The Functional Role of Fecal Microbiota Transplantation on Dextran Sulfate Sodium-Induced Colitis in Mice

Effect of fecal microbiota transplantation on ulcerative colitis model in rats: The gut-brain axis

Study objectives

The impact of fecal microbiota transplantation (FMT) on the TLR4/MYD88/NF-kB signaling pathway in the colon in the ulcerative colitis model, as well as the incidence of anxiety behaviors caused by the colitis model was investigated.

Methods

Twenthy four ats were induced with ulcerative colitis using a 4 % acetic acid solution administered intrarectally and were subsequently treated with prednisolone and FMT. The study examined several indicators, such as TLR4, MYD88, and NF-κB mRNA expression, along with oxidative stress factors. Additionally, it examined the relationship between anxiety-related behaviors and colitis and assessed the pro-inflammatory cytokines in the hippocampus.

Results

FMT led to lower disease score index and improved colon tissue pathology findings. This was associated with reduced mRNA expression of TLR4, MYD88, and NF-κB, as well as lower levels of TOS, and higher levels of TAC, GSH, and GSSG in colon tissues. FMT was found to reduce anxiety in both the open field and elevated plus maze tests. Additionally, levels of IL-6 and TNF-a were decreased in the hippocampus.

Conclusions

FMT suppressed acetic acid-induced colitis by inhibiting the TLR4/MYD88/NF-kB signaling pathway. FMT reduced anxiety in open field and plus maze tests, and resulted in decreased levels of IL-6 and TNF-a in the hippocampus.

The adjuvant treatment role of ω-3 fatty acids by regulating gut microbiota positively in the acne vulgaris

Objectives:We aimed to explore the potential role of omega-3 (ω-3) fatty acids on acne vulgaris by modulating gut microbiota.Materials and Methods:We randomly divided the untreated acne patients into two groups with or without ω-3 fatty acids intervention for 12 weeks. The Sprague Dawley (SD) rats with acne model were given isotretinoin, ω-3 fatty acids or their combination respectively. Then the colonic contents samples of the drug intervention SD rats were transferred to the pseudo sterile rats with acne model. The severity of the disease was assessed by the Global Acne Grading System (GAGS) score of the patients, and the swelling rate of auricle and the pathological section of the rat with acne model. The 16S rDNA gene sequencing was performed to detect the alteration of the gut microbiota.Results:ω-3 fatty acids could increase the diversity of the gut microbiota and regulate the flora structure positively both in the patients and rats, increase the abundance of butyric acid producing bacteria and GAGS score in the patients, and alleviate the inflammation and comedones of rats.Conclusion:Supplementation of ω-3 fatty acids could alleviate the inflammation of acne vulgaris by increasing the abundance of butyric acid producing bacteria.

Restore Intestinal Barrier Integrity: An Approach for Inflammatory Bowel Disease Therapy

The intestinal barrier maintained by various types of columnar epithelial cells, plays a crucial role in regulating the interactions between the intestinal contents (such as the intestinal microbiota), the immune system, and other components. Dysfunction of the intestinal mucosa is a significant pathophysiological mechanism and clinical manifestation of inflammatory bowel disease (IBD). However, current therapies for IBD primarily focus on suppressing inflammation, and no disease-modifying treatments specifically target the epithelial barrier. Given the side effects associated with chronic immunotherapy, effective alternative therapies that promote mucosal healing are highly attractive. In this review, we examined the function of intestinal epithelial barrier function and the mechanisms of behind its disruption in IBD. We illustrated the complex process of intestinal mucosal healing and proposed therapeutic approaches to promote mucosal healing strategies in IBD. These included the application of stem cell transplantation and organ-like tissue engineering approaches to generate new intestinal tissue. Finally, we discussed potential strategies to restore the function of the intestinal barrier as a treatment for IBD.

Li-Hong Tang alleviates dextran sodium sulfate-induced colitis by regulating NRF2/HO-1 signaling pathway and gut microbiota

Introduction

Ulcerative colitis (UC) is marked by recurring inflammation. Existing treatments are ineffective and may have toxic side effects. Thus, new therapeutic agents are urgently needed. We studied the botanical formula "Li-Hong Tang (LHT)", which contains two main ingredients, Salvia plebeia R. Br and Rhodiola crenulata (Hook. f. et Thoms.) H. Ohba. In this study, we aimed to identify the effects of LHT on UC and explore its potential mechanism.

Methods

LHT was analyzed using a mass spectrometer (MS). DSS at a dose of 2.5% was utilized to develop UC in mice. The administered groups received low, medium, and high dosages (0.32 g/kg, 0.64 g/kg, and 1.28 g/kg) of LHT and the positive medication, sulfasalazine (0.2 g/kg), respectively. Body weight, disease activity index (DAI) score, colon length, spleen index, serum myeloperoxidase (MPO), nitric oxide (NO), superoxide dismutase (SOD) and inflammatory factor concentrations were monitored. The expression of NRF2 and HO-1 in colonic tissues was evaluated by immunohistochemistry. 16S rDNA sequencing was employed to investigate alterations in the gut microbiota of the mice, aiming to elucidate the extent of LHT's impact.

Results

LHT may ameliorate DSS-induced colitis in mice by lowering inflammation, reducing oxidative stress, restoring the intestinal barrier, and influencing the NRF2/HO-1 pathway. Moreover, LHT treatment exhibited a regulatory effect on the gut microbiota, characterized by elevated levels of Patescibacteria, Verrucomicrobiota, Candidatus_Saccharimonas, Lactobacillus, and Ligilactobacillus levels while decreasing Oscillibacter and Colidextribacter levels. Further study indicated that MPO, NO, and inflammatory factors were positively correlated with Oscillibacter, Colidextribacter, Escherichia-Shigella, Anaerostines, and negatively with Lactobacillus, Clostridiales_unclassified, Candidatus_Saccharimonas, and Patescibacteria. Furthermore, colony network analysis revealed that Lactobacillus was negatively associated with Oscillibacter and Colidextribacter, whereas Oscillibacter was positively related to Colidextribacter.

Conclusion

LHT protects against DSS-induced mice by inhibiting the inflammatory response, oxidative stress, and mucosal injury. The protective role may involve regulating the NRF2/HO-1 signaling pathway and gut microbiota.

The proteolytic activity in inflammatory bowel disease: insight from gut microbiota

Inflammatory bowel disease (IBD) is a chronic, recurrent inflammatory disease caused by the destruction of the intestinal mucosal epithelium that affects a growing number of people worldwide. Although the etiology of IBD is complex and still elucidated, the role of dysbiosis and dysregulated proteolysis is well recognized. Various studies observed altered composition and diversity of gut microbiota, as well as increased proteolytic activity (PA) in serum, plasma, colonic mucosa, and fecal supernatant of IBD compared to healthy individuals. The imbalance of intestinal microecology and intestinal protein hydrolysis were gradually considered to be closely related to IBD. Notably, the pivotal role of intestinal microbiota in maintaining proteolytic balance received increasing attention. In summary, we have speculated a mesmerizing story, regarding the hidden role of PA and microbiota-derived PA hidden in IBD. Most importantly, we provided the diagnosis and therapeutic targets for IBD as well as the formulation of new treatment strategies for other digestive diseases and protease-related diseases.

Beneficial Effect of Faecal Microbiota Transplantation on Mild, Moderate and Severe Dextran Sodium Sulphate-Induced Ulcerative Colitis in a Pseudo Germ-Free Animal Model

Transplantation of faecal microbiota (FMT) is generally considered a safe therapeutic procedure with few adverse effects. The main factors that limit the spread of the use of FMT therapy for idiopathic inflammatory bowel disease (IBD) are the necessity of minimising the risk of infection and transfer of another disease. Obtaining the animal model of UC (ulcerative colitis) by exposure to DSS (dextran sodium sulphate) depends on many factors that significantly affect the result. Per os intake of DSS with water is individual for each animal and results in the development of a range of various forms of induced UC. For this reason, the aim of our study was to evaluate the modulation and regenerative effects of FMT on the clinical and histopathological responses and the changes in the bowel microenvironment in pseudo germ-free (PGF) mice of the BALB/c line subjected to chemical induction of mild, moderate and serious forms of UC. The goal was to obtain new data related to the safety and effectiveness of FMT that can contribute to its improved and optimised use. The animals with mild and moderate forms of UC subjected to FMT treatment exhibited lower severity of the disease and markedly lower damage to the colon, including reduced clinical and histological disease index and decreased inflammatory response of colon mucosa. However, FMT treatment failed to achieve the expected therapeutic effect in animals with the serious form of UC activity. The results of our study indicated a potential safety risk involving development of bacteraemia and also translocation of non-pathogenic representatives of bowel microbiota associated with FMT treatment of animals with a diagnosed serious form of UC.

Mechanism of Acupuncture and Moxibustion on Promoting Mucosal Healing in Ulcerative Colitis

The latest guideline about ulcerative colitis (UC) clinical practice stresses that mucosal healing, rather than anti-inflammation, is the main target in UC clinical management. Current mucosal dysfunction mainly closely relates to the endoscopic intestinal wall (mechanical barrier) injury with the imbalance between intestinal epithelial cells (IECs) regeneration and death, as well as tight junction (TJ) dysfunction. It is suggested that biological barrier (gut microbiota), chemical barrier (mucus protein layer, MUC) and immune barrier (immune cells) all take part in the imbalance, leading to mechanical barrier injury. Lots of experimental studies reported that acupuncture and moxibustion on UC recovery by adjusting the gut microbiota, MUC and immune cells on multiple targets and pathways, which contributes to the balance of IEC regeneration and death, as well as TJ structure recovery in animals. Moreover, the validity and superiority of acupuncture and moxibustion were also demonstrated in clinic. This study aims to review the achievements of acupuncture and moxibustion on mucosal healing and analyse the underlying mechanisms.

Intestinal microbiota regulates colonic inflammation in fluorosis mice by TLR/NF-κB pathway through short-chain fatty acids

Intestinal inflammation and microbial dysbiosis are found simultaneously in patients with fluorosis. However, whether the inflammation derived from fluoride exposure only or intestinal microbial disorders has not been clarified. In this study, 100 mg/L NaF exposure for 90 days significantly elevated the expressions of inflammatory factors (TNF-α, IL-1β, IL-6, IFN-γ, TGF-β, and IL-10), and the levels of TLR4, TRAF6, Myd88, IKKβ, and NF-κB P65 in mouse colon, while the above factors were reduced in pseudo germ-free mice with fluorosis, hinting that disordered microbiota might play a more direct role in the development of colonic inflammation than fluoride. Fecal microbiota transplantation (FMT) lowered the levels of inflammatory factors and inactivated the TLR/NF-κB pathway in fluoride-exposed mice. In addition, supplementing short-chain fatty acids (SCFAs) exhibited the identical effects to the model of FMT. In summary, intestinal microbiota may alleviate the colonic inflammatory of mice with fluorosis by regulating TLR/NF-κB pathway through SCFAs.

Effects of Different Preparation Methods on Microbiota Composition of Fecal Suspension

Fecal microbiota transplantation is an emerging disease-modifying therapy. The viability of the microbiome in feces and its successful transfer depends on the preparation of fecal microbiota suspension. However, currently, no standard operation procedure is proposed for fecal suspension preparation. This study aims to compare the effect of different preparation methods on the composition of fecal microbiota composition in the rat. Four methods were used to collect the fecal suspension from fresh rat fecal (Group A), including stirring with normal saline (Group B), stirring with normal saline and then standing (Group C), stirring with normal saline and filtered with gauze (Group D), and stirring with normal saline and centrifuged (Group E). 16S ribosomal RNA gene (16S rDNA) sequencing technology was used to analyze the microbiota diversity and composition of each group of samples. Compared with fresh feces, the bacterial richness of the fecal suspension obtained by the four methods was significantly decreased (P < 0.05). The structural similarity with fresh fecal microbiota from high to low is groups B, D, C, and E. All four methods changed the microbiota structure to varying degrees, thus may affect the effect of FMT. In conclusion, choosing different methods to prepare fecal suspensions may help to better optimize the application of FMT.

Metformin Contributes to the Therapeutic Effects of Acne Vulgaris by Modifying the Gut Microbiome

Background. Considering the increasing side effects of the first-line treatment for acne vulgaris, metformin was developed to be an effective adjunct therapy, but its mechanism of action is poorly defined. Recent evidence shows that the gut microbiota is a site of metformin action. The aim of this study was to evaluate the effects and mechanism of action for metformin in the adjuvant treatment of acne vulgaris by regulating gut microbiota. Methods. First, untreated acne patients were randomly allocated into two treatment groups. Both groups were treated with isotretinoin, but only one was additionally treated with metformin, for three months. Sprague Dawley (SD) rats were used as acne models, and they were also separated into groups that received isotretinoin, metformin, a combination of isotretinoin and metformin, and the vehicle, respectively. Then, the fecal samples from drug-intervention rats were transferred to germ-free rats with acne. The severity of the disease was evaluated using the Global Acne Grading System (GAGS) scoring for patients, and the number of comedones and mononuclear cells in pathological sections was used for rats. The composition of the gut microbiota was detected using gene sequencing for 16S rDNA. Results. Metformin had strong effects on the composition and function of the gut microbiota, and this correlated with the reduction in the severity of acne in both humans and rats. The fecal transfer to pseudo-germ-free rats improved both the inflammatory phenotype and comedones of acne in recipients of metformin-altered microbiota. Conclusion. The results suggest that metformin improves the symptoms of acne vulgaris by modulating the gut microbiota.

Effect of faecal microbial transplant via colonoscopy in patients with severe obesity and insulin resistance: A randomized double-blind, placebo-controlled Phase 2 trial

AIM

To assess the effects of faecal microbial transplant (FMT) from lean people to subjects with obesity via colonoscopy.

MATERIAL AND METHODS

In a double-blind, randomized controlled trial, subjects with a body mass index ≥ 35 kg/m² and insulin resistance were randomized, in a 1:1 ratio in blocks of four, to either allogenic (from healthy lean donor; n = 15) or autologous FMT (their own stool; n = 13) delivered in the caecum and were followed for 3 months. The main outcome was homeostatic model assessment of insulin resistance (HOMA-IR) and secondary outcomes were glycated haemoglobin levels, lipid profile, weight, gut hormones, endotoxin, appetite measures, intestinal microbiome (IM), metagenome, serum/faecal metabolites, quality of life, anxiety and depression scores.

RESULTS

In the allogenic versus autologous groups, HOMA-IR and clinical variables did not change significantly, but IM and metabolites changed favourably (P < 0.05): at 1 month, Coprococcus, Bifidobacterium, Bacteroides and Roseburia increased, and Streptococcus decreased; at 3 months, Bacteroides and Blautia increased. Several species also changed significantly. For metabolites, at 1 month, serum kynurenine decreased and faecal indole acetic acid and butenylcarnitine increased, while at 3 months, serum isoleucine, leucine, decenoylcarnitine and faecal phenylacetic acid decreased. Metagenomic pathway representations and network analyses assessing relationships with clinical variables, metabolites and IM were significantly enhanced in the allogenic versus autologous groups. LDL and appetite measures improved in the allogenic (P < 0.05) but not in the autologous group.

CONCLUSIONS

Overall, in those with obeisty, allogenic FMT via colonoscopy induced favourable changes in IM, metabolites, pathway representations and networks even though other metabolic variables did not change. LDL and appetite variables may also benefit.

Fecal microbiota transplantation improves intestinal inflammation in mice with ulcerative colitis by modulating intestinal flora composition and down-regulating NF-kB signaling pathway

Ulcerative colitis (UC) is a chronic inflammatory disease of the intestine. It is characterized with recurrent. The pathogenesis is mainly associated with environmental factors, genetic susceptibility, dysbiosis of the intestinal flora and autoimmunity. The role of intestinal flora disorders in the pathogenesis and progression of UC is becoming increasingly prominent. More and more studies have confirmed that fecal microbiota transplantation (FMT) could reshape the composition of UC intestinal flora and it is expected to be a new strategy for UC treatment. In this study, we used 2% Dextran sulfate sodium (DSS) for 7 days to induce acute colitis model in mice, and interfere with FMT and Enterotoxigenic Escherichia coli (ETEC). ELISA and immunohistochemistry were applied to detect the concentration and expression of NF-κB p65, STAT3 and IL-6. 16SrRNA high-throughput sequencing was performed to explore the composition of intestinal flora. The aim was to study the treatment effect of FMT on UC mice and explore its potential mechanism by observing the changes of intestinal flora composition and diversity, and its relationship with NF-κB p65, STAT3 and IL-6 expression. We conclude that FMT could improve intestinal flora disorder in mice with ulcerative colitis, regulate NF-κB signaling pathway, and significantly reduce intestinal inflammation in UC mice.

Efficacy of oral fecal microbiota transplantation in recurrent bowel disease: A protocol for systematic review and meta-analysis

BACKGROUND

Recurrent bowel disease (RBD) refers to the chronic, recurrent intestinal diseases, including recurrent Clostridium Difficile Infection (rCDI), inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), etc., these diseases have similar clinical characteristics, that is, abdominal pain, diarrhea, repeated attacks, prolonged recovery, etc. Clinically, there are relevant reports on the use of oral capsule fecal microbiota transplantation (oFMT) to treat RBD. However, both the advantages and disadvantages of clinical efficacy have been reported; there are some contradictions, the study sample size is too small, and the purpose of this systematic review was to evaluate the efficacy and safety of oral capsule fecal microbiota transplantation in the treatment of RBD.

METHODS

This systematic review will include articles identified through electronic searches of the PubMed, EMbase, and Cochrane Library. From inception to July 1, 2022. Two reviewers will independently search the database to conduct data extraction and assessment of study quality. Based on heterogeneity tests, data will be integrated using fixed or random effect models. RevMan V.5.4 will be used for data analysis. The results are expressed as the risk ratio of dichotomous data and the mean difference of continuous data.

RESULTS

We analyzed the clinical remission or cure rate, IBS-SSS, quality of life, anxiety, depression, total adverse effects, and total severe adverse effects (TSAE) in patients with RBD.

CONCLUSION

This systematic review evaluated the efficacy and safety of oFMT in the treatment of RBD to provide more comprehensive evidence.

Fecal microbiota transplantation for diseases: Therapeutic potential, methodology, risk management in clinical practice

BACKGROUND

More than 95 % of human diseases may be related to the disturbance of gut microbes. As a treatment method that extensively regulates the gut microbes, fecal microbiota transplantation (FMT) has proven to be an effective therapy for some diseases, becoming a topic of interest among clinicians, patients and scientists.

AIM

To review the latest clinical research results of FMT in the treatment of various diseases and the methodology and risk management in clinical application.

METHODS

Search PubMed and Web of Science for reliable research results of clinical treatment of FMT within 5-10 years, as well as application guidelines and risk management policies in different regions.

RESULTS

As a measure of allogeneic/autologous microbiota transplantation, FMT has been used to treat a variety of diseases. By reviewing the clinical studies of FMT in gastrointestinal diseases, metabolic diseases, neurological diseases and malignant tumors, the various mechanisms in the treatment of diseases are summarized. Such as regulation of receptor microbiota composition, specific metabolites, phage function and immune response. In addition, potential risk factors, donor stool screening indicators, recipient self-specificity and possible prognostic marker molecules in the course of FMT treatment were generalized.

CONCLUSIONS

The potential regulatory mechanisms, risk factors and targets of FMT in gastrointestinal diseases, metabolic diseases, malignancies and neurological diseases were reviewed and proposed. It provides a theoretical basis for the establishment of a standardized treatment system for FMT and a breakthrough in treatment technology.

Glycyrrhiza Polysaccharide Alleviates Dextran Sulfate Sodium-Induced Ulcerative Colitis in Mice

Background

Licorice is one of the most ubiquitous herbs in traditional Chinese medicine, with notable anti-inflammatory and antiulcerative effects as well as potent digestive disease therapeutic impacts; yet, its active components and mechanisms remain unclear. There is a lot of evidence that Glycyrrhiza polysaccharide (GPS) has antioxidants, improving intestinal flora, anti-inflammatory effects, etc. Hypothesis/Purpose. Here, we investigated the effects of GPS on dextran sulfate sodium (DSS)-induced acute ulcerative colitis (UC) mice and its possible mechanisms.

Methods

GPS (100, 200, and 400 mg/kg) or the positive control drug sulfasalazine (SASP) (200 mg/kg) were orally administered to mice for 8 days. Body weight was recorded daily. Symptoms associated with UC, such as disease activity index (DAI), colon length, spleen weight, and mucosal damage were detected. The possible mechanism of GPS ameliorating enteritis symptoms was explored by detecting intestinal permeability and serum levels of inflammatory factors, and changes in intestinal permeability were expressed by serum concentration of FITC-dextran and D-lactic acid.

Results

The results demonstrated that GPS administration alleviated UC symptoms in colitis mice, including weight loss, DAI index, shorting colon length, and mucosal damage. Mechanistic evaluation revealed that GPS treatment reduced intestinal permeability and serum levels of inflammatory factors: IL-1, IL-6, and TNF-α, while increasing serum levels of the anti-inflammatory factor IL-10, suggesting that GPS's mechanism in UC is related to reducing intestinal permeability and inhibiting the inflammatory response, with intestinal permeability implicated as the initiating mechanism.

Conclusion

This study highlights GPS as a promising therapeutic agent, with high therapeutic efficacy and a good safety profile, for enteritis and beyond.

Ileal Microbiota Alters the Immunity Statues to Affect Body Weight in Muscovy Ducks

The ileum is mainly responsible for food absorption and nutrients transportation. The microbes in its intestinal lumen play an essential role in the growth and health of the host. However, it is still unknown how the ileal microbes affect the body weight of the host. In this study, we used Muscovy ducks as an animal model to investigate the relationship between the ileal microbes and body weight and further explore the potential mechanism. The ileum tissue and ileal contents of 200 Muscovy ducks were collected for mRNA extraction and real-time quantitative PCR, as well as DNA separation and 16S rRNA gene sequencing. With body weight being ranked, the bottom 20% (n = 40) and top 20% (n = 40) were set as the low and high groups, respectively. Our results showed that in the ileum of Muscovy ducks, the Bacteroides, Firmicutes, and Proteobacteria were the predominant phyla with the 10 most abundant genera, namely Candidatus Arthromitus, Bacteroides, Streptococcus, Vibrio, Romboutsia, Cetobacterium, Clostridium sensu stricto 1, Terrisporobacter, Escherichia-Shigella, and Lactobacillus. We identified Streptococcus, Escherichia-Shigella, Candidatus Arthromitus, Bacteroides, Faecalibacterium, and Oscillospira were closely correlated to the growth of Muscovy ducks. Streptococcus and Escherichia-Shigella were negatively related to body weight (BW), while Candidatus Arthromitus, Bacteroides, Faecalibacterium, and Oscillospira were positively associated with BW. In addition, we found that the relative expression levels of tight junction proteins (Claudin 1, Claudin 2, ZO-1 and ZO-2) in the high group showed an upward trend, although this trend was not significant (P > 0.05). The expression of pro-inflammatory factors (IL-1β, IL-2 and TNF-α) decreased in the high group, while the anti-inflammatory factor IL-10 increased. Of course, except IL-2, these differences were not significant (P > 0.05). Finally, the correlation analysis showed that Escherichia-Shigella was significantly positively correlated with IL-1β (P < 0.05). These findings may provide fundamental data for the development of next-generation probiotics and assist the development of strategies for changing the gut microbiota to promote the growth performance in the duck industry.

Optimizing therapeutic outcomes of immune checkpoint blockade by a microbial tryptophan metabolite

Background

Despite the great success, the therapeutic benefits of immune checkpoint inhibitors (ICIs) in cancer immunotherapy are limited by either various resistance mechanisms or ICI-associated toxic effects including gastrointestinal toxicity. Thus, novel therapeutic strategies that provide manageable side effects to existing ICIs would enhance and expand their therapeutic efficacy and application. Due to its proven role in cancer development and immune regulation, gut microbiome has gained increasing expectation as a potential armamentarium to optimize immunotherapy with ICI. However, much has to be learned to fully harness gut microbiome for clinical applicability. Here we have assessed whether microbial metabolites working at the interface between microbes and the host immune system may optimize ICI therapy.

Methods

To this purpose, we have tested indole-3-carboxaldehyde (3-IAld), a microbial tryptophan catabolite known to contribute to epithelial barrier function and immune homeostasis in the gut via the aryl hydrocarbon receptor (AhR), in different murine models of ICI-induced colitis. Epithelial barrier integrity, inflammation and changes in gut microbiome composition and function were analyzed. AhR, indoleamine 2,3-dioxygenase 1, interleukin (IL)-10 and IL-22 knockout mice were used to investigate the mechanism of 3-IAld activity. The function of the microbiome changes induced by 3-IAld was evaluated on fecal microbiome transplantation (FMT). Finally, murine tumor models were used to assess the effect of 3-IAld treatment on the antitumor activity of ICI.

Results

On administration to mice with ICI-induced colitis, 3-IAld protected mice from intestinal damage via a dual action on both the host and the microbes. Indeed, paralleling the activation of the host AhR/IL-22-dependent pathway, 3-IAld also affected the composition and function of the microbiota such that FMT from 3-IAld-treated mice protected against ICI-induced colitis with the contribution of butyrate-producing bacteria. Importantly, while preventing intestinal damage, 3-IAld did not impair the antitumor activity of ICI.

Conclusions

This study provides a proof-of-concept demonstration that moving past bacterial phylogeny and focusing on bacterial metabolome may lead to a new class of discrete molecules, and that working at the interface between microbes and the host immune system may optimize ICI therapy.

Beneficial Effects of Repeated Washed Microbiota Transplantation in Children With Autism

OBJECTIVE

While fecal microbiota transplantation is demonstrated to improve symptoms of autism spectrum disorder (ASD), it remains unclear whether additional treatment courses yield better results. This study sought to evaluate the efficacy of repeated washed microbiota transplantation (WMT) in children with ASD.

METHODS

Retrospective data from children who were serially treated with WMT, including ASD symptoms, sleep disorders, gastrointestinal (GI) symptoms, and white blood cell (WBC) and globulin levels were obtained. The effect of WMT on children with ASD and whether additional WMT courses led to a further improvement in symptoms were assessed.

RESULTS

Aberrant Behavior Checklist (ABC), Childhood Autism Rating Scale, and Sleep Disturbance Scale for Children (SDSC) scores, the proportion of children with constipation and abnormal fecal forms, and WBC and globulin levels were all significantly lower in ASD children after WMT. More WMT treatment courses led to significantly lower scores on the ABC and SDSC.

CONCLUSION

WMT significantly improved ASD and GI symptoms and sleep disorders in children with ASD, and reduced systemic inflammation. Additional WMT courses led to more obvious improvements in ASD symptoms within three treatment courses.

MUC2 and related bacterial factors: Therapeutic targets for ulcerative colitis

The mucin2 (MUC2) mucus barrier acts as the first barrier that prevents direct contact between intestinal bacteria and colonic epithelial cells. Bacterial factors related to the MUC2 mucus barrier play important roles in the response to changes in dietary patterns, MUC2 mucus barrier dysfunction, contact stimulation with colonic epithelial cells, and mucosal and submucosal inflammation during the occurrence and development of ulcerative colitis (UC). In this review, these underlying mechanisms are summarized and updated, and related interventions for treating UC, such as dietary adjustment, exogenous repair of the mucus barrier, microbiota transplantation and targeted elimination of pathogenic bacteria, are suggested. Such interventions are likely to induce and maintain a long and stable remission period and reduce or even avoid the recurrence of UC. A better mechanistic understanding of the MUC2 mucus barrier and its related bacterial factors may help researchers and clinicians to develop novel approaches for treating UC.

Kaempferol Alleviates Murine Experimental Colitis by Restoring Gut Microbiota and Inhibiting the LPS-TLR4-NF-κB Axis

Intestinal microbiota dysbiosis is an established characteristic of ulcerative colitis (UC). Regulating the gut microbiota is an attractive alternative UC treatment strategy, considering the potential adverse effects of synthetic drugs used to treat UC. Kaempferol (Kae) is an anti-inflammatory and antioxidant flavonoid derived from a variety of medicinal plants. In this study, we determined the efficacy and mechanism of action of Kae as an anti-UC agent in dextran sulfate sodium (DSS)-induced colitis mice. DSS challenge in a mouse model of UC led to weight loss, diarrhea accompanied by mucous and blood, histological abnormalities, and shortening of the colon, all of which were significantly alleviated by pretreatment with Kae. In addition, intestinal permeability was shown to improve using fluorescein isothiocyanate (FITC)-dextran administration. DSS-induced destruction of the intestinal barrier was also significantly prevented by Kae administration via increases in the levels of ZO-1, occludin, and claudin-1. Furthermore, Kae pretreatment decreased the levels of IL-1β, IL-6, and TNF-α and downregulated transcription of an array of inflammatory signaling molecules, while it increased IL-10 mRNA expression. Notably, Kae reshaped the intestinal microbiome by elevating the Firmicutes to Bacteroidetes ratio; increasing the linear discriminant analysis scores of beneficial bacteria, such as Prevotellaceae and Ruminococcaceae; and reducing the richness of Proteobacteria in DSS-challenged mice. There was also an evident shift in the profile of fecal metabolites in the Kae treatment group. Serum LPS levels and downstream TLR4-NF-κB signaling were downregulated by Kae supplementation. Moreover, fecal microbiota transplantation from Kae-treated mice to the DSS-induced mice confirmed the effects of Kae on modulating the gut microbiota to alleviate UC. Therefore, Kae may exert protective effects against colitis mice through regulating the gut microbiota and TLR4-related signaling pathways. This study demonstrates the anti-UC effects of Kae and its potential therapeutic mechanisms, and offers novel insights into the prevention of inflammatory diseases using natural products.

Investigating causality with fecal microbiota transplantation in rodents: applications, recommendations and pitfalls

In recent years, studies investigating the role of the gut microbiota in health and diseases have increased enormously - making it essential to deepen and question the research methodology employed. Fecal microbiota transplantation (FMT) in rodent studies (either from human or animal donors) allows us to better understand the causal role of the intestinal microbiota across multiple fields. However, this technique lacks standardization and requires careful experimental design in order to obtain optimal results. By comparing several studies in which rodents are the final recipients of FMT, we summarize the common practices employed. In this review, we document the limitations of this method and highlight different parameters to be considered while designing FMT Studies. Standardizing this method is challenging, as it differs according to the research topic, but avoiding common pitfalls is feasible. Several methodological questions remain unanswered to this day and we offer a discussion on issues to be explored in future studies.

An indisputable role of NHE8 in mucosal protection

The loss of the intestinal Na⁺/H⁺ exchanger isoform 8 (NHE8) results in an ulcerative colitis-like condition with reduction of mucin production and dysbiosis, indicating that NHE8 plays an important role in intestinal mucosal protection. The aim of this study was to investigate the potential rebalance of the altered microbiota community of NHE8-deficient mice via fecal microbiota transplantation (FMT) and feeding probiotic VSL#3. We also aimed to stimulate mucin production by sodium butyrate administration via enema. Data from 16S rRNA sequencing showed that loss of NHE8 contributes to colonic microbial dysbiosis with reduction of butyrate-producing bacteria. FMT increased bacterial adhesion in the colon in NHE8 knockout (NHE8KO) mice. Periodic-acid Schiff reagent (PAS) stain and quantitative PCR showed no changes in mucin production during FMT. In mice treated with the probiotic VSL#3, a reduction of Lactobacillus and segmented filamentous bacteria (SFB) in NHE8KO mouse colon was detected and an increase in goblet cell theca was observed. In NHE8KO mice receiving sodium butyrate (NaB), 1 mM NaB stimulated Muc2 expression without changing goblet cell theca, but 10 mM NaB induced a significant reduction of goblet cell theca without altering Muc2 expression. Furthermore, 5 mM and 10 mM NaB-treated HT29-MTX cells displayed increased apoptosis, while 0.5 mM NaB stimulated Muc2 gene expression. These data showed that loss of NHE8 leads to dysbiosis with reduction of butyrate-producing bacteria and FMT and VSL#3 failed to rebalance the microbiota in NHE8KO mice. Therefore, FMT, VSL#3, and NaB are not able to restore mucin production in the absence of NHE8 in the intestine.NEW & NOTEWORTHY Loss of Na⁺/H⁺ exchanger isoform 8 (NHE8), a Slc9 family of exchanger that contributes to sodium uptake, cell volume regulation, and intracellular pH homeostasis, resulted in dysbiosis with reduction of butyrate-producing bacteria and decrease of Muc2 production in the intestine in mice. Introducing fecal microbiota transplantation (FMT) and VSL#3 in NHE8 knockout (NHE8KO) mice failed to rebalance the microbiota in these mice. Furthermore, administration of FMT, VSL#3, and sodium butyrate was unable to restore mucin production in the absence of NHE8 in the intestine.

Electroacupuncture preserves intestinal barrier integrity through modulating the gut microbiota in DSS-induced chronic colitis

AIMS

Electroacupuncture (EA) at ST36 has been verified to ameliorate experimental acute colitis. However, the effect of EA on chronic colitis and its mechanism has not yet been explored. This study aimed to assess the protective effect of EA against chronic colitis and the related mechanisms.

MAIN METHODS

Chronic colitis was induced by dextran sulfate sodium (DSS) in C57BL/6 mice, and EA was applied throughout the entire experiment. Colonic inflammation and intestinal barrier integrity were evaluated. Alterations in the gut microbiota were analyzed by 16S rRNA gene sequencing. The fecal microbiota transplantation (FMT) experiment was used to further confirm the effect of the gut microbiota on the barrier protective effect of EA. The potential molecular mechanisms were explored by western blotting.

KEY FINDINGS

(1) EA lowered the disease activity index (DAI) and histological scores, decreased the levels of TNFα, IL1β, IL6 and iNOS, and increased the IL10 level in DSS-induced chronic colitis. (2) EA upregulated the protein expression of ZO-1, Occludin, E-Cadherin and mucin2 (MUC2), reduced the apoptosis and proliferation of intestinal epithelial cells (IECs) and intestinal permeability. (3) EA enhanced the gut microbiota diversity and restored the community structure. (4) Both the low-frequency EA (LEA) FMT and high-frequency EA (HEA) FMT maintained the intestinal barrier integrity. (5) EA promoted activation of the mitogen activated protein kinase (MAPK) signaling pathway.

SIGNIFICANCE

EA can relieve chronic experimental colitis, and this effect may depend on activation of the MAPK signaling pathway through modulation of the gut microbiota to preserve the intestinal barrier.

Hesperetin ameliorates DSS-induced colitis by maintaining the epithelial barrier via blocking RIPK3/MLKL necroptosis signaling

Hesperetin, a flavonoid from citrus fruits, possess various pharmacological properties, including anti-inflammatory, anti-oxidative, anti-tumor potentials. However, the role and its mechanism in ulcerative colitis (UC) remains unclear. This study aimed to investigate the protective effects and mechanisms of hesperetin on dextran sodium sulfate (DSS) -induced colitis. Our results showed that hesperetin significantly relieved the symptoms of DSS -induced colitis and increased the expressions of zonula occludens-1 (ZO-1), occludin and mucin2 (MUC-2) as well as the decrease of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-18, HMGB1 and IL-6. Of note, results from immunohistochemistry (IHC) and western blotting indicated that hesperetin inhibited the expressions of receptor-interacting protein kinase 3 (RIPK3) and mixed lineage kinase domain-like (MLKL), the two key proteins of necroptosis pathway, and inactivated RIPK3/MLKL necroptosis signalling. Meanwhile, in the cell-coculture system between Caco-2 and RAW264.7 cells, hesperetin treatment significantly ameliorated the decrease of trans epithelial electric resistance (TEER) value while HS-173 (necroptosis inducer) could obviously influence the effect of hesperetin. In addition, hesperetin attenuated the LPS-induced increasing in 4-kDa fluorescein isothiocyanate-dextran (FD4) permeability while HS-173 could weaken the protective effect of hesperetin. Meanwhile, HS-173 reduced the changes in the expressions of phosphorylated RIPK3, phosphorylated MLKL, ZO-1, occludin and MUC-2 as well as TNF-α, IL-1β. These findings demonstrated hesperetin ameliorated DSS-induced colitis by maintaining the epithelial barrier via blocking the intestinal epithelial necroptosis.