Nutrition, IBD and Gut Microbiota: A Review

The Role of Host Genetics and Intestinal Microbiota and Metabolome as a New Insight into IBD Pathogenesis

Inflammatory bowel disease (IBD) is an incurable, chronic disorder of the gastrointestinal tract whose incidence increases every year. Scientific research constantly delivers new information about the disease and its multivariate, complex etiology. Nevertheless, full discovery and understanding of the complete mechanism of IBD pathogenesis still pose a significant challenge to today's science. Recent studies have unanimously confirmed the association of gut microbial dysbiosis with IBD and its contribution to the regulation of the inflammatory process. It transpires that the altered composition of pathogenic and commensal bacteria is not only characteristic of disturbed intestinal homeostasis in IBD, but also of viruses, parasites, and fungi, which are active in the intestine. The crucial function of the microbial metabolome in the human body is altered, which causes a wide range of effects on the host, thus providing a basis for the disease. On the other hand, human genomic and functional research has revealed more loci that play an essential role in gut homeostasis regulation, the immune response, and intestinal epithelial function. This review aims to organize and summarize the currently available knowledge concerning the role and interaction of crucial factors associated with IBD pathogenesis, notably, host genetic composition, intestinal microbiota and metabolome, and immune regulation.

Shenling Baizhu powder attenuates lard diet in a fatigued state-induced diarrhea via targeting microbial metabolites short chain fatty acids-mediated lipid metabolism

Shenling Baizhu Powder (SLBZP), a traditional Chinese medicine (TCM) prescription renowned for its efficacy, is specifically recognized for its therapeutic effects in managing diarrhea associated with spleen qi deficiency. Our previous research has demonstrated that a lard diet in a fatigued state induced diarrhea belonging to spleen qi deficiency in TCM. Through a comprehensive investigation, we aimed to provide insights into the intricate relationship between SLBZP and the modulation of gut microbiota in alleviating symptoms associated with spleen qi deficiency-induced diarrhea. We induced diarrhea in mice by subjecting them to continuous standing on a multiple-platform apparatus while administering lard through intragastric administration for 14 days. Subsequently, we conducted gavage administration of SLBZP at a concentration of 0.637 g/ml for seven days. We observed a therapeutic effect of SLBZP on diarrhea induced by a lard diet in a fatigued state. SLBZP mitigated disorders in lipid metabolism and diminished hepatic oxidative responses. Additionally, SLBZP reversed gut microbiota dysbiosis of diarrheic mice and notably increased the production of short-chain fatty acids (SCFAs), primarily acetic acid, butyric acid, and valeric acid. Through correlation analysis, we additionally identified Lactobacillus reuteri and Lactobacillus intestinalis as potentially pivotal species associated with the therapeutic effects of SLBZP. We demonstrated that SLBZP exerts therapeutic effects on diarrhea caused by a lard diet in a fatigued state by repairing the intestinal mucosal barrier, improving lipid metabolism disorders, and regulating gut microbiota and metabolites SCFAs.

Evaluation of online chat-based artificial intelligence responses about inflammatory bowel disease and diet

INTRODUCTION

The USA has the highest age-standardized prevalence of inflammatory bowel disease (IBD). Both genetic and environmental factors have been implicated in IBD flares and multiple strategies are centered around avoiding dietary triggers to maintain remission. Chat-based artificial intelligence (CB-AI) has shown great potential in enhancing patient education in medicine. We evaluate the role of CB-AI in patient education on dietary management of IBD.

METHODS

Six questions evaluating important concepts about the dietary management of IBD which then were posed to three CB-AI models - ChatGPT, BingChat, and YouChat three different times. All responses were graded for appropriateness and reliability by two physicians using dietary information from the Crohn's and Colitis Foundation. The responses were graded as reliably appropriate, reliably inappropriate, and unreliable. The expert assessment of the reviewing physicians was validated by the joint probability of agreement for two raters.

RESULTS

ChatGPT provided reliably appropriate responses to questions on dietary management of IBD more often than BingChat and YouChat. There were two questions that more than one CB-AI provided unreliable responses to. Each CB-AI provided examples within their responses, but the examples were not always appropriate. Whether the response was appropriate or not, CB-AIs mentioned consulting with an expert in the field. The inter-rater reliability was 88.9%.

DISCUSSION

CB-AIs have the potential to improve patient education and outcomes but studies evaluating their appropriateness for various health conditions are sparse. Our study showed that CB-AIs have the ability to provide appropriate answers to most questions regarding the dietary management of IBD.

Synbiotics containing sea buckthorn polysaccharides ameliorate DSS-induced colitis in mice via regulating Th17/Treg homeostasis through intestinal microbiota and their production of BA metabolites and SCFAs

Inflammatory Bowel Disease (IBD) is a chronic condition whose incidence has been rising globally. Synbiotic (SYN) is an effective means of preventing IBD. This study investigated the preventive effects and potential biological mechanisms of SYN (Bifidobacterium longum, Lactobacillus acidophilus, and sea buckthorn polysaccharides) on DSS-induced colitis in mice. The results indicated that dietary supplementation with SYN has a significant improvement effect on DSS mice. SYN ameliorated disease activity index (DAI), colon length, and intestinal barrier permeability in mice. In addition, RT-qPCR results indicated that after SYN intervention, the expression levels of pro-inflammatory factors (IL-6, IL-1β, TNF-α, and IL-17F) and transcription factor RORγt secreted by Th17 cells were significantly reduced, and the expression levels of anti-inflammatory factors (IL-10 and TGF-β) and transcription factor Foxp3 secreted by Treg cells were robustly increased. 16S rDNA sequencing analysis revealed that key intestinal microbiota related to Th17/Treg balance (Ligilactobacillus, Lactobacillus, Bacteroides, and Akkermansia) was significantly enriched. At the same time, a significant increase in microbial metabolites SCFAs and BAs was observed. We speculate that SYN may regulate the Th17/Treg balance by restructuring the structure and composition of the intestinal microbiota, thereby mitigating DSS-induced colitis.

Enhanced Risk of Gastroesophageal Reflux Disease and Esophageal Complications in the Ulcerative Colitis Population

Background: Although heartburn and reflux are frequently reported in ulcerative colitis [UC], the correlation between UC and gastroesophageal reflux disease [GERD], and its complications, esophageal stricture and Barrett's esophagus [BE], is not well understood. This study aims to examine the prevalence and associated risk of GERD and its complications within the UC population. Methods: We analyzed the National Inpatient Sample (NIS) dataset, consisting of 7,159,694 patients, comparing GERD patients with and without UC to those without GERD. We assessed the degree of colonic involvement in UC and the occurrence of esophageal complications. Bivariate analyses were conducted using the chi-squared test or Fisher exact test (two-tailed). Results: A higher prevalence of GERD (23.0% vs. 16.5%) and GERD phenotypes, such as non-erosive reflux disease (NERD) (22.3% vs. 16%) and erosive esophagitis (EE) (1.2% vs. 0.6%), was found in UC patients (p < 0.01), including pancolitis, proctitis, proctosigmoiditis, left-sided colitis, and indetermined UC (with undefined colonic involvement). UC patients were more likely to develop GERD (1.421), NERD (1.407), and EE (1.681) (p < 0.01). A higher prevalence of esophageal stricture (16.9 vs. 11.4 per 10,000 patients) and BE without dysplasia (94.5 vs. 39.3 per 10,000 patients) was found in UC (p < 0.05). The odds of developing BE without dysplasia were higher (1.892) in patients with UC (p < 0.01), including ulcerative pancolitis, proctitis, and indeterminate UC (OR of 1.657, 3.328, and 1.996, respectively) (p < 0.05). Conclusions: Our study demonstrates an increased risk of developing GERD and its complications in UC. This highlights the importance of vigilant monitoring and early intervention to minimize associated GERD-related risks in patients with UC.

ITGB2 related to immune cell infiltration as a potential therapeutic target of inflammatory bowel disease using bioinformatics and functional research

Inflammatory bowel disease (IBD) is a chronic systemic inflammatory condition regarded as a major risk factor for colitis-associated cancer. However, the underlying mechanisms of IBD remain unclear. First, five GSE data sets available in GEO were used to perform 'batch correction' and Robust Rank Aggregation (RRA) to identify differentially expressed genes (DEGs). Candidate molecules were identified using CytoHubba, and their diagnostic effectiveness was predicted. The CIBERSORT algorithm evaluated the immune cell infiltration in the intestinal epithelial tissues of patients with IBD and controls. Immune cell infiltration in the IBD and control groups was determined using the least absolute shrinkage selection operator algorithm and Cox regression analysis. Finally, a total of 51 DEGs were screened, and nine hub genes were identified using CytoHubba and Cytoscape. GSE87466 and GSE193677 were used as extra data set to validate the expression of the nine hub genes. CD4-naïve T cells, gamma-delta T cells, M1 macrophages and resting dendritic cells (DCs) are the main immune cell infiltrates in patients with IBD. Signal transducer and activator of transcription 1, CCR5 and integrin subunit beta 2 (ITGB2) were significantly upregulated in the IBD mouse model, and suppression of ITGB2 expression alleviated IBD inflammation in mice. Additionally, the expression of ITGB2 was upregulated in IBD-associated colorectal cancer (CRC). The silence of ITGB2 suppressed cell proliferation and tumour growth in vitro and in vivo. ITGB2 resting DCs may provide a therapeutic strategy for IBD, and ITGB2 may be a potential diagnostic marker for IBD-associated CRC.

Protective properties of Ophiopogonin D in DSS-induced colitis: insights into microbiota modulation

BACKGROUND

Ulcerative colitis (UC), a chronic inflammatory gastrointestinal disorder, is becoming increasingly prevalent worldwide. Ophiopogonin D, which is derived from Ophiopogon japonicus, exhibits anti-inflammatory and antioxidant properties, yet its therapeutic potential in UC remains unclear.

METHODS

In this study, we employed a mouse model of DSS-induced colitis to assess the impact of Ophiopogonin D on various parameters, including weight loss, bloody stools, and inflammation in the colon.

RESULTS

Ophiopogonin-D treatment significantly mitigated these DSS-induced effects, improved colon permeability, and modulated inflammatory markers like ZO-1, MUC-2, TNF-α, and IL-1β in mice compared with the control. Furthermore, compared to the DSS-treatment group, Ophiopogonin-D treatment improved the α- and β-diversity indices of the mouse intestinal microbiota, along with an increase in the abundance of genera such as Akkermansia (AKK) and a decrease in the abundance of genera such as Enterobacter. Notably, propionic acid, a metabolite of AKK, demonstrated significant improvement in the symptoms of DSS-induced colitis in mice compared to the control. Moreover, propionic-acid administration also resulted in alterations in the levels of inflammatory factors and calreticulin within the intestinal tissues.

CONCLUSION

Overall, Ophiopogonin D significantly affects intestinal microbiota composition, thereby improving symptoms of DSS-induced colitis in mice. These findings present promising therapeutic strategies and potential pharmaceutical candidates for the treatment of ulcerative colitis.

Does type 1 diabetes serve as a protective factor against inflammatory bowel disease: A Mendelian randomization study

BACKGROUND

The impact of type 1 diabetes (T1D) on inflammatory bowel disease (IBD) remains unclear.

AIM

To analyze the causal relationship between T1D and IBD using Mendelian ran-domization (MR).

METHODS

Single nucleotide polymorphisms were sourced from FinnGen for T1D, IBD, ulcerative colitis (UC) and Crohn's disease (CD). Inverse variance-weighted, MR-Egger, and weighted median tests were used to assess exposure-outcome causality. The MR-Egger intercept was used to assess horizontal pleiotropy. Co-chran's Q and leave-one-out method were used to analyze heterogeneity and sensitivity, respectively.

RESULTS

Our MR analysis indicated that T1D was associated with a reduced risk of IBD [odds ratio (OR): 0.959; 95% confidence interval (CI): 0.938-0.980; P < 0.001] and UC (OR: 0.960; 95%CI: 0.929-0.992; P = 0.015), with no significant association observed in terms of CD risk (OR: 0.966; 95%CI: 0.913-1.022; P = 0.227). The MR-Egger intercept showed no horizontal pleiotropy (P > 0.05). Cochran's Q and leave-one-out sensitivity analyses showed that the results were not heterogeneous (P > 0.05) and were robust.

CONCLUSION

This MR analysis suggests that T1D serves as a potential protective factor against IBD and UC but is independent of CD.

Inflammatory Bowel Disease: A Comprehensive Analysis of Molecular Bases, Predictive Biomarkers, Diagnostic Methods, and Therapeutic Options

In inflammatory bowel diseases (IBDs), such as Crohn's disease (CD) and ulcerative colitis (UC), the immune system relentlessly attacks intestinal cells, causing recurrent tissue damage over the lifetime of patients. The etiology of IBD is complex and multifactorial, involving environmental, microbiota, genetic, and immunological factors that alter the molecular basis of the organism. Among these, the microbiota and immune cells play pivotal roles; the microbiota generates antigens recognized by immune cells and antibodies, while autoantibodies target and attack the intestinal membrane, exacerbating inflammation and tissue damage. Given the altered molecular framework, the analysis of multiple molecular biomarkers in patients proves exceedingly valuable for diagnosing and prognosing IBD, including markers like C reactive protein and fecal calprotectin. Upon detection and classification of patients, specific treatments are administered, ranging from conventional drugs to new biological therapies, such as antibodies to neutralize inflammatory molecules like tumor necrosis factor (TNF) and integrin. This review delves into the molecular basis and targets, biomarkers, treatment options, monitoring techniques, and, ultimately, current challenges in IBD management.

Effectiveness of a novel diet in attenuation of clinical activity of disease in patients with ulcerative colitis: a randomized, clinical trial

Dietary intake plays a pivotal role in ulcerative colitis (UC) initiation and prognosis. The aim of this study was to investigate the effect of a combined Mediterranean, low-FODMAP diet accompanied with partial enteral nutrition (PEN) on clinical and para-clinical characteristics of patients with UC. Fifty patients with active mild to moderate UC were received either a combined diet or a regular diet for 6 weeks. Before and after the intervention, disease activity index, quality of life and some inflammatory and oxidative stress factors were measured using valid and reliable questionnaires and blood sampling. Disease activity index was significantly decreased in the combined diet group in comparison to control diet group (p = 0.043), and baseline data (p < 0.001). Moreover, the quality of life score increased significantly in the combined diet group compared to the control group, and the baseline data (p < 0.001). Serum level of high sensitive C-reactive protein (hs-CRP) decreased significantly in the combined group (p < 0.01), while it increased in the control group non-significantly. Serum total anti-oxidant capacity (TAC) changes were not statistically significant in two groups. This study indicates that this combination diet has the potential to be used as a safe and highly effective approach in patients with significant intestinal symptoms. Further clinical trial studies with different duration of intervention are needed to confirm these results.Trial registration: The study was registered on IRCT.ir with registration number of IRCT20100524004010N38, on 25/04/2023.

Carrageenan in the Diet: Friend or Foe for Inflammatory Bowel Disease?

While the exact pathogenesis of IBD remains unclear, genetic, environmental and nutritional factors as well as the composition of the gut microbiome play crucial roles. Food additives, which are increasingly consumed in the Western diet, are being investigated for their potential effects on IBD. These additives can affect gut health by altering the composition of the microbiota, immune responses, and intestinal permeability, contributing to autoimmune diseases and inflammation. Despite the growing number of studies on food additives and IBD, the specific effects of carrageenan have not yet been sufficiently researched. This review addresses this gap by critically analyzing recent studies on the effects of carrageenan on the gut microbiota, intestinal permeability, and inflammatory processes. We searched the MEDLINE and SCOPUS databases using the following terms: carrageenan, carrageenan and inflammatory bowel disease, carrageenan and cancer, food additives and microbiome, food additives and intestinal permeability, and food additives and autoimmune diseases. In animal studies, degraded carrageenan has been shown to trigger intestinal ulceration and inflammation, highlighting its potential risk for exacerbating IBD. It can affect the gut microbiota, reduce bacterial diversity, and increase intestinal permeability, contributing to "leaky gut" syndrome. Some studies suggest that carrageenan may inhibit the growth of cancer cells by influencing the progression of the cell cycle, but the anti-cancer effect is still unclear. Carrageenan may also increase glucose intolerance and insulin resistance. Further research is needed to determine whether carrageenan should be excluded from the diet of individuals with IBD.

The influence of the gut-brain axis on anxiety and depression: A review of the literature on the use of probiotics

This review aims to argue how using probiotics can improve anxiety and depressive behaviour without adverse effects, also exploring the impact of postbiotics on it. Specifically, probiotics have drawn more attention as effective alternative treatments, considering the rising cost of antidepressant and anti-anxiety drugs and the high risk of side effects. Depression and anxiety disorders are among the most common mental illnesses in the world's population, characterised by low mood, poor general interest, and cognitive or motor dysfunction. Thus, this study analysed published literature on anxiety, depression, and probiotic supplementation from PubMed and Scopus, focusing on the last twenty years. This study focused on the effect of probiotics on mental health as they have drawn more attention because of their extensive clinical applications and positive impact on various diseases. Numerous studies have demonstrated how the gut microbiota might be critical for mood regulation and how probiotics can affect host health by regulating the gut-brain axis. By comparing the different works analysed, it was possible to identify a strategy by which they are selected and employed and, at the same time, to assess how the effect of probiotics can be optimised using postbiotics, an innovation to improve mental well-being in humans.

Calcium deficiency is associated with malnutrition risk in patients with inflammatory bowel disease

BACKGROUND AND AIM

Patients with inflammatory bowel disease (IBD) often have the condition of malnutrition, which can be presented as sarcopenia, micronutrient deficiencies, etc. Trace elements (magnesium, calcium, iron, copper, zinc, plumbum and manganese) belonging to micronutrients, are greatly vital for the assessment of nutritional status in humans. Trace element deficiencies are also the main manifestation of malnutrition. Calcium (Ca) has been proved to play an important part in maintaining body homeostasis and regulating cellular function. However, there are still a lack of studies on the association between malnutrition and Ca deficiency in IBD. This research aimed to investigate the role of Ca for malnutrition in IBD patients.

METHODS

We prospectively collected blood samples from 149 patients and utilized inductively coupled plasma mass spectrometry to examine their venous serum trace element concentrations. Logistic regression analyses were used to investigate the association between Ca and malnutrition. Receiver operating characteristic (ROC) curves were generated to calculate the cutoffs for determination of Ca deficiency.

RESULTS

Except Ca, the concentrations of the other six trace elements presented no statistical significance between non-malnutrition and malnutrition group. In comparison with the non-malnutrition group, the serum concentration of Ca decreased in the malnutrition group (89.36 vs 87.03 mg/L, p = 0.023). With regard to ROC curve, Ca < 87.21 mg/L showed the best discriminative capability with an area of 0.624 (95% CI: 0.520, 0.727, p = 0.023). Multivariate analyses demonstrated that Ca < 87.21 mg/L (OR = 3.393, 95% CI: 1.524, 7.554, p = 0.003) and age (OR = 0.958, 95% CI: 0.926, 0.990, p = 0.011) were associated with malnutrition risk. Serum Ca levels were significantly lower in the malnutrition group than those in the non-malnutrition group among UC patients, those with severe disease state or the female group.

CONCLUSIONS

In patients with IBD, Ca deficiency is an independent factor for high malnutrition risk.

S/O/W Emulsion with CAPE Ameliorates DSS-Induced Colitis by Regulating NF-κB Pathway, Gut Microbiota and Fecal Metabolome in C57BL/6 Mice

Inflammatory bowel disease (IBD) has attracted much attention worldwide due to its prevalence. In this study, the effect of a solid-in-oil-in-water (S/O/W) emulsion with Caffeic acid phenethyl ester (CAPE, a polyphenolic active ingredient in propolis) on dextran sulfate sodium (DSS)-induced colitis in C57BL/6 mice was evaluated. The results showed that CAPE-emulsion could significantly alleviate DSS-induced colitis through its effects on colon length, reduction in the disease activity index (DAI), and colon histopathology. The results of ELISA and Western blot analysis showed that CAPE-emulsion can down-regulate the excessive inflammatory cytokines in colon tissue and inhibit the expression of p65 in the NF-κB pathway. Furthermore, CAPE-emulsion promoted short-chain fatty acids production in DSS-induced colitis mice. High-throughput sequencing results revealed that CAPE-emulsion regulates the imbalance of gut microbiota by enhancing diversity, restoring the abundance of beneficial bacteria (such as Odoribacter), and suppressing the abundance of harmful bacteria (such as Afipia, Sphingomonas). The results of fecal metabolome showed that CAPE-emulsion restored the DSS-induced metabolic disorder by affecting metabolic pathways related to inflammation and cholesterol metabolism. These research results provide a scientific basis for the use of CPAE-emulsions for the development of functional foods for treating IBD.

Shared genetic basis and causality between schizophrenia and inflammatory bowel disease: evidence from a comprehensive genetic analysis

BACKGROUND

The comorbidity between schizophrenia (SCZ) and inflammatory bowel disease (IBD) observed in epidemiological studies is partially attributed to genetic overlap, but the magnitude of shared genetic components and the causality relationship between them remains unclear.

METHODS

By leveraging large-scale genome-wide association study (GWAS) summary statistics for SCZ, IBD, ulcerative colitis (UC), and Crohn's disease (CD), we conducted a comprehensive genetic pleiotropic analysis to uncover shared loci, genes, or biological processes between SCZ and each of IBD, UC, and CD, independently. Univariable and multivariable Mendelian randomization (MR) analyses were applied to assess the causality across these two disorders.

RESULTS

SCZ genetically correlated with IBD (rg = 0.14, p = 3.65 × 10−9), UC (rg = 0.15, p = 4.88 × 10−8), and CD (rg = 0.12, p = 2.27 × 10−6), all surpassed the Bonferroni correction. Cross-trait meta-analysis identified 64, 52, and 66 significantly independent loci associated with SCZ and IBD, UC, and CD, respectively. Follow-up gene-based analysis found 11 novel pleiotropic genes (KAT5, RABEP1, ELP5, CSNK1G1, etc) in all joint phenotypes. Co-expression and pathway enrichment analysis illustrated those novel genes were mainly involved in core immune-related signal transduction and cerebral disorder-related pathways. In univariable MR, genetic predisposition to SCZ was associated with an increased risk of IBD (OR 1.11, 95% CI 1.07–1.15, p = 1.85 × 10−6). Multivariable MR indicated a causal effect of genetic liability to SCZ on IBD risk independent of Actinobacteria (OR 1.11, 95% CI 1.06–1.16, p = 1.34 × 10−6) or BMI (OR 1.11, 95% CI 1.04–1.18, p = 1.84 × 10−3).

CONCLUSIONS

We confirmed a shared genetic basis, pleiotropic loci/genes, and causal relationship between SCZ and IBD, providing novel insights into the biological mechanism and therapeutic targets underlying these two disorders.

Assessment of the Inflammatory Effects of Gut Microbiota from Human Twins Discordant for Ulcerative Colitis on Germ-free Mice

Disturbances in gut microbiota are prevalent in inflammatory bowel disease (IBD), which includes ulcerative colitis (UC). However, whether these disturbances contribute to development of the disease or are a result of the disease is unclear. In pairs of human twins discordant for IBD, the healthy twin has a higher risk of developing IBD and a gut microbiota that is more similar to that of IBD patients as compared with healthy individuals. Furthermore, appropriate medical treatment may mitigate these disturbances. To study the correlation between microbiota and IBD, we transferred stool samples from a discordant human twin pair: one twin being healthy and the other receiving treatment for UC. The stool samples were transferred from the disease-discordant twins to germ-free pregnant dams. Colitis was induced in the offspring using dextran sodium sulfate. As compared with offspring born to mice dams inoculated with stool from the healthy cotwin, offspring born to dams inoculated with stool from the UC-afflicted twin had a lower disease activity index, less gut inflammation, and a microbiota characterized by higher α diversity and a more antiinflammatory profile that included the presence and higher abundance of antiinflammatory species such as Akkermansia spp., Bacteroides spp., and Parabacteroides spp. These findings suggest that the microbiota from the healthy twin may have had greater inflammatory properties than did that of the twin undergoing UC treatment.

Association between dietary calcium to Phosphorus Ratio and the odds of ulcerative colitis: A case-control study

Background & aims

Ulcerative colitis (UC) is a recurrent, inflammatory, autoimmune intestinal disease. The dietary calcium to phosphorus (Ca:P) ratio is suggested to affect the inividuals' normal metabolic and inflammatory pathways. The present study aimed to investigate the association between dietary Ca:P ratio and the odds of developing UC in a case-control format.

Methods

The study included sixty-two currently diagnosed UC patients and one hundred twenty-four matched controls, designed as a case-control study. The dietary intakes of the participants were assessed by a food frequency questionnaire (FFQ), and the dietary Ca:P ratio was calculated. The association between tertiles of Ca:P ratio and UC was examined using the logistic regression. P-values <0.05 were considered as significant.

Results

The study sample consisted of participants with an average age of 36.63 ± 12.42 years and a mean body mass index (BMI) of 25.39 ± 3.82 kg/m2. The overall energy-adjusted ratio of Ca:P was 0.74 ± 0.11. In the multivariate model, after adjustment for potential confounders, participants in the third tertile of dietary Ca:P ratio had a lower odds of developing UC compared to the lowest tertlie (OR: 0.34, 95% CI: 0.13-0.87; p = 0.026).

Conclusion

Our results indicate that a higher ratio of dietary Ca:P ratio might be protective against developing UC. However, further studies are warranted to examine this association in various populations.

Crude Tieguanyin oolong tea polysaccharides regulate intestinal immune and gut microflora in dextran sulfate sodium-induced mice colitis

BACKGROUND

The global incidence and prevalence of inflammatory bowel diseases (IBDs) have been increasing. Epidemiological studies, clinical trials, and animal experiments have indicated a negative association between the consumption of tea and IBD. This study aims to investigate the protective effects of crude Tieguanyin oolong tea polysaccharides (CTPS) on experimental colitis, while also exploring the underlying mechanisms.

RESULTS

The administration of CTPS significantly alleviated IBD in the mouse model, and was found to regulate T-cell mediated immune responses in the colon by modulating cytokine production associated with T cells. Furthermore, CTPS demonstrated a positive impact on the gut microbiota, reversing the increase in pathogenic Helicobacter and enhancing the relative abundances of beneficial bacteria such as Akkermansia, Lachnospiraceae, and Odoribacter. Oral administration of CTPS also led to an improvement in intestinal metabolism, specifically by increasing the levels of short-chain fatty acids.

CONCLUSION

This study provides the first in vivo evidence of the protective effects of CTPS on colitis in mice. The effects are likely facilitated through the regulation of T cell-mediated responses and modulation of the gut microbiota, suggesting that CTPS may be a potential preventive and therapeutic approach for IBD. © 2023 Society of Chemical Industry.

Intestinal Flora Imbalance Induced by Antibiotic Use in Rats

Aim

This study aims to explore the effect of different doses of antibiotics on rats in order to observe alterations in their fecal microbiota, inflammatory changes in the colonic mucosa and four types of inflammatory markers in blood serum.

Methods

Our methodology involved separating 84 female Sprague Dawley rats into groups A-G, with each group consisting of 12 rats. We collected the rat feces for analysis, using a distinct medium for bacterial cultivation and counting colonies under a microscope. On the 11th and 15th days of the experiment, half of the rats from each group were euthanized and 5 mL of abdominal aortic blood and colon tissues were collected. Inflammations changes of colon were observed and assessed by pathological Hematoxylin Eosin (HE) staining. Enzyme-linked immune sorbent assay (ELISA) was adopted for detecting C-reactive protein (CRP), IL-6, IL1-β and TNF-α.

Results

Our findings revealed that the initial average weight of the rats did not differ between groups (p>0.05); but significant differences were observed between stool samples, water intake, food intake and weight (p=0.009, <0.001, 0.016 and 0.04, respectively) within two hours after the experiment. Additionally, there were notable differences among the groups in nine tested microbiota before and after weighting methods (all p<0.001). There were no difference in nine microbiota at day 1 (all p>0.05); at day 4 A/B (p=0.044), A/D (p<0.001), A/E (p=0.029); at day 8, all p<0.01, at day 11, only A/F exist significant difference (p<0.001); at day 14 only A/D has difference (p=0.045). Inflammation changes of colon were observed between groups A-G at days 11 and 15. Significant differences between all groups can be observed for CRP, IL-6, IL1-β and TNF-α (p<0.001).

Conclusion

This study suggests that antibiotics administration can disrupt the balance of bacteria in the rat gut ecosystem, resulting in an inflammatory response in their bloodstream and inducing inflammation changes of colon.

Porphyromonas gingivalis aggravates colitis via a gut microbiota-linoleic acid metabolism-Th17/Treg cell balance axis

Periodontitis is closely related to inflammatory bowel disease (IBD). An excessive and non-self-limiting immune response to the dysbiotic microbiome characterizes the two. However, the underlying mechanisms that overlap still need to be clarified. We demonstrate that the critical periodontal pathogen Porphyromonas gingivalis (Pg) aggravates intestinal inflammation and Th17/Treg cell imbalance in a gut microbiota-dependent manner. Specifically, metagenomic and metabolomic analyses shows that oral administration of Pg increases levels of the Bacteroides phylum but decreases levels of the Firmicutes, Verrucomicrobia, and Actinobacteria phyla. Nevertheless, it suppresses the linoleic acid (LA) pathway in the gut microbiota, which was the target metabolite that determines the degree of inflammation and functions as an aryl hydrocarbon receptor (AHR) ligand to suppress Th17 differentiation while promoting Treg cell differentiation via the phosphorylation of Stat1 at Ser727. Therapeutically restoring LA levels in colitis mice challenged with Pg exerts anti-colitis effects by decreasing the Th17/Treg cell ratio in an AHR-dependent manner. Our study suggests that Pg aggravates colitis via a gut microbiota-LA metabolism-Th17/Treg cell balance axis, providing a potential therapeutically modifiable target for IBD patients with periodontitis.

Alterations of gut microbiota in infants with biliary atresia identified by 16S rRNA-sequencing

BACKGROUND

Biliary atresia (BA) is a severe neonatal disease with progressive intra- and extra-hepatic bile ducts inflammation and hepatic fibrosis. Characterization of gut microbiome profiles in infants with biliary atresia can provide valuable information and potential disease biomarkers. Our study aims to explore the relationship between gut microbiota and biliary atresia.

METHODS

16 S ribosomal RNA (rRNA) gene sequencing was carried out to identify the differences in composition and diversity of gut microbiota between infants with BA and healthy subjects. A total of 31 infants with biliary atresia and 20 healthy subjects were recruited.

RESULTS

The composition of gut microbiota in BA group was significantly different with the normal control group (P < 0.05) and the abundance ratio of Klebsiella/Bifidobacterium showed great potential for identification of BA (P < 0.01). In addition, the differential bacterial taxa were involved in lipid and vitamins metabolism.

CONCLUSION

Our results could provide potential non-invasive biomarker for identification of biliary atresia and contribute to the treatment in terms of ameliorating microbiota dysbiosis.

Potential effects of nutrition-induced alteration of gut microbiota on inflammatory bowel disease: A review

Inflammatory bowel disease (IBD), mainly comprising ulcerative colitis and Crohn's disease, is a group of gradually progressive diseases bringing significant mental anguish and imposes serious economic burdens. Interplay of genetic, environmental, and immunological factors have been implicated in its pathogenesis. Nutrients, as crucial environmental determinants, mainly encompassing carbohydrates, fats, proteins, and micronutrients, are closely related to the pathogenesis and development of IBD. Nutrition is essential for maintaining the dynamic balance of intestinal eco-environments to ensure intestinal barrier and immune homeostasis, while this balance can be disrupted easily by maladjusted nutrition. Research has firmly established that nutrition has the potential to shape the composition and function of gut microbiota to affect the disease course. Unhealthy diet and eating disorders lead to gut microbiota dysbiosis and further destroy the function of intestinal barrier such as the disruption of membrane integrity and increased permeability, thereby triggering intestinal inflammation. Notably, appropriate nutritional interventions, such as the Mediterranean diet, can positively modulate intestinal microecology, which may provide a promising strategy for future IBD prevention. In this review, we provide insights into the interplay between nutrition and gut microbiota and its effects on IBD and present some previously overlooked lines of evidence regarding the role of derived metabolites in IBD processes, such as trimethylamine N-oxide and imidazole propionate. Furthermore, we provide some insights into reducing the risk of onset and exacerbation of IBD by modifying nutrition and discuss several outstanding challenges and opportunities for future study.

Tissue and serum miR-149-3p/5p in hospitalized patients with inflammatory bowel disease: Correlation with disease severity and inflammatory markers

This study aimed to investigate the expression levels of tissue and serum miR-149-3p and miR-149-5p in hospitalized patients with inflammatory bowel disease (IBD). A total of 35 ulcerative colitis (UC) patients, 12 Crohn's disease (CD) patients, and 25 healthy controls were included in the study. The miRNAs expressions were measured in tissue and serum samples using quantitative real-time polymerase chain reaction (qRT-PCR). Inflammatory biomarkers were measured, including serum albumin, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6), and fecal calprotectin. MiR-149-3p and miR-149-5p were significantly decreased in the inflamed areas of both CD and UC patients compared to tissue controls, which was consistent with decreased serum levels in IBD patients compared to healthy controls. When distinguishing UC patients from healthy controls, serum miR-149-3p showed 74% sensitivity and 96% specificity, while serum miR-149-5p exhibited 63% sensitivity and 96% specificity. In the CD versus healthy control comparison, miR-149-3p achieved 100% sensitivity and 96% specificity, while miR-149-5p demonstrated 92% sensitivity and 96% specificity. In the UC versus CD comparison, miR-149-5p showed 75% sensitivity and 77% specificity, while miR-149-3p displayed 67% sensitivity and 80% specificity. Significant correlations were identified between the tissue and serum expression of miR-149-3p/5p and disease activity scores, as well as inflammatory biomarkers in both CD and UC patients. Decreased expression of miR-149-3p and miR-149-5p is associated with disease activity in IBD patients. These miRNAs demonstrate diagnostic potential and may serve as biomarkers for monitoring disease activity in IBD.

Electroacupuncture Reduces Inflammatory Bowel Disease in Obese Mice by Activating the Nrf2/HO-1 Signaling Pathways and Repairing the Intestinal Barrier

Background

Electroacupuncture (EA) is used to treat inflammatory bowel disease (IBD). Nevertheless, the precise mechanisms by which this approach safeguards against obesity-induced intestinal barrier damage has not been fully understood.

Objective

This study aimed to assess whether EA could ameliorate intestinal barrier damage that had been reversed in a mouse model of obesity induced by a high-fat diet (HFD) and whether this repair is correlated with ferroptosis and gut microbiota enhancement.

Methods

To assess the potential of EA to prevent obesity and restore the intestinal barrier, we divided in C57BL/6J mice into two groups; one was fed with HFD and another one with a normal diet. Samples of stool, blood, fat, and intestinal epithelium were then evaluated, along with body weight.

Results

Following EA, we observed a significant reduction in body weight, fat accumulation, and serum triglyceride (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) levels; an increase was seen in high-density lipoprotein cholesterol (HDL-C) levels. EA also activated the Nrf2 signaling pathway; upregulated the expression of GPX4, FTH1, and SLC7A11; and downregulated the expression of TFR1. In addition, the administration of EA resulted in a notable modification of the gut microbiota composition, characterized by a decrease in the Firmicutes to Bacteroidetes ratio.

Conclusion

EA had beneficial effects on weight loss and showed potential ability to repair the intestinal barrier by activating the Nrf2 signaling pathway, inhibiting intestinal inflammation and ferroptosis, and regulating the intestinal microbiota to treat IBD caused by HFD-induced obesity.

Cognitive behavioral and mindfulness with daily exercise intervention is associated with changes in intestinal microbial taxa and systemic inflammation in patients with Crohn's disease

Crohn's disease (CD) is a chronic inflammatory bowel disease associated with psychological distress and intestinal microbial changes. Here, we examined whether a 3-month period of Cognitive Behavioral and Mindfulness with Daily Exercise (COBMINDEX) intervention, which improves the wellbeing and inflammatory state of CD patients, may also affect their gut microbiome. Gut microbiota, circulating inflammatory markers and hormones were analyzed in 24 CD patients before (T1) and after 3 months of COBMINDEX (T2), and in 25 age- and sex-matched wait-list control patients at the corresponding time-points. Microbiota analysis examined relative taxonomical abundance, alpha and beta diversity, and microbiome correlations with inflammatory and psychological parameters. At T1, CD patients exhibited a characteristic microbial profile mainly constituted of Proteobacteria (17.71%), Firmicutes (65.56%), Actinobacteria (8.46%) and Bacteroidetes (6.24%). Baseline bacterial abundances showed significant correlations with psychological markers of distress and with IFNγ . Following COBMINDEX, no significant changes in alpha and beta diversity were observed between both study groups, though a trend change in beta diversity was noted. Significant changes occurred in the abundance of phyla, families and genera only among the COBMINDEX group. Furthermore, abundance of phyla, families and genera that were altered following COBMNIDEX, significantly correlated with levels of cytokines and psychological parameters. Our results demonstrated that a short-term intervention of COBMINDEX was associated with changes in microbial indices, some of which are linked to psychological manifestations and systemic inflammation in CD patients. Psychological interventions to reduce chronic stress, such as COBMINDEX, appear to be beneficial in mitigating the pathobiology of CD patients, and may thus provide a useful adjunct to pharmacological therapy.

Gut microbiota in pathophysiology, diagnosis, and therapeutics of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a multifactorial disease, which is thought to be an interplay between genetic, environment, microbiota, and immune-mediated factors. Dysbiosis in the gut microbial composition, caused by antibiotics and diet, is closely related to the initiation and progression of IBD. Differences in gut microbiota composition between IBD patients and healthy individuals have been found, with reduced biodiversity of commensal microbes and colonization of opportunistic microbes in IBD patients. Gut microbiota can, therefore, potentially be used for diagnosing and prognosticating IBD, and predicting its treatment response. Currently, there are no curative therapies for IBD. Microbiota-based interventions, including probiotics, prebiotics, synbiotics, and fecal microbiota transplantation, have been recognized as promising therapeutic strategies. Clinical studies and studies done in animal models have provided sufficient evidence that microbiota-based interventions may improve inflammation, the remission rate, and microscopic aspects of IBD. Further studies are required to better understand the mechanisms of action of such interventions. This will help in enhancing their effectiveness and developing personalized therapies. The present review summarizes the relationship between gut microbiota and IBD immunopathogenesis. It also discusses the use of gut microbiota as a noninvasive biomarker and potential therapeutic option.

Gut-brain axis interacts with immunomodulation in inflammatory bowel disease

The brain and the gastrointestinal (GI) tract are important sensory organs in the body and the two-way interaction that exists between them regulates key physiological and homeostatic functions. A growing body of research suggests that this bidirectional communication influences the development and progression of functional GI disorders and plays an important role in the treatment of central nervous system (CNS) disorders. Inflammatory bowel disease (IBD) is a classic intestinal disorder with a high prevalence but still unclear pathogenesis that has been widely discussed in recent years. However, in the studies available to date, we find that many authors have chosen to discuss the influence of the brain on intestinal disorders from the top down, starting with physical and psychological disorders. Coming very naturally, based on these substantial research evidence, we focus on exploring the links between bidirectional communication in the gut-brain axis and IBD, and highlight the role of the gut microbiota, vagus nerve (VN), receptors and immune cells involved in regulating IBD through the gut-brain axis in this review.

Bacterial membrane vesicles in the pathogenesis and treatment of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic and debilitating condition of relapsing and remitting inflammation in the gastrointestinal tract. Conventional therapeutic approaches for IBD have shown limited efficacy and detrimental side effects, leading to the quest for novel and effective treatment options for the disease. Bacterial membrane vesicles (MVs) are nanosized lipid particles secreted by lysis or blebbing processes from both Gram-negative and Gram-positive bacteria. These vesicles, known to carry bioactive components, are facsimiles of the parent bacterium and have been implicated in the onset and progression, as well as in the amelioration of IBD. This review discusses the overview of MVs and their impact in the pathogenesis, diagnosis, and treatment of IBD. We further discuss the technical challenges facing this research area and possible research questions addressing these challenges. We summarize recent advances in the diverse relationship between IBD and MVs, and the application of this knowledge as a viable and potent therapeutic strategy for IBD.

A Narrative Review: Analysis of Supplemental Parenteral Nutrition in Adults at the End of Life

"End of life" is a stage defined by the existence of an irreversible prognosis that ends with a person's death. One of the aspects of interest regarding end of life focuses on parenteral nutrition, which is usually administered in order to avoid malnutrition and associated complications. However, parenteral nutrition can be adapted to specific circumstances and evolve in its functionality through supplementation with certain nutrients that can have a beneficial effect. This narrative review aims to carry out a situation analysis of the role that could be adopted by supplemental parenteral nutrition in attenuating alterations typical of end of life and potential improvement in quality of life.

Emergent Functional Organization of Gut Microbiomes in Health and Diseases

Continuous and significant progress in sequencing technologies and bioinformatics pipelines has revolutionized our comprehension of microbial communities, especially for human microbiomes. However, most studies have focused on studying the taxonomic composition of the microbiomes and we are still not able to characterize dysbiosis and unveil the underlying ecological consequences. This study explores the emergent organization of functional abundances and correlations of gut microbiomes in health and disease. Leveraging metagenomic sequences, taxonomic and functional tables are constructed, enabling comparative analysis. First, we show that emergent taxonomic and functional patterns are not useful to characterize dysbiosis. Then, through differential abundance analyses applied to functions, we reveal distinct functional compositions in healthy versus unhealthy microbiomes. In addition, we inquire into the functional correlation structure, revealing significant differences between the healthy and unhealthy groups, which may significantly contribute to understanding dysbiosis. Our study demonstrates that scrutinizing the functional organization in the microbiome provides novel insights into the underlying state of the microbiome. The shared data structure underlying the functional and taxonomic compositions allows for a comprehensive macroecological examination. Our findings not only shed light on dysbiosis, but also underscore the importance of studying functional interrelationships for a nuanced understanding of the dynamics of the microbial community. This research proposes a novel approach, bridging the gap between microbial ecology and functional analyses, promising a deeper understanding of the intricate world of the gut microbiota and its implications for human health.

A proteomic insight reveals the role of food-associated Lactiplantibacillus plantarum C9O4 in reverting intestinal inflammation

Nowadays, Western diets and lifestyle lead to an increasing occurrence of chronic gut inflammation that represents an emerging health concern with still a lack of successful therapies. Fermented foods, and their associated lactic acid bacteria, have recently regained popularity for their probiotic potential including the maintenance of gut homeostasis by modulating the immune and inflammatory response. Our study aims to investigate the crosstalk between the food-borne strain Lactiplantibacillus plantarum C9O4 and intestinal epithelial cells in an in vitro inflammation model. Cytokines profile shows the ability of C9O4 to significantly reduce levels of IL-2, IL-5, IL-6, and IFN-γ. Proteomic functional analysis reveals an immunoregulatory role of C9O4, able to revert the detrimental effects of IFN-γ through the JAK/STAT pathway in inflamed intestinal cells. These results suggest a promising therapeutic role of fermented food-associated microbes for the management of gastrointestinal inflammatory diseases. Data are available via ProteomeXchange with identifier PXD042175.

Inactivation of Group 1B Phospholipase A2 Enhances Disease Recovery and Reduces Experimental Colitis in Mice

Phospholipase A2 (PLA2) enzymes influence inflammatory bowel disease in both positive and negative manners depending on the type of PLA2 that is expressed. This study explored the influence of the abundantly expressed Group 1B PLA2 (PLA2G1B) on ulcerative colitis. Wild-type C57BL/6J mice and Pla2g1b-/- mice were treated with dextran sulfate sodium (DSS) for 5 days to induce epithelial injury, followed by another 5 days without DSS for recovery. The Pla2g1b-/- mice displayed significantly less body weight loss, colitis pathology, and disease activity indexes compared to the wild-type mice. The differences in colitis were not due to differences in the colonic lysophospholipid levels, but higher numbers of stem and progenitor cells were found in the intestines of Pla2g1b-/- mice compared to the wild-type mice. The DSS-treated Pla2g1b-/- mice also showed higher expressions of genes that are responsible for epithelial repair and lower expressions of proinflammatory cytokine genes in the colon, as well as reduced inflammatory cytokine levels in the plasma. In vitro experiments revealed the PLA2G1B stimulation of inflammatory cytokine expression by myeloid cells. PLA2G1B inactivation protects against DSS-induced colitis in mice by increasing the intestinal stem cell reservoir for epithelial repair and reducing myeloid cell inflammation in the diseased colon. Thus, PLA2G1B may be a target for colitis management.

Association between inflammatory bowel disease, nephrolithiasis, tubulointerstitial nephritis, and chronic kidney disease: A propensity score-matched analysis of US nationwide inpatient sample 2016-2018

OBJECTIVES

The incidence and prevalence of inflammatory bowel disease (IBD), mainly including ulcerative colitis (UC) and Crohn's disease (CD), are increasing globally. We aimed to evaluate the potential association between IBD and nephrolithiasis, tubulointerstitial nephritis, and chronic kidney disease (CKD).

METHODS

Data of hospitalized adults ≥20 years of age were extracted from the U.S. National Inpatient Sample (NIS) during 2016-2018. Patients with UC, CD, or CKD were identified through the International Classification of Diseases, Tenth Revision (ICD-10) codes. Propensity score matching (PSM) analysis (1:1) was conducted to balance the characteristics between groups. Logistic regression analyses were performed to determine the relationships between UC or CD and kidney conditions.

RESULTS

Three cohorts were included for analysis after PSM analysis. Cohorts 1, 2 and 3 contained 235 262 subjects (117 631 with CD or without IBD), 140 856 subjects (70 428 with UC or without IBD), and 139 098 subjects (69 549 with CD or UC), respectively. Multivariate analysis revealed that compared to non-IBD individuals, CD patients were significantly associated with greater odds for nephrolithiasis (adjusted odds ratio [aOR] 2.25, 95% confidence interval [CI] 2.08-2.43), tubulointerstitial nephritis (aOR 1.31, 95% CI 1.24-1.38), CKD at any stage (aOR 1.28, 95% CI 1.24-1.32), and moderate-to-severe CKD (aOR 1.22, 95% CI 1.17-1.26), while UC was associated with a higher rate of nephrolithiasis. Compared to UC, CD was associated with higher odds for all such kidney conditions.

CONCLUSIONS

Patients with CD are more likely to have nephrolithiasis, tubulointerstitial nephritis, CKD at any stage, and moderate-to-severe CKD compared to non-IBD individuals.

Targeted delivery of budesonide in acetic acid induced colitis: impact on miR-21 and E-cadherin expression

Inflammatory bowel disease (IBD) is characterized by chronic inflammation along the gastrointestinal tract. For IBD effective treatment, developing an orally administered stable drug delivery system capable of targeting inflammation sites is a key challenge. Herein, we report pH responsive hyaluronic (HA) coated Eudragit S100 (ES) nanoparticles (NPs) for the targeted delivery of budesonide (BUD) (HA-BUD-ES-NPs). HA-BUD-ES-NPs showed good colloidal properties (274.8 ± 2.9 nm and - 24.6 ± 2.8 mV) with high entrapment efficiency (98.3 ± 3.41%) and pH-dependent release profile. The negative potential following incubation in simulated gastrointestinal fluids reflected the stability of HA coat. In vitro studies on Caco-2 cells showed HA-BUD-ES-NPs biocompatibility and enhanced cellular uptake and anti-inflammatory effects as shown by the significant reduction in IL-8 and TNF-α. The oral administration of HA-BUD-ES-NPs in an acetic acid induced colitis rat model significantly mitigated the symptoms of IBD, and improved BUD therapeutic efficacy compared to drug suspension. This was proved via the improvement in disease activity index and ulcer score in addition to refined histopathological findings. Also, the assessment of inflammatory markers, epithelial cadherin, and mi-R21 all reflected the higher efficiency of HA-BUD-ES-NPs compared to free drug and uncoated formulation. We thus suggest that HA-BUD-ES-NPs provide a promising drug delivery platform for the management and site specific treatment of IBD.

Activation of the aryl hydrocarbon receptor in inflammatory bowel disease: insights from gut microbiota

Inflammatory bowel disease (IBD) is a chronic inflammatory intestinal disease that affects more than 3.5 million people, with rising prevalence. It deeply affects patients' daily life, increasing the burden on patients, families, and society. Presently, the etiology of IBD remains incompletely clarified, while emerging evidence has demonstrated that altered gut microbiota and decreased aryl hydrocarbon receptor (AHR) activity are closely associated with IBD. Furthermore, microbial metabolites are capable of AHR activation as AHR ligands, while the AHR, in turn, affects the microbiota through various pathways. In light of the complex connection among gut microbiota, the AHR, and IBD, it is urgent to review the latest research progress in this field. In this review, we describe the role of gut microbiota and AHR activation in IBD and discussed the crosstalk between gut microbiota and the AHR in the context of IBD. Taken as a whole, we propose new therapeutic strategies targeting the AHR-microbiota axis for IBD, even for other related diseases caused by AHR-microbiota dysbiosis.

Microbiota as key factors in inflammatory bowel disease

Inflammatory Bowel Disease (IBD) is characterized by prolonged inflammation of the gastrointestinal tract, which is thought to occur due to dysregulation of the immune system allowing the host's cells to attack the GI tract and cause chronic inflammation. IBD can be caused by numerous factors such as genetics, gut microbiota, and environmental influences. In recent years, emphasis on commensal bacteria as a critical player in IBD has been at the forefront of new research. Each individual harbors a unique bacterial community that is influenced by diet, environment, and sanitary conditions. Importantly, it has been shown that there is a complex relationship among the microbiome, activation of the immune system, and autoimmune disorders. Studies have shown that not only does the microbiome possess pathogenic roles in the progression of IBD, but it can also play a protective role in mediating tissue damage. Therefore, to improve current IBD treatments, understanding not only the role of harmful bacteria but also the beneficial bacteria could lead to attractive new drug targets. Due to the considerable diversity of the microbiome, it has been challenging to characterize how particular microorganisms interact with the host and other microbiota. Fortunately, with the emergence of next-generation sequencing and the increased prevalence of germ-free animal models there has been significant advancement in microbiome studies. By utilizing human IBD studies and IBD mouse models focused on intraepithelial lymphocytes and innate lymphoid cells, this review will explore the multifaceted roles the microbiota plays in influencing the immune system in IBD.

A Potential Role for Gut Microbes in Mediating Effects of Omega-3 Fatty Acids in Inflammatory Bowel Diseases: A Comprehensive Review

Omega-3 polyunsaturated fatty acids (ω-3 PUFAs) have been associated with several inflammatory conditions, including inflammatory bowel diseases (IBDs), and found to have an impact on gut microbiota. In fact, some randomized controlled studies suggest benefits to IBD patients, but others do not. Our aim was to review recent evidence on the effects of omega-3 on IBD and establish the contribution of the gut microbiome. Omega-3 mediate anti-inflammatory effects in IBD through various mechanisms, including suppression of NLR family pyrin domain-containing 3 (NLRP3) inflammasome, Toll-like receptor-4 (TLR4), and nucleotide-binding oligomerization domain 2 (NOD2) signaling; this results in the repression of the nuclear factor-kappa B (Nf-kB) pathway and the secretion of pro-inflammatory cytokines. Omega-3 can also affect gut microbiota and revert the bacterial community to patterns associated with healthy status by increasing short-chain fatty acid (SCFA)-producing bacteria and enhancing the mucosal gut barrier, thus promoting homeostasis. The combination of these immunoregulatory effects and anti-inflammation properties with the promotion of a balanced gut microbiome environment could suggest that omega-3 might benefit IBD patients. Considering the microbiota of IBD patients while using omega-3 might predict and improve omega-3 effectiveness. Combining omega-3 with bacteria-altering therapy, such as probiotics and fecal microbiota transplantation, may further enhance its efficacy; however, further studies are required to elucidate mechanisms and potential preventive or treatment roles of omega-3 in IBD.

Exploring the gut microbiota: lifestyle choices, disease associations, and personal genomics

The gut microbiota is a rich and dynamic ecosystem that actively interacts with the human body, playing a significant role in the state of health and disease of the host. Diet, exercise, mental health, and other factors have exhibited the ability to influence the gut bacterial composition, leading to changes that can prevent and improve, or favor and worsen, both intestinal and extra-intestinal conditions. Altered gut microbial states, or 'dysbiosis', associated with conditions and diseases are often characterized by shifts in bacterial abundance and diversity, including an impaired Firmicutes to Bacteroidetes ratio. By understanding the effect of lifestyle on the gut microbiota, personalized advice can be generated to suit each individual profile and foster the adoption of lifestyle changes that can both prevent and ameliorate dysbiosis. The delivery of effective and reliable advice, however, depends not only on the available research and current understanding of the topic, but also on the methods used to assess individuals and to discover the associations, which can introduce bias at multiple stages. The aim of this review is to summarize how human gut microbial variability is defined and what lifestyle choices and diseases have shown association with gut bacterial composition. Furthermore, popular methods to investigate the human gut microbiota are outlined, with a focus on the possible bias caused by the lack of use of standardized methods. Finally, an overview of the current state of personalized advice based on gut microbiota testing is presented, underlining its power and limitations.

The NRF2/Keap1 pathway as a therapeutic target in inflammatory bowel disease

Oxidative stress (OS) is an important pathophysiological mechanism in inflammatory bowel disease (IBD). However, clinical trials investigating compounds directly targeting OS in IBD yielded mixed results. The NRF2 (nuclear factor erythroid 2-related factor 2)/Keap1 (Kelch-like ECH-associated protein 1) pathway orchestrates cellular responses to OS, and dysregulation of this pathway has been implicated in IBD. Activation of the NRF2/Keap1 pathway may enhance antioxidant responses. Although this approach could help to attenuate OS and potentially improve clinical outcomes, an overview of human evidence for modulating the NRF2/Keap1 axis and more recent developments in IBD is lacking. This review explores the NRF2/Keap1 pathway as potential therapeutic target in IBD and presents compounds activating this pathway for future clinical applications.

Inhibition of NLRP3 attenuates sodium dextran sulfate-induced inflammatory bowel disease through gut microbiota regulation

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic, life-threatening inflammatory disease of gastrointestinal tissue characterized by inflammation of the gut. Recent studies have shown that gut microbiota is involved in the pathophysiology of IBD. However, it is unknown whether direct inhibition of NLR family pyrin domain containing 3 (NLRP3) inflammasome regulates IBD and alters gut microbiota.

METHODS

Here, the NLRP3 expression was evaluated in the colon of IBD subjects. Then, we investigated the effects of NLRP3 inhibition by MCC950 on the gut microbiota and IBD-like symptoms induced by dextran sulfate sodium (DSS).

RESULTS

Firstly, NLRP3 and IL-1β levels were increased in patients with IBD as compared with healthy individuals. Then, the animal experiment showed that NLRP3 inhibition by MCC950 significantly attenuated IBD-like symptoms such as diarrhea and colonic inflammation in DSS-induced mice. In addition, NLRP3 inhibition inhibited NLRP3/ASC/caspase-1/IL-1β signaling pathway in the colon, which was over-activated by DSS. Furthermore, MCC950 increased the abundance of phylum Firmicutes, decreased the abundance of phylum Bacteroidetes, and increased the Firmicutes/Bacteroidetes ratio, indicating that the inhibition of NLRP3 inflammasome could regulate the abundance of intestinal flora. According to correlation analysis, NLRP3 might produce its functional role in the regulation of oxidation indicators by changing the gut microbiota composition, especially the phylum Bacteroidota, genus Lactobacillus and species Lactobacillus reuteri.

CONCLUSIONS

This study suggests that NLRP3 inflammasome inhibition attenuates IBD-like symptoms by regulating gut microbiota, and provides a basis for the clinical application of NLRP3 as a target for the treatment of IBD.

The Effects of Acupuncture on Crohn's Disease: a systematic review and meta-analysis

Objectives

Crohn's disease is a chronic gastrointestinal disease that belongs to inflammatory bowel disease. This systematic review aims to assess the level of evidence in randomized controlled trials (RCTs) on the effects of acupuncture for Crohn's disease.

Methods

We searched 12 databases from the date of the establishment of each database up to May, 2023 for relevant RCTs. The risk of bias of each study was assessed independently by three reviewers. The level of evidence of meta-analysis was assessed using GRADE (Grading of Recommendations, Assessment, Development, and Evaluation).

Results

A total of 12 studies were included. The effective rate (odds ratio [OR] 3.23, 95% confidence interval [CI] 1.43, 7.30) for mild to moderate Crohn's disease patients showed a significant difference between the acupuncture with moxibustion group and the sham-acupuncture with sham-moxibustion group. CDAI change (mean difference [MD] -74.15, 95% CI -93.28, -55.01) for mild to moderate Crohn's disease showed a significant difference between the acupuncture with moxibustion group and the sham-acupuncture with sham-moxibustion group.

Conclusion

Although acupuncture with moxibustion showed significant effects compared to sham-acupuncture with sham-moxibustion, the effect of acupuncture alone is inconclusive. Moreover, only the effect of acupuncture treatment on mild to moderate Crohn's disease patients was derived as a remarkable result. To confirm the effectiveness of acupuncture treatment for Crohn's disease, studies using only acupuncture for intervention or more RCTs targeting various Crohn's disease patients according to the CDAI are required.

Pro-Inflammatory Diet Is Correlated with High Veillonella rogosae, Gut Inflammation and Clinical Relapse of Inflammatory Bowel Disease

Inflammatory bowel diseases (IBD) are chronic conditions arising from an intricate interplay of genetics and environmental factors, and are associated with gut dysbiosis, inflammation, and gut permeability. In this study, we investigated whether the inflammatory potential of the diet is associated with the gut microbiota profile, inflammation, and permeability in forty patients with IBD in clinical remission. The dietary inflammatory index (DII) score was used to assess the inflammatory potential of the diet. The fecal microbiota profile was analyzed using 16SrRNA (V3-V4) gene sequencing, while fecal zonulin and calprotectin levels were measured with enzyme-linked immunosorbent assays. We found a positive correlation between the DII score and elevated calprotectin levels (Rho = 0.498; p = 0.001), but not with zonulin levels. Although α- and β-diversity did not significantly differ across DII quartiles, the most pro-inflammatory diet group exhibited a higher fecal abundance of Veillonella rogosae (p = 0.026). In addition, the abundance of some specific bacteria sequences showed an exponential behavior across DII quartiles and a correlation with calprotectin or zonulin levels (p ≤ 0.050). This included a positive correlation between sq702. Veillonella rogosae and fecal calprotectin levels (Rho = 0.419, p = 0.007). DII, calprotectin, and zonulin levels were identified as significant predictors of 6-month disease relapse (p ≤ 0.050). Our findings suggest a potential relationship of a pro-inflammatory diet intake with Veillonella rogosae and calprotectin levels in IBD patients in clinical remission, which may contribute to disease relapse.

Taurocholate uptake by Caco-2 cells is inhibited by pro-inflammatory cytokines and butyrate

Inflammatory bowel disease (IBD) is a group of chronic and life-threating inflammatory diseases of the gastrointestinal tract. The active intestinal absorption of bile salts is reduced in IBD, resulting in higher luminal concentrations of these agents that contribute to the pathophysiology of IBD-associated diarrhea. Butyrate (BT) is a short-chain fatty acid produced by colonic bacterial fermentation of dietary fibers. BT utilization is impaired in the intestinal inflamed mucosa of IBD patients. Our aim was to investigate the link between IBD and bile acid absorption, by testing the effect of the pro-inflammatory cytokines TNF-α and IFN-γ and of BT upon 3H-TC uptake by Caco-2 cells. The proinflammatory cytokines TNF-α and IFN-γ inhibit Na+-independent, non-ASBT (sodium-dependent bile acid transporter)-mediated 3H-TC uptake by Caco-2 cells. The inhibitory effect of these cytokines on Na+-independent 3H-TC uptake is PI3K- and JAK/STAT1-mediated. These two compounds upregulate ASBT expression levels, but no corresponding increase in Na+-dependent component of 3H-TC is observed. Moreover, BT was also found to inhibit 3H-TC uptake and showed an additive effect with IFN-γ in reducing 3H-TC uptake. We conclude that an interaction between BT and bile acids appears to exist in IBD, which may participate in the link between diet, microbiota and IBD.

Short-Term Clinical Response and Changes in the Fecal Microbiota and Metabolite Levels in Patients with Crohn's Disease After Stem Cell Infusions

Recent studies have shown a close relationship between the gut microbiota and Crohn's disease (CD). This study aimed to determine whether mesenchymal stem cell (MSC) treatment alters the gut microbiota and fecal metabolite pathways and to establish the relationship between the gut microbiota and fecal metabolites. Patients with refractory CD were enrolled and received 8 intravenous infusions of MSCs at a dose of 1.0 × 106 cells/kg. The MSC efficacy and safety were evaluated. Fecal samples were collected, and their microbiomes were analyzed by 16S rDNA sequencing. The fecal metabolites at baseline and after 4 and 8 MSC infusions were identified by liquid chromatography-mass spectrometry (LC--MS). A bioinformatics analysis was conducted using the sequencing data. No serious adverse effects were observed. The clinical symptoms and signs of patients with CD were substantially relieved after 8 MSC infusions, as revealed by changes in weight, the CD activity index (CDAI) score, C-reactive protein (CRP) level, and erythrocyte sedimentation rate (ESR). Endoscopic improvement was observed in 2 patients. A comparison of the gut microbiome after 8 MSC treatments with that at baseline showed that the genus Cetobacterium was significantly enriched. Linoleic acid was depleted after 8 MSC treatments. A possible link between the altered Cetobacterium abundance and linoleic acid metabolite levels was observed in patients with CD who received MSCs. This study enabled an understanding of both the gut microbiota response and bacterial metabolites to obtain more information about host-gut microbiota metabolic interactions in the short-term response to MSC treatment.

Food for Thought: Remission of Perianal Pediatric Crohn's Disease on Specific Carbohydrate Diet Monotherapy

There is growing interest among patients about the specific carbohydrate diet (SCD) as a treatment for Crohn's disease. In the meantime, deep remission in patients using SCD as their sole treatment has not been documented. We report a case with perianal and ileocolonic Crohn's disease in whom SCD monotherapy successfully induced and maintained not only clinical, but also endoscopic, radiographic and histologic (ie, deep mucosal remission) remission as well.

Unraveling the Impact of Gut and Oral Microbiome on Gut Health in Inflammatory Bowel Diseases

Inflammatory bowel disease (IBD) is a complex disorder characterized by chronic inflammation of the gastrointestinal tract (GIT). IBD mainly includes two distinct diseases, namely Crohn's disease and ulcerative colitis. To date, the precise etiology of these conditions is not fully elucidated. Recent research has shed light on the significant role of the oral and gut microbiome in the development and progression of IBD and its collective influence on gut health. This review aims to investigate the connection between the oral and gut microbiome in the context of IBD, exploring the intricate interplay between these microbial communities and their impact on overall gut health. Recent advances in microbiome research have revealed a compelling link between the oral and gut microbiome, highlighting their pivotal role in maintaining overall health. The oral cavity and GIT are two interconnected ecosystems that harbor complex microbial communities implicated in IBD pathogenesis in several ways. Reduction in diversity and abundance of beneficial bacterial species with the colonization of opportunistic pathogens can induce gut inflammation. Some of these pathogens can arise from oral origin, especially in patients with oral diseases such as periodontitis. It is essential to discern the mechanisms of microbial transmission, the impact of oral health on the gut microbiome, and the potential role of dysbiosis in disease development. By elucidating this relationship, we can enhance our understanding of IBD pathogenesis and identify potential therapeutic avenues for managing the disease. Furthermore, innovative strategies for modulating the oral and gut microbiome can promote health and prevent disease occurrence and progression.

High-Fiber Diet and Crohn's Disease: Systematic Review and Meta-Analysis

Crohn's disease (CD) is a subtype of inflammatory bowel disease (IBD). CD is a health problem in Western countries such as the US and European nations and is an idiopathic disease; however, certain cases of CD have been associated with intestinal dysbiosis. A systematic review with a meta-analysis was carried out to determine the efficacy of a diet rich in fiber with or without cointervention to improve remission rates for CD. The literature in the PubMed, Scopus, Web of Science, and ClinicalTrials databases was reviewed. The quality of the studies was evaluated using the Johanna Briggs Institute (JBI) scale. This review was conducted in accordance with the structure outlined in the PRISMA statement. In addition, a meta-analysis was performed with a 95% confidence interval (CI) and a random effects model. Eleven studies were included, totaling 2389 patients with CD. Applying a diet rich in fiber with or without the administration of routine therapies improved CD remission rates. Data regarding CD activity, remission time, and adverse effects derived from fiber consumption were analyzed. Consumption of fiber in the diet could improve remission rates for CD patients who receive or do not receive other treatment to maintain remission.

TRP (transient receptor potential) ion channel family: structures, biological functions and therapeutic interventions for diseases

Transient receptor potential (TRP) channels are sensors for a variety of cellular and environmental signals. Mammals express a total of 28 different TRP channel proteins, which can be divided into seven subfamilies based on amino acid sequence homology: TRPA (Ankyrin), TRPC (Canonical), TRPM (Melastatin), TRPML (Mucolipin), TRPN (NO-mechano-potential, NOMP), TRPP (Polycystin), TRPV (Vanilloid). They are a class of ion channels found in numerous tissues and cell types and are permeable to a wide range of cations such as Ca²⁺, Mg²⁺, Na⁺, K⁺, and others. TRP channels are responsible for various sensory responses including heat, cold, pain, stress, vision and taste and can be activated by a number of stimuli. Their predominantly location on the cell surface, their interaction with numerous physiological signaling pathways, and the unique crystal structure of TRP channels make TRPs attractive drug targets and implicate them in the treatment of a wide range of diseases. Here, we review the history of TRP channel discovery, summarize the structures and functions of the TRP ion channel family, and highlight the current understanding of the role of TRP channels in the pathogenesis of human disease. Most importantly, we describe TRP channel-related drug discovery, therapeutic interventions for diseases and the limitations of targeting TRP channels in potential clinical applications.

Nutritional aspects of inflammatory bowel disease

INTRODUCTION

The number of people diagnosed with inflammatory bowel disease (IBD) continues to increase in most parts of the world. Although the exact etiology of this chronic intestinal disease is not fully understood, nutritional factors appear to play key roles. Furthermore, individuals with IBD are at increased risk of adverse nutritional impacts, including micronutrient deficiencies.

AREAS COVERED

This review aims to summarize recent reports focusing on nutritional factors relevant to the development of IBD and to also review data on nutritional deficiencies seen in individuals with IBD.

EXPERT OPINION

The typical western diet, characterized by high-fat/high-sugar foods, along with food additives, appears to contribute to the etiopathogenesis of IBD. In contrast, some reports indicate that some foods are likely protective. However, there are inconsistencies in the currently available data, reflecting study design and other confounding factors. Furthermore, some of the conclusions are inferred from animal or in vitro studies. The presence of IBD can compromise the nutrition of individuals with one of these disorders: ongoing monitoring is critical. Nutrition and diet in the setting of IBD remain key areas for further and ongoing study.

Butyrate Protects Myenteric Neurons Loss in Mice Following Experimental Ulcerative Colitis

The enteric nervous system is affected by inflammatory bowel diseases (IBD). Gut microbiota ferments dietary fibers and produces short-chain fatty acids, such as Butyrate, which bind to G protein-coupled receptors, such as GPR41, and contribute to maintaining intestinal health. This work aimed to study the GPR41 in myenteric neurons and analyze the effect of Butyrate in mice submitted to experimental ulcerative colitis. The 2, 4, 6 trinitrobenzene sulfonic acid (TNBS) was injected intrarectally in C57BL/6 mice (Colitis). Sham group received ethanol (vehicle). One group was treated with 100 mg/kg of Sodium Butyrate (Butyrate), and the other groups received saline. Animals were euthanized 7 days after colitis induction. Analyzes demonstrated colocalization of GPR41 with neurons immunoreactive (-ir) to nNOS and ChAT-ir and absence of colocalization of the GPR41 with GFAP-ir glia. Quantitative results demonstrated losses of nNOS-ir, ChAT-ir, and GPR41-ir neurons in the Colitis group and Butyrate treatment attenuated neuronal loss. The number of GFAP-ir glia increased in the Colitis group, whereas Butyrate reduced the number of these cells. In addition, morphological alterations observed in the Colitis group were attenuated in the Butyrate group. The presence of GPR41 in myenteric neurons was identified, and the treatment with Butyrate attenuated the damage caused by experimental ulcerative colitis.