Inflammatory Bowel Disease: A Global Disease That Needs a Broader Ensemble of Populations

Ulva lactuca polysaccharides combined with fecal microbiota transplantation ameliorated dextran sodium sulfate-induced colitis in C57BL/6J mice

BACKGROUND

Fecal microbiota transplantation (FMT) of healthy donors improves ulcerative colitis (UC) patients by restoring the balance of the gut microbiota. However, donors vary in microbial diversity and composition, often resulting in weak or even ineffective FMT. Improving the efficacy of FMT through combination treatment has become a promising strategy. Ulva lactuca polysaccharides (ULP) have been found to benefit host health by regulating gut microbiota. The effect of the combination of ULP and FMT in ameliorating UC has not yet been evaluated.

RESULTS

The present study found that supplementation with ULP combined with FMT showed better effects in ameliorating UC than supplementation with FMT alone. Results suggested that FMT or ULP combined with FMT alleviated the symptoms of UC in mice, as evidenced by prevention of body weight loss, improvement of disease activity index and protection of the intestinal mucus. Notably, ULP in combination with FMT was more effective than FMT in reducing levels of cytokines and related inflammatory enzymes. In addition, ULP combined with FMT effectively restored the dysbiosis induced by dextran sulfate sodium (DSS) and further enriched probiotics (such as Bifidobacterium). The production of short-chain fatty acids, especially acetic acid, was also significantly enriched by ULP combined with FMT.

CONCLUSION

Supplementation of ULP combined with FMT could significantly ameliorate DSS-induced colitis in mice by inhibiting inflammation and restoring dysbiosis of gut microbiota. These results suggested that ULP combined with FMT has potential application in ameliorating UC. © 2024 Society of Chemical Industry.

Amerindian ancestry proportion as a risk factor for inflammatory bowel diseases: results from a Latin American Andean cohort

Background and aims

Latin American populations remain underrepresented in genetic studies of inflammatory bowel diseases (IBDs). Most genetic association studies of IBD rely on Caucasian, African, and Asian individuals. These associations have yet to be evaluated in detail in the Andean region of South America. We explored the contribution of IBD-reported genetic risk variants to a Chilean cohort and the ancestry contribution to IBD in this cohort.

Methods

A total of 192 Chilean IBD patients were genotyped using Illumina's Global Screening Array. Genotype data were combined with similar information from 3,147 Chilean controls. The proportions of Aymara, African, European, and Mapuche ancestries were estimated using the software ADMIXTURE. We calculated the odds ratios (ORs) and 95% confidence intervals (CIs) for gender, age, and ancestry proportions. We also explored associations with previously reported IBD-risk variants independently and in conjunction with genetic ancestry.

Results

The first and third quartiles of the proportion of Mapuche ancestry in IBD patients were 24.7 and 34.2%, respectively, and the corresponding OR was 2.30 (95%CI 1.52-3.48) for the lowest vs. the highest group. Only one variant (rs7210086) of the 180 reported IBD-risk SNPs was associated with IBD risk in the Chilean cohort (adjusted P = 0.01). This variant is related to myeloid cells.

Conclusion

The type and proportion of Native American ancestry in Chileans seem to be associated with IBD risk. Variants associated with IBD risk in this Andean region were related to myeloid cells and the innate immune response.

Impact of purple sweet potato (Ipomoea batatas L.) polysaccharides on the fecal metabolome in a murine colitis model

Purple sweet potato polysaccharides (PSPP) play an important role in regulating the gut microbiota, modulating intestinal immunity and ameliorating colonic inflammation. In this study, the impact of two PSPPs (PSWP-I and PSAP-I) on the metabolomic profiling of feces from dextran sulfate sodium (DSS)-induced colitis mice was evaluated by ultra-high performance liquid chromatography coupled with triple time-of-flight tandem mass spectrometry (UPLC-Triple-TOF-MS/MS). Results indicated that there were twenty-five metabolites with significant changes and four remarkable metabolic pathways, i.e., cutin, suberine and wax biosynthesis, biosynthesis of unsaturated fatty acids, fatty acid biosynthesis, and steroid hormone biosynthesis. Two key biomarkers of oleic acid and 17-hydroxyprogesterone were screened that responded to PSPPs in colitis mice. The identified metabolites were correlated with the amelioration of intestinal immune function and the modulation of the gut microbiota. Nine pro-inflammatory and eight anti-inflammatory compounds responded to PSPPs, which were related to Bacteroides, norank_f__Clostridiales_vadinBB60_group, unclassified_o__Bacteroidales, Rikenella and Lachnospiraceae_UCG-001. Moreover, PSWP-I and PSAP-I had different regulating effects on intestinal metabolites. Our results revealed a possible metabolomic mechanism of PSPPs to regulate intestinal inflammation function.

Purple sweet potato polysaccharides (PSPP) play an important role in regulating the gut microbiota, modulating intestinal immunity and ameliorating colonic inflammation.

Jellyfish skin polysaccharides enhance intestinal barrier function and modulate the gut microbiota in mice with DSS-induced colitis

Jellyfish skin polysaccharides (JSP) were isolated from Rhopilema esculentum Kishinouye and contained 55.11% polysaccharides and 2.26% uronic acid. To examine the anti-inflammatory, antioxidant and immunomodulatory activities of JSP in vivo, C57BL/6 mice were induced to develop ulcerative colitis by dextran sulfate sodium (DSS) and the roles of dietary JSP supplementation in modulating colitis were explored. JSP supplementation reduced the symptoms of colitis in mice, increased colon length, protected goblet cells, and improved intestinal epithelial integrity and permeability. JSP modulated oxidative stress and inflammatory responses, which was demonstrated by reduced MPO activity, NO level, and levels of pro-inflammatory cytokines including TNF-α, IL-1β and IL-6 in mice. JSP suppressed NF-κB signaling pathways as evidenced by lower levels of phosphorylated p65 and IKB. Moreover, JSP supplementation enhanced the expression of tight junction proteins and mucins, and modulated the composition of the gut microbiota and the production of short-chain fatty acids. Taken together, these results reveal the anti-inflammatory effect of dietary JSP in vivo, suggesting the potential of JSP as a nutritional supplement or adjunct strategy in preventing or ameliorating colitis.

Anti-TNF and immunosuppressive combination therapy is preferential to inducing clinical remission in patients with active inflammatory bowel disease: A systemic review and meta-analysis

OBJECTIVE

To compare the efficacy and safety of a combination therapy of biologics and immunosuppressants with biological monotherapy in inflammatory bowel disease (IBD) in a systematic review and meta-analysis.

METHODS

Eligible randomized controlled trials (RCTs) on the comparison of the efficacy and safety of biologics and immunomodulators with biological monotherapy were identified from the EMBASE, PubMed and the Cochrane Library databases published up to 1 May 2020. Raw data were extracted, pooled relative risk (RR) and 95% confidence interval (CI) was calculated, the fixed-effect and inverse variance models were used. Funnel plots were performed to analyze publication bias.

RESULTS

Twelve RCTs were eligible for analysis. Overall, there was statistically a benefit for combination treatment over biologic monotherapy (IFX/ADA) in inducing clinical remission and preventing relapse in patients with IBD (RR 0.89, 95% CI 0.80-0.98). Moreover, the combination therapy was superior to biological monotherapy for active CD (RR 0.83, 95% CI 0.73-0.94). Also, there were significant benefits for combination therapy in the subgroup treated with infliximab (IFX) (RR 0.83, 95% CI 0.70-0.97).

CONCLUSIONS

Combination therapy has slight benefits in inducing clinical remission in active CD compared with biological monotherapy. Patients with IBD who receive therapy with IFX and immunomodulator also have a mild advantage in comparison with those treated with IFX monotherapy.

Construction and benchmarking of a multi-ethnic reference panel for the imputation of HLA class I and II alleles

Genotype imputation of the human leukocyte antigen (HLA) region is a cost-effective means to infer classical HLA alleles from inexpensive and dense SNP array data. In the research setting, imputation helps avoid costs for wet lab-based HLA typing and thus renders association analyses of the HLA in large cohorts feasible. Yet, most HLA imputation reference panels target Caucasian ethnicities and multi-ethnic panels are scarce. We compiled a high-quality multi-ethnic reference panel based on genotypes measured with Illumina’s Immunochip genotyping array and HLA types established using a high-resolution next generation sequencing approach. Our reference panel includes more than 1,300 samples from Germany, Malta, China, India, Iran, Japan and Korea and samples of African American ancestry for all classical HLA class I and II alleles including HLA-DRB3/4/5. Applying extensive cross-validation, we benchmarked the imputation using the HLA imputation tool HIBAG, our multi-ethnic reference and an independent, previously published data set compiled of subpopulations of the 1000 Genomes project. We achieved average imputation accuracies higher than 0.924 for the commonly studied HLA-A, -B, -C, -DQB1 and -DRB1 genes across all ethnicities. We investigated allele-specific imputation challenges in regard to geographic origin of the samples using sensitivity and specificity measurements as well as allele frequencies and identified HLA alleles that are challenging to impute for each of the populations separately. In conclusion, our new multi-ethnic reference data set allows for high resolution HLA imputation of genotypes at all classical HLA class I and II genes including the HLA-DRB3/4/5 loci based on diverse ancestry populations.

The Impact of Ethnicity and Country of Birth on Inflammatory Bowel Disease Phenotype: a Prospective Cohort Study

BACKGROUND AND AIMS

The number of patients with inflammatory bowel disease [IBD], of non-Caucasian descent in Western Europe, is increasing. We aimed to explore the impact of ethnicity and country of birth on IBD phenotype.

METHODS

IBD patients treated in the eight University Medical Centers in The Netherlands [Dutch IBD Biobank] were divided into two groups according to their ethnicity: 1] Caucasian patients of Western and Central European descent [CEU]; and 2] patients of non-Caucasian descent [non-CEU]. The non-CEU group was subdivided according to country of birth, into: born in The Netherlands or Western Europe [non-CEU European born]; or born outside Western-Europe who migrated to The Netherlands [non-CEU non-European born]. Both comparisons were analysed for phenotype differences [by chi-square test].

RESULTS

The Dutch IBD Biobank included 2921 CEU patients and 233 non-CEU patients. Non-CEU Crohn's disease [CD] patients more often had upper gastro-intestinal disease [16% vs 8%, p = 0.001] and anal stenosis [10% vs 4%, p = 0.002] than CEU CD patients. The use of anti-tumour necrosis factor [TNF] agents and immunomodulators was higher in non-CEU IBD patients than in CEU IBD patients [45% vs 38%, p = 0.042] and [77% vs 66%, p = 0.001], respectively. Non-CEU IBD patients born in Europe [n = 116] were diagnosed at a lower age than non-CEU IBD patients born outside Europe [n = 115] [at 22.7 vs 28.9 years old, p < 0.001].

CONCLUSION

Non-Caucasians had more severe disease behaviour than Caucasians. Non-CEU patients born in Europe were diagnosed at a lower age with IBD than those born outside Europe who migrated to The Netherlands.