Relationship between intestinal microbiota and ulcerative colitis: Mechanisms and clinical application of probiotics and fecal microbiota transplantation

[Fecal microbiome change in patients with ulcerative colitis after fecal microbiota transplantation]

Intestinal human microbiota is a dynamic system that is under the pressures of its host organism and external factors. Microbiota disruption caused by these factors can lead to severe diseases including inflammatory and oncological diseases of the gastrointestinal tract. One of the possible approaches in managing the intestinal microbiota is fecal microbiota transplantation (FT) - transfer of the microbiota from the stool of a healthy donor to the intestinal tract of a recipient patient. Currently, this procedure is recognized as an efficacious method to normalize the intestinal microbiota mainly in inflammatory diseases of the gastrointestinal tract. In Russia, pilot studies of the effectiveness of FT in patients with ulcerative colitis have been conducted for several years, and these studies were started in Novosibirsk. The aim of this study was to assess the change of intestinal microbiome in 20 patients with ulcerative colitis after a single FT procedure. The main method is a comparative analysis of 16S ribosomal RNA sequence libraries constructed using fecal samples obtained from patients with ulcerative colitis before and after FT and sequenced on the Illumina MiSeq platform. The obtained results showed that FT led to an increase in average biodiversity in samples after FT compared to samples before FT; however, the difference was not significant. In the samples studied, the proportion of Firmicutes sequences, the major gastrointestinal microbiota of healthy people, was decreased (~32 % vs. >70 %), while the proportion of Proteobacteria sequences was increased (>9 % vs. <5 %). In some samples collected before FT, sequences of pathogenic Firmicutes and Proteobacteria were detected, including Acinetobacter spp., Enterococcus spp., Klebsiella pneumoniae, Proteus mirabilis, Staphylococcus aureus, Stenotrophomonas maltophylia, Streptococcus spp. In most cases, the proportion of such sequences after FT substantially decreased in appropriate samples. The exception was the Clostridium difficile sequences, which accounted for <0.5 % of the sequences in samples from almost half of the patients and after FT, the share of such C. difficile sequences was significantly reduced only in samples from three patients. It should be noted that the proportion of Lactobacillus spp. increased ten-fold and their species composition significantly expanded. According to the obtained results, a preliminary conclusion can be made that even a single FT procedure can lead to an increase in the biodiversity of the gastrointestinal microbiota in patients and to the optimization of the taxonomic composition of the microbiota.

Fusobacterium nucleatum Secretes Outer Membrane Vesicles and Promotes Intestinal Inflammation

Multiple studies have implicated microbes in the development of inflammation, but the mechanisms remain unknown. Bacteria in the genus Fusobacterium have been identified in the intestinal mucosa of patients with digestive diseases; thus, we hypothesized that Fusobacterium nucleatum promotes intestinal inflammation. The addition of >50 kDa F. nucleatum conditioned media, which contain outer membrane vesicles (OMVs), to colonic epithelial cells stimulated secretion of the proinflammatory cytokines interleukin-8 (IL-8) and tumor necrosis factor (TNF). In addition, purified F. nucleatum OMVs, but not compounds <50 kDa, stimulated IL-8 and TNF production; which was decreased by pharmacological inhibition of Toll-like receptor 4 (TLR4). These effects were linked to downstream effectors p-ERK, p-CREB, and NF-κB. F. nucleatum >50-kDa compounds also stimulated TNF secretion, p-ERK, p-CREB, and NF-κB activation in human colonoid monolayers. In mice harboring a human microbiota, pretreatment with antibiotics and a single oral gavage of F. nucleatum resulted in inflammation. Compared to mice receiving vehicle control, mice treated with F. nucleatum showed disruption of the colonic architecture, with increased immune cell infiltration and depleted mucus layers. Analysis of mucosal gene expression revealed increased levels of proinflammatory cytokines (KC, TNF, IL-6, IFN-γ, and MCP-1) at day 3 and day 5 in F. nucleatum-treated mice compared to controls. These proinflammatory effects were absent in mice who received F. nucleatum without pretreatment with antibiotics, suggesting that an intact microbiome is protective against F. nucleatum-mediated immune responses. These data provide evidence that F. nucleatum promotes proinflammatory signaling cascades in the context of a depleted intestinal microbiome.IMPORTANCE Several studies have identified an increased abundance of Fusobacterium in the intestinal tracts of patients with colon cancer, liver cirrhosis, primary sclerosing cholangitis, gastroesophageal reflux disease, HIV infection, and alcoholism. However, the direct mechanism(s) of action of Fusobacterium on pathophysiological within the gastrointestinal tract is unclear. These studies have identified that F. nucleatum subsp. polymorphum releases outer membrane vesicles which activate TLR4 and NF-κB to stimulate proinflammatory signals in vitro Using mice harboring a human microbiome, we demonstrate that F. nucleatum can promote inflammation, an effect which required antibiotic-mediated alterations in the gut microbiome. Collectively, these results suggest a mechanism by which F. nucleatum may contribute to intestinal inflammation.

Postoperative Ileus after Stimulation with Probiotics before Ileostomy Closure

Loop ileostomy closure after colorectal surgery is often associated with Postoperative ileus, with an incidence between 13-20%. The aim of this study is to evaluate the efficacy and safety of preoperative stimulation of the efferent loop with probiotics prior to ileostomy closure in patients operated on for colorectal carcinoma. For this, a prospective, randomized, double-blind, controlled study is designed. All patients who underwent surgery for colorectal carcinoma with loop ileostomy were included. Randomized and divided into two groups, 34 cases and 35 controls were included in the study. Postoperative ileus, the need for nasogastric tube insertion, the time required to begin tolerating a diet, restoration of bowel function, and duration of hospital stay were evaluated. The incidence of Postoperative ileus was similar in both groups, 9/34 patients stimulated with probiotics and 10/35 in the control group (CG) with a p = 0.192. The comparative analysis showed a direct relationship between Postoperative ileus after oncological surgery and Postoperative ileus after reconstruction surgery, independently of stimulation. Postoperative ileus after closure ileostomy is independent of stimulation of the ileostomy with probiotics through the efferent loop. There seem to be a relationship between Postoperative ileus after reconstruction and the previous existence of Postoperative ileus after colorectal cancer surgery.

Effect of antibiotic therapy in patients with ulcerative colitis: a meta-analysis of randomized controlled trials

BACKGROUND

Gut microbiota may play a role in the pathogenesis of ulcerative colitis (UC). Antibiotic therapy for patients with UC has shown conflicting results.

OBJECTIVES

To evaluate the effect of antibiotic therapy in treating UC.

METHODS

PubMed, EMBASE, Cochrane Library, Wanfang Data, and China National Knowledge Infrastructure (CNKI) databases were searched to identify randomized controlled trials (RCTs) that evaluated antibiotics compared with placebo or no antibiotics in patients with UC. We extracted and pooled the risk ratio (RR).

RESULTS

Twelve RCTs were included in this systematic review and meta-analysis, which included 739 patients with active UC. Antibiotic therapy had statistically significant efficacy in inducing remission rate in patients with UC, observed at the end of trials (random-effect RR = 0.77; 95% confidence interval [CI] 0.60 to 0.98, p = .03) or at 12 months after trials (fixed-effect RR = 0.83; 95% CI 0.73 to 0.94, p = .003).

CONCLUSIONS

Antibiotic therapy appeared to induce remission more effectively than a placebo or no antibiotic intervention not only in the short-term but also in the long-term for patients with UC. More high-quality clinical trials are needed before clinical recommendations for antibiotic therapy in UC management are made.

Baitouweng decoction alleviates dextran sulfate sodium-induced ulcerative colitis by regulating intestinal microbiota and the IL-6/STAT3 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Baitouweng (BTW) decoction, a Chinese traditional medicine prescription, has been used to treat ulcerative colitis (UC) over hundreds of years. In this study, we investigated the anti-inflammatory effects of BTW and intestinal flora of dextran sulfate sodium (DSS)-induced UC mice, and we investigated the mechanism of BTW in the preliminary treatment of UC.

AIM OF STUDY

The aim of this study was to elucidate the mechanism of BTW in treating UC through molecular biology and high-throughput sequencing.

METHODS

DSS-induced UC mice were established and randomly divided into the following four groups: control group, DSS group, BTW group and sulfasalazine (SASP) group. Except for the control group, 3% DSS drinking water was given to each group for 7 days, and the other two groups were intragastrically administered with BTW and SASP. Mice were sacrificed after gavage for 10 days. Body weight loss, disease activity index (DAI), colon length, colon histopathology and the expression of inflammatory cytokines were measured. Intestinal content samples were collected, and intestinal flora differences were analyzed by 16 S rDNA sequencing.

RESULTS

BTW effectively reduced the symptoms and histopathological score of UC mice, and it reduced the production of IL-6, IL-1β and TNF-α. Activation of the IL-6/STAT3 pathway was also suppressed by BTW treatment. Moreover, 16 S rDNA sequencing showed that the intestinal flora of mice in the DSS group was disordered compared to the control group. After treatment with BTW, the diversity of intestinal flora was significantly improved. At the phylum level, the proportion of Firmicutes to Bacteroidetes was decreased, and the ratio of Proteobacteria was decreased. At the genus level, the relative abundance of Escherichia-Shigella was decreased, but that of Lactobacillus and Akkermansia were increased.

CONCLUSION

BTW significantly improved the inflammatory symptoms of mice with acute colitis, and the latent mechanism of BTW may be related to various signaling pathways, including the modulation of intestinal microflora and inflammatory signaling pathways, such as IL-6/STAT3.

Gut Microbiota and Related Metabolites Were Disturbed in Ulcerative Colitis and Partly Restored After Mesalamine Treatment

Mesalamine has been well used in the improvement of ulcerative colitis (UC) in clinics, however, the underlying mechanisms were not well illustrated. To explore its efficacy from the perspective of gut microbiota and related metabolites, we employed 16S rRNA sequencing and metabolomics approaches in stool samples across 14 normal healthy controls (NC group), 10 treatment-naïve UC patients (UC group) and 14 UC patients responded to mesalamine treatment (mesalamine group). We noted that the gut microbiota diversity and community composition were remarkably perturbed in UC group and partially restored by mesalamine treatment. The relative abundance of 192 taxa in genus level were significantly changed in UC group, and 168 genera were significantly altered after mesalamine intervention. Meanwhile, a total of 127 metabolites were significantly changed in UC group and 129 metabolites were significantly altered after mesalamine treatment. Importantly, we observed that many candidates including 49 genera (such as Escherichia-shigella, Enterococcus and Butyricicoccus) and 102 metatoblites (such as isoleucine, cholic acid and deoxycholic acid) were reversed by mesalamine. Spearman correlation analysis revealed that most of the candidates were significantly correlated with Mayo score of UC, and the relative abundance of specific genera were significant correlated with the perturbation of metabolites. Pathway analysis demonstrated that genera and metabolites candidates were enriched in many similar molecular pathways such as amino acid metabolism and secondary metabolites biosynthesis. Importantly, ROC curve analysis identified a gut microbiota signature composed of five genera including Escherichia-Shigella, Streptococcus, Megamonas, Prevotella_9 and [Eubacterium] _coprostanoligenes _group which might be used to distinguish UC group from both NC and mesalamine group. In all, our results suggested that mesalamine might exert a beneficial role in UC by modulating gut microbiota signature with correlated metabolites in different pathways, which may provide a basis for developing novel candidate biomarkers and therapeutic targets of UC.

Gut microbiota modulation induced by Zika virus infection in immunocompetent mice

Gut microbiota composition can modulate neuroendocrine function, inflammation, and cellular and immunological responses against different pathogens, including viruses. Zika virus (ZIKV) can infect adult immunocompetent individuals and trigger brain damage and antiviral responses. However, it is not known whether ZIKV infection could impact the gut microbiome from adult immunocompetent mice. Here, we investigated modifications induced by ZIKV infection in the gut microbiome of immunocompetent C57BL/6J mice. Adult C57BL/6J mice were infected with ZIKV and the gut microbiota composition was analyzed by next-generation sequencing of the V4 hypervariable region present in the bacterial 16S rDNA gene. Our data showed that ZIKV infection triggered a significant decrease in the bacteria belonging to Actinobacteria and Firmicutes phyla, and increased Deferribacteres and Spirochaetes phyla components compared to uninfected mice. Interestingly, ZIKV infection triggered a significant increase in the abundance of bacteria from the Spirochaetaceae family in the gut microbiota. Lastly, we demonstrated that modulation of microbiota induced by ZIKV infection may lead to intestinal epithelium damage and intense leukocyte recruitment to the intestinal mucosa. Taken together, our data demonstrate that ZIKV infection can impact the gut microbiota composition and colon tissue homeostasis in adult immunocompetent mice.

Capparis spinosa Alleviates DSS-Induced Ulcerative Colitis via Regulation of the Gut Microbiota and Oxidative Stress

Ulcerative colitis (UC) is a chronic inflammatory disease. Here, the potential effects of Capparis spinosa water extract (CSWE) on colonic histopathology, inflammation, and gut microbiota composition in dextran sulfate sodium (DSS) induced UC mice were evaluated. Our results showed that CSWE treatment improved the colonic histopathology of UC mice, increased the levels of tight junction protein gene ZO-1 and Occludin in intestinal epithelial cells, and inhibited the expression of proinflammatory cytokines (IL-1β, IL-6, and TNF-α). Furthermore, CSWE administration alleviated oxidative stress in the colon of UC mice. The effects of CSWE on the compositions and metabolomic profiles of the gut microbiota in UC mice were investigated. It was found that CSWE could enhance the diversity of gut microbes and the abundance of probiotics and metabonomics had the strongest association with Firmicutes. Our results indicated that CSWE might be an ideal candidate as a potential therapeutic natural product for the treatment of UC.

The rectal mucosal but not fecal microbiota detects subclinical ulcerative colitis

Ulcerative colitis (UC), a subtype of inflammatory bowel disease, is characterized by repetitive remission and relapse. Gut microbiome is critically involved in pathogenesis of UC. The shifts in microbiome profile during disease remission remain under-investigated. Recent studies revealed that UC pathogenesis is likely to originate in the mucosal barrier. Therefore, we investigated the effectiveness of mucosal tissue microbiomes to differentiate patients with subclinical UC from healthy individuals. The microbiomes of cecal and rectal biopsies and feces were characterized from 13 healthy individuals and 45 patients with subclinical UC. Total genomic DNA was extracted from the samples, and their microbial communities determined using next-generation sequencing. We found that changes in relative abundance of subclinical UC were marked by a decrease in Proteobacteria and an increase in Bacteroidetes phyla in microbiome derived from rectal tissues but not cecal tissue nor feces. Only in the microbiome of rectal tissue had significantly higher community richness and evenness in subclinical UC patients than controls. Twenty-seven operational taxonomic units were enriched in subclinical UC cohort with majority of the taxa from the Firmicutes phylum. Inference of putative microbial functional pathways from rectal biopsy microbiome suggested a differential increase in interleukin-17 signaling and T-helper cell differentiation pathways. Rectal biopsy tissue was suggested to be more suitable than fecal samples for microbiome assays to distinguish patients with subclinical UC from healthy adults. Assessment of the rectal biopsy microbiome may offer clinical insight into UC disease progression and predict relapse of the diseases.

Bacterial infections in lupus: Roles in promoting immune activation and in pathogenesis of the disease

BACKGROUND

Bacterial infections of the lung, skin, bloodstream and other tissues are common in patients with systemic lupus erythematosus (lupus) and are often more severe and invasive than similar infections in control populations. A variety of studies have explored the changes in bacterial abundance in lupus patients, the rates of infection and the influence of particular bacterial species on disease progression, using both human patient samples and mouse models of lupus.

OBJECTIVE

The aim of this review is to summarize human and mouse studies that describe changes in the bacterial microbiome in lupus, the role of a leaky gut in stimulating inflammation, identification of specific bacterial species associated with lupus, and the potential roles of certain common bacterial infections in promoting lupus progression.

METHODS

Information was collected using searches of the Pubmed database for articles relevant to bacterial infections in lupus and to microbiome changes associated with lupus.

RESULTS

The reviewed studies demonstrate significant changes in the bacterial microbiome of lupus patients as compared to control subjects and in lupus-prone mice compared to control mice. Furthermore, there is evidence supporting the existence of a leaky gut in lupus patients and in lupus-prone mice. This leaky gut may allow live bacteria or bacterial components to enter the circulation and cause inflammation. Invasive bacterial infections are more common and often more severe in lupus patients. These include infections caused by Staphylococcus aureus, Salmonella enterica, Escherichia coli, Streptococcus pneumoniae and mycobacteria. These bacterial infections can trigger increased immune activation and inflammation, potentially stimulating activation of autoreactive lymphocytes and leading to worsening of lupus symptoms.

CONCLUSIONS

Together, the evidence suggests that lupus predisposes to infection, while infection may trigger worsening lupus, leading to a feedback loop that may reinforce autoimmune symptoms.

Select animal models of colitis and their value in predicting clinical efficacy of biological therapies in ulcerative colitis

Introduction: Advancing new therapies from discovery to development usually requires proof-of-concept in animal models to justify the costs of continuing the program. While animal models are useful for understanding the mechanism of action (MOA) of a target, limitations of many published colitis models restrict their value to predict clinical efficacy.Areas covered: The authors focused their literature search on published studies of chronic animal models used to evaluate the pre-clinical efficacy of therapeutic molecules subsequently evaluated in clinical trials for UC. The UC therapies evaluated were anti-α4β7, anti-IL13, anti-IL12p40, and anti-IL23p19. The models of chronic colitis evaluating these molecules were: mdra1a-/-, chronic dextran sulfate sodium (DSS), chronic 2,4,6-trinitrobenzene sulfonic acid (TNBS), and the T cell transfer model.Expert opinion: While some models provide insight into target MOA in UC, none is consistently superior in predicting efficacy. Evaluation of multiple models, with varying mechanisms of colitis induction, is needed to understand potential drug efficacy. Additional models of greater complexity, reflecting the disease chronicity/heterogeneity seen in humans, are needed. Although helpful in prioritizing targets, animal models alone will likely not improve outcomes of UC clinical trials. Transformational changes to clinical efficacy will likely only occur when precision medicine approaches are employed.

Anti-Inflammatory Effects of Heritiera littoralis Fruits on Dextran Sulfate Sodium- (DSS-) Induced Ulcerative Colitis in Mice by Regulating Gut Microbiota and Suppressing NF-κB Pathway

Materials and Methods

The chemical compositions of EFH were identified using LC-ESI-MS. The mice with 3% DSS-induced UC were administered EFH (200, 400, and 800 mg/kg), sulfasalazine (SASP, 200 mg/kg), and azathioprine (AZA, 13 mg/kg) for 10 days via daily gavage. The colonic inflammation was evaluated by the disease activity index (DAI), colonic length, histological scores, and levels of inflammatory mediators. The gut microbiota was characterized by 16S rRNA gene sequencing and analysis.

Results

LC-ESI-MS analysis showed that EFH was rich in alkaloids and flavones. The results indicated that EFH significantly improved the DAI score, relieved colon shortening, and repaired pathological colonic variations in colitis. In addition, proteins in the NF-κB pathway were significantly inhibited by EFH. Furthermore, EFH recovered the diversity and balance of the gut microbiota.

Conclusions

EFH has protective effects against DSS-induced colitis by keeping the balance of the gut microbiota and suppressing the NF-κB pathway.

Recurrence of moderate to severe ulcerative colitis after fecal microbiota transplantation treatment and the efficacy of re-FMT: a case series

Background

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD), the pathogenesis of which is complicated, and it is difficult to treat. In recent years, the emerging fecal microbiota transplantation (FMT) has shown good effects in UC treatment and is therefore accepted by increasing numbers of patients. Our hospital has carried out FMT since 2017, and has achieved good results in UC treatment. We have found in our clinical work that the efficacy of re-FMT after recurrence decreased. This is difference from reported literatures. In order to attract clinical attention, here we selected typical cases for analysis.

Methods

Among all UC patients who received FMT in our hospital, 12 patients with moderate to severe UC were selected. They all received multiple FMT and were followed up for 52 weeks. Besides, none of them had other underlying diseases. Colonoscopy images of patients were presentated, SCCAI and UCDAI were used assess the effect of FMT.

Results

On the whole, FMT has a significant effect on moderate to severe UC. Of the 12 patients, 11 (91.7%) achieved a clinical response, 9 (75.0%) achieved clinical remission, and only one patient did not respond to FMT treatment. However, 6 patients relapsed within 52 weeks after remission, with a recurrence rate of 54.5%. Four of the six relapsed patients received FMT again, but the efficacy of FMT after relapse was significantly lower than that of the initial FMT. Fortunately, compared to before the initial FMT treatment, the severity of the disease after relapse was significantly reduced.

Conclusion

FMT has a good effect on the relief of moderate to severe UC. However, the effect of FMT treatment after relapse is reduced. For patients who relapse after remission, the efficacy of FMT reapplication requires more experiments to verify.

Protective effects of tryptophan-catabolizing Lactobacillus plantarum KLDS 1.0386 against dextran sodium sulfate-induced colitis in mice

Tryptophan is an essential amino acid for the human body, whose intake is through the diet. Several studies support the theory that microbiota-derived tryptophan metabolite played a crucial role in maintaining the balance between gut microbiota and the mucosal immune system. Previously, we selected the Lactobacillus plantarum KLDS 1.0386 strain with high tryptophan-metabolic activity after the screening of 16 Lactobacillus strains. The current study aimed to assess the effects of L. plantarum KLDS 1.0386 combination with tryptophan in improving ulcerative colitis (UC) induced by dextran sodium sulfate (DSS) and the potential mechanisms involved. Our results showed that L. plantarum KLDS 1.0386 combined with tryptophan (LAB + Trp) decreased DAI score, MPO level, and pro-inflammatory cytokine (TNF-α, IL-1β, and IL-6) concentration. It also increased anti-inflammatory cytokine (IL-10) production, tight junction proteins (claudin-1, occludin, and ZO-1), and mucin (MUC1 and MUC2) mRNA expressions. The level of indole-3-acetic acid (IAA), an important tryptophan metabolite in the liver, serum, and colon, was elevated after LAB + Trp treatment, which further upregulated aryl hydrocarbon receptor (AHR) mRNA expression to activate the IL-22/STAT3 signaling pathway. Moreover, the supplementation with LAB + Trp modulated gut microbiota composition. The present study provided novel insights that can be used to reduce the number of UC patients by employing a method utilizing tryptophan-catabolizing Lactobacillus strains.

Intestinal Barrier Function in Health and Disease-Any role of SARS-CoV-2?

Alterations in the structure and function of the intestinal barrier play a role in the pathogenesis of a multitude of diseases. During the recent and ongoing coronavirus disease (COVID-19) pandemic, it has become clear that the gastrointestinal system and the gut barrier may be affected by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, and disruption of barrier functions or intestinal microbial dysbiosis may have an impact on the progression and severity of this new disease. In this review, we aim to provide an overview of current evidence on the involvement of gut alterations in human disease including COVID-19, with a prospective outlook on supportive therapeutic strategies that may be investigated to rescue intestinal barrier functions and possibly facilitate clinical improvement in these patients.

The Influence of Probiotics on the Firmicutes/Bacteroidetes Ratio in the Treatment of Obesity and Inflammatory Bowel disease

The two most important bacterial phyla in the gastrointestinal tract, Firmicutes and Bacteroidetes, have gained much attention in recent years. The Firmicutes/Bacteroidetes (F/B) ratio is widely accepted to have an important influence in maintaining normal intestinal homeostasis. Increased or decreased F/B ratio is regarded as dysbiosis, whereby the former is usually observed with obesity, and the latter with inflammatory bowel disease (IBD). Probiotics as live microorganisms can confer health benefits to the host when administered in adequate amounts. There is considerable evidence of their nutritional and immunosuppressive properties including reports that elucidate the association of probiotics with the F/B ratio, obesity, and IBD. Orally administered probiotics can contribute to the restoration of dysbiotic microbiota and to the prevention of obesity or IBD. However, as the effects of different probiotics on the F/B ratio differ, selecting the appropriate species or mixture is crucial. The most commonly tested probiotics for modifying the F/B ratio and treating obesity and IBD are from the genus Lactobacillus. In this paper, we review the effects of probiotics on the F/B ratio that lead to weight loss or immunosuppression.

The impact of tobacco smoking on treatment choice and efficacy in inflammatory bowel disease

Smoking significantly increases the risk of developing and worsens Crohn's disease (CD), yet protects against the development and reduces the severity of ulcerative colitis. It is less clear whether smoking impacts the efficacy of therapeutics in inflammatory bowel disease (IBD). We review the literature regarding the relationship between smoking and the efficacy of medical and surgical therapy in IBD. Smoking is associated with alterations in thiopurine metabolism and may affect time to disease relapse. The outcomes of anti-tumor necrosis factor therapy in active smokers appear neutral with data lacking for newer biologics. Smoking increases the risk of postoperative recurrence in those requiring resection for CD, likely attributable to perturbations of the gut microbiota although further implications of these for disease onset/progression and treatment efficacy remain unclear. Multiple lifestyle and psychosocial confounders are likely under-recognized cofactors in the association between smoking and IBD. Despite the widely promulgated risks associated with cigarette smoking in CD, more incisive data are required to further elucidate the actual relationship between smoking and disease pathways, while accounting for the several negative cofactors prevalent in smokers which cast uncertainty on the magnitude of the direct effect of smoking on disease pathophysiology and the efficacy of therapy.

Distinct Stage Changes in Early-Life Colonization and Acquisition of the Gut Microbiota and Its Correlations With Volatile Fatty Acids in Goat Kids

In livestock, a comprehensive understanding of the early-life establishment and acquisition of commensal gut microbiota allow us to develop better husbandry management operations and manipulate the gut microbiota for young animals, improving the efficiency of animal production. Here, we collected 123 microbial samples of 11 healthy goat kids and their mothers to investigate the colonization and acquisition of the gut microbiota and their correlations with volatile fatty acids (VFAs) in goat kids from birth to day 56. An age-dependent increasing and more homogeneous diversity were observed for the feces of goat kids. Overall, Firmicutes, Bacteroidetes, and Proteobacteria were the predominant phyla in the fecal microbiota of goat kids, but their relative abundance varied considerably with age. Accordingly, the colonization of the fecal microbiota in goat kids was divided into three distinct stages: newborn (day 0), non-rumination stage (days 7–21), and transition stages (days 28–56). LEfSe analysis revealed a total of 49 bacterial biomarkers that are stage-specific (LDA score > 3, P < 0.05). Significant Spearman correlations (P < 0.05) were observed between the abundances of several bacterial biomarkers and the VFA concentrations. Furthermore, a substantial difference in the fecal microbiota composition was present between 56-day-old goat kids and mothers, whereas there was a moderate difference in the rumen microbiota between them. Among four body sites (i.e., feces, oral cavity, vagina, and breast milk) of mothers, the maternal vaginal and breast milk microbiota were the major source of the fecal microbiota of goat kids in the first 56 days after birth, although their contributions decreased with age and unknown sources increased after day 28. In summary, we concluded that the gut bacterial community in goat kids after birth was mainly acquired from the maternal vagina and breast milk. Its colonization showed three distinct phases with dramatic shifts of composition mainly driven by age and diet changes. Our results provide a framework for a better understanding of the roles of the gut microbiota in young ruminants.

The role of in utero endotoxin exposure in the development of inflammatory bowel disease in mice

PROBLEM

Although early environmental influences are thought to influence the development of inflammatory bowel disease (IBD), little is known about the role of the in utero environment on subsequent IBD risk. We hypothesized that prenatal exposure to bacterial lipopolysaccharide (LPS) could modify the subsequent development of dextran sulfate sodium (DSS)-induced ulcerative colitis in adulthood by influencing the associated cellular and immune response.

METHOD OF STUDY

To test this hypothesis, we exposed developing mice in utero to LPS or saline (PBS) at E17.5, and then induced colitis at 5 weeks. We then assessed colitis severity and effects on the microbiome. In order to define the developmental impact of any potential LPS effect, we also exposed 1-week-old mice to either LPS or saline before inducing colitis at 5 weeks.

RESULTS

Mice that had been exposed to LPS but not saline in utero were protected from subsequent colitis development, and their intestinal barrier integrity and tight junction expression distribution were similar to that of control mice that were not exposed to DSS. By contrast, mice exposed to either LPS or saline at day 7 of life all developed severe colitis upon subsequent DSS exposure.

CONCLUSION

These results identify an informative time window during fetal development during which exposure to an otherwise pro-inflammatory agent like LPS protects against an inflammatory disease in adulthood.

Distinctive probiotic features share common TLR2-dependent signalling in intestinal epithelial cells

The underlying mechanisms of probiotics and postbiotics are not well understood, but it is known that both affect the adaptive and innate immune responses. In addition, there is a growing concept that some probiotic strains have common core mechanisms that provide certain health benefits. Here, we aimed to elucidate the signalization of the probiotic bacterial strains Lactobacillus paragasseri K7, Limosilactobacillus fermentum L930BB, Bifidobacterium animalis subsp. animalis IM386 and Lactiplantibacillus plantarum WCFS1. We showed in in vitro experiments that the tested probiotics exhibit common TLR2- and TLR10-dependent downstream signalling cascades involving inhibition of NF-κB signal transduction. Under inflammatory conditions, the probiotics activated phosphatidylinositol 3-kinase (PI3K)/Akt anti-apoptotic pathways and protein kinase C (PKC)-dependent pathways, which led to regulation of the actin cytoskeleton and tight junctions. These pathways contribute to the regeneration of the intestinal epithelium and modulation of the mucosal immune system, which, together with the inhibition of canonical TLR signalling, promote general immune tolerance. With this study we identified shared probiotic mechanisms and were the first to pinpoint the role of anti-inflammatory probiotic signalling through TLR10.

The amelioration of ulcerative colitis induced by Dinitrobenzenesulfonic acid with Radix Hedysari

Ulcerative colitis (UC) is a chronic inflammatory disease with an unknown precise etiology. This study proves that Radix Hedysari (RH) ameliorates UC. Four RH extracts were used to ameliorate UC induced by 2,4-Dinitrobenzenesulfonic acid by 7 days intervention in agreement to preliminary studies. Compared to treatment with RH extracts, the RH ethanol extract (EE) was found to be more effective in ameliorating UC. With EE, the DAI were significantly decreased. Macroscopic and histopathological assessments suggest that the colon mucosa was repaired, the organizational structure of the colon had been rebuilt. The levels of MPO, TNF-α, IL-1β, and MDA were significantly decreased (p < .01), the levels of T-SOD and CAT were significantly increased (p < .01). Moreover, the compounds in EE were analyzed by HPLC. The results show that EE can ameliorate UC, and its anti-inflammatory capability probably plays an important role. RH can act as a functional food and ameliorate UC. PRACTICAL APPLICATIONS: In this work, the ameliorative effect of RH on UC was evaluated from multiple angles. There are two practical applications of this work. On the one hand, a new approach to ameliorating UC is provided by this work. In addition, UC patients have a new option for improving their symptoms. On the other hand, this work also provides information on how best to process RH for therapeutic use. In addition, we can utilize some compounds of RH that were once considered useless and reduce the waste of natural resources.

Weissella paramesenteroides WpK4 plays an immunobiotic role in gut-brain axis, reducing gut permeability, anxiety-like and depressive-like behaviors in murine models of colitis and chronic stress

The relationship between inflammatory bowel disease (IBD) and mood disorders is complex and involves overlapping metabolic pathways, which may determine comorbidity. Several studies have been shown that this comorbidity could worsen IBD clinical course. The treatment of ulcerative colitis is complex, and involves traditional therapy to promote the function of epithelial barrier, reducing exacerbated inflammatory responses. Recently, it has been shown that some probiotic strains could modulate gut-brain axis, reducing depressive and anxiety scores in humans, including IBD patients. Accordingly, this study aimed to evaluate the role of Weissella paramesenteroides WpK4 in murine models of ulcerative colitis and chronic stress. It was observed that bacterium ingestion improved health of colitis mice, reducing intestinal permeability, besides improving colon histopathological appearance. In stressed mice, bacterial consumption was associated with a reduced anxiety-like and depressive-like behaviors. In both assays, the beneficial role of W. paramesenteroides WpK4 was related to its immunomodulatory feature. It is possible to state that W. paramesenteroides WpK4 exerted their beneficial roles in gut-brain axis through their immunomodulatory effects with consequences in several metabolic pathways related to intestinal permeability and hippocampal physiology.

Intervention with kimchi microbial community ameliorates obesity by regulating gut microbiota

The objective of this study was to evaluate anti-obesity effects of kimchi microbial community (KMC) on obesity and gut microbiota using a high fat diet-induced mouse model compared to effects of a single strain. Administration of KMC decreased body weight, adipose tissue, and liver weight gains. Relative content of Muribaculaceae in the gut of the KMC-treated group was higher than that in the high-fat diet (HFD) group whereas relative contents of Akkermansiaceae, Coriobacteriaceae, and Erysipelotrichaceae were lower in KMC-treated group. Metabolic profile of blood was found to change differently according to the administration of KMC and a single strain of Lactobacillus plantarum. Serum metabolites significantly increased in the HFD group but decreased in the KMC-treated group included arachidic acid, stearic acid, fumaric acid, and glucose, suggesting that the administration of KMC could influence energy metabolism. The main genus in KMC was not detected in guts of mice in KMC-treated group. Since the use of KMC has advantages in terms of safety, it has potential to improve gut microbial community for obese people.

The protective effect of Lactobacillus versus 5-aminosalicylic acid in ulcerative colitis model by modulation of gut microbiota and Nrf2/Ho-1 pathway

AIMS

Ulcerative colitis (UC) has many complications, from colonic damage to colorectal cancer. The mystery of both etiology and effective treatment of UC still challenging process. The role of gut microbiota in UC is still unclear. In the current study we compare the difference in gut microbiota abundance in both UC and normal colon besides the therapeutic effect of Lactobacillus spp. in treating UC versus the standard drug.

MATERIALS AND METHODS

The experimental panel included five group of rats; normal control, UC diseased rats, sterilizing rats, ASA treated and Lactobacillus treated. The change in the microbiota abundance was investigated using conventional and real time PCR. In parallel, clinical evaluation of UC and macroscopic examination scoring was also done. Colonic oxidants/antioxidant stress biomarkers; MDA, GSH, catalase, myeloperoxidase activity, and SOD activity were assessed. Colon Nrf2, HO-1 contents and TNF-α was evaluated.

KEY FINDINGS

The current study revealed a significant difference in the relative abundance of microbiota where, UC is associated with massive increase of E. coli and Fusobacterium spp., while enormous decrease in Bifidobacteria spp. in contrast with negative control. Both 5-ASA and Lactobacillus show a significant amelioration of all antioxidant enzymes and marked decline of inflammatory and oxidative stress markers. Both Lactobacillus and 5-ASA show significant increase of NrF2 and HO-1 and marked decrease of TNF-α.

SIGNIFICANCE

Lactobacillus spp. exerted a beneficial effect on the inflammation, oxidative stress and the symbiosis of gut microbiota that improve structural intestinal defect and promote healing in UC.

Transplanting fecal material from wild-type mice fed black raspberries alters the immune system of recipient mice

By constantly stimulating intestinal immunity, gut microbes play important regulatory roles, and their possible involvement in human physical and mental disorders beyond intestinal diseases suggests the importance of maintaining homeostasis in the gut microbiota. Both transplantation of fecal microbiota and dietary interventions have been shown to restore microbial homeostasis in recipients. In the current study with wild-type mice, we combined these two approaches to determine if transplanting fecal material from mice fed black raspberries (BRB, 5%) altered recipients' immune system. The donors received a control or 5% BRB diet, and fecal transplantation was performed every other day 15 times into recipients fed control diet. Afterward, we used flow cytometry to analyze populations of CD3+ T, CD4+ T, CD8+ T cells, and NK cells among bone marrow cells, splenocytes, and peripheral blood mononuclear cells (PBMCs) collected from the recipients. We found that BRB-fecal material that contained both fecal microbiota and their metabolites increased NK cell populations among bone marrow cells, splenocytes, and PBMCs, and raised levels of CD8+ T cells in splenocytes. Our findings suggest that fecal transplantation can modulate the immune system and might therefore be valuable for managing a range of physical and mental disorders.

The Role of the Microbiome in Cancer and the Development of Cancer Therapeutics

Cancer is caused by a compilation of hereditary and environmental factors. In the past decade, next-generation sequencing has revealed the extent to which the microbiome influences the maintenance of homeostasis and therefore the prevention of diseases such as cancer. Current research efforts explore the interaction between cancer and the microbiome, and the results are anticipated to transform how clinicians approach cancer treatment. There is a plausible transition from the use of human genetic biomarkers to microbiomic biomarkers for genomic diagnostics. Considering the expanding knowledge of the ways in which the microbiome can affect the development of cancer, clinicians treating cancer patients should be considerate of how the microbiome can influence the host-drug or microbiome-cancer interactions. Recognition of the importance of the microbiome within the field of oncology is pertinent to understanding and furthering cancer development and treatment.

Regulation of the intestinal microbiota: An emerging therapeutic strategy for inflammatory bowel disease

The rapid development of metagenomics, metabolomics, and metatranscriptomics provides novel insights into the intestinal microbiota factors linked to inflammatory bowel disease (IBD). Multiple microorganisms play a role in intestinal health; these include bacteria, fungi, and viruses that exist in a dynamic balance to maintain mucosal homeostasis. Perturbations in the intestinal microbiota disrupt mucosal homeostasis and are closely related to IBD in humans and colitis in mice. Therefore, preventing or correcting the imbalance of microbiota may serve as a novel prevention or treatment strategy for IBD. We review the most recent evidence for direct or indirect interventions targeting intestinal microbiota for treatment of IBD in order to overcome the current limitations of IBD therapies and shed light on personalized treatment options.

Pingkui Enema Alleviates TNBS-Induced Ulcerative Colitis by Regulation of Inflammatory Factors, Gut Bifidobacterium, and Intestinal Mucosal Barrier in Rats

Background

Ulcerative colitis (UC) is a chronic recurrent inflammation of the colon, and clinical outcome of UC is still unsatisfied. Pingkui enema, a traditional Chinese medicine prescription, has been safely applied for the treatment of diarrhea and dysentery in clinic for many years. However, its mechanism is still elusive. The present study is designed to investigate the effect of Pingkui enema on trinitrobenzene sulfonic acid- (TNBS-) induced ulcerative colitis (UC) and possible mechanism in rats.

Methods

UC was induced by intracolonic instillation of TNBS in male Sprague-Dawley rats, which were treated with different dosages of Pingkui enema (low, medium, and high) or sulfasalazine for ten days. Survival rate was calculated. A clinical disease activity score was evaluated. Histological colitis severity was analyzed by hematoxylin-eosin (HE) staining. Content of Bifidobacterium in intestinal tissue was analyzed by RT-PCR. Concentration of IL-8, IL-13, TNF-α, D-lactic acid (D-LA), and diamine oxidase (DAO) in serum and contents of adhesin and receptor of Bifidobacterium adhesion in rat intestinal mucus were measured by ELISA.

Results

The results showed that Pingkui enema treatment with high dosage markedly improved the survival rate compared with untreated and sulfasalazine treated groups. All dosages of Pingkui enema reduced pathological score. High dosage of Pingkui enema and sulfasalazine treatments significantly reduced the serum concentration of IL-8, TNF-α, D-LA, and DAO and markedly increased the serum concentration of IL-13. In addition, high-dose Pingkui enema and sulfasalazine treatments increased gut content of Bifidobacterium, gut mucus expressions of adhesin, and adhesin receptor of Bifidobacterium.

Conclusions

Pingkui enema has therapeutic effect on TNBS-induced UC, and possible mechanism may be via regulation of gut probiotics (Bifidobacterium) and inflammatory factors and protection of intestinal mucosal barrier.

Neurological and cognitive significance of probiotics: a holy grail deciding individual personality

The role of the human microbiome in the brain and behavioral development is an area of increasing attention. Recent investigations have found that diverse mechanisms and signals including the immune, endocrine and neural associations are responsible for the communication between gut microbiota and the brain. The studies have suggested that alteration of intestinal microbiota using probiotic formulations may offer a significant role in the maturation and organization of the brain and can shape the brain and behavior as well as mood and cognition in human subjects. The understanding of the possible impact of gut microflora on neurological function is a promising phenomenon that can surely transform the neurosciences and may decipher the novel etiologies for neurodegenerative and psychiatric disorders.

The Effectiveness of Multi-Session FMT Treatment in Active Ulcerative Colitis Patients: A Pilot Study

The modification of the microbiome through fecal microbiota transplantation (FMT) is becoming a very promising therapeutic option for inflammatory bowel disease (IBD) patients. Our pilot study aimed to assess the effectiveness of multi-session FMT treatment in active ulcerative colitis (UC) patients. Ten patients with UC were treated with multi-session FMT (200 mL) from healthy donors, via colonoscopy/gastroscopy. Patients were evaluated as follows: at baseline, at week 7, and after 6 months, routine blood tests (including C reactive protein (CRP) and calprotectin) were performed. 16S rRNA gene (V3V4) sequencing was used for metagenomic analysis. The severity of UC was classified based on the Truelove–Witts index. The assessment of microbial diversity showed significant differences between recipients and healthy donors. FMT contributed to long-term, significant clinical and biochemical improvement. Metagenomic analysis revealed an increase in the amount of Lactobacillaceaea, Micrococcaceae, Prevotellaceae, and TM7 phylumsp.oral clone EW055 during FMT, whereas Staphylococcaceae and Bacillaceae declined significantly. A positive increase in the proportion of the genera Bifidobacterium, Lactobacillus, Rothia, Streptococcus, and Veillonella and a decrease in Bacillus, Bacteroides, and Staphylococcus were observed based on the correlation between calprotectin and Bacillus and Staphylococcus; ferritin and Lactobacillus, Veillonella, and Bifidobacterium abundance was indicated. A positive change in the abundance of Firmicutes was observed during FMT and after 6 months. The application of multi-session FMT led to the restoration of recipients’ microbiota and resulted in the remission of patients with active UC.

Probiotics as a functional food ingredient in allergic diseases: regulation of CD4+ T helper cell differentiation

Allergic diseases are increasing worldwide, associating with increased health costs and decreased quality of life. Allergy is immune-related diseases caused by an allergic immune response to innocuous substance in the environment. At present, research has focussed on the study of the relevance to the microbiome and the phenotypes of allergy, including the relationships among the gastrointestinal microbiome, immune function, and allergic sensitisation. Probiotics as functional food ingredient are thought to secrete functional metabolites that have antibacterial effects on ameliorating intestinal health and CD4+ T helper cells-mediated immunity. This review will summarise the role of probiotics in the immune regulation and flora balance, highlighting recent advances in our understanding of the imbalance of Th subsets and cytokine leading to the immunopathology of allergic reactions. Finally, we discussed the unresolved problems and future research directions in order to promote the clinical application of probiotics immunotherapy.

Barrier Protection and Recovery Effects of Gut Commensal Bacteria on Differentiated Intestinal Epithelial Cells In Vitro

Alterations in the gut microbiota composition play a crucial role in the pathogenesis of inflammatory bowel disease (IBD) as specific commensal bacterial species are underrepresented in the microbiota of IBD patients. In this study, we examined the therapeutic potential of three commensal bacterial species, Faecalibacterium prausnitzii (F. prausnitzii), Roseburia intestinalis (R. intestinalis) and Bacteroides faecis (B. faecis) in an in vitro model of intestinal inflammation, by using differentiated Caco-2 and HT29-MTX cells, stimulated with a pro-inflammatory cocktail consisting of interleukin-1β (IL-1β), tumor necrosis factor-α (TNFα), interferon-γ (IFNγ), and lipopolysaccharide (LPS). Results obtained in this work demonstrated that all three bacterial species are able to recover the impairment of the epithelial barrier function induced by the inflammatory stimulus, as determined by an amelioration of the transepithelial electrical resistance (TEER) and the paracellular permeability of the cell monolayer. Moreover, inflammatory stimulus increased claudin-2 expression and decreased occludin expression were improved in the cells treated with commensal bacteria. Furthermore, the commensals were able to counteract the increased release of interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) induced by the inflammatory stimulus. These findings indicated that F. prausnitzii, R. intestinalis and B. faecis improve the epithelial barrier integrity and limit inflammatory responses.

Ulcerative colitis: Gut microbiota, immunopathogenesis and application of natural products in animal models

Ulcerative colitis (UC) is an inflammatory bowel disease with increasing incidence in the world, especially in developing countries. Although knowledge of its pathogenesis has progressed over the last years, some details require clarification. Studies have highlighted the role of microbial dysbiosis and immune dysfunction as essential factors that may initiate the typical high-grade inflammatory outcome. In order to better understand the immunopathophysiological aspects of UC, experimental murine models are valuable tools. Some of the most commonly used chemicals to induce colitis are trinitrobenzene sulfonic acid, oxazolone and dextran sodium sulfate. These may also be used to investigate new ways of preventing or treating UC and therefore improving targeting in human studies. The use of functional foods or bioactive compounds from plants may constitute an innovative direction towards the future of alternative medicine. Considering the above, this review focused on updated information regarding the 1. gut microbiota and immunopathogenesis of UC; 2. the most utilized animal models of the disease and their relevance; and 3. experimental application of natural products, not yet tested in clinical trials.

Interplay between Cellular and Molecular Mechanisms Underlying Inflammatory Bowel Diseases Development-A Focus on Ulcerative Colitis

Inflammatory bowel diseases (IBD) are defined by the continuous inflammation of the gastrointestinal tract. During inflammation, the number of pathogens in the intestinal epithelium increases, leading to inflammasome assembly. Inflammasome activation is meant to protect the intestinal epithelial barrier from further damage by maintaining homeostasis. Although its purpose is to protect the cells, excessive nucleotide-binding oligomerization domain-like receptor and pyrin domain-containing protein 3 (NLRP3) inflammasome assembly is responsible for the synthesis of a high number of pro-inflammatory cytokines. The activation of two crucial pathways, autophagy process, and unfolded protein response, is initiated for restoring homeostasis. Aberrant expression of miRNAs and lncRNAs also interfere with the pathogenic mechanisms of IBD, as these non-coding transcripts play key roles in regulation of biological processes, such as inflammation and immunity. This review thoroughly describes the cellular and molecular mechanism that trigger and perpetuate inflammation in ulcerative colitis (UC) patients.

Anti-colonic Inflammation by Black Raspberries through Regulating Toll-like Receptor-4 Signaling in Interlukin-10 Knockout Mice

Ulcerative colitis (UC) is a chronic inflammatory disease of the colon, with a steadily rising prevalence in Western and newly industrialized countries. UC patients have a cancer incidence as high as 10% after 20 years of the disease. Although the importance of fruits and vegetables in defense against UC is beginning to be appreciated, the mechanisms remain largely unclear. In the current study, we reported that dietary black raspberries (BRBs) decreased colonic inflammation in the mucosa and submucosa of interleukin (IL)-10 knockout (KO) mice. We then used colon, spleen, and plasma from those mice to investigate whether BRBs exert their anti-inflammatory effects by correcting dysregulated toll-like receptor (TLR)-4 signaling to downregulate prostaglandin E2 (PGE2). Other studies reported that spleen is the reservoir of macrophages and depletion of macrophages in IL-10 KO mice prevents the development of colitis. Our results showed that BRBs decreased the percentages of macrophages in spleens of IL-10 KO mice. Moreover, mechanistically, the BRB diet corrected dysregulated TLR-4 signaling in cells from the colon and spleen, decreased PGE2 and prostaglandin I2, and increased 15-lipoxygenase and its product, 13-S-hydroxyoctadecadienoic acid, in plasma of IL-10 KO mice. Therefore, we have elucidated one of the anti-inflammatory mechanisms of BRBs, and have identified biomarkers that could be indicators of response in UC patients treated with them. Our findings with BRBs could well apply to many other commonly consumed fruits and vegetables.

A Novel Cecropin-LL37 Hybrid Peptide Protects Mice Against EHEC Infection-Mediated Changes in Gut Microbiota, Intestinal Inflammation, and Impairment of Mucosal Barrier Functions

Intestinal inflammation can cause impaired epithelial barrier function and disrupt immune homeostasis, which increases the risks of developing many highly fatal diseases. Enterohemorrhagic Escherichia coli (EHEC) O157:H7 causes intestinal infections worldwide and is a major pathogen that induces intestinal inflammation. Various antibacterial peptides have been described as having the potential to suppress and treat pathogen-induced intestinal inflammation. Cecropin A (1–8)-LL37 (17–30) (C-L), a novel hybrid peptide designed in our laboratory that combines the active center of C with the core functional region of L, shows superior antibacterial properties and minimized cytotoxicity compared to its parental peptides. Herein, to examine whether C-L could inhibit pathogen-induced intestinal inflammation, we investigated the anti-inflammatory effects of C-L in EHEC O157:H7-infected mice. C-L treatment improved the microbiota composition and microbial community balance in mouse intestines. The hybrid peptide exhibited improved anti-inflammatory effects than did the antibiotic, enrofloxacin. Hybrid peptide treated infected mice demonstrated reduced clinical signs of inflammation, reduced weight loss, reduced expression of pro-inflammatory cytokines [tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interferon-gamma (IFN-γ)], reduced apoptosis, and reduced markers of jejunal epithelial barrier function. The peptide also affected the MyD88–nuclear factor κB signaling pathway, thereby modulating inflammatory responses upon EHEC stimulation. Collectively, these findings suggest that the novel hybrid peptide C-L could be developed into a new anti-inflammatory agent for use in animals or humans.

Dihydrotanshinone attenuates chemotherapy-induced intestinal mucositis and alters fecal microbiota in mice

Chemotherapy-induced intestinal mucositis (CIM) is a principal reason for reduced living quality of patients undergoing chemotherapy. Growing evidence showed gut microbiota played an important role in the development of intestinal mucositis. Dihydrotanshinone I (DHTS) is a liposoluble extract of Salvia miltiorrhiza Bunge with many bioactivities. Here we investigated the effect of DHTS on intestinal mucositis induced by 5-fluorouracil and irinotecan in mice. We detected the degree of intestinal mucosal damage and inflammatory response in CIM mice with or without DHTS administration. The body weight and disease activity index (DAI) of mice were monitored each day. H&E staining was used to evaluate pathological damage. The contents of interleukin 6 (IL-6), tumor necrosis factor (TNFα), diacylglycerol (DAO) and triglyceride (TG) in serum were determined by commercial kits. We also investigated the changes of fecal microbiota by 16S rRNA high-throughput sequencing. Spearman correlation analysis was used to evaluate the correlation between fecal microbiota and inflammatory factors. Tax4Funwas performed to infer the potential function of the microbial community. Results showed DHTS significantly reduced DAI, intestinal mucosal damage and inflammatory response in CIM mice by decreasing serum IL-6 and TNFα. In addition, there is an intense correlation between fecal microbiota and inflammatory factors. DHTS efficiently reversed disordered fecal microflora close to normal and increased the abundance of g__Akkermansia. DHTS also enriched bacterial species which promote butyric acid metabolism or negatively correlated with inflammatory factors. Besides, species enriched by DHTS in fecal microbiota were probably involved in glutamine production and ammonia oxidation. In conclusion, our study provides evidence that DHTS effectively attenuates CIM induced by 5-fluorouracil and irinotecan in mice. Regulation of the composition and function of fecal microbiota probably plays a critical role in the therapeutic effect of DHTS in CIM mice.

The gallbladder and vermiform appendix influence the assemblage of intestinal microorganisms

Surgical procedures for the symptomatic removal of the gallbladder and the vermiform appendix have been posited to adversely shift the assemblage of the intestinal microbiome increasing the risk of disease. The associated mechanisms have been linked with dysbiosis of the gut microbiota. Cholecystectomy causes changes of bile acid compositions and bile secretion patterns as bile acids interact with the intestinal microbiota in a bidirectional capacity. An appendectomy precludes the further recolonization of the proximal colon with a commensal biofilm that could maintain a stable intestinal microbiome. Epidemiological studies indicate that there is an increased risk of disease rather than causality following a cholecystectomy and appendectomy. This narrative review summarizes studies that report on the role that bile salts and the appendix, contribute to the assemblage of the intestinal microbiome in health and disease.

Indigo Naturalis Alleviates Dextran Sulfate Sodium-Induced Colitis in Rats via Altering Gut Microbiota

Ulcerative colitis is a gastrointestinal disorder intricately associated with intestinal dysbiosis, but effective treatments are currently limited. Indigo naturalis, a traditional Chinese medicine derived from indigo plants, has been widely used in the treatment of ulcerative colitis. However, the specific mechanisms have not yet been identified. Accordingly, in this study, we evaluated the effects and mechanisms of indigo naturalis on dextran sulfate sodium (DSS)-induced colitis in rats. Our results showed that indigo naturalis potently alleviated DSS-induced colitis in rats, and reversed DSS-induced intestinal dysbiosis using bacterial 16S rRNA amplicon sequencing. The protective effects of indigo naturalis were gut microbiota dependent, as demonstrated by antibiotic treatments and fecal microbiota transplantation. Depletion of the gut microbiota through a combination of antibiotic treatments blocked the anti-inflammatory effect of indigo naturalis on the DSS-induced colitis, and the recipients of the gut microbiota from indigo naturalis-treated rats displayed a significantly attenuated intestinal inflammation, which was actively responsive to therapeutic interventions with indigo naturalis. Notably, supplement with indigo naturalis greatly increased the levels of feces butyrate, which was positively correlated with the relative abundances of Ruminococcus_1 and Butyricicoccus. We further showed that indigo naturalis-dependent attenuation of colitis was associated with elevated expression of short-chain fatty acid-associated receptors GPR41 and GPR43. Collectively, these results suggested that indigo naturalis alleviates DSS-induced colitis in rats through a mechanism of the microbiota-butyrate axis, particularly alterations in Ruminococcus_1 and Butyricicoccus abundances, and target-specific microbial species may have unique therapeutic promise for ulcerative colitis.

Ulcerative colitis: understanding its cellular pathology could provide insights into novel therapies

Dynamic interactions between the gastrointestinal epithelium and the mucosal immune system normally contribute to ensuring intestinal homeostasis and optimal immunosurveillance, but destabilisation of these interactions in genetically predisposed individuals can lead to the development of chronic inflammatory diseases. Ulcerative colitis is one of the main types of inflammatory diseases that affect the bowel, but its pathogenesis has yet to be completely defined. Several genetic factors and other inflammation-related genes are implicated in mediating the inflammation and development of the disease. Some susceptibility loci associated with increased risk of ulcerative colitis are found to be implicated in mucosal barrier function. Different biomarkers that cause damage to the colonic mucosa can be detected in patients, including perinuclear ANCA, which is also useful in distinguishing ulcerative colitis from other colitides. The choice of treatment for ulcerative colitis depends on disease severity. Therapeutic strategies include anti-tumour necrosis factor alpha (TNF-α) monoclonal antibodies used to block the production of TNF-α that mediates intestinal tract inflammation, an anti-adhesion drug that prevents lymphocyte infiltration from the blood into the inflamed gut, inhibitors of JAK1 and JAK3 that suppress the innate immune cell signalling and interferons α/β which stimulate the production of anti-inflammatory cytokines, as well as faecal microbiota transplantation. Although further research is still required to fully dissect the pathophysiology of ulcerative colitis, understanding its cellular pathology and molecular mechanisms has already proven beneficial and it has got the potential to identify further novel, effective targets for therapy and reduce the burden of this chronic disease.

Depolymerized RG-I-enriched pectin from citrus segment membranes modulates gut microbiota, increases SCFA production, and promotes the growth of Bifidobacterium spp., Lactobacillus spp. and Faecalibaculum spp

Rhamnogalacturonan-I (RG-I)-enriched pectin (WRP) was recovered from citrus processing water by sequential acid and alkaline treatments in a previous study. RG-I-enriched pectin was proposed as a potential supplement for functional food and pharmaceutical development. However, previous studies illustrated that favorable modulations of gut microbiota by RG-I-enriched pectin were based on in vitro changes in the overall microbial structure and the question of whether there is a structure-dependent modulation of gut microbiota remains largely enigmatic. In the present study, modulations of gut microbiota by commercial pectin (CP), WRP and its depolymerized fraction (DWRP) with different RG-I contents and Mw were compared in vivo. It was revealed by 16s rRNA high-throughput sequencing that WRP and DWRP mainly composed of RG-I modulated the gut microbiota in a positive way. DWRP significantly increased the abundance of prebiotic such as Bifidobacterium spp., Lactobacillus spp., while WRP increased SCFAs producers including species in Ruminococcaceae family. By maintaining a more balanced gut microbiota composition and enriching some SCFA producers, dietary WRP and DWRP also elevated the SCFA content in the colon. Collectively, our findings offer new insights into the structure-activity correlation of citrus pectin and provide impetus towards the development of RG-I-enriched pectin with small molecular weight for specific use in health-promoting prebiotic ingredients and therapeutic products.

Effects of alternate-day fasting, time-restricted fasting and intermittent energy restriction DSS-induced on colitis and behavioral disorders

Intermittent fasting (IF) has been reported to have beneficial effects on improving gut function via lowering gut inflammation and altering the gut microbiome diversity. In this study, we aimed to investigate the differential effects of three different common IF treatments, alternate day fasting (ADF), time-restricted fasting (TRF), and intermittent energy restriction (IER), on a dextran sodium sulfate (DSS)-induced colitis mouse model. The results indicated that TRF and IER, but not ADF improved the survival rates of the colitis mice. TRF and IER, but not ADF, reversed the colitis pathological development by improving the gut barrier integrity and colon length. Importantly, TRF and IER suppressed the inflammatory responses and oxidative stress in colon tissues. Interestingly, TRF and IER also attenuated colitis-related anxiety-like and obsessive-compulsive disorder behavior and alleviated the neuroinflammation and oxidative stress. TRF and IER also altered the gut microbiota composition, including the decrease of the enrichments of colitis-related microbes such as Shigella and Escherichia Coli, and increase of the enrichments of anti-inflammatory-related microbes. TRF and IER also improved the short chain fatty acid formation in colitis mice. In conclusion, the TRF and IER but not ADF exhibited the protective effects against colitis and related behavioral disorders, which could be partly explained by improving the gut microbiome compositions and preventing gut leak, and consequently suppressing the inflammation and oxidative damages in both colon and brain. The current research indicates that proper IF regimens could be effective strategies for nutritional intervention for the prevention and treatment of colitis.

Mucosal expression of defensin-5, soluble phospholipase A2 and lysozyme in the intestine in a rat model of acute liver failure and its relationship to intestinal bacterial translocation

INTRODUCTION

To study the expression of defensin-5 (RD-5), soluble phospholipase A2 (sPLA2) and lysozyme in the intestine in a rat model of acute liver failure and its relationship with intestinal bacterial translocation (BT).

PATIENTS AND METHODS

Sprague-Dawley (SD) rats were divided into two groups. The experimental group was divided into five subgroups according to the lapsing time after the model was established, which were designated accordingly as 8h, 16h, 24h, 48h, and 72h groups. Acute liver failure (ALF) model was induced by intraperitoneal injection of 10% d-galactosamine. The homogenates of mesenteric lymph nodes (MLNs), liver and spleen from each group were cultured in agar to determine the bacterial outgrowth. The mRNA expression of RD-5, sPLA2, lysozyme and the protein expression of sPLA2, lysozyme were determined.

RESULTS

No bacteria grew in the organ cultures from the control group while experimental groups had positive cultures. Expression of the RD-5 and sPLA2 mRNA in the experimental groups gradually increased at early time points and peaked 16h after induction of ALF, then progressively decreased. The mRNA expression of lysozyme in the experimental group peaked at 8h after ALF induction, then progressively decreased. Similar results were obtained with Western blot and immunohistochemical staining.

DISCUSSION

The immune barrier function of the ileal mucosa in the rat model of acute liver failure was compromised as demonstrated by the decreased expression of RD-5, sPLA2 and lysozyme in Paneth cells along with increased intestinal bacterial translocation.

The early life microbiota protects neonatal mice from pathological small intestinal epithelial cell shedding

The early life gut microbiota plays a crucial role in regulating and maintaining the intestinal barrier, with disturbances in these communities linked to dysregulated renewal and replenishment of intestinal epithelial cells. Here we sought to determine pathological cell shedding outcomes throughout the postnatal developmental period, and which host and microbial factors mediate these responses. Surprisingly, neonatal mice (Day 14 and 21) were highly refractory to induction of cell shedding after intraperitoneal administration of liposaccharide (LPS), with Day 29 mice showing strong pathological responses, more similar to those observed in adult mice. These differential responses were not linked to defects in the cellular mechanisms and pathways known to regulate cell shedding responses. When we profiled microbiota and metabolites, we observed significant alterations. Neonatal mice had high relative abundances of Streptococcus, Escherichia, and Enterococcus and increased primary bile acids. In contrast, older mice were dominated by Candidatus Arthromitus, Alistipes, and Lachnoclostridium, and had increased concentrations of SCFAs and methyamines. Antibiotic treatment of neonates restored LPS-induced small intestinal cell shedding, whereas adult fecal microbiota transplant alone had no effect. Our findings further support the importance of the early life window for microbiota-epithelial interactions in the presence of inflammatory stimuli and highlights areas for further investigation.

Assessing the efficacy and safety of fecal microbiota transplantation and probiotic VSL#3 for active ulcerative colitis: A systematic review and meta-analysis

BACKGROUND

Fecal microbiota transplantation is an effective treatment for many gastrointestinal diseases, such as Clostridium difficile infection and inflammatory bowel disease, especially ulcerative colitis. Changes in colonic microflora may play an important role in the pathogenesis of ulcerative colitis, and improvements in the intestinal microflora may relieve the disease. Fecal bacterial transplants and oral probiotics are becoming important ways to relieve active ulcerative colitis.

PURPOSE

This systematic review with meta-analysis compared the efficacy and safety of basic treatment combined with fecal microbiota transplantation or mixed probiotics therapy in relieving mild to moderate ulcerative colitis.

METHODS

The PubMed, Embase, and Cochrane libraries (updated September 2019) were searched to identify randomized, placebo-controlled, or head-to-head trials assessing fecal microbiota transplantation or probiotic VSL#3 as induction therapy in active ulcerative colitis. We analyze data using the R program to obtain evidence of direct comparison and to generate intermediate variables for indirect treatment comparisons.

RESULTS

Seven randomized, double-blind, placebo-controlled trials were used as the sources of the induction data. All treatments were superior to placebo. In terms of clinical remission and clinical response to active ulcerative colitis, direct comparisons showed fecal microbiota transplantation (OR = 3.47, 95% CI = 1.93-6.25) (OR = 2.48, 95% CI = 1.18-5.21) and mixed probiotics VSL#3 (OR = 2.40, 95% CI = 1.49-3.88) (OR = 3.09, 95% CI = 1.53-6.25) to have better effects than the placebo. Indirect comparison showed fecal microbiota transplantation and probiotic VSL#3 did not reach statistical significance either in clinical remission (RR = 1.20, 95% CI = 0.70-2.06) or clinical response (RR = 0.95, 95% CI = 0.62-1.45). In terms of safety, fecal microbiota transplantation (OR = 1.15, 95% CI = 0.51-2.61) and VSL #3 (OR = 0.90, 95% CI = 0.33-2.49) showed no statistically significant increase in adverse events compared with the control group. In terms of serious adverse events, there was no statistical difference between the fecal microbiota transplantation group and the control group (OR = 1.29, 95% CI = 0.46-3.57). The probiotics VSL#3 seems more safer than fecal microbiota transplantation, because serious adverse events were not reported in the VSL#3 articles.

CONCLUSIONS

Fecal microbiota transplantation or mixed probiotics VSL#3 achieved good results in clinical remission and clinical response in active ulcerative colitis, and there was no increased risk of adverse reactions. There was no statistical difference between the therapeutic effect of fecal microbiota transplantation and that of mixed probiotics VSL#3. However, the use of fecal microbiota transplantation and probiotics still has many unresolved problems in clinical applications, and more randomized controlled trials are required to confirm its efficacy.