Fecal Microbiota Transplant in Two Ulcerative Colitis Pediatric Cases: Gut Microbiota and Clinical Course Correlations

Faecal microbiota transplantation in children: A systematic review

AIM

Novel technologies offer insights into the potential role of the intestinal microbiota in human health and disease. Dysbiosis has been associated with several diseases, and it is thought to play a role in the pathogenesis of different gastrointestinal diseases. Faecal microbiota transplantation (FMT) is emerging as a method to modulate the gastrointestinal microbial ecosystem. While recurrent Clostridioides difficile infection is the recognised FMT indication, exploration of other therapeutic uses is ongoing.

METHODS

Following PRISMA guidelines, we conducted a systematic review, extracting 583 articles from Embase and PubMed (index date to October 2022).

RESULTS

The search yielded 58 studies for full review, with 50 included in the systematic review. Articles were categorised by FMT indication, study design, efficacy, adverse events, donor selection and administration route. FMT appears safe and effective for recurrent Clostridioides difficile infection, although severe adverse events are reported in children. However, there are currently insufficient data to support the use of FMT for other potential therapeutic indications (such as irritable or inflammatory bowel disease or obesity), beside the potential to decolonise multi-drug resistant organisms.

CONCLUSION

This underscores the need for randomised, controlled, prospective cohort studies in children to assess FMT effectiveness in diverse conditions and counteract publication bias.

Colonization of microbiota derived from Macaca fascicularis, Bama miniature pigs, beagle dogs, and C57BL/6J mice alleviates DSS-induced colitis in germ-free mice

Fecal microbiota transplantation (FMT) is an innovative and promising treatment for inflammatory bowel disease (IBD), which is related to the capability of FMT to supply functional microorganisms to improve recipient gut health. Numerous studies have highlighted considerable variability in the efficacy of FMT interventions for IBD. Several factors, including the composition of the donor microorganisms, significantly affect the efficacy of FMT in the treatment of IBD. Consequently, identifying the functional microorganisms in the donor is crucial for enhancing the efficacy of FMT. To explore potential common anti-inflammatory bacteria with therapeutic implications for IBD, germ-free (GF) BALB/c mice were pre-colonized with fecal microbiota obtained from diverse donors, including Macaca fascicularis (MCC_FMT), Bama miniature pigs (BP_FMT), beagle dogs (BD_FMT), and C57BL/6 J mice (Mice_FMT). Subsequently, mice were treated with dextran sodium sulfate (DSS). As expected, the symptoms of colitis were alleviated by MCC_FMT, BP_FMT, BD_FMT, and Mice_FMT, as demonstrated by the prevention of an elevated disease activity index in mice. Additionally, the utilization of distinct donors protected the intestinal barrier and contributed to the regulation of cytokine homeostasis. Metagenomic sequencing data showed that the microbial community structure and dominant species were significantly different among the four groups, which may be linked to variations in the anti-inflammatory efficacy observed in the respective groups. Notably, Lactobacillus reuteri and Flavonifractor plautii were consistently present in all four groups. L. reuteri exhibited a significant negative correlation with IL-1β, and animal studies further confirmed its efficacy in alleviating IBD, suggesting the presence of common functional bacteria across different donors that exert anti-inflammatory effects. This study provides essential foundational data for the potential clinical applications of FMT.IMPORTANCEDespite variations in efficacy observed among donors, numerous studies have underscored the potential of fecal microbiota transplantation (FMT) for managing inflammatory bowel disease (IBD), indicating the presence of shared anti-IBD bacterial species. In the present study, the collective anti-inflammatory efficacy observed across all four donor groups prompted the identification of two common bacterial species using metagenomics. A significant negative correlation between Lactobacillus reuteri and IL-1β was revealed. Furthermore, mice gavaged with L. reuteri successfully managed the colitis challenge induced by dextran sodium sulfate (DSS), suggesting that L. reuteri may act as an efficacious bacterium mediating shared anti-inflammatory effects among variable donors. This finding highlights the utilization of variable donors to screen FMT core bacteria, which may be a novel strategy for developing FMT applications.

Complementary Therapeutic Effect of Fecal Microbiota Transplantation in Ulcerative Colitis after the Response to Anti-Tumor Necrosis Factor Alpha Agent Was Lost: A Case Report

In patients with ulcerative colitis (UC), the development of an antidrug antibody (ADA) to anti-tumor necrosis factor (TNF)α agent is a crucial problem which aggravates the clinical course of the disease, being cited as one of the most common causes for discontinuing anti-TNFα treatment. This is due to ADA eventually causing secondary LOR, leading to discontinuation of anti-TNFα treatment. Recently, research on the microbiome and relationship between worsening UC and dysbiosis has been conducted. Further, investigations on the association between the microbiome and secondary LOR are increasing. Here, we present the therapeutic effect of fecal microbiota transplantation (FMT) on a 42-year-old man with secondary LOR and high ADA levels. FMT has recently been used for the treatment of, and for overcoming, drug resistance through microbiome modification. Stool samples were collected from the patient before and 4 weeks after FMT. Symptoms, including hematochezia and Mayo endoscopy sub-scores, improved after FMT, while ADA levels decreased by one-third to less than half the value (29 ng/mL) compared to before FMT (79 ng/mL). Additionally, the trough level of infliximab became measurable, which reflects the improvement in the area under the concentration (AUC). Butyricicoccus, Faecalibacterium, Bifidobacterium, Ligilactobacillus, Alistipes, and Odoribacter, which regulate immune responses and alleviate inflammation, also increased after FMT. We report a case in which microbiome modification by FMT increased the AUC of anti-TNFα in a patient who developed secondary LOR during anti-TNFα treatment, thereby improving symptoms and mucosal inflammation.

Agaricus bisporus polysaccharides ameliorate ulcerative colitis in mice by modulating gut microbiota and its metabolism

The gut microbiota plays a central role in maintaining human health and has been linked to many gastrointestinal diseases such as ulcerative colitis (UC). Agaricus bisporus is a famous edible mushroom, and Agaricus bisporus polysaccharides (ABPs) and the two purified fractions (ABP-1 and ABP-2) were demonstrated to exhibit immunomodulatory activity in our previous study. Herein, we further found that ABPs, ABP-1, and ABP-2 possessed therapeutic effects against dextran sodium sulfate (DSS)-induced colitis in mice. ABPs, ABP-1, and ABP-2 could relieve body weight loss, colon atrophy, and histological injury, increase tight junction proteins, restore gut-barrier function, and inhibit inflammation. ABP-2 with a lower molecular weight (1.76 × 104 Da) showed a superior therapeutic effect than ABP-1 with a higher molecular weight (8.86 × 106 Da). Furthermore, the effects of ABP-1 and ABP-2 were microbiota-dependent, which worked by inducing Norank_f__Muribaculaceae and Akkermansia and inhibiting Escherichia-Shigella and Proteus. In addition, untargeted fecal metabolomic analysis revealed distinct modulation patterns of ABP-1 and ABP-2. ABP-1 mainly enriched steroid hormone biosynthesis, while ABP-2 significantly enriched bile secretion and tryptophan metabolism. In summary, ABPs, especially low-molecular-weight fraction, represent novel prebiotics for treatment of inflammatory gastrointestinal diseases.

Age-related effects on the modulation of gut microbiota by pectins and their derivatives: an in vitro study

Introduction

The present study investigates whether supplementation with pectin-type polysaccharides has potential to improve aging-associated dysbiosis of the gut microbiota. The influence of different types of pectins on the gut microbiota composition and short-chain fatty acids (SCFAs) profiles of elderly was compared to younger adults.

Methods

Pectins studied included a pectin polysaccharide (PEC), a partially hydrolyzed pectin (PPH), and a pectin oligosaccharide (POS). Additionally, inulin was used as a reference prebiotic substrate. Individual fecal samples were collected from healthy elderly volunteers (70-75 years) and younger adults (30-35 years). In vitro fermentations were performed using the CoMiniGut model with controlled temperature and pH. Samples were withdrawn at baseline and after 24 h fermentation for measurement of SCFAs production and microbiota composition by 16S rRNA gene sequencing.

Results and Discussion

The results showed that fermentations with PEC and PPH resulted in a specific stimulation of Faecalibacterium prausnitzii regardless of the age groups. Collinsella aerofaciens became a dominating species in the young adult group with fermentations of all three pectins, which was not observed in the elderly group. No significant differences in SCFAs production were found among the pectins, indicating a high level of functional redundancy. Pectins boosted various bacterial groups differently from the reference prebiotic substrate (inulin). We also found inulin had reduced butyrogenic and bifidogenic effects in the elderly group compared to the younger adult group. In conclusion, the in vitro modulating effects of pectins on elderly gut microbiota showed potential of using pectins to improve age-related dysbiosis.

Therapeutic Perspectives for Microbiota Transplantation in Digestive Diseases and Neoplasia-A Literature Review

In a mutually beneficial connection with its host, the gut microbiota affects the host's nutrition, immunity, and metabolism. An increasing number of studies have shown links between certain types of disease and gut dysbiosis or specific microorganisms. Fecal microbiota transplantation (FMT) is strongly advised for the treatment of recurrent or resistant Clostridium difficile infection (CDI) due to its outstanding clinical effectiveness against CDI. The therapeutic potential of FMT for other disorders, particularly inflammatory bowel diseases and malignancies, is currently gaining more and more attention. We summarized the most recent preclinical and clinical evidence to show the promise of FMT in the management of cancer as well as complications related to cancer treatment after reviewing the most recent research on the gut microbiota and its relationship to cancer.

Impact of helminth-microbiome interactions on childhood health and development-A clinical perspective

Humans have co-existed with parasites for virtually the entirety of our existence as a species. Today, nearly one third of the human population is infected with at least one helminthic species, most of which reside in the intestinal tract, where they have co-evolved alongside the human gut microbiota (GM). Appreciation for the interconnected relationship between helminths and GM has increased in recent years. Here, we review the evidence of how helminths and GM can influence various aspects of childhood development and the onset of paediatric diseases. We discuss the emerging evidence of how many of the changes that parasitic worms inflict on their host is enacted through gut microbes. In this light, we argue that helminth-induced microbiota modifications are of great importance in both facing the global challenge of overcoming parasitic infections, and in replicating helminthic protective effects against inflammatory diseases. We propose that deepening our knowledge of helminth-microbiota interactions will uncover novel, safer and more effective therapeutic strategies in combatting an array of childhood disorders.

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.

The Hypolipidemic Effect of Hawthorn Leaf Flavonoids through Modulating Lipid Metabolism and Gut Microbiota in Hyperlipidemic Rats

Objective. The purpose of this study was to explore the potential mechanisms of the lipid-regulating effects and the effect on modulating the gut microbiota of hawthorn leaf flavonoids (HLF) in the high-fat diet-induced hyperlipidemic rats. Methods. The hypolipidemic effect of HLF was investigated in the high-fat diet-induced hyperlipidemic rats. The action targets of HLF in the treatment of hyperlipidemia were predicted by network pharmacology and KEGG enrichment bubble diagram, which were verified by the test of western blotting. Meanwhile, we used 16S rRNA sequencing to evaluate the effects of HLF on the microbes. Results. The results of animal experiments showed that HLF could reduce the body weight and regulate the levels of serum lipid in high-fat diet (HFD) rats. Meanwhile, for the related targets of cholesterol metabolism, HLF could significantly upregulate the expression of LDLR, NR1H3, and ABCG5/ABCG8; reduce the expression of PCSK9; and increase the level of CYP7A1 in the intestinal tissue, whereas cholesterol biosynthetic protein expressions including HMGCR and SCAP were lowered by HLF. In addition, HLF increased the activities of plasma SOD, CAT, and GSH-Px and decreased the levels of Casp 1, NLRP3, IL-1β, IL-18, and TNF-α, improving the degree of hepatocyte steatosis and inflammatory infiltration of rats. Notably, HLF significantly regulated the relative abundance of major bacteria such as g_Lactobacillus, g_Anaerostipes, g_[Eubacterium]_hallii_group, g_Fusicatenibacter, g_Akkermansia, and g_Collinsella. Synchronously, we found that HLF could regulate the disorder of plasma HEPC and TFR levels caused by HFD. Conclusion. This study demonstrates that HLF can regulate metabolic hyperlipidemia syndromes and modulate the relative abundance of major bacteria, which illustrated that it might be associated with the modulation of gut microbiota composition and metabolites.

Variability of strain engraftment and predictability of microbiome composition after fecal microbiota transplantation across different diseases

Fecal microbiota transplantation (FMT) is highly effective against recurrent Clostridioides difficile infection and is considered a promising treatment for other microbiome-related disorders, but a comprehensive understanding of microbial engraftment dynamics is lacking, which prevents informed applications of this therapeutic approach. Here, we performed an integrated shotgun metagenomic systematic meta-analysis of new and publicly available stool microbiomes collected from 226 triads of donors, pre-FMT recipients and post-FMT recipients across eight different disease types. By leveraging improved metagenomic strain-profiling to infer strain sharing, we found that recipients with higher donor strain engraftment were more likely to experience clinical success after FMT (P = 0.017) when evaluated across studies. Considering all cohorts, increased engraftment was noted in individuals receiving FMT from multiple routes (for example, both via capsules and colonoscopy during the same treatment) as well as in antibiotic-treated recipients with infectious diseases compared with antibiotic-naïve patients with noncommunicable diseases. Bacteroidetes and Actinobacteria species (including Bifidobacteria) displayed higher engraftment than Firmicutes except for six under-characterized Firmicutes species. Cross-dataset machine learning predicted the presence or absence of species in the post-FMT recipient at 0.77 average AUROC in leave-one-dataset-out evaluation, and highlighted the relevance of microbial abundance, prevalence and taxonomy to infer post-FMT species presence. By exploring the dynamics of microbiome engraftment after FMT and their association with clinical variables, our study uncovered species-specific engraftment patterns and presented machine learning models able to predict donors that might optimize post-FMT specific microbiome characteristics for disease-targeted FMT protocols.

Extremely small and incredibly close: Gut microbes as modulators of inflammation and targets for therapeutic intervention

Chronic inflammation is a hallmark for a variety of disorders and is at least partially responsible for disease progression and poor patient health. In recent years, the microbiota inhabiting the human gut has been associated with not only intestinal inflammatory diseases but also those that affect the brain, liver, lungs, and joints. Despite a strong correlation between specific microbial signatures and inflammation, whether or not these microbes are disease markers or disease drivers is still a matter of debate. In this review, we discuss what is known about the molecular mechanisms by which the gut microbiota can modulate inflammation, both in the intestine and beyond. We identify the current gaps in our knowledge of biological mechanisms, discuss how these gaps have likely contributed to the uncertain outcome of fecal microbiota transplantation and probiotic clinical trials, and suggest how both mechanistic insight and -omics-based approaches can better inform study design and therapeutic intervention.

Features of Gut Microbiome Associated With Responses to Fecal Microbiota Transplantation for Inflammatory Bowel Disease: A Systematic Review

Fecal microbiota transplantation (FMT) has been seen as a novel treatment for inflammatory bowel disease (IBD). The results on microbial alterations and their relationship to treatment efficacy are varied among studies. We performed a systematic review to explore the association between microbial features and therapy outcomes. We searched PubMed, Web of Science, Embase, and Cochrane Library databases from inception to November 2020. Studies that investigated the efficacy of FMT and baseline microbial features or dynamic alteration of the microbiome during FMT were included. The methodological quality of the included cohort studies and randomized controlled trials (RCTs) was assessed using the Newcastle-Ottawa Scale (NOS) and the Cochrane risk of bias tool, respectively. A total of 30 studies were included in the analysis. Compared to non-responders, the microbial structure of patients who responded to FMT had a higher similarity to that of their donors after FMT. Donors of responders (R-d) and non-responders (NR-d) had different microbial taxa, but the results were inconsistent. After FMT, several beneficial short-chain fatty acids- (SCFA-) producing taxa, such as Faecalibacterium, Eubacterium, Roseburia, and species belonging to them, were enriched in responders, while pathogenic bacteria (Escherichia coli and Escherichia-Shigella) belonging to the phylum Proteobacteria were decreased. Alterations of microbial functional genes and metabolites were also observed. In conclusion, the response to FMT was associated with the gut microbiota and their metabolites. The pre-FMT microbial features of recipients, the comparison of pre- and post-FMT microbiota, and the relationship between recipients and donors at baseline should be further investigated using uniform and standardized methods.

Gut bacteriobiota and mycobiota are both associated with Day-28 mortality among critically ill patients

Introduction

Gut microbiota is associated with host characteristics such as age, sex, immune condition or frailty and is thought to be a key player in numerous human diseases. Nevertheless, its association with outcome in critically ill patients has been poorly investigated. The aim of this study is to assess the association between gut microbiota composition and Day-28 mortality in critically ill patients.

Methods

Rectal swab at admission of every patient admitted to intensive care unit (ICU) between October and November 2019 was frozen at − 80 °C. DNA extraction was performed thanks to QIAamp^® PowerFecal^® Pro DNA kit (QIAgen^®). V3–V4 regions of 16SRNA and ITS2 coding genes were amplified by PCR. Sequencing (2x250 bp paired-end) was performed on MiSeq sequencer (Illumina^®). DADA2 pipeline on R software was used for bioinformatics analyses. Risk factors for Day-28 mortality were investigated by logistic regression.

Results

Fifty-seven patients were consecutively admitted to ICU of whom 13/57 (23%) deceased and 44/57 (77%) survived. Bacteriobiota α-diversity was lower among non-survivors than survivors (Shannon and Simpson index respectively, p < 0.001 and p = 0.001) as was mycobiota α-diversity (respectively p = 0.03 and p = 0.03). Both gut bacteriobiota and mycobiota Shannon index were independently associated with Day-28 mortality in multivariate analysis (respectively OR: 0.19, 97.5 CI [0.04–0.60], p < 0.01 and OR: 0.29, 97.5 CI [0.09–0.75], p = 0.02). Bacteriobiota β-diversity was significantly different between survivors and non-survivors (p = 0.05) but not mycobiota β-diversity (p = 0.57). Non-survivors had a higher abundance of Staphylococcus haemolyticus, Clostridiales sp., Campylobacter ureolyticus, Akkermansia sp., Malassezia sympodialis, Malassezia dermatis and Saccharomyces cerevisiae, whereas survivors had a higher abundance of Collinsella aerofaciens, Blautia sp., Streptococcus sp., Faecalibacterium prausnitzii and Bifidobacterium sp.

Conclusion

The gut bacteriobiota and mycobiota α diversities are independently associated with Day-28 mortality in critically ill patients. The causal nature of this interference and, if so, the underlying mechanisms should be further investigated to assess if gut microbiota modulation could be a future therapeutic approach.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-03980-8.

Human Fecal Microbiota Transplantation Reduces the Susceptibility to Dextran Sulfate Sodium-Induced Germ-Free Mouse Colitis

In clinical practice, fecal microbiota transplantation (FMT) has been used to treat inflammatory bowel disease (IBD), and has shown certain effects. However, the selection of FMT donors and the mechanism underlying the effect of FMT intervention in IBD require further exploration. In this study, dextran sodium sulfate (DSS)-induced colitis mice were used to determine the differences in the protection of colitis symptoms, inflammation, and intestinal barrier, by FMT from two donors. Intriguingly, pre-administration of healthy bacterial fluid significantly relieved the symptoms of colitis compared to the ulcerative colitis (UC) bacteria. In addition, healthy donor (HD) bacteria significantly reduced the levels of inflammatory markers Myeloperoxidase (MPO) and Eosinophil peroxidase (EPO), and various pro-inflammatory factors, in colitis mice, and increased the secretion of the anti-inflammatory factor IL-10. Metagenomic sequencing indicated higher species diversity and higher abundance of anti-inflammatory bacteria in the HD intervention group, including Alistipes putredinis, Akkermansia muciniphila, Bifidobacterium adolescentis, short-chain fatty acids (SCFAs)-producing bacterium Christensenella minuta, and secondary bile acids (SBAs)-producing bacterium Clostridium leptum. In the UC intervention group, the SCFA-producing bacterium Bacteroides stercoris, IBD-related bacterium Ruminococcus gnavus, Enterococcus faecalis, and the conditional pathogen Bacteroides caccae, were more abundant. Metabolomics analysis showed that the two types of FMT significantly modulated the metabolism of DSS-induced mice. Moreover, compared with the UC intervention group, indoleacetic acid and unsaturated fatty acids (DHA, DPA, and EPA) with anti-inflammatory effects were significantly enriched in the HD intervention group. In summary, these results indicate that FMT can alleviate the symptoms of colitis, and the effect of HD intervention is better than that of UC intervention. This study offers new insights into the mechanisms of FMT clinical intervention in IBD.

Dietary Magnesium Alleviates Experimental Murine Colitis through Modulation of Gut Microbiota

Nutritional deficiencies are common in inflammatory bowel diseases (IBD). In patients, magnesium (Mg) deficiency is associated with disease severity, while in murine models, dietary Mg supplementation contributes to restoring mucosal function. Since Mg availability modulates key bacterial functions, including growth and virulence, we investigated whether the beneficial effects of Mg supplementation during colitis might be mediated by gut microbiota. The effects of dietary Mg modulation were assessed in a murine model of dextran sodium sulfate (DSS)-induced colitis by monitoring magnesemia, weight, and fecal consistency. Gut microbiota were analyzed by 16S-rRNA based profiling on fecal samples. Mg supplementation improved microbiota richness in colitic mice, increased abundance of Bifidobacterium and reduced Enterobacteriaceae. KEEG pathway analysis predicted an increase in biosynthetic metabolism, DNA repair and translation pathways during Mg supplementation and in the presence of colitis, while low Mg conditions favored catabolic processes. Thus, dietary Mg supplementation increases bacteria involved in intestinal health and metabolic homeostasis, and reduces bacteria involved in inflammation and associated with human diseases, such as IBD. These findings suggest that Mg supplementation may be a safe and cost-effective strategy to ameliorate disease symptoms and restore a beneficial intestinal flora in IBD patients.

Current and future applications of fecal microbiota transplantation for children

Fecal microbiota transplantation (FMT) is a new and adequate route to modify the microbial ecosystem in gastrointestinal tract of the hosts. Intestinal microbiota is highly associated with human health and disease. According to the reports of human clinical trials or case series, the application of FMT ranged from Clostridiodes difficile infection (CDI), inflammatory bowel disease (IBD), irritable bowel syndrome, refractory diarrhea, diabetes mellitus, metabolic syndrome, and even neurologic diseases, including Parkinson disease, and neuropsychiatric disorder (autism spectrum disorder, ASD). Although the current allowed indication of FMT is CDI in Taiwan, more application and development are expectable in the future. There is a relative rare data available for children in application of fecal microbiota transplantation. Thus, we review previous published research inspecting FMT in children, and address particular considerations when conducting FMT in pediatric patients.

Orally Administered Natural Lipid Nanoparticle-Loaded 6-Shogaol Shapes the Anti-Inflammatory Microbiota and Metabolome

The past decade has seen increasing interest in microbiota-targeting therapeutic strategies that aim to modulate the gut microbiota's composition and/or function to treat chronic diseases, such as inflammatory bowel disease (IBD), metabolic symptoms, and obesity. While targeting the gut microbiota is an innovative means for treating IBD, it typically requires an extended treatment time, hampering its potential application. Herein, using an established natural-lipid nanoparticle (nLNP) platform, we demonstrate that nLNPs encapsulated with the drug candidate 6-shogaol (6S/nLNP) distinctly altered microbiota composition within one day of treatment, significantly accelerating a process that usually requires five days using free 6-shogaol (6S). In addition, the change in the composition of the microbiota induced by five-day treatment with 6S/nLNP was maintained for at least 15 days (from day five to day 20). The consequent alteration in the fecal metabolic profile stemming from this compositional change manifested as functional changes that enhanced the in vitro anti-inflammatory and wound-healing efficacy of macrophage cells (Raw 264.7) and epithelial cells (Caco-2 BBE1), respectively. Further, this metabolic compositional change, as reflected in an altered metabolic profile, promoted a robust anti-inflammatory effect in a DSS-induced mouse model of acute colitis. Our study demonstrates that, by near-instantly modulating microbiota composition and function, an nLNP-based drug-delivery platform might be a powerful tool for treating ulcerative colitis.

Cross Talk between Gut Microbiota and Intestinal Mucosal Immunity in the Development of Ulcerative Colitis

Ulcerative colitis (UC), a nonspecific inflammatory disease, is characterized by inflammation and mucosal damage in the colon, and its prevalence in the world is increasing. Nevertheless, the exact pathogenesis of UC is still unclear. Accumulating data have suggested that its pathogenesis is multifactorial, involving genetic predisposition, environmental factors, microbial dysbiosis, and dysregulated immune responses. Generally, UC is aroused by inappropriate immune activation based on the interaction of host and intestinal microbiota. The relationship between microbiota and host immune system in the pathogenesis of UC is complicated. However, increasing evidence indicates that the shift of microbiota composition can substantially influence intestinal immunity. In this review, we primarily focus on the delicate balance between microbiota and gut mucosal immunity during UC progression.

Lactobacillus rhamnosus from human breast milk ameliorates ulcerative colitis in mice via gut microbiota modulation

Gut microbiota imbalance is one of the major causes of ulcerative colitis (UC). L. rhamnosus SHA113 (LRS), a strain isolated from healthy human milk, influences the regulation of gut flora. This study aims to determine whether this strain can ameliorate UC by modulating gut microbiota. Mouse models of UC were established using C57BL/6Cnc mice with intragastric administration of 3.0% (w/v) dextran sodium sulfate (DSS). LRS was used to treat the mouse models of UC with 109 cfu mL-1 cell suspension via intragastric administration. To verify the effect of gut microbiota on UC, fecal microbiota collected from the mice after the treatment with LRS were also used to treat the UC mouse models (FMT). The severity of UC was evaluated based on body weight, colon length, disease activity index (DAI), and hematoxylin-eosin staining. The microbial composition was analyzed by 16S rRNA sequencing. The mRNA expression levels of cytokines, mucins, tight junction proteins, and antimicrobial peptides in the gastrointestinal tract were detected by quantitative real-time polymerase chain reaction. The short-chain fatty acid (SCFAs) in the cecal contents of all mice were quantitatively detected by gas chromatography and mass spectrometry. Both LRS and FMT exerted excellent therapeutic effects on UC, as evidenced by the reduction in body weight loss, colon length, and colon structural integrity, as well as the increase in the DAI (disease activity index). LRS and FMT treatments showed similar effects: (1) an increase of total SCFA production in the cecal contents and the abundance of gut microbial diversity and flora composition; (2) decreases in two genera (Parabacteroides and Escherichia/Shigella) related to the DAI and the enhancement of SCFAs and IL-10 positively related genera in the gut microbiota (Bilophila, Roseburia, Akkermansia, and Bifidobacterium); (3) downregulation of the expression of tumor necrosis factor-α, interleukin IL-6, and IL-1β, and upregulation of the expression of the anti-inflammatory cytokine IL-10; and (4) upregulation of the expression of mucins (Muc1-4) and tight junction protein ZO-1. Overall, L. rhamnosus SHA113 relieves UC via the regulation of gut microbiota: increases in SCFA-producing genera and decreases in UC-related genera. In addition, a single strain is sufficient to induce a significant change in the gut microbiota and exert therapeutic effects on UC.