Changes in the Intestinal Microbiota Are Seen Following Treatment with Infliximab in Children with Crohn's Disease

Prediction of early remission after infliximab in Crohn's disease using baseline microbiome and metabolomics

To characterize the microbiome and metabolic profile in Crohn's disease (CD) patients with different outcome after infliximab (IFX) treatment. The clinical data of a cohort of 35 patients with moderate-to-severe CD admitted at Jinling hospital between Oct 2022 and Dec 2023 were collected. Stool samples at baseline were collected to perform 16SrRNA and ITS2 sequencing and LC-MS untargeted metabolomics. Of these, seven discontinued IFX and underwent surgery during the induction period, and 28 received IFX at weeks 0, 2, and 6, each administered intravenously. Clinical remission was assessed based on the clinical symptoms and HBI at baseline and week 14. Baseline microbial richness and evenness was not significantly different between remission and non-remission group. The taxonomic community analysis identified decrease of Ruminococcus, Lachnoclostridium, Akkermansia in bacterial community and decrease of Asterotremella and Wallemia in fungal community in the non-remission group. LC-MS analysis showed that histamine, creatinine and L-proline significantly increased in remission group, while androsterone, berberine and episterol significantly decreased. The combined prediction model of histamine, androsterone, and episterol demonstrated a high predictive value of remission in patients after IFX treatment (AUC=0.898, p<0.001). Together, these data might facilitate a priori determination of optimal therapeutics for CD patients.

Gut microbiota and metabolites as predictors of biologics response in inflammatory bowel disease: A comprehensive systematic review

Nonresponse to biologic agents in patients with inflammatory bowel disease (IBD) poses a significant public health burden, and the prediction of response to biologics offers valuable insights for IBD management. Given the pivotal role of gut microbiota and their endogenous metabolites in IBD, we conducted a systematic review to investigate the potential of fecal microbiota and mucosal microbiota and endogenous metabolomic markers as predictors for biotherapy response in IBD patients. A total of 38 studies were included in the review. Following anti-TNF-α treatment, the bacterial community characteristics of IBD patients exhibited a tendency to resemble those observed in healthy controls, indicating an improved clinical response. The levels of endogenous metabolites butyrate and deoxycholic acid were significantly associated with clinical remission following anti-TNF-α therapy. IBD patients who responded well to vedolizumab treatment had higher levels of specific bacteria that produce butyrate, along with increased levels of metabolites such as butyrate, branched-chain amino acids and acetamide following vedolizumab treatment. Crohn's disease patients who responded positively to ustekinumab treatment showed higher levels of Faecalibacterium and lower levels of Escherichia/Shigella. In conclusion, fecal microbiota and mucosal microbiota as well as their endogenous metabolites could provide a predictive tool for assessing the response of IBD patients to various biological agents and serve as a valuable reference for precise drug selection in clinical IBD patients.

Oral microbiota study of the patients after hospitalisation for COVID-19, considering selected dental indices and antibiotic therapy using the next generation sequencing method (NGS)

Background

Poor oral hygiene and the increased incidence and severity of periodontitis may exacerbate SARS-CoV-2 infection. The aim was to evaluate the oral microbiota of 60 participants divided into groups: COVID-19 convalescents who received antibiotics during hospitalization (I), COVID-19 convalescents without antibiotic therapy (II) and healthy individuals (III).

Materials and Methods

Dental examination was conducted, and oral health status was evaluated using selected dental indexes. Clinical samples (saliva, dorsal swabs, supragingival and subgingival plaque) were collected and used for metagenomic library to the next-generation sequencing (NGS) preparation.

Results

Each of the clinical materials in particular groups of patients showed a statistically significant and quantitatively different bacterial composition. Patients from group I showed significantly worse oral health, reflected by higher average values of dental indexes and also a higher percentage of Veillonella, Tannerella, Capnocytophaga and Selenomonas genera in comparison to other groups. Additionally, a statistically significant decrease in the amount of Akkermansia type in both groups with COVID-19 was observed for all materials.

Conclusions

The primary factor affecting the composition of oral microbiota was not the SARS-CoV-2 infection itself, but the use of antibiotic therapy. The increased percentage of pro-inflammatory pathogens observed in COVID-19 patients underscores the importance of preventing periodontal disease and improving oral hygiene in the future.

Assessing the Relationship between the Gut Microbiota and Inflammatory Bowel Disease Therapeutics: A Systematic Review

Current inflammatory bowel disease (IBD) treatments including non-biological, biological, and nutritional therapies aim to achieve remission and mucosal healing. Treatment efficacy, however, is highly variable, and there is growing evidence that the gut microbiota influences therapeutic efficacy. The aim of this study was to conduct a systematic review and meta-analysis to define changes in the gut microbiota following IBD treatment and to identify microbial predictors of treatment response. A systematic search using MEDLINE/Embase and PubMed was performed in July 2022. The review was conducted based on the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. Studies were included if they reported longitudinal microbiota analysis (>2 weeks) using next-generation sequencing or high-throughput sequencing of faecal/mucosal samples from IBD patients commencing treatment. Meta-analysis on alpha-diversity changes following infliximab treatment was conducted. Thirty-nine studies met the inclusion criteria, and four studies were included in the meta-analysis. An increase in alpha diversity was observed following treatment with 5-aminosalicylates, corticosteroids, and biological therapies in most studies. Characteristic signatures involving the enrichment of short-chain-fatty-acid-producing bacteria including Faecalibacterium prausnitzii and a reduction of pathogenic bacteria including various Proteobacteria were demonstrated following treatment with specific signatures identified based on treatment outcome. The meta-analysis demonstrated a statistically significant increase in bacterial richness following infliximab treatment (standardised mean difference -1.16 (-1.50, -0.83), p < 0.00001). Conclusion: Distinct microbial signatures are seen following treatment and are associated with treatment response. The interrogation of large longitudinal studies is needed to establish the link between the gut microbiota and IBD therapeutic outcomes.

Current evidence and clinical relevance of drug-microbiota interactions in inflammatory bowel disease

Background

Inflammatory bowel disease (IBD) is a chronic relapsing-remitting disease. An adverse immune reaction toward the intestinal microbiota is involved in the pathophysiology and microbial perturbations are associated with IBD in general and with flares specifically. Although medical drugs are the cornerstone of current treatment, responses vary widely between patients and drugs. The intestinal microbiota can metabolize medical drugs, which may influence IBD drug (non-)response and side effects. Conversely, several drugs can impact the intestinal microbiota and thereby host effects. This review provides a comprehensive overview of current evidence on bidirectional interactions between the microbiota and relevant IBD drugs (pharmacomicrobiomics).

Methods

Electronic literature searches were conducted in PubMed, Web of Science and Cochrane databases to identify relevant publications. Studies reporting on microbiota composition and/or drug metabolism were included.

Results

The intestinal microbiota can both enzymatically activate IBD pro-drugs (e.g., in case of thiopurines), but also inactivate certain drugs (e.g., mesalazine by acetylation via N-acetyltransferase 1 and infliximab via IgG-degrading enzymes). Aminosalicylates, corticosteroids, thiopurines, calcineurin inhibitors, anti-tumor necrosis factor biologicals and tofacitinib were all reported to alter the intestinal microbiota composition, including changes in microbial diversity and/or relative abundances of various microbial taxa.

Conclusion

Various lines of evidence have shown the ability of the intestinal microbiota to interfere with IBD drugs and vice versa. These interactions can influence treatment response, but well-designed clinical studies and combined in vivo and ex vivo models are needed to achieve consistent findings and evaluate clinical relevance.

Liujunanwei decoction attenuates cisplatin-induced nausea and vomiting in a Rat-Pica model partially mediated by modulating the gut micsrobiome

Studies show that traditional Chinese medicine (TCM), such as Liujunanwei (LJAW) decoction, can play important roles in alleviating side effects of chemotherapy. The purpose of this study was to understand how LJAW can counter chemotherapy-induced emesis via alteration of gut microbiota. We evaluated the effect of LJAW on cisplatin (DDP)-induced nausea and vomiting using a rat-pica model. Rats react to emetic-producing stimuli with increased kaolin consumption, a phenomenon called pica. The rats were injected with cisplatin and then randomly assigned to the control (DDP), Ondansetron or LJAW. The intake of kaolin and chow diet as well as body weights were recorded every 24 hours. Fecal samples were collected prior to, after three and seven days of treatment. The expression of proteins was measured by western blot. The concentration of cytokines and serotonin was evaluated using ELISA assay kits. Kaolin consumption in rats induced by cisplatin was reduced by 16.5%, 22.5%, and 30.1% in the LJAW group compared to the DDP group at 24 hours, 48 hours and 72 hours, respectively (p&gt;0.05). LJAW significantly increased the food intake of the rats (13.94 ± 4.73 g) during the first 24 hours as opposed to the DDP (9.23 ± 3.77 g) (p&lt;0.05). 16S rRNA gene sequencing showed the abundance of Bacteroidetes increased in cisplatin treated rats. In addition, cisplatin injection caused an enrichment of Escherichia-Shigella and Enterococcus at the genus level. While, enrichment of Blautia and Lactobacillus was presented in LJAW treated rats. Serotonin decreased in LJAW treated intestine and medulla oblongata tissues. Further, the protein expression of tryptophan hydroxylase 1 (TPH1) a rate limiting enzyme of serotonin was inhibited in LJAW treated rat’s jejunum compared with cisplatin only treated rats. In addition, LJAW downregulated chemotherapy induced elevated inflammation. The results of this study indicated that LJAW is capable of decreasing cisplatin-induced kaolin intake in rat-nausea model (pica), which might be mediated through gut microbiome-induced anti-inflammation and anti-serotonin synthesis functions.

Alterations and Potential Applications of Gut Microbiota in Biological Therapy for Inflammatory Bowel Diseases

Inflammatory bowel disease (IBD), including Crohn’s disease and ulcerative colitis, is a chronic immune-mediated inflammatory disorder of the gastrointestinal tract that is closely associated with dysbiosis of the intestinal microbiota. Currently, biologic agents are the mainstream therapies for IBD. With the increasing incidence of IBD, limitations of biologic agents have gradually emerged during treatment. Recent studies have indicated that gut microbiota is highly correlated with the efficacy of biologic agents. This review focuses on alterations in both the components and metabolites of gut microbiota during biological therapy for IBD, systematically summarises the specific gut microbiota closely related to the clinical efficacy, and compares current predictive models for the efficacy of biologics, further highlighting the predictive value of intestinal microbiota. Based on the mechanistic analysis of faecal microbiota transplantation (FMT) and biologic agents, a new therapeutic strategy, comprising a combination of FMT and biologics, has been proposed as a promising treatment for IBD with improved efficacy.

MicroRNA and Gut Microbiota: Tiny but Mighty-Novel Insights into Their Cross-talk in Inflammatory Bowel Disease Pathogenesis and Therapeutics

MicroRNAs [miRNAs], small non-coding RNAs, have recently been described as crucial contributors to intestinal homeostasis. They can interact with the gut microbiota in a reciprocal manner and deeply affect host health status, leading to several disorders when unbalanced. Inflammatory bowel disease [IBD] is a chronic inflammation of the gastrointestinal tract that co-occurs with alterations of the gut microbiota, and whose aetiology remains largely unclear. On one hand, host miRNA could be playing a relevant role in IBD pathophysiology by shaping the gut microbiota. The gut microbiome, on the other hand, may regulate the expression of host miRNAs, resulting in intestinal epithelial dysfunction, altered autophagy, and immune hyperactivation. Interestingly, it has been hypothesised that their reciprocal impact may be used for therapeutic goals. This review describes the latest research and suggests mechanisms through which miRNA and intestinal microbiota, as joint actors, may participate specifically in IBD pathophysiology. Furthermore, we discuss the diagnostic power and therapeutic potential resulting from their bidirectional communication after faecal transplantation, probiotics intake, or anti-miRNAs or miRNA mimics administration. The current literature is summarised in the present work in a comprehensive manner, hoping to provide a better understanding of the miRNA-microbiota cross-talk and to facilitate their application in IBD.

Fecal Microbiome Changes and Specific Anti-Bacterial Response in Patients with IBD during Anti-TNF Therapy

Inflammatory bowel diseases (IBD) are chronic disorders of the gastrointestinal tract that have been linked to microbiome dysbiosis and immune system dysregulation. We investigated the longitudinal effect of anti-TNF therapy on gut microbiota composition and specific immune response to commensals in IBD patients. The study included 52 patients tracked over 38 weeks of therapy and 37 healthy controls (HC). To characterize the diversity and composition of the gut microbiota, we used amplicon sequencing of the V3V4 region of 16S rRNA for the bacterial community and of the ITS1 region for the fungal community. We measured total antibody levels as well as specific antibodies against assorted gut commensals by ELISA. We found diversity differences between HC, Crohn's disease, and ulcerative colitis patients. The bacterial community of patients with IBD was more similar to HC at the study endpoint, suggesting a beneficial shift in the microbiome in response to treatment. We identified factors such as disease severity, localization, and surgical intervention that significantly contribute to the observed changes in the gut bacteriome. Furthermore, we revealed increased IgM levels against specific gut commensals after anti-TNF treatment. In summary, this study, with its longitudinal design, brings insights into the course of anti-TNF therapy in patients with IBD and correlates the bacterial diversity with disease severity in patients with ulcerative colitis (UC).

Crosstalk Between Intestinal Serotonergic System and Pattern Recognition Receptors on the Microbiota-Gut-Brain Axis

Disruption of the microbiota-gut-brain axis results in a wide range of pathologies that are affected, from the brain to the intestine. Gut hormones released by enteroendocrine cells to the gastrointestinal (GI) tract are important signaling molecules within this axis. In the search for the language that allows microbiota to communicate with the gut and the brain, serotonin seems to be the most important mediator. In recent years, serotonin has emerged as a key neurotransmitter in the gut-brain axis because it largely contributes to both GI and brain physiology. In addition, intestinal microbiota are crucial in serotonin signaling, which gives more relevance to the role of the serotonin as an important mediator in microbiota-host interactions. Despite the numerous investigations focused on the gut-brain axis and the pathologies associated, little is known regarding how serotonin can mediate in the microbiota-gut-brain axis. In this review, we will mainly discuss serotonergic system modulation by microbiota as a pathway of communication between intestinal microbes and the body on the microbiota-gut-brain axis, and we explore novel therapeutic approaches for GI diseases and mental disorders.

Bacterial Translocation as Inflammatory Driver in Crohn's Disease

Crohn’s disease (CD) is a chronic inflammatory disorder of the gastrointestinal tract responsible for intestinal lesions. The multifactorial etiology attributed to CD includes a combination of environmental and host susceptibility factors, which result in an impaired host–microbe gut interaction. Bacterial overgrowth and dysbiosis, increased intestinal barrier permeability, and altered inflammatory responses in patients with CD have been described in the past. Those events explain the pathogenesis of luminal translocation of bacteria or its products into the blood, a frequent event in CD, which, in turn, favors a sustained inflammatory response in these patients. In this review, we navigate through the interaction between bacterial antigen translocation, permeability of the intestinal barrier, immunologic response of the host, and genetic predisposition as a combined effect on the inflammatory response observed in CD. Several lines of evidence support that translocation of bacterial products leads to uncontrolled inflammation in CD patients, and as a matter of fact, the presence of gut bacterial genomic fragments at a systemic level constitutes a marker for increased risk of relapse among CD patients. Also, the significant percentage of CD patients who lose response to biologic therapies may be influenced by the translocation of bacterial products, which are well-known drivers of proinflammatory cytokine production by host immune cells. Further mechanistic studies evaluating cellular and humoral immune responses, gut microbiota alterations, and genetic predisposition will help clinicians to better control and personalize the management of CD patients in the future.

The influence of biologics on the microbiome in immune-mediated inflammatory diseases: A systematic review

BACKGROUND

Immune-mediated inflammatory diseases (IMIDs) are a group of several chronic disorders with elusive pathogenesis that results in dysregulation of the normal immune response and leads to organ-specific or systemic inflammation. There are many reports on gastrointestinal or skin dysbiosis in patients with IMIDs; however, it is not clear whether dysbiosis is a cause or a result of the observed inflammation. We aimed to determine whether treatment of IMIDs patients with biologics affects their microbiota in comparison with baseline or placebo.

METHODS

We searched for studies in MEDLINE, Embase, Scopus, and Web of Science. Due to both high heterogeneity and lacking data, vote-counting and structured tables were used to summarize the data.

RESULTS AND LIMITATIONS

A total of 25 longitudinal human studies with 816 IMIDs patients receiving biologics were included. Data on α-diversity change are inconclusive. Most evidence supports the increase in all α-diversity metrics in responding inflammatory bowel disease (IBD) patients; however, vote counting did not confirm the significance of the directional change. In case of β-diversity, treatment with biologics made patients' microbiome more similar to the microbiome of healthy controls in 5 out of 7 studies. The changes in taxa abundance and predicted functionality of microbiome were systematically summarized. Limited number and quality of the included studies highly restricted the conclusions of the study.

CONCLUSIONS

Local inflammation may play pivotal role in the gut microbiome disruption in IMIDs patients. The effect of the biologics on human microbiota should be evaluated in randomized controlled trials and transparently reported.

Microbiota and Drug Response in Inflammatory Bowel Disease

A mutualistic relationship between the composition, function and activity of the gut microbiota (GM) and the host exists, and the alteration of GM, sometimes referred as dysbiosis, is involved in various immune-mediated diseases, including inflammatory bowel disease (IBD). Accumulating evidence suggests that the GM is able to influence the efficacy of the pharmacological therapy of IBD and to predict whether individuals will respond to treatment. Additionally, the drugs used to treat IBD can modualate the microbial composition. The review aims to investigate the impact of the GM on the pharmacological therapy of IBD and vice versa. The GM resulted in an increase or decrease in therapeutic responses to treatment, but also to biotransform drugs to toxic metabolites. In particular, the baseline GM composition can help to predict if patients will respond to the IBD treatment with biologic drugs. On the other hand, drugs can affect the GM by incrementing or reducing its diversity and richness. Therefore, the relationship between the GM and drugs used in the treatment of IBD can be either beneficial or disadvantageous.

Gut Microbiota Profile in Pediatric Patients With Inflammatory Bowel Disease: A Systematic Review

Background and Aim: Accumulating evidence have implicated gut microbiota alterations in pediatric and adult patients with inflammatory bowel disease (IBD); however, the results of different studies are often inconsistent and even contradictory. It is believed that early changes in new-onset and treatment-naïve pediatric patients are more informative. We performed a systematic review to investigate the gut microbiota profiles in pediatric IBD and identify specific microbiota biomarkers associated with this disorder. Methods: Electronic databases were searched from inception to 31 July 2020 for studies that observed gut microbiota alterations in pediatric patients with IBD. Study quality was assessed using the Newcastle-Ottawa scale. Results: A total of 41 original studies investigating gut microbiota profiles in pediatric patients with IBD were included in this review. Several studies have reported a decrease in α-diversity and an overall difference in β-diversity. Although no specific gut microbiota alterations were consistently reported, a gain in Enterococcus and a significant decrease in Anaerostipes, Blautia, Coprococcus, Faecalibacterium, Roseburia, Ruminococcus, and Lachnospira were found in the majority of the included articles. Moreover, there is insufficient data to show specific microbiota bacteria associated with disease activity, location, and behavior in pediatric IBD. Conclusions: This systematic review identified evidence for differences in the abundance of some bacteria in pediatric patients with IBD when compared to patients without IBD; however, no clear overall conclusion could be drawn from the included studies due to inconsistent results and heterogeneous methodologies. Further studies with large samples that follow more rigorous and standardized methodologies are needed.

Multiomic features associated with mucosal healing and inflammation in paediatric Crohn's disease

BACKGROUND

The gastrointestinal microbiota has an important role in mucosal immune homoeostasis and may contribute to maintaining mucosal healing in Crohn's disease (CD).

AIM

To identify changes in the microbiota, metabolome and protease activity associated with mucosal healing in established paediatric CD METHODS: Twenty-five participants aged 3-18 years with CD, disease duration of over 6 months, and maintenance treatment with biological therapy were recruited. They were divided into a low calprotectin group (faecal calprotectin <100 μg/g, "mucosal healing," n = 11), and a high calprotectin group (faecal calprotectin >100 μg/g, "mucosal inflammation," n = 11). 16S gene-based metataxonomics, ¹ H-NMR spectroscopy-based metabolic profiling and protease activity assays were performed on stool samples.

RESULTS

Relative abundance of Dialister species was six-times greater in the low calprotectin group (q = 0.00999). Alpha and beta diversity, total protease activity and inferred metagenomic profiles did not differ between groups. Pentanoate (valerate) and lysine were principal discriminators in a machine-learning model which differentiated high and low calprotectin samples using NMR spectra (R² 0.87, Q² 0.41). Mean relative concentration of pentanoate was 1.35-times greater in the low calprotectin group (95% CI 1.03-1.68, P = 0.036) and was positively correlated with Dialister. Mean relative concentration of lysine was 1.54-times greater in the high calprotectin group (95% CI 1.05-2.03, P = 0.028).

CONCLUSIONS

This multiomic study identified an increase in Dialister species and pentanoate, and a decrease in lysine, in patients with "mucosal healing." It supports further investigation of these as potential novel therapeutic targets in CD.

Type I and II Interferon Signatures Can Predict the Response to Anti-TNF Agents in Inflammatory Bowel Disease Patients: Involvement of the Microbiota

BACKGROUND

Anti-TNF agents have been a cornerstone of IBD therapy; however, response to treatment has been variable, and clinically applicable biomarkers are urgently needed. We hypothesized that the type I and type II interferon (IFN) signatures may be a confounding factor for response to antitumor necrosis factor (TNF) treatment via interactions with the host and its gut microbiota.

METHODS

Peripheral blood from 30 IBD patients and 10 healthy controls was subjected to real-time quantitative real-time polymerase chain reaction for type I and type II IFN genes (IFNGs), both at baseline and after treatment with anti-TNF. Correlation between IFN signatures and microbiota composition was also determined for a subgroup of patients and controls.

RESULTS

At baseline, type I IFN score was significantly higher in IBD patients (P = 0.04 vs controls). Responders to subsequent anti-TNF treatment had significantly lower baseline scores for both type I and II IFN signatures (P < 0.005 vs nonresponders for both comparisons). During treatment with anti-TNF, the expression of type I and II IFNGs was significantly elevated in responders and decreased in nonresponders. In addition, changes in IFN signatures correlated to specific alterations in the abundance of several microbial taxa of the gut microbiome.

CONCLUSIONS

Baseline expression of type I and II IFN signatures and their kinetics during anti-TNF administration significantly correlate to treatment responses in IBD patients. Peripheral blood IFN signatures may serve as clinically meaningful biomarkers for the identification of subgroups of patients with favorable response to anti-TNF treatment. Additionally, the distinct synergies between different IFN types and microbiota might help drive therapeutic intervention.

Enteric dysbiosis in liver and kidney transplant recipients: a systematic review

Several factors mediate intestinal microbiome (IM) alterations in transplant recipients, including immunosuppressive (IS) and antimicrobial drugs. Studies on the structure and function of the IM in the post-transplant scenario and its role in the development of metabolic abnormalities, infection, and cancer are limited. We conducted a systematic review to study the taxonomic changes in liver (LT) and kidney (KT) transplantation, and their potential contribution to post-transplant complications. The review also includes pre-transplant taxa, which may play a critical role in microbial alterations post-transplant. Two reviewers independently screened articles, and assessed risk of bias. The review identified 13 clinical studies, which focused on adult kidney and liver transplant recipients. Patient characteristics and methodologies varied widely between studies. Ten studies reported increased an abundance of opportunistic pathogens (Enterobacteriaceae, Enterococcaceae, Fusobacteriaceae, and Streptococcaceae) followed by butyrate-producing bacteria (Lachnospiraceae and Ruminococcaceae) in nine studies in post-transplant conditions. The current evidence is mostly based on observational data and studies with no proof of causality. Therefore, further studies exploring the bacterial gene functions rather than taxonomic changes alone are in demand to better understand the potential contribution of the IM in post-transplant complications.