Intestinal microbiota pathogenesis and fecal microbiota transplantation for inflammatory bowel disease

Targeted modulation of gut and intra-tumor microbiota to improve the quality of immune checkpoint inhibitor responses

Immune checkpoint inhibitor (ICI) therapies, such as those blocking the interaction of PD-1 with its ligands, can restore the immune-killing function of T cells. However, ICI therapy is clinically beneficial in only a small number of patients, and it is difficult to predict post-treatment outcomes, thereby limiting its widespread clinical use. Research suggests that gut microbiota can regulate the host immune system and affect cancer progression and treatment. Moreover, the effectiveness of immunotherapy is related to the composition of the patient's gut microbiota; different gut microbial strains can either activate or inhibit the immune response. However, the importance of the microbial composition within the tumor has not been explored until recently. This study describes recent advances in the crosstalk between microbes in tumors and gut microbiota, which can modulate the tumor microbiome by directly translocating into the tumor and altering the tumor microenvironment. This study focused on the potential manipulation of the tumor and gut microbiota using fecal microbiota transplantation (FMT), probiotics, antimicrobials, prebiotics, and postbiotics to enrich immune-boosting bacteria while decreasing unfavorable bacteria to proactively improve the efficacy of ICI treatments. In addition, the use of genetic technologies and nanomaterials to modify microorganisms can largely optimize tumor immunotherapy and advance personalized and precise cancer treatment.

Differential analysis of serum immunology and gut microbiota in patients with gastrointestinal diseases

Objective

Gastric and intestinal diseases possess distinct characteristics although they are interconnected. The primary objective of this study was to investigate the pathogenesis of gastrointestinal diseases through different analyses of clinical characteristics, serum immunology, and gut microbiota in patients with gastrointestinal diseases.

Methods

We collected serum samples from 89 patients with gastrointestinal diseases and 9 healthy controls for immunological assessment, stool samples for DNA extraction, library construction, sequencing, as well as clinical data for subsequent analysis.

Results

Regarding clinical characteristics, there were significant differences between the disease group and the healthy control (HC) group, particularly in terms of age, cancer antigen 125 (CA125), cancer antigen 199 (CA199), alpha-fetoprotein (AFP), total bilirubin (TBIL) and indirect bilirubin (IBIL). The intestinal disease (ID) group exhibited the highest IL-6 level, which significantly differed from the stomach disease (SD) group (p < 0.05). In comparing the HC with the ID groups, significant differences in abundance were detected across 46 species. The HC group displayed a greater abundance of Clostridiales, Clostridia, Firmicutes, Bifidobacterium, Bifidobacteriaceae, Bifidobacteriales, Actinobacteria, Veillonellaceae, Longum, Copri, Megamonas and Callidus than other species. Similarly, when comparing the HC with the SD groups, significant differences in abundance were identified among 49 species, with only one species that the Lachnospiraceae in the HC group exhibited a higher abundance than others. Furthermore, certain clinical characteristics, such as CA125, CA199, glucose (Glu), creatine kinase-MB (CKMB) and interleukin-22 (IL-22), displayed positive correlations with enriched gut species in the ID and SD groups, while exhibiting a negative correlation with the HC group.

Conclusion

The disturbance in human gut microbiota is intimately associated with the development and progression of gastrointestinal diseases. Moreover, the gut microbiota in the HC group was found more diverse than that in the ID and SD groups, and there were significant differences in microbial species among the three groups at different classification levels. Notably, a correlation was identified between specific clinical characteristics (e.g., CA125, CA199, Glu, CKMB and IL-22) and gut microbiota among patients with gastrointestinal diseases.

Gastrointestinal microbiota-directed nutritional and therapeutic interventions for inflammatory bowel disease: opportunities and challenges

Evidence-based research has confirmed the role of gastrointestinal microbiota in regulating intestinal inflammation. These data have generated interest in developing microbiota-based therapies for the prevention and management of inflammatory bowel disease (IBD). Despite in-depth understanding of the etiology of IBD, it currently lacks a cure and requires ongoing management. Accumulating data suggest that an aberrant gastrointestinal microbiome, often referred to as dysbiosis, is a significant environmental instigator of IBD. Novel microbiome-targeted interventions including prebiotics, probiotics, fecal microbiota transplant, and small molecule microbiome modulators are being evaluated as therapeutic interventions to attenuate intestinal inflammation by restoring a healthy microbiota composition and function. In this review, the effectiveness and challenges of microbiome-centered interventions that have the potential to alleviate intestinal inflammation and improve clinical outcomes of IBD are explored.

Immunomodulatory functions of microorganisms in tissue regenerative healing

External pathogenic microorganisms and commensal microorganisms in the body have either harmful or beneficial impacts on the regenerative repair of tissues, and the immune system plays a crucial regulatory role in this process. This review summarises our current understanding of microorganism-immune system interactions, with a focus on how these interactions impact the renewal and repair ability of tissues, including skin, bone, gut, liver, and nerves. This review concludes with a discussion of the mechanisms by which microbes act on various types of immune cells to affect tissue regeneration, offers potential strategies for using microbial therapies to enhance the regenerative repair function of tissues, and suggest novel therapeutic approaches for regenerative medicine. STATEMENT OF SIGNIFICANCE: Microbiological communities have crucial impacts on human health and illness by participating in energy collection and storage and performing various metabolic processes. External pathogenic microorganisms and commensal microorganisms in the body have either harmful or beneficial impacts on the regenerative repair of tissues, and the immune system plays a critical regulatory role in this process. This study reviews the important correlation between microorganisms and the immune system and investigates the mechanism of various microorganism that participate in the regeneration and repair of tissues and organs by modulating immune system.

Hyaluronic acid/inulin-based nanocrystals with an optimized ratio of indigo and indirubin for combined ulcerative colitis therapy via immune and intestinal flora regulation

Indigo (IND) and indirubin (INB) have demonstrated a synergistic effect in treating ulcerative colitis at a ratio of 7.5:1. However, the colon mucus layer, a critical physiological barrier against external threats, is also a biological barrier, limiting the potential for effective drug delivery to the lamina propria for regulating inflammatory cells. Inspired by the potential of Hyaluronic acid (HA), to enhance cellular uptake by inflammatory cells, and Pluronic® F127 (F127), known for overcoming the mucus barrier, this study innovatively developed INB/IND nanosuspensions by co-modifying with F127 and HA. Moreover, inulin serves a dual purpose as a spray protective agent and a regulator of intestinal flora. Therefore, it was incorporated into INB/IND nanosuspensions for subsequent spray drying, resulting in the preparation of INB/IND nanocrystals (INB/IND-NC). The mucus penetration of INB/IND-NC was 24.30 times that of the control group. Besides, INB/IND-NC exhibited enhanced cellular uptake properties proximately twice that of Raw INB/IND. Importantly, INB/IND-NC exhibited improved therapeutic efficacy in DSS-induced mice by regulating the expression of cytokines, regulating immune responses via downregulating the expression of macrophages, neutrophils, and dendritic cells and maintaining intestinal flora homeostasis. Our study provides a new perspective for applying natural products for treating inflammatory diseases.

Fecal Microbiota Transplantation in Liver Cirrhosis

The human gastrointestinal tract houses a diverse array of probiotic and pathogenic bacteria and any alterations in this microbial composition can exert a significant influence on an individual's well-being. It is well-established that imbalances in the gut microbiota play a pivotal role in the development of liver diseases. In light of this, a new adjuvant therapy for liver diseases could be regulating the intestinal microbiota. Through fecal microbiota transplantation, patients whose microbiomes are compromised are treated with stool from healthy donors in an attempt to restore a normal microbiome and alleviate their symptoms. A review of cross-sectional studies and case reports suggests that fecal microbiota transplants may offer effective treatment for chronic liver diseases. Adding to the potential of this emerging therapy, recent research has indicated that fecal microbiota transplantation holds promise as a therapeutic approach specifically for liver cirrhosis. By introducing a diverse range of beneficial microorganisms into the gut, this innovative treatment aims to address the microbial imbalances often observed in cirrhotic patients. While further validation is still required, these preliminary findings highlight the potential impact of fecal microbiota transplantation as a novel and targeted method for managing liver cirrhosis. We aimed to summarize the current state of understanding regarding this procedure, as a new therapeutic method for liver cirrhosis, as well as to explain its clinical application and future potential.

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.

Targeting microbiota to alleviate the harm caused by sleep deprivation

Sleep deprivation has become a common health hazard, affecting 37-58% of the population and promoting the occurrence and development of many diseases. To date, effective treatment strategies are still elusive. Accumulating evidence indicates that modulating the intestinal microbiota harbors significant potential for alleviating the deleterious impacts of sleep deprivation. This paper first reviews the effects of sleep deprivation on gastrointestinal diseases, metabolic diseases, and neuropsychiatric diseases, discussing its specific mechanisms of influence. We then focus on summarizing existing interventions, including probiotics, melatonin, prebiotics, diet, and fecal microbiota transplantation (FMT). Finally, we have discussed the advantages and limitations of each strategy. Compared with other strategies, probiotics showed a high potential in alleviating sleep deprivation-related hazards due to their reduced risk and high security. We suggest that future research should focus on the specific mechanisms by which probiotics mitigate the harms of sleep deprivation, such insights may unveil novel pathways for treating diseases exacerbated by insufficient sleep.

Causal association between common rheumatic diseases and glaucoma: a Mendelian randomization study

Background

Autoimmunity and inflammation are the main characteristics of rheumatic diseases and have both been found to be related to glaucoma. However, it remains unclear whether rheumatic diseases increase the risk of glaucoma. Here, we performed a Mendelian randomization (MR) analysis to investigate the causal effects of six common rheumatic diseases on glaucoma.

Methods

Six rheumatic diseases were included: ankylosing spondylitis (AS), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), Sicca syndrome/Sjögren's sydrome (SS), dermatomyositis (DM), and gout. Glaucoma included primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG). Genetic variants associated with these rheumatic diseases and glaucoma were extracted from the genome-wide association studies and FinnGen8 database, respectively. First, a two-sample MR was used to investigate the potential causal association. Then, a multivariable MR was conducted to further verify the results. Inverse-variance weighted MR analysis was used as the main method, together with several sensitivity analyses.

Results

Two-sample MR suggests that AS is related to a higher risk of both POAG [odds ratio (OR): 1.28, 95% confidence interval (CI) 1.13-1.44; p = 1.1 × 10-4] and PACG (OR: 1.55, 95% CI: 1.09-2.09, p = 1.4 × 10-2). Multivariable MR shows a similar trend of the effect of AS on POAG (OR: 1.52, 95% CI: 1.22-1.90, p = 1.9 × 10-4) and PACG (OR: 2.05, 95% CI: 1.06-3.95, p = 3.2 × 10-2). No significant association was observed between the other five rheumatic diseases and glaucoma.

Conclusions

AS is related to an increased risk of POAG and PACG. We stress the importance of glaucoma screening for AS patients.

Fecal Microbiota Transplantation in Inflammatory Bowel Disease

Inflammatory bowel diseases represent a complex array of diseases of incompletely known etiology that led to gastrointestinal tract chronic inflammation. In inflammatory bowel disease, a promising method of treatment is represented by fecal microbiota transplantation (FMT), FMT has shown its increasing effectiveness and safety in recent years for recurrent CDI; moreover, it showed real clinical benefits in treating SARS-CoV-2 and CDI co-infection. Crohn’s disease and ulcerative colitis are characterized by immune dysregulation, resulting in digestive tract damage caused by immune responses. Most current therapeutic strategies are associated with high costs and many adverse effects by directly targeting the immune response, so modifying the microbial environment by FMT offers an alternative approach that could indirectly influence the host’s immune system in a safe way. Studies outline the endoscopic and clinical improvements in UC and CD in FMT patients versus control groups. This review outlines the multiple benefits of FMT in the case of IBD by improving patients unbalanced gut, therefore improving endoscopic and clinical symptomatology. We aim to emphasize the clinical importance and benefits of FMT in order to prevent flares or complications of IBD and to highlight that further validation is needed for establishing a clinical protocol for FMT in IBD.

Ginsenoside Rg3 Ameliorates DSS-Induced Colitis by Inhibiting NLRP3 Inflammasome Activation and Regulating Microbial Homeostasis

Ulcerative colitis (UC) is a recurrent inflammatory disease without a specific cure or treatment for improvement. Here, we investigated the potential therapeutic effect and mechanism of ginsenoside Rg3 (Gin Rg3) on UC. We constructed an in vitro cellular inflammatory model and a dextran sulfate sodium (DSS)-induced UC mouse model. We also used Gin Rg3, MCC950 (NLRP3 inhibitor), MSU (NLRP3 activator), and fecal transplantation (FMT) to intervene the model. The results showed that Gin Rg3 inhibited NLRP3 inflammasome activation, pyroptosis, and apoptosis in vitro and in vivo. DSS-induced changes in the abundance of gut microbiota at the phylum or genus level were partially restored by Gin Rg3. Furthermore, gin Rg3 affected intestinal metabolism in mice by inhibiting the activation of NLRP3 inflammasome. The gut microbiota treated with Gin Rg3 was sufficient to alleviate DSS-induced UC. In summary, Gin Rg3 alleviated DSS-induced UC by inhibiting NLRP3 inflammasome activation and regulating gut microbiota homeostasis.

Association between Inflammatory Bowel Disease and Iridocyclitis: A Mendelian Randomization Study

BACKGROUND

Iridocyclitis (IC) is a common extraintestinal manifestation of inflammatory bowel disease (IBD). Observational studies showed patients with ulcerative colitis (UC) and Crohn's disease (CD) both have a higher risk of IC. However, due to the inherent limitations of observational studies, the association and its directionality between the two forms of IBD and IC remain undiscerned.

METHODS

Genetic variants for IBD and IC were selected as instruments from genome-wide association studies (GWAS) and FinnGen database as instrumental variables, respectively. A bidirectional Mendelian randomization (MR) and multivariable MR were performed successively. Three different MR methods were performed to determine the causal association, including inverse-variance weighted (IVW), MR Egger, and weighted median, whereas IVW was used as the main analysis. Different methods for sensitivity analysis were used, including MR-Egger intercept test, MR Pleiotropy RESidual Sum and Outlier test, Cochran's Q test, and leave-one-out analysis.

RESULTS

Bidirectional MR suggested both UC and CD were positively associated with IC as a whole, acute and subacute IC, and chronic IC. However, in the MVMR analysis, only the association from CD to IC remained stable. In the reverse analysis, no association was observed from IC to UC or CD.

CONCLUSIONS

Both UC and CD are associated with an increased risk of IC compared with healthy individuals. However, the association between CD and IC is stronger. In the reverse direction, patients with IC do not suffer a higher risk of UC or CD. We emphasize the importance of ophthalmic examinations for IBD patients, especially for CD patients.

Gut Microbiota in Colorectal Cancer: Biological Role and Therapeutic Opportunities

Colorectal cancer (CRC) is the second-leading cause of cancer-related deaths worldwide. While CRC is thought to be an interplay between genetic and environmental factors, several lines of evidence suggest the involvement of gut microbiota in promoting inflammation and tumor progression. Gut microbiota refer to the ~40 trillion microorganisms that inhabit the human gut. Advances in next-generation sequencing technologies and metagenomics have provided new insights into the gut microbial ecology and have helped in linking gut microbiota to CRC. Many studies carried out in humans and animal models have emphasized the role of certain gut bacteria, such as Fusobacterium nucleatum, enterotoxigenic Bacteroides fragilis, and colibactin-producing Escherichia coli, in the onset and progression of CRC. Metagenomic studies have opened up new avenues for the application of gut microbiota in the diagnosis, prevention, and treatment of CRC. This review article summarizes the role of gut microbiota in CRC development and its use as a biomarker to predict the disease and its potential therapeutic applications.

Upper airway microbiome transplantation for patients with chronic rhinosinusitis

BACKGROUND

Chronic or recurrent rhinosinusitis without polyps (CRSsNP) is characterized by a persistent inflammation of the sinonasal mucosa. The underlying cause is unclear but increasing interest has been directed toward changes in the sinonasal microbiome as a potential driver.

METHODS

Twenty-two patients diagnosed with CRSsNP were treated with antibiotics for 13 days, followed by 5 consecutive days of nasal microbiome transplants from healthy donors. Outcome measures were 22-item Sino-Nasal Outcome Test (SNOT-22) questionnaire, total nasal symptom score (TNSS), endoscopic grading, 16S ribosomal RNA (rRNA) next generation sequencing (microbiome analysis), and nasal lavage fluid analysis of inflammatory cytokines. Patients were examined at the start of the study and after antibiotic treatment as well as 10 days and 3 months after the transplant series.

RESULTS

At the end of the study, patients reported significantly reduced SNOT-22 scores and microbiome analysis showed significantly increased abundance and diversity. No significant change was observed for TNSS or endoscopic scoring.

CONCLUSION

Nasal microbiome transplants obtained from healthy individuals and administered as nasal lavages to patients with CRSsNP are feasible. The patients reported significant and lasting reduction of symptoms and these findings were associated with a lasting increase in abundance and diversity of the local bacterial flora. The observations, which need to be confirmed by randomized controlled trials, may constitute a new treatment avenue for these difficult to treat patients where antibiotics only provide short lasting symptom control.

GLP-1 and GLP-2 Orchestrate Intestine Integrity, Gut Microbiota, and Immune System Crosstalk

The intestine represents the body’s largest interface between internal organs and external environments except for its nutrient and fluid absorption functions. It has the ability to sense numerous endogenous and exogenous signals from both apical and basolateral surfaces and respond through endocrine and neuronal signaling to maintain metabolic homeostasis and energy expenditure. The intestine also harbours the largest population of microbes that interact with the host to maintain human health and diseases. Furthermore, the gut is known as the largest endocrine gland, secreting over 100 peptides and other molecules that act as signaling molecules to regulate human nutrition and physiology. Among these gut-derived hormones, glucagon-like peptide 1 (GLP-1) and -2 have received the most attention due to their critical role in intestinal function and food absorption as well as their application as key drug targets. In this review, we highlight the current state of the literature that has brought into light the importance of GLP-1 and GLP-2 in orchestrating intestine–microbiota–immune system crosstalk to maintain intestinal barrier integrity, inflammation, and metabolic homeostasis.

Exploration of Potential Gut Microbiota-Derived Biomarkers to Predict the Success of Fecal Microbiota Transplantation in Ulcerative Colitis: A Prospective Cohort in Korea

Background/Aims

Although fecal microbiota transplantation (FMT) has been proven as one of the promising treatments for patients with ulcerative colitis (UC), potential prognostic markers regarding the clinical outcomes of FMT remain elusive.

Methods

We collected fecal samples of 10 participants undergoing FMT to treat UC and those from the corresponding donors. We categorized them into two groups: responders and nonresponders. Sequencing of the bacterial 16S rRNA gene was conducted on the samples to explore bacterial composition.

Results

Analyzing the gut microbiota of patients who showed different outcomes in FMT presented a distinct microbial niche. Source tracking analysis showed the nonresponder group had a higher rate of preservation of donor microbiota, underscoring that engraftment degrees are not one of the major drivers for the success of FMT. At the phylum level, Bacteroidetes bacteria were significantly depleted (p<0.003), and three genera, including Enterococcus, Rothia, and Pediococcus, were enriched in the responder group before FMT (p=0.003, p=0.025, and p=0.048, respectively). Furthermore, we applied a machine learning algorithm to build a prediction model that might allow the prediction of FMT outcomes, which yielded an area under the receiver operating characteristic (ROC) curve of 0.844. Notably, the microbiota-based model was much better at predicting outcomes than the clinical features model (area under the ROC curve=0.531).

Conclusions

This study is the first to suggest the significance of indigenous microbiota of recipients as a critical factor. The result highlights that bacterial composition should be evaluated before FMT to select suitable patients and achieve better efficiency.

The Combination of Phages and Faecal Microbiota Transplantation Can Effectively Treat Mouse Colitis Caused by Salmonella enterica Serovar Typhimurium

Salmonella enterica serovar Typhimurium (S. Typhimurium) is one of the common causes of human colitis. In the present study, two lytic phages vB_SenS-EnJE1 and vB_SenS-EnJE6 were isolated and the therapeutic effect of the combination of phages and faecal microbiota transplantation (FMT) on S. Typhimurium-induced mouse colitis was investigated. The characteristics and genome analysis indicated that they are suitable phages for phage therapy. Results showed that vB_SenS-EnJE1 lysis 41/54 Salmonella strains of serotype O4, and vB_SenS-EnJE6 lysis 46/54 Salmonella strains of serotypes O4 and O9. Severe inflammatory symptoms and disruption of the intestinal barrier were observed in S. Typhimurium -induced colitis. Interestingly, compared with a single phage cocktail (Pc) or single FMT, the combination of Pc and FMT (PcFMT) completely removed S. Typhimurium after 72 h of treatment, and significantly improved pathological damage and restored the intestinal barrier. Furthermore, PcFMT effectively restored the intestinal microbial diversity, especially for Firmicutes/Bacteroidetes [predominantly bacterial phyla responsible for the production of short-chain fatty acids (SCFA)]. Additionally, we found that PcFMT treatment significantly increased the levels of SCFA. All these data indicated that the combination of phages and FMT possesses excellent therapeutic effects on S. Typhimurium -induced intestinal microbiota disorder diseases. Pc and FMT played roles in “eliminating pathogens” and “strengthening vital qi,” respectively. This study provides a new idea for the treatment of intestinal microbiota disorder diseases caused by specific bacterial infections.

Dual Role of Indoles Derived From Intestinal Microbiota on Human Health

Endogenous indole and its derivatives (indoles), considered as promising N-substituted heterocyclic compounds, are tryptophan metabolites derived from intestinal microbiota and exhibit a range of biological activities. Recent studies indicate that indoles contribute to maintaining the biological barrier of the human intestine, which exert the anti-inflammatory activities mainly through activating AhR and PXR receptors to affect the immune system’s function, significantly improving intestinal health (inflammatory bowel disease, hemorrhagic colitis, colorectal cancer) and further promote human health (diabetes mellitus, central system inflammation, and vascular regulation). However, the revealed toxic influences cannot be ignored. Indoxyl sulfate, an indole derivative, performs nephrotoxicity and cardiovascular toxicity. We addressed the interaction between indoles and intestinal microbiota and the indoles’ effects on human health as double-edged swords. This review provides scientific bases for the correlation of indoles with diseases moreover highlights several directions for subsequent indoles-related studies.

Wide Range Applications of Spirulina: From Earth to Space Missions

Spirulina is the most studied cyanobacterium species for both pharmacological applications and the food industry. The aim of the present review is to summarize the potential benefits of the use of Spirulina for improving healthcare both in space and on Earth. Regarding the first field of application, Spirulina could represent a new technology for the sustainment of long-duration manned missions to planets beyond the Lower Earth Orbit (e.g., Mars); furthermore, it could help astronauts stay healthy while exposed to a variety of stress factors that can have negative consequences even after years. As far as the second field of application, Spirulina could have an active role in various aspects of medicine, such as metabolism, oncology, ophthalmology, central and peripheral nervous systems, and nephrology. The recent findings of the capacity of Spirulina to improve stem cells mobility and to increase immune response have opened new intriguing scenarios in oncological and infectious diseases, respectively.

Microbiota in health and diseases

The role of microbiota in health and diseases is being highlighted by numerous studies since its discovery. Depending on the localized regions, microbiota can be classified into gut, oral, respiratory, and skin microbiota. The microbial communities are in symbiosis with the host, contributing to homeostasis and regulating immune function. However, microbiota dysbiosis can lead to dysregulation of bodily functions and diseases including cardiovascular diseases (CVDs), cancers, respiratory diseases, etc. In this review, we discuss the current knowledge of how microbiota links to host health or pathogenesis. We first summarize the research of microbiota in healthy conditions, including the gut-brain axis, colonization resistance and immune modulation. Then, we highlight the pathogenesis of microbiota dysbiosis in disease development and progression, primarily associated with dysregulation of community composition, modulation of host immune response, and induction of chronic inflammation. Finally, we introduce the clinical approaches that utilize microbiota for disease treatment, such as microbiota modulation and fecal microbial transplantation.

Association between intestinal microbiome and inflammatory bowel disease: insights from bibliometric analysis

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Intestinal microbiota has been increasingly studied in the field of IBD over the last 20 years.

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The gut microbiome, metabolites, and their corresponding host signaling pathways are highly associated with IBD.

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Probiotics may relieve IBD as a complementary therapy.

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The pathogenesis and treatment strategies of IBD need to be further studied.

The gut microbiome is highly linked to inflammatory bowel disease (IBD). A total of 3890 publications related to the two terms from 2000 to 2020 were extracted from the Web of Science Core Collection to study the association from a bibliometric perspective. Publications on this topic have grown rapidly since 2008. The United States and Harvard University are the country and institution with the largest number of publications, respectively. Inflammatory Bowel Diseases is the most productive journal with 211 published articles. The most influential journal in this field is Gut with 13,359 citations. The co-citation analysis of references showed that the IBD-related topics with the highest focus are “gut microbiota,” “metagenomics,” “bacterial community,” “fecal microbiota transplantation,” “probiotics,” and “colitis-associated colorectal cancer.” Keyword cluster and keyword burst analyses showed that “gut microbiota,” “metagenomics,” and “fecal microbiota transplantation” are currently the most researched topics in the field of IBD. The literature in this field is mainly distributed between alterations of the intestinal microbiota, microbial metabolites, and related host signaling pathways. Probiotic treatment also frequently appears in literature. This bibliometric analysis can guide future research and promote the development of the field of gut microbiome and IBD.

In vitro Prebiotic Effect of Bread-Making Process in Inflammatory Bowel Disease Microbiome

Inflammatory bowel disease (IBD), including its two main categories (Crohn's disease and ulcerative colitis), has been linked both to gut microbiota and to diet. Bread is a daily food that has a potential capacity as a prebiotic. Our aim was to evaluate different bread-making processes and their effect on fecal colonic microbiota in IBD patients. The microbial composition of several sourdoughs and dough samples was analyzed by high-throughput sequencing of 16S and 18S rRNA genes. Three types of bread, which followed different bread-making processes, were in vitro digested and incubated with feces from IBD patients. Changes in gut microbiota were assessed by a quantitative polymerase chain reaction using specific bacterial sequence targets. Short-chain fatty acid production was also analyzed by gas chromatography. Lactobacillus sanfranciscensis was the dominant lactic acid bacteria species found in sourdough and bread doughs prepared using sourdough, whereas Saccharomyces cerevisiae was the most dominant yeast in all groups, especially in bread doughs before baking. Differences in microbial composition in raw bread doughs were more related to the type of dough and elaboration than to fermentation time lengths. The analysis of in vitro fecal incubations with bread conditions revealed an increase in most bacterial groups analyzed and short-chain fatty acid production, both in Crohn's disease and ulcerative colitis samples. Most remarkable increases in short-chain fatty acid production mirrored higher abundances of Roseburia species. The potential prebiotic properties observed were mainly obtained when using a high quantity of bread, regardless of bread type. Overall, this study highlights the bacterial dynamics within the bread-making process and the potential prebiotic effect in IBD patients.

A Link between Chronic Kidney Disease and Gut Microbiota in Immunological and Nutritional Aspects

Chronic kidney disease (CKD) is generally progressive and irreversible, structural or functional renal impairment for 3 or more months affecting multiple metabolic pathways. Recently, the composition, dynamics, and stability of a patient's microbiota has been noted to play a significant role during disease onset or progression. Increasing urea concentration during CKD can lead to an acceleration of the process of kidney injury leading to alterations in the intestinal microbiota that can increase the production of gut-derived toxins and alter the intestinal epithelial barrier. A detailed analysis of the relationship between the role of intestinal microbiota and the development of inflammation within the symbiotic and dysbiotic intestinal microbiota showed significant changes in kidney dysfunction. Several recent studies have determined that dietary factors can significantly influence the activation of immune cells and their mediators. Moreover, dietary changes can profoundly affect the balance of gut microbiota. The aim of this review is to present the importance and factors influencing the differentiation of the human microbiota in the progression of kidney diseases, such as CKD, IgA nephropathy, idiopatic nephropathy, and diabetic kidney disease, with particular emphasis on the role of the immune system. Moreover, the effects of nutrients, bioactive compounds on the immune system in development of chronic kidney disease were reviewed.

Role of germ-free animal models in understanding interactions of gut microbiota to host and environmental health: A special reference to zebrafish

Numerous pieces of evidence documented the importance of gut microbiota in regulating human health and evaluating the toxicity of environmental pollutants, which are closely related to the host health in various aspects, including nutrition, energy translation, metabolism, pathogen resistance, and immune function. A variety of environmental factors can disrupt gut microbiota and their functions, and inevitably cause immune diseases, obesity and diabetes. However, deciphering the inner mechanisms involved in the functional interaction of gut microbes with host health is still needed extensive investigations. This review focused on the essential roles of intestinal microbes in host-related diseases and highlighted the development and applications of germ-free (GF) animal models, mainly zebrafish. Moreover, the generation, immunity characters, advantages and challenges of GF zebrafish models were also summarized. Importantly, the composition and isolation of zebrafish gut bacteria for further application and toxicity evaluation of aquatic environmental pollutants were also discussed. In conclusion, GF zebrafish play irreplaceable roles in understanding the potential functions and responses of customized microbiota towards human and environmental health implications.

Diarrhea as a Potential Cause and Consequence of Reduced Gut Microbial Diversity Among Undernourished Children in Peru

Background

Detrimental effects of diarrhea on child growth and survival are well documented, but details of the underlying mechanisms remain poorly understood. Recent evidence demonstrates that perturbations to normal development of the gut microbiota in early life may contribute to growth faltering and susceptibility to related childhood diseases. We assessed associations between diarrhea, gut microbiota configuration, and childhood growth in the Peruvian Amazon.

Methods

Growth, diarrhea incidence, illness, pathogen infection, and antibiotic exposure were assessed monthly in a birth cohort of 271 children aged 0–24 months. Gut bacterial diversity and abundances of specific bacterial taxa were quantified by sequencing 16S rRNA genes in fecal samples collected at 6, 12, 18, and 24 months. Linear and generalized linear models were used to determine whether diarrhea was associated with altered microbiota and, in turn, if features of the microbiota were associated with the subsequent risk of diarrhea.

Results

Diarrheal frequency, duration, and severity were negatively associated with bacterial diversity and richness (P < .05). Children born stunted (length-for-age z-score [LAZ] ≤ −2) who were also severely stunted (LAZ ≤ −3) at the time of sampling exhibited the greatest degree of diarrhea-associated reductions in bacterial diversity and the slowest recovery of bacterial diversity after episodes of diarrhea. Increased bacterial diversity was predictive of reduced subsequent diarrhea from age 6 to 18 months.

Conclusions

Persistent, severe growth faltering may reduce the gut microbiota's resistance and resilience to diarrhea, leading to greater losses of diversity and longer recovery times. This phenotype, in turn, denotes an increased risk of future diarrheal disease and growth faltering.

The microbiota-gut-bone axis and bone health

The gastrointestinal tract is colonized by trillions of microorganisms, consisting of bacteria, fungi, and viruses, known as the "second gene pool" of the human body. In recent years, the microbiota-gut-bone axis has attracted increasing attention in the field of skeletal health/disorders. The involvement of gut microbial dysbiosis in multiple bone disorders has been recognized. The gut microbiota regulates skeletal homeostasis through its effects on host metabolism, immune function, and hormonal secretion. Owing to the essential role of the gut microbiota in skeletal homeostasis, novel gut microbiota-targeting therapeutics, such as probiotics and prebiotics, have been proven effective in preventing bone loss. However, more well-controlled clinical trials are still needed to evaluate the long-term efficacy and safety of these ecologic modulators in the treatment of bone disorders.

Fermented Maillard Reaction Products by Lactobacillus gasseri 4M13 Alters the Intestinal Microbiota and Improves Dysfunction in Type 2 Diabetic Mice with Colitis

Inflammatory bowel disease is a chronic relapsing disease. Multiple factors can cause inflammatory bowel disease (IBD), including diet, imbalance of the immune system, and impaired intestinal barrier function. Type 2 diabetes mellitus is a complex and chronic metabolic disease caused by a combination of insulin resistance and an ineffective insulin secretory response. The co-occurrence of these two diseases, demonstrating interrelated effects within the gut microbiota, has been frequently reported. This study evaluated the effects of a fermented glycated conjugate of whey protein and galactose with Lactobacillus gasseri 4M13 (FMRP) to prevent type 2 diabetes mellitus with inflammatory bowel disease. C57BLKS/J- db/db mice were orally administered FMRP for 14 consecutive days and 2% dextran sulfate sodium (DSS) in water ad libitum for 5 days to induce colitis. FMRP-fed mice showed improved insulin secretion and symptoms of colitis. Compared to the DSS group, the FMRP group showed a decreased abundance of six bacterial genera and increased abundance of Alistipes and Hungateiclostridium. In cecal contents, the levels of short-chain fatty acids increased in the FMRP group compared to those in the DSS group. Continuous administration of FMRP thus may improve the homeostasis of not only insulin secretion and inflammation, but also the intestinal environment in inflammatory bowel disease and type 2 diabetes mellitus.

Effect of berberine on hyperglycaemia and gut microbiota composition in type 2 diabetic Goto-Kakizaki rats

BACKGROUND

A recent investigation showed that the prevalence of type 2 diabetes mellitus (T2DM) is 12.8% among individuals of Han ethnicity. Gut microbiota has been reported to play a central role in T2DM. Goto-Kakizaki (GK) rats show differences in gut microbiota compared to non-diabetic rats. Previous studies have indicated that berberine could be successfully used to manage T2DM. We sought to understand its hypoglycaemic effect and role in the regulation of the gut microbiota.

AIM

To determine whether berberine can regulate glucose metabolism in GK rats via the gut microbiota.

METHODS

GK rats were acclimatized for 1 wk. The GK rats were randomly divided into three groups and administered saline (Mo), metformin (Me), or berberine (Be). The observation time was 8 wk, and weight, fasting blood glucose (FBG), insulin, and glucagon-like peptide-1 (GLP-1) were measured. Pancreatic tissue was observed for pathological changes. Additionally, we sequenced the 16S rRNA V3-V4 region of the gut microbiota and analysed the structure.

RESULTS

Compared with the Mo group, the Me and Be groups displayed significant differences in FBG (P < 0.01) and GLP-1 (P < 0.05). A significant decrease in weight and homeostatic model assessment-insulin resistance was noted in the Be group compared with those in the Me group (P < 0.01). The pancreatic islets of the Me- and Be-treated rats showed improvement in number, shape, and necrosis compared with those of Mo-treated rats. A total of 580 operational taxonomic units were obtained in the three groups. Compared to the Mo group, the Me and Be groups showed a shift in the structure of the gut microbiota. Correlation analysis indicated that FBG was strongly positively correlated with Clostridia_UCG-014 (P < 0.01) and negatively correlated with Allobaculum (P < 0.01). Body weight showed a positive correlation with Desulfovibrionaceae (P < 0.01) and a negative correlation with Akkermansia (P < 0.01). Importantly, our results demonstrated that Me and Be could significantly decrease Bacteroidetes (P < 0.01) and the Bacteroidetes/Firmicutes ratio (P < 0.01). Furthermore, Muribaculaceae (P < 0.01; P < 0.05) was significantly decreased in the Me and Be groups, and Allobaculum (P < 0.01) was significantly increased.

CONCLUSION

Berberine has a substantial effect in improving metabolic parameters and modulating the gut microbiota composition in T2DM rats.

Inflammatory bowel disease: tri-directional relationship between microbiota, immune system and intestinal epithelium

Human gut microbiota contributes to host nutrition and metabolism, sustains intestinal cell proliferation and differentiation, and modulates host immune system. The alterations in their composition lead to severe gut disorders, including inflammatory bowel disease (IBD) or inflammatory bowel syndrome (IBS). IBD including ulcerative colitis (UC) and Crohn's disease (CD) are gamut of chronic inflammatory disorders of gut, mediated by complex interrelations among genetic, environmental, and internal factors. IBD has debateable aetiology, however in recent years, exploring the central role of a tri-directional relationship between gut microbiota, mucosal immune system, and intestinal epithelium in pathogenesis is getting the most attention. Increasing incidences and early onset explains the exponential rise in IBD burden on health-care systems. Industrialization, hypersensitivity to allergens, lifestyle, hygiene hypothesis, loss of intestinal worms, and gut microbial composition, explains this shifted rise. Hitherto, the interventions modulating gut microbiota composition, microfluidics-based in vitro gastrointestinal models, non-allergic functional foods, nutraceuticals, and faecal microbiota transplantation (FMT) from healthy donors are some of the futuristic approaches for the disease management.

Clinical efficacy of fecal microbiota transplantation for patients with small intestinal bacterial overgrowth: a randomized, placebo-controlled clinic study

Background

Small intestinal bacterial overgrowth (SIBO) is characterized by the condition that bacteria overgrowth in the small intestine. Fecal microbiota transplantation (FMT) has been applied as an effective tool for reestablishing the structure of gut microbiota. However, whether FMT could be applied as a routine SIBO treatment has not been investigated.

Methods

In this trial, 55 SIBO patients were enrolled. All participants were randomized in two groups, and were given FMT capsule or placebo capsules once a week for 4 consecutive weeks. Measurements including the lactulose hydrogen breath test gastrointestinal symptoms, as well as fecal microbiota diversity were assessed before and after FMT therapy.

Results

Gastrointestinal symptoms significantly improved in SIBO patients after treatment with FMT compared to participants in placebo group. The gut microbiota diversity of FMT group had a significant increase, while placebo group showed none.

Conclusions

This study suggests that applying FMT for patients with SIBO can alleviate gastrointestinal symptoms, indicating that FMT may be a promising and novel therapeutic regimen for SIBO.

Trial registry

This study was retrospectively registered with the Chinese Clinical Trial registry on 2019.7.10 (ID: ChiCTR1900024409, http://www.chictr.org.cn).

Modern concept of probiotics and principles of development of new-generation symbiotic preparations

The purpose of this work is to review data on the biological effectiveness of probiotics, their mechanisms of action, and the prospects for the development of new-generation preparations. Scientific and practical justification of symbiotic drugs of a new generation – metabiotics as a continuation of the probiotic concept is given. The authors discuss the literature data and their own results, which allow them to propose new approaches to the creation of symbiotic drugs. The authors scientifically substantiate the main scientific provisions of the probiotic concept for the development of new-generation symbiotic drugs:

Fecal microbiota transplantation for COVID-19; a potential emerging treatment strategy

At the end of 2019, an emerging outbreak caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that first reported from Wuhan, China. The first manifestations of patients infected with SARS-CoV-2 was flu-like symptoms, while other type of manifestations, especially gastrointestinal manifestations were discovered recently. As of June 2020, there is no specific drug or treatment strategy for COVID-19, a disease caused by SARS-CoV-2, so different combination of antiviral drugs is currently being used. Gut microbiota mostly consists of four phyla, including Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria. The interaction between gut microbiota and immune system through releasing some cytokines such as IL-1β, IL-2, IL-10, TNF-α, and IFN-γ that play roles in the severity of COVID-19. In this article, a new potential treatment for COVID-19 by fecal microbiota transplantation (FMT) is described. FMT revealed promising results in different diseases, especially recurrent clostridium difficile infection, and it might reduce length of hospital admission and severity of the disease by modification of gut microbiota composition.

The Intestinal Microbiota and Colorectal Cancer

The intestinal microbiota, composed of a large population of microorganisms, is often considered a “forgotten organ” in human health and diseases. Increasing evidence indicates that dysbiosis of the intestinal microbiota is closely related to colorectal cancer (CRC). The roles for intestinal microorganisms that initiated and facilitated the CRC process are becoming increasingly clear. Hypothesis models have been proposed to illustrate the complex relationship between the intestinal microbiota and CRC. Recent studies have identified Streptococcus bovis, enterotoxigenic Bacteroides fragilis, Fusobacterium nucleatum, Enterococcus faecalis, Escherichia coli, and Peptostreptococcus anaerobius as CRC candidate pathogens. In this review, we summarized the mechanisms involved in microbiota-related colorectal carcinogenesis, including inflammation, pathogenic bacteria, and their virulence factors, genotoxins, oxidative stress, bacterial metabolites, and biofilm. We also described the clinical values of intestinal microbiota and novel strategies for preventing and treating CRC.

Alterations in the intestinal microbiome associated with PCOS affect the clinical phenotype

Polycystic ovarian syndrome (PCOS), characterized by chronic anovulation and hyperandrogenaemia, is a complex endocrine and metabolic disorder commonly seen in women of reproductive age. Multiple factors, including the intestinal microbiome, affect the pathogenesis and development of PCOS. However, the specific mechanisms by which gut microbes play a role in PCOS remain elusive. This review summarizes recent research about the transformational changes in gut microbes revealed in PCOS patients and the possible mechanisms and pathways by which the intestinal microbiome exerts influence on PCOS progression and phenotypes. In addition to the intestinal microbiome, evidence from animal studies suggests changes in the vaginal microbiome under PCOS conditions. The alteration of microbiome could affect oestrus cycle and PCOS phenotypes. Microbiome is closely associated with medicine and therapeutic approaches. Microbiome influences drug and therapy response and itself is a new source of therapy. Accurate modulation of the intestinal and vaginal microbiome is a potential therapy for PCOS patients. Future studies are required to elucidate the specific role of each particular genera of microbiota and the mechanism by which microbiome impacts the pathogenesis, progression and phenotypes of PCOS.

Fecal Microbiota Transplantation (FMT) Alleviates Experimental Colitis in Mice by Gut Microbiota Regulation

Inflammatory bowel disease (IBD) is an increasing global burden and a predisposing factor to colorectal cancer. Although a number of treatment options are available, the side effects could be considerable. Studies on fecal microbiota transplantation (FMT) as an IBD intervention protocol require further validation as the underlying mechanisms for its attenuating effects remain unclear. This study aims to demonstrate the ameliorative role of FMT in an ulcerative colitis (UC) model induced by dextran sulfate sodium (DSS) and elucidate its relative mechanisms in a mouse model. It was shown that FMT intervention decreased disease activity index (DAI) levels and increased the body weight, colon weight and colon length of experimental animals. It also alleviated histopathological changes, reduced key cytokine expression and oxidative status in the colon. A down-regulated expression level of genes associated with NF-κB signaling pathway was also observed. The results of 16S rRNA gene sequencing showed that FMT intervention restored the gut microbiota to the pattern of the control group by increasing the relative abundance of Firmicutes and decreasing the abundances of Bacteroidetes and Proteobacteria. The relative abundances of the genera Lactobacillus, Butyricicoccus, Lachnoclostridium, Olsenella and Odoribacter were upregulated but Helicobacter, Bacteroides and Clostridium were reduced after FMT administration. Furthermore, FMT administration elevated the concentrations of SCFAs in the colon. In conclusion, FMT intervention could be suitable for UC control, but further validations via clinical trials are recommended.

Pilot study of cytokine changes evaluation after fecal microbiota transplantation in patients with ulcerative colitis

AIMS

To evaluate the changes of serum cytokines levels after fecal microbiota transplantation (FMT) in patients with active ulcerative colitis (UC) and the correlation with UC disease activity.

METHODS

Patients with active UC who meet the inclusion and exclusion criteria were recruited, and received FMT from a single donor for three times with an interval of 2-3 months. Serum samples were collected before every FMT. Clinical responses to FMT were assessed according to the criteria of Mayo score. 41 serum cytokines, C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were quantitatively detected. Changes in serum cytokines levels after FMT and their correlation with CRP, ESR and Mayo scores were investigated.

RESULTS

16 active UC patients were enrolled, and 14(87.5%) patients achieved clinical response to FMT. Compared with those before FMT, serum concentrations of IL-1Ra, IL-6, IP-10 and ENA-78 decreased significantly after the second FMT (P < 0.05), and serum concentrations of MEC, VCAM-1 and G-CSF decreased significantly after both the first and second FMT (P < 0.05). Serum levels of IL-6, IL-1Ra and VCAM-1 were all significantly positively correlated with CRP and ESR. Serum level of IP-10 was significantly positively correlated with CRP, ESR and Mayo score. Serum level of G-CSF was significantly positively correlated with Mayo score.

CONCLUSIONS

FMT may play a therapeutic role partly through modulating the host immune response. IL-6, IL-1Ra, IP-10, VCAM-1 and G-CSF may be biomarkers to evaluate the effect of FMT on UC.

Gut microbiota modulation: a novel strategy for prevention and treatment of colorectal cancer

Research about the role of gut microbiome in colorectal cancer (CRC) is a newly emerging field of study. Gut microbiota modulation, with the aim to reverse established microbial dysbiosis, is a novel strategy for prevention and treatment of CRC. Different strategies including probiotics, prebiotics, postbiotics, antibiotics, and fecal microbiota transplantation (FMT) have been employed. Although these strategies show promising results, mechanistically by correcting microbiota composition, modulating innate immune system, enhancing gut barrier function, preventing pathogen colonization and exerting selective cytotoxicity against tumor cells, it should be noted that they are accompanied by risks and controversies that can potentially introduce clinical complications. During bench-to-bedside translation, evaluation of risk-and-benefit ratio, as well as patient selection, should be carefully performed. In view of the individualized host response to gut microbiome intervention, developing personalized microbiome therapy may be the key to successful clinical treatment.

Individual and cohort-specific gut microbiota patterns associated with tissue-specific insulin sensitivity in overweight and obese males

A growing body of evidence suggests that the human gut microbiota plays a role in the development of obesity and related metabolic diseases. However, there is little consensus between studies, which could be due to biological as well as technical variation. In addition, little human data are available to investigate whether tissue-specific insulin sensitivity is related to specific microbial patterns. We examined this relation in two independent cohorts of overweight and obese pre-diabetic men, using phylogenetic microarray data and hepatic, peripheral and adipose tissue insulin sensitivity that were determined by a two-step hyperinsulinemic-euglycemic clamp with [6,6-²H₂]-glucose tracer infusion. Despite a prominent subject-specific microbiota, we found significant associations of microbial taxa with tissue-specific insulin sensitivity using regression analysis. Using random forests we found moderate associations with other measures of glucose homeostasis in only one of the cohorts (fasting glucose concentrations AUC = 0.66 and HbA_1c AUC = 0.65). However, all findings were cohort-specific due to pronounced variation in microbiota between cohorts, suggesting the existence of alternative states for dysbiosis in metabolic syndrome patients. Our findings suggest individual or group related dynamics, instead of universal microbiota signals, related to the host when the overweight or obese state has already developed and argue that care should be taken with extrapolating significant correlations from single cohorts, into generalized biological relevance.

Effects of polysaccharide from Pueraria lobata on gut microbiota in mice

Polysaccharide was derived from Pueraria lobata (PPL) which was considered as one of the traditional Chinese medicinal and edible herbs. In the present study, PPL was administered in equal doses (12.5 mg/kg) to both normal mice and antibiotic-associated diarrhea (AAD) mice for two weeks, and was evaluated in terms of body weight, organ indices, gut structure, gut microbiota and short chain fatty acids. The results showed that normal mice treated with PPL not only reduced the isovaleric acid concentration (P < 0.05), but also significantly increased the abundance of beneficial bacteria, involving Oscillospira and Anaerotruncus (P < 0.05). In addition, PPL could relieve colonic pathological changes and gut microbiota dysbiosis caused by AAD. It indicated that PPL was a potential functional food ingredient by modulating gut microbiota.

Characteristics of Fecal Microbiota Transplantation Use in Inflammatory Bowel Disease Cohort

BACKGROUND

There is a growing interest in the role of gut bacteria in a number of diseases and an emerging hypothesis that inflammatory bowel disease (IBD) is triggered by microbial dysbiosis in genetically susceptible individuals. Currently, fecal microbiota transplantation (FMT) is utilized for the treatment of Clostridium difficile colitis. Data on the efficacy of FMT for IBD are mixed, but patients are interested in its use for the treatment of IBD. We sought to describe the use of FMT (self or medical professional administered) in individuals with IBD using IBD Partners, an Internet-based cohort.

METHODS

Patients enrolled in the IBD Partners cohort were offered the opportunity to complete an optional survey on the use of FMT between January 2017 to September 2018 (n = 5430). A cross-sectional analysis was performed within patients who completed the survey and did not have a pouch or ostomy. Patients' demographic characteristics, disease activity and phenotype, mode of FMT delivery, and patient-reported efficacy were compared.

RESULTS

Among 3274 eligible patients, 51 (1.6%) responded that they had an FMT in the past. Of patients undergoing FMT, 22 patients had the FMT for C. difficile while 29 reported that the FMT was for another indication. Most patients receiving FMT for an indication other than C. difficile had ulcerative colitis/indeterminate colitis (25, 86.2%). Colonoscopy (68.2%) and nasogastric tube (18.2%) were the most common routes of administration for patients receiving FMT for C. difficile colitis. Self-administration (72.4%) and enemas (17.2%) were the most common routes of administration in patients receiving FMT for an alternate indication. Patients reporting FMT for an indication other than C. difficile were less likely to have a physician directing their FMT treatment (20.6%) as compared to patients receiving FMT for C. difficile (86.3%). Patient-reported efficacy was lower for FMT given for a non-C. difficile indication.

CONCLUSIONS

Patients undergoing FMT for an indication other than C. difficile infection were more likely to have ulcerative colitis, self-administer FMT, and were less likely to be receiving FMT under the guidance of a medical professional. FMT was not as effective for symptoms when given for a non-C. difficile indication. Patients should be counseled on potential harms and lack of proven benefit associated with FMT for IBD indications to try to discourage self-administered FMT without proper medical oversite.

Association Between Impaired Vα7.2+CD161++CD8+ (MAIT) and Vα7.2+CD161-CD8+ T-Cell Populations and Gut Dysbiosis in Chronically HIV- and/or HCV-Infected Patients

Both HIV and HCV infections feature increased microbial translocation (MT) and gut dysbiosis that affect immune homeostasis and disease outcome. Given their commitment to antimicrobial mucosal immunity, we investigated mucosal-associated invariant T (MAIT) cells and Vα7.2+CD161- T-cell frequency/function and their possible associations with MT and gut dysbiosis, in chronic HIV and/or HCV infections. We enrolled 56 virally infected (VI) patients (pts): 13 HIV+ on suppressive cART (HIV-RNA < 40cp/ml), 13 HCV+ naive to DAA (direct-acting antiviral) anti-HCV agents; 30 HCV+/HIV+ on suppressive cART and naive to anti-HCV. 13 age-matched healthy controls (HC) were enrolled. For Vα7.2+CD161++ and Vα7.2+CD161-CD8+ T cells we assessed: activation (CD69), exhaustion (PD1/CD39), and cytolytic activity (granzymeB/perforin). Following PMA/ionomycin and Escherichia coli stimulation we measured intracellular IL17/TNFα/IFNγ. Markers of microbial translocation (Plasma LPS, 16S rDNA, EndoCAb and I-FABP) were quantified. In 5 patients per group we assessed stool microbiota composition by 16S targeted metagenomics sequencing (alpha/beta diversity, relative abundance). Compared to controls, virally infected pts displayed significantly lower circulating Vα7.2+CD161++CD8+ MAIT cells (p = 0.001), yet expressed higher perforin (p = 0.004) and granzyme B (p = 0.002) on CD8+ MAIT cells. Upon E. coli stimulation, the residual MAIT cells are less functional particularly those from HIV+/HCV+ patients. Conversely, in virally infected pts, Vα7.2+CD161-CD8+ cells were comparable in frequency, highly activated/exhausted (CD69+: p = 0.002; PD-1+: p = 0.030) and with cytolytic potential (perforin+: p < 0.0001), yet were poorly responsive to ex vivo stimulation. A profound gut dysbiosis characterized virally infected pts, especially HCV+/HIV+ co-infected patients, delineating a Firmicutes-poor/Bacteroidetes-rich microbiota, with significant associations with MAIT cell frequency/function. Irrespective of mono/dual infection, HIV+ and HCV+ patients display depleted, yet activated/cytolytic MAIT cells with reduced ex vivo function, suggesting an impoverished pool, possibly due to continuous bacterial challenge. The MAIT cell ability to respond to bacterial stimulation correlates with the presence of Firmicutes and Bacteroidetes, possibly suggesting an association between gut dysbiosis and MAIT cell function and posing viral-mediated dysbiosis as a potential key player in the hampered anti-bacterial MAIT ability.

Carbapenemases in Enterobacteriaceae: Detection and Antimicrobial Therapy

Carbapenem-resistant Enterobacteriaceae (CRE) have spread rapidly around the world in the past few years, posing great challenges to human health. The plasmid-mediated horizontal transmission of carbapenem-resistance genes is the main cause of the surge in the prevalence of CRE. Therefore, the timely and accurate detection of CRE, especially carbapenemase-producing Enterobacteriaceae, is very important for the clinical prevention and treatment of these infections. A variety of methods for the rapid detection of CRE phenotypes and genotypes have been developed for use in clinical microbiology laboratories. To overcome the lack of efficient antibiotics, CRE infections are often treated with combination therapies. Moreover, novel drugs and emerging strategies appeared successively and in various stages of development. In this article, we summarized the global distribution of various carbapenemases. And we focused on summarizing and comparing the advantages and limitations of the detection methods and the therapeutic strategies of CRE primarily.

Initial experience of fecal microbiota transplantation in gastrointestinal disease: A case series

Current studies have proven the strong association between gut microbiota dysbiosis and the pathogenesis of gastrointestinal diseases. Fecal microbiota transplantation (FMT) from a healthy donor is a promising therapeutic strategy to change and restore composition of the recipient's gut microbiota. Rapidly increasing clinical literatures confirmed the truth of the benefits of FMT on recurrent Clostridium difficile infection (rCDI) and inflammatory bowel disease. This article retrospectively reviewed nine cases (four cases had ulcerative colitis [UC], five cases had rCDI) who received FMT in Kaohsiung Medical University Hospital from April 2016 to November 2018. We summarized the procedure including donor selection, fecal materials preparation, transplantation delivery methods, and clinical outcomes. All of the four UC cases got clinical improvement and four rCDI cases achieved clinical remission after FMT. The other one rCDI case remained positive stool Toxin A+B result after FMT, and got remission after salvage treatment with fidaxomicin. FMT is considered to be a well-tolerated adjuvant treatment for UC and effective salvage treatment for rCDI in our initial experience. Multiple infusions of FMT in UC and rCDI might have exceptional clinical efficiency, and enteral tube insertion could be a useful method to reach this goal and make multiple sessions of FMT easier.

Fecal Microbial Transplantation and Its Potential Application in Cardiometabolic Syndrome

Newly revealed links between inflammation, obesity, and cardiometabolic syndrome have created opportunities to try previously unexplored therapeutic modalities in these common and life-risking disorders. One potential modulator of these complex disorders is the gut microbiome, which was described in recent years to be altered in patients suffering from features of cardiometabolic syndrome and to transmit cardiometabolic phenotypes upon transfer into germ-free mice. As a result, there is great interest in developing new modalities targeting the altered commensal bacteria as a means of treatment for cardiometabolic syndrome. Fecal microbiota transplantation (FMT) is one such modality in which a disease-associated microbiome is replaced by a healthy microbiome configuration. So far clinical use of FMT has been overwhelmingly successful in recurrent Clostridium difficile infection and is being extensively studied in other microbiome-associated pathologies such as cardiometabolic syndrome. This review will focus on the rationale, promises and challenges in FMT utilization in human disease. In particular, it will overview the role of the gut microbiota in cardiometabolic syndrome and the rationale, experience, and prospects of utilizing FMT treatment as a potential preventive and curative treatment of metabolic human disease.

Current applications of fecal microbiota transplantation in intestinal disorders

Fecal microbiota transplantation (FMT) had been an ancient remedy for severe illness several centuries ago. Under modern medical analysis and evidence-based research, it has been proved as an alternative treatment for recurrent Clostridium difficile infection and recent randomized control study also showed that FMT could be an adjuvant treatment for inflammatory bowel disease. As we get a better understanding of the relationship between gut microbiota and systemic disease, FMT became a potential treatment to explore. This article summarized procedures such as donor selection, fecal material preparation, transplantation delivery methods, and adverse events. We also review the present evidence about FMT in clinical practice.

Therapeutic effects of lentinan on inflammatory bowel disease and colitis-associated cancer

In this study, we investigated the therapeutic potential of lentinan in mouse models of inflammatory bowel disease (IBD) and colitis-associated cancer (CAC). Lentinan decreased the disease activity index and macroscopic and microscopic colon tissue damage in dextran sulphate sodium (DSS)-induced or TNBS-induced models of colitis. High-dose lentinan was more effective than salicylazosulfapyridine in the mouse models of colitis. Lentinan decreased the number of tumours, inflammatory cell infiltration, atypical hyperplasia and nuclear atypia in azoxymethane/DSS-induced CAC model. It also decreased the expression of pro-inflammatory cytokines, such as IL-13 and CD30L, in IBD and CAC model mice possibly by inhibiting Toll-like receptor 4 (TLR4)/NF-κB signalling and the expression of colon cancer markers, such as carcinoembryonic antigen, cytokeratin 8, CK18 and p53, in CAC model mice. In addition, lentinan restored the intestinal bacterial microbiotal community structure in IBD model mice. Thus, it shows therapeutic potential in IBD and CAC model mice possibly by inhibiting TLR4/NF-κB signalling-mediated inflammatory responses and disruption of the intestinal microbiotal structure.

Fecal microbiota transplantation in refractory ulcerative colitis - a case report

Studies comparing gut microbiota profiles of inflammatory bowel disease (IBD) patients have shown several changes in microbiota composition, with marked reduction of local biodiversity relative to that of healthy controls. Modulation of the bacterial community is a promising strategy to reduce the proportion of harmful microorganisms and increase the proportion of beneficial bacteria; this is expected to prevent or treat IBD. The exact mechanism of fecal microbiota transplantation (FMT) remains unknown; however, replacing the host microbiota can reestablish gut microbial composition and function in IBD patients. The present report describes an ulcerative colitis patient who underwent FMT. A 17-year-old male with moderate to severe clinical activity, which was refractory to mesalazine, azathioprine, and infliximab, underwent FMT as alternative therapy. The patient exhibited clinical improvement after the procedure; however, the symptoms returned. A second FMT was performed 8 months after the first procedure, but the patient did not improve. In conclusion, despite the FMT failure observed in this patient, the procedure is a promising therapeutic option for IBD patients, and more in-depth studies of this method are needed.

Fecal microbiota transplantation: donor relation, fresh or frozen, delivery methods, cost-effectiveness

Fecal microbiota transplantation (FMT) has evolved into a robust and efficient means for treating recurrent Clostridium difficile infection (CDI). Our narrative review looks at the donor selection, preparation, delivery techniques and cost-effectiveness of FMT. We searched electronic databases, including PubMed, MEDLINE, Google Scholar, and Cochrane Databases, for studies that compared the biological effects of donor selection, fresh or frozen fecal preparation, and various delivery techniques. We also evaluated the cost-effectiveness and manually searched references to identify additional relevant studies. Overall, there is a paucity of studies that directly compare outcomes associated with related and non-related stool donors. However, inferences from prior studies indicate that the success of FMT does not depend on the donor-patient relationship. Over time, the use of unrelated donors has increased because of the formation of stool banks and the need to save processing time and capital. However, longitudinal studies are needed to clarify the optimal freezing time before microbial function declines. Several FMT techniques have been developed, such as colonoscopy, enema, nasogastric or nasojejunal tubes, and capsules. The comparable and high efficacy of FMT capsules, combined with their convenience, safety and aesthetically tolerable mode of delivery, makes it an attractive option for many patients. Cost-effective models comparing these various approaches support the use of FMT via colonoscopy as being the best strategy for the treatment of recurrent CDI.

Hypoglycemic Mechanism of the Berberine Organic Acid Salt under the Synergistic Effect of Intestinal Flora and Oxidative Stress

Both alterations to the intestinal microflora and chronic systemic inflammation predispose towards type 2 diabetes (T2D). Changes in the composition of the intestinal microflora are associated with glucose metabolism changes in rats with T2D. Here, we demonstrate that a berberine fumarate (BF) has a hypoglycemic effect by regulating the intestinal microflora and metabolism of diabetic rats. The T2D rats had disorders of glucose and lipid metabolism, an abnormal intestinal microflora, fewer butyrate-producing and probiotic-type bacteria, larger numbers of potentially pathogenic and sulfate-reducing bacteria, and tissue inflammation. Administration of berberine fumarate significantly ameliorated the metabolic disorder; increased the populations of Bacteroidetes, Clostridia, Lactobacillales, Prevotellaceae, and Alloprevotella; and reduced those of Bacteroidales, Lachnospiraceae, Rikenellaceae, and Desulfovibrio. In addition, it reduced inflammation, inhibiting the overexpression of TLR4 and p-JNK and increasing the expression of PI3K, GLUT2, and other proteins, which are closely related to oxidative stress, thereby promoting the metabolism of glucose.