Risultati per: Microbiota e barriera intestinale distanti ma non troppo: implicazioni metaboliche sistemiche

Objective
Microbiome and dietary manipulation therapies are being explored for treating ulcerative colitis (UC). We aimed to examine the efficacy of multidonor faecal microbiota transplantation (FMT) and anti-inflammatory diet in inducing remission followed by long-term maintenance with anti-inflammatory diet in patients with mild-moderate UC.

Design
This open-labelled randomised controlled trial (RCT) randomised patients with mild-moderate (Simple Clinical Colitis Activity Index (SCCAI) 3–9) endoscopically active UC (Ulcerative Colitis Endoscopic Index of Severity (UCEIS) >1) on stable baseline medications in 1:1 ratio to FMT and anti-inflammatory diet (FMT-AID) versus optimised standard medical therapy (SMT). The FMT-AID arm received seven weekly colonoscopic infusions of freshly prepared FMT from multiple rural donors(weeks 0–6) with anti-inflammatory diet. Baseline medications were optimised in the SMT arm. Clinical responders (decline in SCCAI >3) at 8 weeks in both arms were followed until 48 weeks on baseline medications (with anti-inflammatory diet in the FMT-AID arm). Primary outcome measures were clinical response and deep remission (clinical—SCCAI

Objective
Cigarette smoking is a major risk factor for colorectal cancer (CRC). We aimed to investigate whether cigarette smoke promotes CRC by altering the gut microbiota and related metabolites.

Design
Azoxymethane-treated C57BL/6 mice were exposed to cigarette smoke or clean air 2 hours per day for 28 weeks. Shotgun metagenomic sequencing and liquid chromatography mass spectrometry were parallelly performed on mice stools to investigate alterations in microbiota and metabolites. Germ-free mice were transplanted with stools from smoke-exposed and smoke-free control mice.

Results
Mice exposed to cigarette smoke had significantly increased tumour incidence and cellular proliferation compared with smoke-free control mice. Gut microbial dysbiosis was observed in smoke-exposed mice with significant differential abundance of bacterial species including the enrichment of Eggerthella lenta and depletion of Parabacteroides distasonis and Lactobacillus spp. Metabolomic analysis showed increased bile acid metabolites, especially taurodeoxycholic acid (TDCA) in the colon of smoke-exposed mice. We found that E. lenta had the most positive correlation with TDCA in smoke-exposed mice. Moreover, smoke-exposed mice manifested enhanced oncogenic MAPK/ERK (mitogen-activated protein kinase/extracellular signal-regulated protein kinase 1/2) signalling (a downstream target of TDCA) and impaired gut barrier function. Furthermore, germ-free mice transplanted with stools from smoke-exposed mice (GF-AOMS) had increased colonocyte proliferation. Similarly, GF-AOMS showed increased abundances of gut E. lenta and TDCA, activated MAPK/ERK pathway and impaired gut barrier in colonic epithelium.

Conclusion
The gut microbiota dysbiosis induced by cigarette smoke plays a protumourigenic role in CRC. The smoke-induced gut microbiota dysbiosis altered gut metabolites and impaired gut barrier function, which could activate oncogenic MAPK/ERK signalling in colonic epithelium.

Circulation, Volume 146, Issue Suppl_1, Page A12300-A12300, November 8, 2022. Introduction:Phenylacetylglutamine (PAGln) has been recently discovered as a gut-microbiota-related metabolite, and circulating PAGln may be related to risks of cardiometabolic abnormalities. Gut microbiota-related dietary intakes and high-protein foods may affect circulating PAGln levels.Hypothesis:We assessed whether circulating PAGln levels may be related to intakes of gut-microbiota-related food intakes, and higher levels of PAGln may be associated with greater degrees of cardiometabolic abnormalities. We also tested a hypothesis that higher levels of circulating PAGln may be related to higher risk of the incident coronary heart disease (CHD).Methods:Circulating levels of PAGln, diet assessed using 7-day dietary records, and cardiometabolic abnormalities were assessed in the Women’s Lifestyle Validation Study (WLVS) (n=723). The associations between plasma PAGln levels and risk of incident CHD were analyzed in a prospective nested case-control of 1520 women (760 incident cases of fatal CHD and nonfatal myocardial infarction and 760 controls) from the Nurses’ Health Study (NHS). We identified incident cases of CHD over 10-14 years of follow-up time.Results:Higher levels of PAGln were associated with higher levels of circulating insulin, triglycerides, as well as lower levels of HDL cholesterol. We found that greater intakes of red meat and processed meat (p=0.01), but not of poultry or fish (p >0.05), and lower intakes of vegetables (p=0.03) were significant factors associated with higher levels of circulating PAGln. In the prospective nested case-control study setting, higher levels of PAGln were associated with higher risk of the incident CHD. Every 1 unit increment of log-transformed PAGln was associated with a relative risk of 1.21 (95% CI: 1.01, 1.45) for the incident CHD.Conclusions:Gut-microbiota-affecting diet quality were related to circulating levels of PAGln. Circulating PAGln levels may be associated with cardiometabolic abnormalities and risk of incident CHD among women.

Accumulating evidence not only supports the functional role of the gut microbiome in cancer development and progression but also its role in defining the efficacy and toxicity of chemotherapeutic agents (5-fluorouracil, CTX, Irinotecan, Oxaliplatin, Gemcitabine, Methotrexate) and immunotherapeutic (anti-PD-L1/ anti-PD-1 and anti-CTLA-4) compounds. This evidence is supported in numerous in-vitro, animal and clinical studies which highlight the importance of microbial mechanisms in defining therapeutic responses.

Objective
This study is to investigate the role of gut dysbiosis in triggering inflammation in the brain and its contribution to Alzheimer’s disease (AD) pathogenesis.

Design
We analysed the gut microbiota composition of 3xTg mice in an age-dependent manner. We generated germ-free 3xTg mice and recolonisation of germ-free 3xTg mice with fecal samples from both patients with AD and age-matched healthy donors.

Results
Microbial 16S rRNA sequencing revealed Bacteroides enrichment. We found a prominent reduction of cerebral amyloid-β plaques and neurofibrillary tangles pathology in germ-free 3xTg mice as compared with specific-pathogen-free mice. And hippocampal RNAseq showed that inflammatory pathway and insulin/IGF-1 signalling in 3xTg mice brain are aberrantly altered in the absence of gut microbiota. Poly-unsaturated fatty acid metabolites identified by metabolomic analysis, and their oxidative enzymes were selectively elevated, corresponding with microglia activation and inflammation. AD patients’ gut microbiome exacerbated AD pathologies in 3xTg mice, associated with C/EBPβ/asparagine endopeptidase pathway activation and cognitive dysfunctions compared with healthy donors’ microbiota transplants.

Conclusions
These findings support that a complex gut microbiome is required for behavioural defects, microglia activation and AD pathologies, the gut microbiome contributes to pathologies in an AD mouse model and that dysbiosis of the human microbiome might be a risk factor for AD.

We read with great interest the recent article by Yeoh et al, demonstrating an altered stool microbiome composition in patients with COVID-19 compared with controls, with greater dysbiosis correlating with elevated inflammatory markers.1 Additionally, dysbiosis was seen after disease resolution.1 To our knowledge, gut microbiome studies in young children with COVID-19 have not been reported. Critically, the developing gut microbiome of very young children differs from adults and establishes immune and inflammatory pathways.2 3 Moreover, children with COVID-19 can subsequently develop autoimmune and autoinflammatory diseases including Multisystem Inflammatory Syndrome in Children (MIS-C)4 5, which may in part be microbiome mediated, given recent findings by Yeoh et al.1 It is difficult to study this in young children, as many with SARS-CoV-2 infection are asymptomatic and rarely tested.6 To address this, knowing that SARS-CoV-2 can…

We read with interest the work by Camilleri and Vella1 reporting the potential role of ‘leaky gut’ or reduced barrier function in some pathophysiological states. The detrimental effects of dietary emulsifiers on host intestinal barrier have also been evaluated.1–3 However, their role on promoting skin-related diseases and whether modulation of the microbiota can reversibly impact their underlying chemical effects are unknown. Herein, we showed that a common emulsifier, polysorbate-80 (P80), together with a soybean-deprived diet, promoted alopecia in mice. Importantly, the pathogenic process was exacerbated by antibiotics through aggravating gut dysbiosis and reversed following faecal microbiota transplantation (FMT) or administration of a targeted probiotic (Bifidobacterium longum HK003) isolated from faeces of healthy subjects (figures 1A–C and 2A,B). P80 and antibiotics-treated mice developed severe alopecia with large balding patches. Antibiotics exacerbated the microbial compositions induced by P80 including…

We investigate interrelationships between gut microbes, metabolites, and cytokines that characterize COVID-19 and its complications, and validate the results with follow-up, Japanese 4D microbiome cohort, and non-Japanese datasets.

Introduction
Gut microbiota (GM) appears critical for gastrointestinal symptoms, but whether alterations in GM are associated with increased risk of postoperative gastrointestinal dysfunction (POGID) in older patients with colon cancer (CC) undergoing elective colon resection remains unclear.

Methods and analysis
This study aims to prospectively recruit 284 elderly patients with CC undergoing elective colon resection. GM of fresh faeces specimens is characterised using 16S rRNA gene sequencing. Data are collected preoperatively, daily postoperatively during the in-hospital stay, and follow-up visits are scheduled four times within 30 days after discharge. Associations with POGID will be investigated using logistic regression models to calculate ORs with 95% CIs. The models include the adjustment for age, sex, frequency of spicy diet, coffee drinking and tea drinking, tobacco and alcohol history, diabetes, obesity, gastroenteritis, preoperative gut microbial composition. Furthermore, we will use joint modelling for longitudinal data to study several outcome variables simultaneously.

Ethics and dissemination
This study was approved by the Institutional Review Board of West China Hospital, Sichuan University (IRB Number: 20201334). The results will be disseminated through peer-reviewed publications or conference presentations.

Trial registration number
It has been registered in PROSPERO, number CRD42019145032. It has been registered in the Chinese clinical trial registry, number ChiCTR2100043646.

Objective
Using faecal shotgun metagenomic sequencing, we identified the depletion of Lactobacillus gallinarum in patients with colorectal cancer (CRC). We aimed to determine the potential antitumourigenic role of L. gallinarum in colorectal tumourigenesis.

Design
The tumor-suppressive effect of L. gallinarum was assessed in murine models of CRC. CRC cell lines and organoids derived from patients with CRC were cultured with L. gallinarum or Escherichia coli MG1655 culture-supernatant to evaluate cell proliferation, apoptosis and cell cycle distribution. Gut microbiota was assessed by 16S ribosomal DNA sequencing. Antitumour molecule produced from L. gallinarum was identified by liquid chromatography mass spectrometry (LC-MS/MS) and targeted mass spectrometry.

Results
L. gallinarum significantly reduced intestinal tumour number and size compared with E. coli MG1655 and phosphate-buffered saline in both male and female murine intestinal tumourigenesis models. Faecal microbial profiling revealed enrichment of probiotics and depletion of pathogenic bacteria in L. gallinarum-treated mice. Culturing CRC cells with L. gallinarum culture-supernatant (5%, 10% and 20%) concentration-dependently suppressed cell proliferation and colony formation. L. gallinarum culture-supernatant significantly promoted apoptosis in CRC cells and patient-derived CRC organoids, but not in normal colon epithelial cells. Only L. gallinarum culture-supernatant with fraction size

This multicenter cohort study analyzes the associations between intratumoral microbiota and prognostication in patients with nasopharyngeal carcinoma.

Objective
Reducing FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) can be clinically beneficial in IBS but the mechanism is incompletely understood. We aimed to detect microbial signatures that might predict response to the low FODMAP diet and assess whether microbiota compositional and functional shifts could provide insights into its mode of action.

Design
We used metagenomics to determine high-resolution taxonomic and functional profiles of the stool microbiota from IBS cases and household controls (n=56 pairs) on their usual diet. Clinical response and microbiota changes were studied in 41 pairs after 4 weeks on a low FODMAP diet.

Results
Unsupervised analysis of baseline IBS cases pre-diet identified two distinct microbiota profiles, which we refer to as IBSP (pathogenic-like) and IBSH (health-like) subtypes. IBSP microbiomes were enriched in Firmicutes and genes for amino acid and carbohydrate metabolism, but depleted in Bacteroidetes species. IBSH microbiomes were similar to controls. On the low FODMAP diet, IBSH and control microbiota were unaffected, but the IBSP signature shifted towards a health-associated microbiome with an increase in Bacteroidetes (p=0.009), a decrease in Firmicutes species (p=0.004) and normalisation of primary metabolic genes. The clinical response to the low FODMAP diet was greater in IBSP subjects compared with IBSH (p=0.02).

Conclusion
50% of IBS cases manifested a ‘pathogenic’ gut microbial signature. This shifted towards the healthy profile on the low FODMAP diet; and IBSP cases showed an enhanced clinical responsiveness to the dietary therapy. The effectiveness of FODMAP reduction in IBSP may result from the alterations in gut microbiota and metabolites produced. Microbiota signatures could be useful as biomarkers to guide IBS treatment; and investigating IBSP species and metabolic pathways might yield insights regarding IBS pathogenic mechanisms.