinical features and the intestinal microbiota, including bacteria and fungi, in Chinese patients with UC.

METHODS

Eligible inpatients were enrolled from January 1, 2018 to June 30, 2019, and stool and mucosa samples were collected. UC was diagnosed by endoscopy, pathology, Mayo Score, and Montreal classification. Gene amplicon sequencing of 16S rRNA gene and fungal internal transcribed spacer gene was used to detect the intestinal microbiota composition. Alpha diversity, principal component analysis, similarity analysis, and Metastats analysis were employed to evaluate differences among groups.

RESULTS

A total of 89 patients with UC and 33 non-inflammatory bowel disease (IBD) controls were enrolled. For bacterial analysis, 72 stool and 48 mucosa samples were obtained from patients with UC and 21 stool and 12 mucosa samples were obtained from the controls. For fungal analysis, stool samples were obtained from 43 patients with UC and 15 controls. A significant difference existed between the fecal and mucosal bacteria of patients with UC. The α-diversity of intestinal bacteria and the relative abundance of some families, such as Lachnospiraceae and Ruminococcaceae, decreased with the increasing severity of bowel inflammation, while Escherichia-Shigella showed the opposite trend. More intermicrobial correlations in UC in remission than in active patients were observed. The bacteria-fungi correlations became single and uneven in patients with UC.

CONCLUSION

The intestinal bacteria flora of patients with UC differs significantly in terms of various sample types and disease activities. The intermicrobial correlations change in patients with UC compared with non-IBD controls.

Selecting End Points for Disease-Modification Trials in Inflammatory Bowel Disease: the SPIRIT Consensus From the IOIBD

BACKGROUND AND AIMS

Inflammatory bowel diseases (IBD), encompassing Crohn's disease (CD) and ulcerative colitis (UC), are chronic and disabling disorders. Prospective disease-modification trials to prevent disease progression are eagerly awaited. However, disease progression is not clearly defined. The objective of the Selecting End PoInts foR Disease-ModIfication Trials (SPIRIT) initiative was to achieve international expert consensus on the endpoints to be used in future IBD-disease modification trials.

METHODS

This initiative under the auspices of the International Organization for the Study of Inflammatory Bowel Diseases (IOIBD) began with a systematic literature search to evaluate the current evidence on the definition of disease progression in IBD. On October 22, 2019, a consensus meeting took place during the United European Gastroenterology Week (UEGW) Congress in Barcelona, during which predefined proposed statements were discussed in a plenary session and voted on anonymously. Agreement was defined as at least 75% of participants voting for any one statement.

RESULTS

The group agreed that the ultimate therapeutic goal in both CD and UC is to prevent disease impact on patient's life (health-related quality of life, disability, fecal incontinence), midterm complications (encompass bowel damage in CD, IBD-related surgery and hospitalizations, disease extension in UC, extraintestinal manifestations, permanent stoma, short bowel syndrome), and long-term complications (gastrointestinal and extraintestinal dysplasia or cancer, mortality).

CONCLUSIONS

Recommendations on which goals to achieve in disease-modification trials for preventing disease progression in patients with IBD are proposed by the SPIRIT consensus. However, these recommendations will require validation in actual clinical studies before implementation in disease-modification trials.

Bactericidal Permeability Increasing Protein Deficiency Aggravates Acute Colitis in Mice by Increasing the Serum Levels of Lipopolysaccharide

Objective

The objective of this study was to understand the role of bactericidal permeability increasing protein (BPI) in the pathogenesis of experimental murine colitis.

Methods

We used the Cre-LoxP system to generate BPI knockout (BPI KO) mice. Acute colitis was induced in BPI KO mice and wild-type (WT) mice by subjecting the mice to 5% dextran sulfate sodium (DSS). Mice were observed for symptoms of experimental colitis. The survival of BPI KO mice to infection with Acinetobacter baumannii, a gram-negative bacterium, was also assessed.

Results

Southern blot, RT-PCR, and western blot results showed that the 2nd and 3rd exons of the murine Bpi gene were knocked out systemically, confirming successful construction of the BPI KO mouse. BPI KO mice subjected to DSS showed increased symptoms of experimental colitis, increased colonic mucosal damage, increased epithelial permeability, elevated levels of serum LPS, and a disrupted fecal microbiome as compared with WT mice. Furthermore, BPI KO mice challenged intraperitoneally with A. baumannii died sooner than WT mice, and the total number of bacteria in the abdominal cavity, spleen, and liver was increased in BPI KO mice as compared to WT mice.

Conclusions

We successfully generated BPI KO mice. The BPI KO mice developed worse colitis than WT mice by increased colitis symptoms and colonic mucosal damage, elevated levels of serum LPS, and a disrupted microbiome. BPI could be a potential target for treatment of ulcerative colitis in humans.

Microbiota and mucosal defense in IBD: an update

Introduction: Inflammatory bowel diseases (IBD) are on the rise worldwide. This review covers the current concepts of the etiology of Crohn´s disease and ulcerative colitis by focusing on an unbalanced interaction between the intestinal microbiota and the mucosal barrier. Understanding these issues is of paramount importance for the development of targeted therapies aiming at the disease cause.Area covered: Gut microbiota alterations and a dysfunctional intestinal mucosa are associated with IBD. Here we focus on specific defense structures of the mucosal barrier, namely antimicrobial peptides and the mucus layer, which keep the gut microbiota at a distance under healthy conditions and are defective in IBD.Expert commentary: The microbiology of both forms of IBD is different but characterized by a reduced bacterial diversity and richness. Abundance of certain bacterial species is altered, and the compositional changes are related to disease activity. In IBD the mucus layer above the epithelium is contaminated by bacteria and the immune reaction is dominated by the antibacterial response. Human genetics suggest that many of the basic deficiencies in the mucosal response, due to Paneth cell, defensin and mucus defects, are primary. Nutrition may also be important but so far there is no therapy targeting the mucosal barrier.

Review of the scientific evidence and technical opinion on noncaloric sweetener consumption in gastrointestinal diseases

The present review of noncaloric sweeteners (NCSs) by the Asociación Mexicana de Gastroenterología was carried out to analyze and answer some of the most frequent questions and concerns about NCS consumption in patients with gastrointestinal disorders, through a thorough review of the medical literature. A group of gastroenterologists and experts on nutrition, toxicology, microbiology, and endocrinology reviewed and analyzed the published literature on the topic. The working group formulated conclusions, based on the scientific evidence published, to give an opinion with respect to NCS ingestion. Current evidence does not confirm the carcinogenic potential of NCSs. However, the studies analyzed showed that saccharin could have a proinflammatory effect and that polyols can cause gastrointestinal symptoms and manifestations, depending on the dose and type of compound. The ingestion of xylitol, erythritol, sucralose, aspartame, acesulfame K, and saccharin could increase the secretion of the gastrointestinal hormones that regulate intestinal motility, and stevia and its derivatives could have a favorable effect on the percentage of liver fat. Caution should be taken in recommending aspartame consumption in patients with chronic liver disease because it reduces the ratio of branched-chain amino acids to aromatic amino acids. In addition, NCS ingestion could modify the composition of the intestinal microbiota, having an effect on gastrointestinal symptoms and manifestations. It is important to continue conducting causality studies on humans to be able to establish recommendations on NSC consumption.

Diversity analysis of intestinal microflora between healthy and diarrheal neonatal piglets from the same litter in different regions

Though the problem of neonatal piglet diarrhea is well known, the differences in the bacterial diversity and community composition between healthy and diarrheal piglets are still unknown. We investigated these differences in neonatal piglets from Jiangxi Province, China. Healthy (H, n = 20) and diarrheal (D, n = 20) piglets were selected from six regions. The fecal microbial communities were analyzed by sequencing the V3V4 region of 16S rRNA gene. We found the ratio of major phyla (Fusobacteria, Bacteroidetes, Firmicutes and Proteobacteria) was >99% of 7 phyla. The overall alpha diversity indices, such as chao, sobs, coverage and Shannon, were not significantly different. Moreover, the relative abundance of the predicted functions was highly similar in the two groups. Our results indicated that Clostridium was divided into two major groups: Clostridium sensu stricto_1 and stricto_2. Sensu stricto_2 was highly abundant in the D group and low abundance in the H group, whereas the results of sensu stricto_1 were opposite. Comparative analyses within the H or D groups showed that Escherichia-Shigella and Streptococcus at the genus level and unclassified Lactobacillus at the species level were significant difference. Comparative analyses of the two groups showed that unclassified Prevotellaceae at the genus level and Fusobacterium mortifierum were significantly different and had high linear discriminant analysis (LDA) scores. The significantly different microbes composition results also existed in the same litter, based on excluding regions influence. These results suggested that piglet diarrhea was closely associated with these microbes. This study provides insights into gut microbial interactions and prevention of piglet diarrhea.

Altered intestinal antibacterial gene expression response profile in irritable bowel syndrome is linked to bacterial composition and immune activation

BACKGROUND

Immune activity and gut microbiota may impact the pathophysiology of irritable bowel syndrome (IBS). We aimed to determine whether antibacterial gene expression of immune activity-defined IBS patients differed compared to healthy subjects (HS) and ulcerative colitis (UC) patients and whether antibacterial profiles reflected gut microbiota composition and IBS symptoms.

METHODS

Expression of 84 antibacterial genes in biopsies from HS, IBS patients (clustered according to immune activity (systemic and intestinal cytokines): immunonormal or immunoactive), and UC patients was assessed by Human Antibacterial Response RT² Profiler PCR Array. In IBS patients, 16S rRNA gene sequencing of fecal and mucosal bacteria was performed and symptom pattern and severity were assessed.

KEY RESULTS

Intestinal antibacterial gene expression profiles differed between IBS patients (n = 31) and HS (n = 16), but did not differ between IBS subgroups based on bowel habit predominance or symptom severity. Based on previously identified IBS clusters, IBS patients with normal (n = 15) and enhanced immune activity (n = 16) had clearly separate antibacterial gene expression profiles from active UC patients (n = 12) and differed compared to each other and to HS. The differences in antibacterial gene expression profiles between immunonormal and immunoactive IBS patients were also reflected in distinct fecal and mucosal microbiota composition profiles, but not in symptom pattern or severity.

CONCLUSIONS & INFERENCES

This study demonstrates an altered antibacterial gene expression profile in IBS patients compared to HS and UC patients. While not linked to symptoms, immune activity-defined IBS clusters showed different intestinal antibacterial gene expression and distinct fecal and mucosal bacterial profiles.

Partial to complete abrogation of the subepithelial macrophage barrier against the gut microbiota in patients with ulcerative colitis and Crohn's colitis

AIMS

The integrity of the band of indigenous macrophages in the subepithelial layer of the lamina propria (SLP) is crucial in preventing the commensal gut microbiota from attacking the host. The breakdown of the SLP macrophage barrier results in microbiota inflow and improper immune responses; this might lead to inflammatory bowel disease (IBD). During inflammation, the SLP macrophage barrier is reinforced by inflammation-elicited macrophages (IEMs), which are derived from blood-circulating monocytes. The aim was to explore the characteristics of the SLP macrophage band in a cohort of biopsies without inflammation, in patients with ulcerative colitis in remission (UCre), and in patients with right-sided Crohn's colitis (RCC).

METHODS AND RESULTS

Endoscopic biopsies were taken from endoscopically normal descending colon in 247 patients; 80 with IBD (27 UCre and 53 RCC), and 167 without IBD [90 had colonic diarrhoea, 63 were enrolled in a colorectal cancer (CRC) surveillance programme, seven had microscopic colitis in remission, and seven had miscellaneous colonic ailments]. Sections showed no inflammatory changes; they were immunostained with CD68. Among patients with UCre and RCC, the SLP band of CD68+ macrophages was fragmented or minute in 59% (47/80) and negative in 9% (7/80). In contrast, only 31% (51/167) of the biopsies from control patients had a fragmented/minute SLP band of CD68+ macrophages, and none had a negative SLP band of CD68+ macrophages (IBD versus controls, P < 0.05).

CONCLUSIONS

The finding that the SLP macrophage barrier was fragmented to totally abrogated in UCre and RCC patients suggests a longlasting defect in the SLP CD68+ macrophage barrier in these patients. The lack of ongoing inflammation in colonic biopsies should rule out the participation of bone marrow-derived IEMs in the abrogation of the SLP macrophage barrier reported here.