Pathobionts in Inflammatory Bowel Disease: Origins, Underlying Mechanisms, and Implications for Clinical Care.

The gut microbiota plays a significant role in the pathogenesis of both forms of inflammatory bowel disease (IBD), namely, Crohn's disease (CD) and ulcerative colitis (UC). Although evidence suggests dysbiosis and loss of beneficial microbial species can exacerbate IBD, many new studies have identified microbes with pathogenic qualities, termed "pathobionts," within the intestines of patients with IBD. The concept of pathobionts initiating or driving the chronicity of IBD has largely focused on the putative aggravating role that adherent invasive Escherichia coli may play in CD. However, recent studies have identified additional bacterial and fungal pathobionts in patients with CD and UC. This review will highlight the characteristics of these pathobionts and their implications for IBD treatment. Beyond exploring the origins of pathobionts, we discuss those associated with specific clinical features and the potential mechanisms involved, such as creeping fat (Clostridium innocuum) and impaired wound healing (Debaryomyces hansenii) in patients with CD as well as the increased fecal proteolytic activity (Bacteroides vulgatus) seen as a biomarker for UC severity. Finally, we examine the potential impact of pathobionts on current IBD therapies, and several new approaches to target pathobionts currently in the early stages of development. Despite recognizing that pathobionts likely contribute to the pathogenesis of IBD, more work is needed to define their modes of action. Determining whether causal relationships exist between pathobionts and specific disease characteristics could pave the way for improved care for patients, particularly for those not responding to current IBD therapies.

Anti-Inflammatory, Barrier Maintenance, and Gut Microbiome Modulation Effects of Saccharomyces cerevisiae QHNLD8L1 on DSS-Induced Ulcerative Colitis in Mice.

The use of probiotics has been considered as a new therapy option for ulcerative colitis (UC), and yeast has recently received widespread recommendation for human health. In this study, the probiotic characteristics of four yeast strains, Saccharomyces boulardii CNCMI-745, Kluyveromyces marxianus QHBYC4L2, Saccharomyces cerevisiae QHNLD8L1, and Debaryomyces hansenii QSCLS6L3, were evaluated in vitro; their ability to ameliorate dextran sulfate sodium (DSS)-induced colitis was investigated. Among these, S. cerevisiae QHNLD8L1 protected against colitis, which was reflected by increased body weight, colon length, histological injury relief, decreased gut inflammation markers, and intestinal barrier restoration. The abundance of the pathogenic bacteria Escherichia-Shigella and Enterococcaceae in mice with colitis decreased after S. cerevisiae QHNLD8L1 treatment. Moreover, S. cerevisiae QHNLD8L1 enriched beneficial bacteria Lactobacillus, Faecalibaculum, and Butyricimonas, enhanced carbon metabolism and fatty acid biosynthesis function, and increased short chain fatty acid (SCFAs) production. Taken together, our results indicate the great potential of S. cerevisiae QHNLD8L1 supplementation for the prevention and alleviation of UC.

Specific fungi associated with response to capsulized fecal microbiota transplantation in patients with active ulcerative colitis.

Objective: Fecal microbiota transplantation (FMT) is a novel microbial treatment for patients with ulcerative colitis (UC). In this study, we performed a clinical trial of capsulized FMT in UC patients to determine the association between the gut fungal community and capsulized FMT outcomes. Design: This study recruited patients with active UC (N = 22) and healthy individuals (donor, N = 9) according to the criteria. The patients received capsulized FMT three times a week. Patient stool samples were collected before (week 0) and after FMT follow-up visits at weeks 1, 4, and 12. Fungal communities were analysed using shotgun metagenomic sequencing. Results: According to metagenomic analysis, fungal community evenness index was greater in samples collected from patients, and the overall fungal community was clustered among the samples collected from donors. The dominant fungi in fecal samples collected from donors and patients were Ascomycota and Basidiomycota. However, capsulized FMT ameliorated microbial fungal diversity and altered fungal composition, based on metagenomic analysis of fecal samples collected before and during follow-up visits after capsulized FMT. Fungal diversity decreased in samples collected from patients who achieved remission after capsulized FMT, similar to samples collected from donors. Patients achieving remission after capsulized FMT had specific enrichment of Kazachstania naganishii, Pyricularia grisea, Lachancea thermotolerans, and Schizosaccharomyces pombe compared with patients who did not achieve remission. In addition, the relative abundance of P. grisea was higher in remission fecal samples during the follow-up visit. Meanwhile, decreased levels of pathobionts, such as Candida and Debaryomyces hansenii, were associated with remission in patients receiving capsulized FMT. Conclusion: In the metagenomic analysis of fecal samples from donors and patients with UC receiving capsulized FMT, shifts in gut fungal diversity and composition were associated with capsulized FMT and validated in patients with active UC. We also identified the specific fungi associated with the induction of remission. ClinicalTrails.gov (NCT03426683).

Psoriasis increases the risk of concurrent inflammatory bowel disease: A population-based nationwide study in Korea.

BACKGROUND: The epidemiology of the association between psoriasis and inflammatory bowel disease is poorly defined and remains controversial. AIM: To evaluate the prevalence of inflammatory bowel disease in patients with psoriasis compared with the general population. METHODS: We searched the nationwide health claims database between 2011 and 2015 and evaluated the prevalence of inflammatory bowel disease, including Crohn's disease and ulcerative colitis. RESULTS: Prevalence of inflammatory bowel disease, Crohn's disease and ulcerative colitis in patients with psoriasis vs the general population in 2011 were 0.16, 0.05 and 0.12% vs 0.08, 0.03 and 0.06%, respectively, which increased significantly with time between 2011 and 2015. Patients with psoriasis consistently revealed higher standardized prevalence (age and sex adjusted) of inflammatory bowel disease, Crohn's disease and ulcerative colitis compared with the general population. Subgroup analysis revealed the highest risk of prevalent inflammatory bowel disease in patients younger than 19 years (crude odds ratio 5.33, 95% confidence interval 3.74-7.59). Severe psoriasis demonstrated higher odds of inflammatory bowel disease (odds ratio 2.96, 95% confidence interval 2.54-3.45) than mild psoriasis (odds ratio 1.68, 95% confidence interval 1.51-1.88). LIMITATIONS: Limited data for doing adjustment and cross-sectional study design. CONCLUSIONS: Psoriasis patients revealed higher risk of inflammatory bowel disease. In particular, young patients and those with severe psoriasis may require closer monitoring and comprehensive management.

Protective effect of Sesbania grandiflora on acetic acid induced ulcerative colitis in mice by inhibition of TNF-α and IL-6.

ETHNOPHARMACOLOGICAL RELEVANCE: The plant Sesbania grandiflora (Linn) belonging to the family Fabaceae is commonly known as sesbania, agathi, and katurai. The plant is accredited for alleviating a spectrum of ailments including inflammation, colitis, diarrhea, dysentery, leprosy, gout, rheumatism, jaundice, bronchitis, convulsion and anxiety. It is also used as antitumour, anthelmintic, and laxatives in Ayurveda and Siddha system of Indian traditional medicine. AIM: To reveal protective effect of Sesbania grandiflora in acetic acid induced ulcerative colitis in mice. MATERIALS AND METHOD: Polyphenol, flavonoid and flavanone contents of different extracts of S. grandiflora leaves were quantified and correlated with their antioxidant capacity in-vitro (DPPH assay) for identification of potential fraction. In further studies hydroalocholic extract (HASG, 100 and 200 mg/kg) was evaluated for protective effect towards acetic acid induced ulcerative colitis (UC) animals administered with 150 µl of 5% acetic acid once, intrarectally. The colonic mucosal injury was assessed by estimating disease activity index (DAI), which took into account weight loss, stool consistency and occult/gross bleeding. Macroscopic changes like colon length, spleen weights, ulcer area and ulcer index were determined. Haematological parameters like WBC count, RBC count, Hb (g/dL), HCT (%), PLT count and FFA level were determined. Biochemical analysis was carried out for asserting the levels of tissue myeloperoxidase (MPO) accumulation, SOD concentrations, reduced GSH and lipid peroxidation in UC induced and treated animals. The cardinal inflammatory biomarkers like nitric oxide (NO), tumor necrosis factor-α (TNF-α) and interleukin (IL-6) were determined. Histopathological investigation was carried out and scores were calculated. RESULTS: HASG showed presence of highly polymerized polyphenols and flavonoids amongst other extracts of S. grandiflora, which is correlated to its rich antioxidant potential (IC50 =19.21). HPLC fingerprinting quantifies the presence of quercetin in concentration of 81.7 µg/mg of HASG. HASG (200 mg/kg) and Prednisolone (2 mg/kg) significantly reduced DAI and macroscopic scores. The haematological changes in experimental animals were restored upon treatment with HASG and Prednisolone. HASG showed potent antioxidant activity (In-vivo) by restoring the levels of SOD, GSH, MPO, MDA and NO. HASG was found to inhibit FFA levels, which may indicate inhibition of TLR4 receptor mediated inflammation. The levels of serological biomarkers like TNF-α and IL-6 were found to be suppressed. Histopathological investigation reveals decrease signs of ulceration, necrosis, cellular infiltration, hyperaemia in HASG treated animals. The results of HASG (200 mg/kg) were found to be comparable with Prednisolone (2 mg/kg) significantly. CONCLUSION: The protective action of HASG against acetic acid induced UC is attributed to the antioxidant like action (In-vitro and In-vivo) of highly polymerized polyphenols and flavonoids especially quercetin. Also HASG was found to reduce the levels of TNF-α and IL-6, thereby suppressing their inflammatory response in UC.

Functional Toll-Like Receptor (TLR)2 polymorphisms in the susceptibility to inflammatory bowel disease.

BACKGROUND: The recent genome-wide association studies (GWAS) in inflammatory bowel disease (IBD) suggest significant genetic overlap with complex mycobacterial diseases like tuberculosis or leprosy. TLR variants have previously been linked to susceptibility for mycobacterial diseases. Here we investigated the contribution to IBD risk of two TLR2 polymorphisms, the low-prevalence variant Arg753Gln and the GTn microsatellite repeat polymorphism in intron 2. We studied association with disease, possible correlations with phenotype and gene-gene interactions. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a large study in 843 patients with Crohn's disease, 426 patients with ulcerative colitis and 805 healthy, unrelated controls, all of European origin. Overall, the frequency for carriers of shorter GTn repeats in intron 2 of the TLR2 gene, which have previously been associated with low TLR2 expression and high IL-10 production, was slightly elevated in Crohn's disease and ulcerative colitis compared to healthy controls (16.0% resp. 16.7% vs. 12.8%). The highest frequency of short GTn carriers was noted among IBD patients on anti TNF-alpha therapy. However, none of these differences was significant in the multivariate analysis. The Arg753Gln polymorphism showed no association with any clinical subtype of IBD, including extensive colitis, for which such an association was previously described. We found no association with specific phenotypic disease subgroups. Also, epistasis analysis revealed no significant interactions between the two TLR2 variants and confirmed IBD susceptibility genes. CONCLUSIONS: The two functional relevant polymorphisms in TLR2, the GTn microsatellite repeat polymorphism in intron 2 and the Arg753Gln variant do not seem to play a role in the susceptibility to Crohn's disease or ulcerative colitis.

LACC1 polymorphisms in inflammatory bowel disease and juvenile idiopathic arthritis.

The function of the Laccase domain-containing 1 (LACC1) gene is unknown, but genetic variation at this locus has been reported to consistently affect the risk of Crohn's disease (CD) and leprosy. Recently, a LACC1 missense mutation was found in patients suffering from monogenic forms of CD, but also systemic juvenile idiopathic arthritis. We tested the hypothesis that LACC1 single nucleotide polymorphisms (SNPs), in addition to CD, are associated with juvenile idiopathic arthritis (JIA, non-systemic), and another major form of inflammatory bowel disease, ulcerative colitis (UC). We selected 11 LACC1 tagging SNPs, and tested their effect on disease risk in 3855 Swedish individuals from three case-control cohorts of CD, UC and JIA. We detected false discovery rate corrected significant associations with individual markers in all three cohorts, thereby expanding previous results for CD also to UC and JIA. LACC1's link to several inflammatory diseases suggests a key role in the human immune system and justifies further characterization of its function(s).

[Tuberculoid leprosy revealed by active ulcerative colitis: a case report]. / Une rectocolite hémorragique révélant une lèpre tuberculoïde.

Leprosy is endemic in Senegal. In 2011, there were 73 new cases reported in Dakar. The circumstances of discovery are often dermatologic or neurologic. Few case reports describe an association with chronic inflammatory colitis, probably fortuitous. We report the case of a 30-year-old woman who had a tuberculoid leprosy revealed by active ulcerative colitis. Treatment according to the WHO protocol of leprosy, combined with corticosteroids and then methotrexate, resulted in healing of the leprosy and remission of the colitis.

On the prevalence of M. avium subspecies paratuberculosis DNA in the blood of healthy individuals and patients with inflammatory bowel disease.

BACKGROUND: Mycobacteria, such as M. leprae and M. tuberculosis infect billions of humans. However, because of appropriate immune responses and antibiotic therapy, overt mycobacterial diseases occur far less frequently. M. avium subspecies paratuberculosis (MAP) causes Johne's disease in ruminants, an affliction evocative of inflammatory bowel disease (IBD). Several agents used to treat IBD (5-ASA, methotrexate, azathioprine and its metabolite 6-MP) have recently been shown to be antiMAP antibiotics. We herein evaluate the prevalence of MAP DNA in healthy individuals and compare them with IBD patients on antiMAP antibiotics. METHODS: We studied 100 healthy individuals (90 blood donors) and 246 patients with IBD. IS900 MAP DNA was identified using a nested primer PCR in the buffy coat of blood. Positive signal was confirmed as MAP by DNA sequence analysis. PCR positive results frequencies were compared according to medications used. Significance was accepted at p<0.05. RESULTS: 47% (47/100) healthy controls and 16% (40/246) IBD patients were IS900 positive (p<0.0001). MAP DNA was identified in 17% of 143 patients receiving mesalamine and 6% of 16 receiving sulfasalazine. None of the IBD patients receiving methotrexate (n = 9), 6-MP (n = 3), ciprofloxacin (n = 5) or Tacrolimus (n = 3) had MAP DNA detectable in their blood. DISCUSSION: We found a disquietingly large percentage of healthy individuals have MAP DNA in their blood, the significance of which remains to be determined. Counter-intuitively, the incidence of MAP DNA was significantly lower in patients with IBD. Agents with the most potent in vitro antiMAP activity were associated with clearance of blood MAP DNA. We posit that the use antiMAP antibiotics was responsible for the decreased prevalence of MAP DNA in patients with IBD.

Culture of Mycobacterium avium subspecies paratuberculosis from the blood of patients with Crohn's disease.

BACKGROUND: Crohn's disease, a form of inflammatory bowel disease, resembles some aspects of tuberculosis, leprosy, and paratuberculosis. The role of Mycobacterium avium subspecies paratuberculosis (MAP) in Crohn's disease is controversial. METHODS: We tested for MAP by PCR and culture in buffy coat preparations from 28 individuals with Crohn's disease, nine with ulcerative colitis, and 15 without inflammatory bowel disease. FINDINGS: MAP DNA in uncultured buffy coats was identified by PCR in 13 (46%) individuals with Crohn's disease, four (45%) with ulcerative colitis, and three (20%) without inflammatory bowel disease. Viable MAP was cultured from the blood of 14 (50%) patients with Crohn's disease, two (22%) with ulcerative colitis, and none of the individuals without inflammatory bowel disease. Current use of immunosuppressive medication did not correlate with a positive MAP culture. Sequencing of PCR products from MAP cultures confirmed the presence of the MAP-specific IS900 fragment. Among 11 MAP isolates assessed, we identified nine strains that were not identical. INTERPRETATION: We detected viable MAP in peripheral blood in a higher proportion of individuals with Crohn's disease than in controls. These data contribute to the evidence that MAP might be a cause of Crohn's disease.

Is there clinical, epidemiological and molecular evidence for two forms of Crohn's disease?

Crohn's disease is an idiopathic chronic panenteric intestinal inflammatory disease. Data concerning the pathogenesis of, and the immune responses occurring in, Crohn's disease are often conflicting. Current therapy is empirical and either non-specifically immunosuppressive or surgically ablative in nature. Although controversial, Crohn's disease may be thought of as having two different presentations, an aggressive fistulizing form and an indolent obstructive form. This is analogous to the tuberculoid and lepromatous manifestations of leprosy. If correct, this subclassification may provide key insights into the pathogenesis and differing host immune responses in Crohn's disease and also allow the development of more rational therapies.

Agalactosyl IgG in inflammatory bowel disease: correlation with C-reactive protein.

The proportion of oligosaccharide chains on the Fc fragment of IgG which terminate with N-acetylglucosamine (GlcNAc) rather than galactose is increased in rheumatoid arthritis and tuberculosis, and in sera from patients with Crohn's disease, probably because of decreased activity of a galactosyltransferase in B lymphocytes. We have assayed the prevalence of agalactosyl oligosaccharides on IgG in sera from 67 patients with inflammatory bowel disease (32 ulcerative colitis and 35 Crohn's disease). The prevalence of agalactosyl IgG significantly increases in the majority of Crohn's patients (19/35 patients), and correlates with the level of C-reactive protein (r = 0.79), and inversely with the concentration of serum albumin. Sera from ulcerative colitis patients show less frequent (nine of 32) and less marked rises in agalactosyl IgG, and sera with high C-reactive protein values can contain normal levels. Thus in ulcerative colitis no correlation was seen between the two assays. The diseases in which the percentage of agalactosyl IgG is raised (rheumatoid arthritis, tuberculosis, Crohn's disease and some ulcerative colitis) are characterised by simultaneous T cell mediated granulomatous tissue damage, and acute phase responses. Levels are normal in less tissue damaging granulomatous conditions, including sarcoidosis, and leprosy (except during episodes of erythema nodosum leprosum). We suggest therefore that a raised percentage of agalactosyl IgG is a correlate of a particular type of T cell mediated pathology which may be relevant to the pathogenesis of inflammatory bowel disease.

Sulfapyridine and sulfones decrease glycosaminoglycans viscosity in dermatitis herpetiformis, ulcerative colitis, and pyoderma gangrenosum.

Shortly after the introduction of sulfa drugs, sulfapyridine was found to have unique therapeutic properties, unrelated to antibacterial activity. Later, sulfones were found to share the same properties. The disorders initially improved were dermatitis herpetiformis, pyoderma gangrenosum, subcorneal pustular dermatosis, acrodermatitis continua, impetigo herpetiformis and ulcerative colitis. They were also sometimes helpful in many other disorders. They are effective in select disorders characterized by edema followed by granulocytic inflammation or edema followed by vesicle or bullae formation. The sulfones work in low doses in leprosy and their mode of action is not fully understood. Several pieces of experimental information are available. It is proposed that these drugs are entering or influencing the protein moiety of glycosaminoglycans and decreasing tissue viscosity. This decreased tissue viscosity prevents edema and dilution of tissue fluid and decreases acute inflammation and vesicle and bullae formation.

Reaction to Kveim test material in sarcoidosis and other diseases.

81 patients, 24 with sarcoidosis and the remainder with various other diseases, were tested with three batches of Kveim material prepared from the same spleen. Positive Kveim tests were observed in sarcoidosis, tuberculosis, Hodgkin's disease, ulcerative colitis, rheumatoid arthritis, and Weber-Christian disease. These results show that a positive Kveim reaction to the material under test was not specific to sarcoidosis.