Publications
444 results found
Woodhouse C, Edwards L, Mullish BH, et al., 2020, LBP29 Results of the PROFIT trial, a PROspective randomised placebo controlled feasibility trial of Faecal mIcrobiota Transplantation in advanced cirrhosis, Digital International Liver Congress, Publisher: Elsevier, Pages: S77-S78, ISSN: 0168-8278
Michael DR, Jack AA, Masetti G, et al., 2020, A randomised controlled study shows supplementation of overweight and obese adults with lactobacilli and bifidobacteria reduces bodyweight and improves well-being, Scientific Reports, Vol: 10, ISSN: 2045-2322
In an exploratory, block-randomised, parallel, double-blind, single-centre, placebo-controlled superiority study (ISRCTN12562026, funded by Cultech Ltd), 220 Bulgarian participants (30 to 65 years old) with BMI 25–34.9 kg/m2 received Lab4P probiotic (50 billion/day) or a matched placebo for 6 months. Participants maintained their normal diet and lifestyle. Primary outcomes were changes in body weight, BMI, waist circumference (WC), waist-to-height ratio (WtHR), blood pressure and plasma lipids. Secondary outcomes were changes in plasma C-reactive protein (CRP), the diversity of the faecal microbiota, quality of life (QoL) assessments and the incidence of upper respiratory tract infection (URTI). Significant between group decreases in body weight (1.3 kg, p < 0.0001), BMI (0.045 kg/m2, p < 0.0001), WC (0.94 cm, p < 0.0001) and WtHR (0.006, p < 0.0001) were in favour of the probiotic. Stratification identified greater body weight reductions in overweight subjects (1.88%, p < 0.0001) and in females (1.62%, p = 0.0005). Greatest weight losses were among probiotic hypercholesterolaemic participants (−2.5%, p < 0.0001) alongside a significant between group reduction in small dense LDL-cholesterol (0.2 mmol/L, p = 0.0241). Improvements in QoL and the incidence rate ratio of URTI (0.60, p < 0.0001) were recorded for the probiotic group. No adverse events were recorded. Six months supplementation with Lab4P probiotic resulted in significant weight reduction and improved small dense low-density lipoprotein-cholesterol (sdLDL-C) profiles, QoL and URTI incidence outcomes in overweight/obese individuals.
Ovadia C, Perdones Montero A, Fan HM, et al., 2020, Ursodeoxycholic acid enriches intestinal bile salt hydrolase-expressing Bacteroidetes in cholestatic pregnancy, Scientific Reports, Vol: 10, ISSN: 2045-2322
Ursodeoxycholic acid (UDCA) treatment can reduce itch and lower endogenous serum bile acids in intrahepatic cholestasis of pregnancy (ICP). We sought to determine how it could influence the gut environment in ICP to alter enterohepatic signalling.The gut microbiota and bile acid content were determined in faeces from 35 pregnant women (14 with uncomplicated pregnancies and 21 with ICP, 17 receiving UDCA). Faecal bile salt hydrolase activity was measured using a precipitation assay. Serum fibroblast growth factor 19 (FGF19) and 7α-hydroxy-4-cholesten-3-one (C4) concentrations were measured following a standardised diet for 21 hours. Women with a high ratio of Bacteroidetes to Firmicutes were more likely to be treated with UDCA (Fisher’s exact test p=0.0178) than those with a lower ratio. Bile salt hydrolase activity was reduced in women with low Bacteroidetes:Firmicutes. Women taking UDCA had higher faecal lithocholic acid (p<0.0001), with more unconjugated bile acids than women with untreated ICP or uncomplicated pregnancy. UDCA-treatment increased serum FGF19, and reduced C4 (reflecting lower bile acid synthesis). During ICP, UDCA treatment can be associated with enrichment of the gut microbiota with Bacteroidetes. These demonstrate high bile salt hydrolase activity, which deconjugates bile acids enabling secondary modification to FXR agonists, enhancing enterohepatic feedback via FGF19.
Gallacher D, Mitchell E, Alber D, et al., 2020, Dissimilarity of the gut-lung axis and dysbiosis of the lower airways in ventilated preterm infants., European Respiratory Journal, Vol: 55, ISSN: 0903-1936
BACKGROUND: Chronic lung disease of prematurity (CLD), also called bronchopulmonary dysplasia, is a major consequence of preterm birth but the role of the microbiome in its development remains unclear. We, therefore, assessed the progression of the bacterial community in ventilated preterm infants over time in the upper and lower airways, and assessed the gut-lung axis by comparing the upper and lower airways bacterial communities with the stool findings. Finally, we assessed if the bacterial communities were associated with lung inflammation to suggest dysbiosis. METHODS: We serially sampled multiple anatomical sites including the upper airway (nasopharyngeal aspirates, NPA), lower airways (tracheal aspirate fluid, TAF, and bronchoalveolar lavage fluid, BAL) and the gut (stool) of ventilated preterm-born infants. Bacterial DNA load was measured in all samples and sequenced using the V3-V4 region of the 16S rRNA gene RESULTS: From 1102 (539 NPA, 276 TAF, 89 BAL, 198 stool) samples from 55 preterm infants, 352 (32%) amplified suitably for 16 s RNA gene sequencing. Bacterial load was low at birth, quickly increased with time but was associated with predominant operational taxonomic units (OTUs) in all sample types. There was dissimilarity in bacterial communities between the upper and lower airways and the gut with a separate dysbiotic inflammatory process occurring in the lower airways of infants. Individual OTUs were associated with increased inflammatory markers. CONCLUSIONS: Taken together, these findings suggest that targeted treatment of the predominant organisms, including those not routinely treated such as Ureaplasma spp., may decrease the development of CLD in preterm-born infants.
Ghani R, Mullish BH, McDonald J, et al., 2020, Disease prevention not decolonisation: a cohort study for faecal microbiota transplantation for patients colonised with multidrug-resistant organisms, ECCMID 2020
Segal J, Mullish B, Clark S, et al., 2020, P844 Higher proportions of genera and species in the Firmicutes phylum are associated with a healthy pouch compared with patients with chronic pouchitis, Journal of Crohn's and Colitis, Vol: 14, Pages: S652-S652, ISSN: 1873-9946
BackgroundStudies highlighting changes in bacterial composition in the ileoanal pouch are limited by heterogeneity in analysis techniques and sampling strategies Therefore, caution must be used when interpreting microbiota data. Similar to findings in IBD, a decrease in bacterial diversity and ‘dysbiosis’ are associated with acute and chronic inflammation in the pouch. Changes in Clostridium spp. and E. coli are associated with inflamed pouches and treatment response. This study aimed to compare the bacterial microbiota composition in patients with chronic pouchitis who responded to antibiotics vs. those who did not.MethodsPatients with confirmed chronic pouchitis defined by a pouch disease activity score ≥ 7 were treated with antibiotics. If patients were already on antibiotics, they were offered the opportunity to stop. Follow up was at 4 weeks to check clinical status. Patients who came off antibiotics who flared were given the opportunity to restart the antibiotics to prevent deterioration. Patients were analysed as either on antibiotics if they received antibiotics 2 weeks prior to the clinic or off antibiotics if they had stopped all antibiotics 2 weeks prior to follow-up. Stool was collected from patients on follow-up and DNA was extracted from this stool. Sequencing was performed on an Illumina platform. Statistical analysis was performed using STAMP 2.1.3 software with Welch’s two-sided t-test for comparing two groups with false discovery rate correction.ResultsThere were 28 patients in the cohort; 23 patients with chronic pouchitis and 5 healthy controls who had never had pouchitis. Ten patients were female. The median age of the cohort was 47 years (range 26–74 years). A total of 12 samples on antibiotics and 11 off antibiotics. There were 10 responders and 13 non-responders. There were no differences between responders and non-responders and no differences in those taking antibiotics vs. those not taking antibiotics with chroni
Pinato DJ, Cole T, Bengsch B, et al., 2020, 750P - A phase Ib study of pembrolizumab following trans-arterial chemoembolization (TACE) in hepatocellular carcinoma (HCC): PETAL, Annual Meeting of the American-Association-for-the-Study-of-Liver-Diseases (AASLD) / Liver Meeting, Publisher: Wiley, Pages: 209A-210A, ISSN: 0270-9139
BackgroundThe efficacy of TACE is secondary to its dual ischaemic and cytotoxic effect, which promotes immunogenic tumor cell death. TACE may prime adaptive immunity and facilitate pembrolizumab (pembro; anti-PD1) in promoting tumour immune rejection and improve outcome in HCC. We designed this phase Ib study to evaluate safety, preliminary activity of TACE+pembrolizumab and explore mechanisms of efficacy.MethodsUp to 32 patients (pts) with intermediate-stage HCC were planned to receive up to 2 rounds of conventional TACE followed by pembro 200 mg q3w 30 days post-TACE until disease progression or unacceptable toxicity for up to 1 year. Primary endpoint was safety with dose-limiting toxicities emerging from the combination being evaluated over a 21-days window from commencement of pembro. Secondary endpoints included PFS rates q12w. We explored tumour and host determinants of response in tissue, blood and stool samples to confirm the bioactivity of the combination.ResultsIn cohort 1 (n = 6) patients were all of BCLC-B stage, 83% males, 16% HCV-positive, 50% ECOG PS 0, median age 62 years. Child-Pugh (CP) was A in 5 and B7 in 1 pt. Median tumour size was 4 cm, and median number of lesions was 2. All-grade adverse events potentially related to treatment (tx) occurred in 50% of pts including diarrhoea (n = 1, G3), skin rash (n = 2, G2), infusion reaction (n = 1, G2) and adrenal insufficiency (n = 1, G2). Pembro yielded no synergistic toxicity with TACE and no DLTs were reported. At data cut-off, tx was ongoing for 3 pts with a median duration of tx of 2.8 months. Of the 4 radiologically evaluable patients, 3 had stable disease on pembro, 1 had progressive disease. Cause of withdrawal included disease progression/death (n = 2) and worsening liver failure in the CP B7 pt, non tx-related (n = 1). Updated data from an expanded pt cohort will be shown and efficacy data will be correlated with T-cell responses to recognized tumor-associated antigens, tumour-infiltrating lymp
Sequeira RP, McDonald JAK, Marchesi JR, et al., 2020, Commensal Bacteroidetes protect against Klebsiella pneumoniae colonization and transmission through IL-36 signalling, Nature Microbiology, Vol: 5, Pages: 313-313, ISSN: 2058-5276
The microbiota primes immune defences but the identity of specific commensal microorganisms that protect against infection is unclear. Conversely, how pathogens compete with the microbiota to establish their host niche is also poorly understood. In the present study, we investigate the antagonism between the microbiota and Klebsiella pneumoniae during colonization and transmission. We discover that maturation of the microbiota drives the development of distinct immune defence programmes in the upper airways and intestine to limit K. pneumoniae colonization within these niches. Immune protection in the intestine depends on the development of Bacteroidetes, interleukin (IL)-36 signalling and macrophages. This effect of Bacteroidetes requires the polysaccharide utilization locus of their conserved commensal colonization factor. Conversely, in the upper airways, Proteobacteria prime immunity through IL-17A, but K. pneumoniae overcomes these defences through encapsulation to effectively colonize this site. Ultimately, we find that host-to-host spread of K. pneumoniae occurs principally from its intestinal reservoir, and that commensal-colonization-factor-producing Bacteroidetes are sufficient to prevent transmission between hosts through IL-36. Thus, our study provides mechanistic insight into when, where and how commensal Bacteroidetes protect against K. pneumoniae colonization and contagion, providing insight into how these protective microorganisms could be harnessed to confer population-level protection against K. pneumoniae infection.
Al-Memar M, Bobdiwala S, Fourie H, et al., 2020, The association between vaginal bacterial composition and miscarriage: a nested case-control study, BJOG: an International Journal of Obstetrics and Gynaecology, Vol: 127, Pages: 264-274, ISSN: 1470-0328
OBJECTIVE: To characterise vaginal bacterial composition in early pregnancy and investigate its relationship with first and second trimester miscarriages. DESIGN: Nested case-control study. SETTING: Queen Charlotte's and Chelsea Hospital, Imperial College Healthcare NHS Trust, London. POPULATION: 161 pregnancies; 64 resulting in first trimester miscarriage, 14 in second trimester miscarriage and 83 term pregnancies. METHODS: Prospective profiling and comparison of vaginal bacteria composition using 16S rRNA gene-based metataxonomics from 5 weeks gestation in pregnancies ending in miscarriage or uncomplicated term deliveries matched for age, gestation and body-mass index. MAIN OUTCOME MEASURES: Relative vaginal bacteria abundance, diversity and richness. Pregnancy outcomes defined as first or second trimester miscarriage, or uncomplicated term delivery. RESULTS: First trimester miscarriage associated with reduced prevalence of Lactobacillus spp.-dominated vaginal microbiota classified using hierarchical clustering analysis (65.6% vs. 87·7%; P=0·005), higher alpha diversity (mean Inverse Simpson Index 2.5 (95% confidence interval 1.8-3.0) vs. 1.5 (1.3-1.7), P=0·003) and higher richness 25.1 (18.5-31.7) vs. 16.7 (13.4-20), P=0·017), compared to viable pregnancies. This was independent of vaginal bleeding and observable before first trimester miscarriage diagnosis (P=0·015). Incomplete/complete miscarriage associated with higher proportions of Lactobacillus spp.-deplete communities compared to missed miscarriage. Early pregnancy vaginal bacterial stability was similar between miscarriage and term pregnancies. CONCLUSIONS: These findings associate the bacterial component of vaginal microbiota with first trimester miscarriage and indicate suboptimal community composition is established in early pregnancy. While further studies are required to elucidate the mechanism, vaginal bacterial composition may represent a modifiable risk factor fo
Taylor H, McDonald J, Contreras JIS, et al., 2020, Deep remission in paediatric Crohn's disease is associated with increased abundance of dialister species and increased valerate, Publisher: OXFORD UNIV PRESS, Pages: S045-S046, ISSN: 1873-9946
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Lowe J, Gillespie D, Hubbard M, et al., 2020, Study protocol: azithromycin therapy for chronic lung disease of prematurity (AZTEC)-a randomised, placebo-controlled trial of azithromycin for the prevention of chronic lung disease of prematurity in preterm infants, BMJ OPEN, Vol: 10, ISSN: 2044-6055
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- Citations: 13
May S, Mcdermott G, Marchesi JR, et al., 2020, Impact of black raspberries on the normal and malignant <i>Apc</i> deficient murine gut microbiome, JOURNAL OF BERRY RESEARCH, Vol: 10, Pages: 61-76, ISSN: 1878-5093
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- Citations: 6
Walters JR, Marchesi JR, 2019, Chronic diarrhea, bile acids, and Clostridia., Journal of Clinical Investigation, Vol: 130, Pages: 77-79, ISSN: 0021-9738
Excessive fecal bile acid (BA) loss causes symptoms in a large proportion of people diagnosed with irritable bowel syndrome with diarrhea, a common functional bowel disorder. This BA diarrhea (BAD) results from increased hepatic synthesis of BAs, with impaired negative feedback regulation by the ileal hormone fibroblast growth factor 19 (FGF19). In this issue of the JCI, Zhao et al. investigated BA metabolism, including fecal BAs, serum BAs, and FGF19, in patients and controls. They identified associations between fecal bacterial BA metabolism and specific microbiota, especially Clostridium scindens. These findings have been tested in a mouse model using microbiota transplants and antibiotic treatment. This group of organisms has potential as a biomarker for BAD and to be a target for therapy.
Jukes CA, Ijaz UZ, Buckley A, et al., 2019, Bile salt metabolism is not the only factor contributing to Clostridioides (Clostridium) difficile disease severity in the murine model of disease, Gut Microbes, Vol: 11, Pages: 481-496, ISSN: 1949-0976
Susceptibility of patients to antibiotic-associated C. difficile disease is intimately associated with specific changes to gut microbiome composition. In particular, loss of microbes that modify bile salt acids (BSA) play a central role; primary bile acids stimulate spore germination whilst secondary bile acids limit C. difficile vegetative growth. To determine the relative contribution of bile salt (BS) metabolism on C. difficile disease severity, we treated mice with three combinations of antibiotics prior to infection. Mice given clindamycin alone became colonized but displayed no tissue pathology while severe disease, exemplified by weight loss and inflammatory tissue damage occurred in animals given a combination of five antibiotics and clindamycin. Animals given only the five antibiotic cocktails showed only transient colonization and no disease. C. difficile colonization was associated with a reduction in bacterial diversity, an inability to amplify bile salt hydrolase (BSH) sequences from fecal DNA and a relative increase in primary bile acids (pBA) in cecal lavages from infected mice. Further, the link between BSA modification and the microbiome was confirmed by the isolation of strains of Lactobacillus murinus that modified primary bile acids in vitro, thus preventing C. difficile germination. Interestingly, BSH activity did not correlate with disease severity which appeared linked to alternations in mucin, which may indirectly lead to increased exposure of the epithelial surface to inflammatory signals. These data confirm the role of microbial metabolic activity in protection of the gut and highlights the need for greater understanding the function of bacterial communities in disease prevention.
Yalchin M, Segal JP, Mullish BH, et al., 2019, Gaps in knowledge and future directions for the use of faecal microbiota transplant in the treatment of inflammatory bowel disease, Therapeutic Advances in Gastroenterology, Vol: 12, ISSN: 1756-2848
Faecal microbiota transplant (FMT) has now been established into clinical guidelines for the treatment of recurrent and refractory Clostridioides difficile infection (CDI). Its therapeutic application in inflammatory bowel disease (IBD) is currently at an early stage. To date there have been four randomised controlled trials for FMT in IBD and a multitude of observational studies. However significant gaps in our knowledge regarding optimum methods for FMT preparation, technical and logistics of its administration, as well as mechanistic underpinnings, still remain. This article aims to highlight these gaps by reviewing evidence and makes key recommendations on the direction of future studies in this field. In addition, we provide an overview of the current evidence of potential mechanistics of FMT in IBD.
Pinato DJ, Gramenitskaya D, Altmann DM, et al., 2019, Antibiotic therapy and outcome from immune-checkpoint inhibitors, Journal for ImmunoTherapy of Cancer, Vol: 7, ISSN: 2051-1426
Sensitivity to immune checkpoint inhibitor (ICPI) therapy is governed by a complex interplay of tumor and host-related determinants. Epidemiological studies have highlighted that exposure to antibiotic therapy influences the probability of response to ICPI and predict for shorter patient survival across malignancies. Whilst a number of studies have reproducibly documented the detrimental effect of broad-spectrum antibiotics, the immune-biologic mechanisms underlying the association with outcome are poorly understood. Perturbation of the gut microbiota, an increasingly well-characterized factor capable of influencing ICPI-mediated immune reconstitution, has been indicated as a putative mechanism to explain the adverse effects attributed to antibiotic exposure in the context of ICPI therapy. Prospective studies are required to validate antibiotic-mediated gut perturbations as a mechanism of ICPI refractoriness and guide the development of strategies to overcome this barrier to an effective delivery of anti-cancer immunotherapy.
Cameron SJS, Alexander JL, Bolt F, et al., 2019, Evaluation of direct from sample metabolomics of human feces using rapid evaporative ionization mass spectrometry, Analytical Chemistry, Vol: 91, Pages: 13448-13457, ISSN: 0003-2700
Mass spectrometry is a powerful tool in the investigation of the human fecal metabolome. However, current approaches require time-consuming sample preparation, chromatographic separations, and consequently long analytical run times. Rapid evaporative ionization mass spectrometry (REIMS) is a method of ambient ionization mass spectrometry and has been utilized in the metabolic profiling of a diverse range of biological materials, including human tissue, cell culture lines, and microorganisms. Here, we describe the use of an automated, high-throughput REIMS robotic platform for direct analysis of human feces. Through the analysis of fecal samples from five healthy male participants, REIMS analytical parameters were optimized and used to assess the chemical information obtainable using REIMS. Within the fecal samples analyzed, bile acids, including primary, secondary, and conjugate species, were identified, and phospholipids of possible bacterial origin were detected. In addition, the effect of storage conditions and consecutive freeze/thaw cycles was determined. Within the REIMS mass spectra, the lower molecular weight metabolites, such as fatty acids, were shown to be significantly affected by storage conditions for prolonged periods at temperatures above −80 °C and consecutive freeze/thaw cycles. However, the complex lipid region was shown to be unaffected by these conditions. A further cohort of 50 fecal samples, collected from patients undergoing bariatric surgery, were analyzed using the optimized REIMS parameters and the complex lipid region mass spectra used for multivariate modeling. This analysis showed a predicted separation between pre- and post-surgery specimens, suggesting that REIMS analysis can detect biological differences, such as microbiome-level differences, which have traditionally been reliant upon methods utilizing extensive sample preparations and chromatographic separations and/or DNA sequencing.
Ferreira MR, Andreyev HJN, Mohammed K, et al., 2019, Microbiota- and radiotherapy-induced gastrointestinal side-effects (MARS) study: a large pilot study of the microbiome in acute and late-radiation enteropathy, Clinical Cancer Research, Vol: 25, Pages: 6487-6500, ISSN: 1078-0432
Purpose: Radiotherapy is important in managing pelvic cancers. However, radiation enteropathy may occur and can be dose limiting. The gut microbiota may contribute to the pathogenesis of radiation enteropathy. We hypothesized that the microbiome differs between patients with and without radiation enteropathy.Experimental Design: Three cohorts of patients (n = 134) were recruited. The early cohort (n = 32) was followed sequentially up to 12 months post-radiotherapy to assess early radiation enteropathy. Linear mixed models were used to assess microbiota dynamics. The late cohort (n = 87) was assessed cross-sectionally to assess late radiation enteropathy. The colonoscopy cohort compared the intestinal mucosa microenvironment in patients with radiation enteropathy (cases, n = 9) with healthy controls (controls, n = 6). Fecal samples were obtained from all cohorts. In the colonoscopy cohort, intestinal mucosa samples were taken. Metataxonomics (16S rRNA gene) and imputed metataxonomics (Piphillin) were used to characterize the microbiome. Clinician- and patient-reported outcomes were used for clinical characterization.Results: In the acute cohort, we observed a trend for higher preradiotherapy diversity in patients with no self-reported symptoms (P = 0.09). Dynamically, diversity decreased less over time in patients with rising radiation enteropathy (P = 0.05). A consistent association between low bacterial diversity and late radiation enteropathy was also observed, albeit nonsignificantly. Higher counts of Clostridium IV, Roseburia, and Phascolarctobacterium significantly associated with radiation enteropathy. Homeostatic intestinal mucosa cytokines related to microbiota regulation and intestinal wall maintenance were significantly reduced in radiation enteropathy [IL7 (P = 0.05), IL12/IL23p40 (P = 0.03), IL15 (P = 0.05), and IL16 (P = 0.009)]. IL15 inversely correlated with counts of Roseburia and Propionibacterium.Conclusions: The microbiota presents opportunities t
Semertzidou A, MacIntyre D, Marchesi J, et al., 2019, CHARACTERISATION OF THE MICROBIOME ALONG THE FEMALE GENITAL TRACT AND RECTUM IN ENDOMETRIAL CANCER, Publisher: BMJ PUBLISHING GROUP, Pages: A363-A364, ISSN: 1048-891X
Mitra A, Macintyre D, Ntritsos G, et al., 2019, THE ROLE OF THE VAGINAL MICROBIOTA IN THE REGRESSION OF UNTREATED CIN2 LESIONS, Publisher: BMJ PUBLISHING GROUP, Pages: A37-A37, ISSN: 1048-891X
Mitra A, Macintyre D, Lee Y, et al., 2019, CERVICAL INTRAEPITHELIAL NEOPLASIA IS ASSOCIATED WITH AN ALTERED VAGINAL MICROBIOME AND INNATE IMMUNE DISRUPTION, Publisher: BMJ PUBLISHING GROUP, Pages: A71-A71, ISSN: 1048-891X
Marchesi JR, McDonald JAK, Mullish BH, 2019, Clostridioides difficile
The invention relates to Clostridioides difficile, and in particular to compounds, polypeptides and mixtures for the treatment of C. difficile infections. The invention also relates to nucleic acids, vectors comprising these nucleic acids and microorganisms for the treatment of C. difficile infections, and to methods of identifying and matching faecal microbiota transplant (FMT) donors to FMT recipients.
Allegretti JR, Mullish B, Nativ L, et al., 2019, Evaluating dynamics of bile acid metabolism to predict recurrence of clostridioides difficile infection, American Journal of Gastroenterology, Vol: 114, Pages: S113-S114, ISSN: 0002-9270
Pinato DJ, Cole T, Bengsch B, et al., 2019, A phase Ib study of pembrolizumab following trans-arterial chemoembolization (TACE) in hepatocellular carcinoma (HCC): PETAL, 44th Congress of the European-Society-for-Medical-Oncology (ESMO), Publisher: OXFORD UNIV PRESS, Pages: 288-288, ISSN: 0923-7534
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Allegretti JR, Mullish B, Hurtado J, et al., 2019, Short chain fatty acid profiles are altered by fecal microbiota transplantation for the treatment of inflammatory bowel disease and recurrent clostridioides difficile infection, American Journal of Gastroenterology, Vol: 114, Pages: S484-S485, ISSN: 0002-9270
Turkes FS, Crux R, Cunningham D, et al., 2019, iSCORE: Immunotherapy sequencing in colon and rectal cancer, 44th Congress of the European-Society-for-Medical-Oncology (ESMO), Publisher: OXFORD UNIV PRESS, ISSN: 0923-7534
Mullish BH, McDonald JAK, Pechlivanis A, et al., 2019, Microbial bile salt hydrolases mediate the efficacy of faecal microbiota transplant in the treatment of recurrent Clostridioides difficile infection, Gut, Vol: 68, Pages: 1791-1800, ISSN: 0017-5749
Objective Faecal microbiota transplant (FMT) effectively treats recurrent Clostridioides difficile infection (rCDI), but its mechanisms of action remain poorly defined. Certain bile acids affect C. difficile germination or vegetative growth. We hypothesised that loss of gut microbiota-derived bile salt hydrolases (BSHs) predisposes to CDI by perturbing gut bile metabolism, and that BSH restitution is a key mediator of FMT’s efficacy in treating the condition.Design Using stool collected from patients and donors pre-FMT/post-FMT for rCDI, we performed 16S rRNA gene sequencing, ultra performance liquid chromatography mass spectrometry (UPLC-MS) bile acid profiling, BSH activity measurement, and qPCR of bsh/baiCD genes involved in bile metabolism. Human data were validated in C. difficile batch cultures and a C57BL/6 mouse model of rCDI.Results From metataxonomics, pre-FMT stool demonstrated a reduced proportion of BSH-producing bacterial species compared with donors/post-FMT. Pre-FMT stool was enriched in taurocholic acid (TCA, a potent C. difficile germinant); TCA levels negatively correlated with key bacterial genera containing BSH-producing organisms. Post-FMT samples demonstrated recovered BSH activity and bsh/baiCD gene copy number compared with pretreatment (p<0.05). In batch cultures, supernatant from engineered bsh-expressing E. coli and naturally BSH-producing organisms (Bacteroides ovatus, Collinsella aerofaciens, Bacteroides vulgatus and Blautia obeum) reduced TCA-mediated C. difficile germination relative to culture supernatant of wild-type (BSH-negative) E. coli. C. difficile total viable counts were ~70% reduced in an rCDI mouse model after administration of E. coli expressing highly active BSH relative to mice administered BSH-negative E. coli (p<0.05).Conclusion Restoration of gut BSH functionality contributes to the efficacy of FMT in treating rCDI.
Mullish BH, 2019, The role of bile-metabolising enzymes in the pathogenesis of Clostridioides difficile infection, and the impact of faecal microbiota transplantation
McIlvride S, Nikolova V, Fan HM, et al., 2019, Obeticholic acid ameliorates dyslipidemia but not glucose tolerance in mouse model of gestational diabetes., Am J Physiol Endocrinol Metab, Vol: 317, Pages: E399-E410
Metabolism alters markedly with advancing gestation, characterized by progressive insulin resistance, dyslipidemia, and raised serum bile acids. The nuclear receptor farnesoid X receptor (FXR) has an integral role in bile acid homeostasis and modulates glucose and lipid metabolism. FXR is known to be functionally suppressed in pregnancy. The FXR agonist, obeticholic acid (OCA), improves insulin sensitivity in patients with type 2 diabetes with nonalcoholic fatty liver disease. We therefore hypothesized that OCA treatment during pregnancy could improve disease severity in a mouse model of gestational diabetes mellitus (GDM). C57BL/6J mice were fed a high-fat diet (HFD; 60% kcal from fat) for 4 wk before and throughout pregnancy to induce GDM. The impact of the diet supplemented with 0.03% OCA throughout pregnancy was studied. Pregnant HFD-fed mice displayed insulin resistance and dyslipidemia. OCA significantly reduced plasma cholesterol concentrations in nonpregnant and pregnant HFD-fed mice (by 22.4%, P < 0.05 and 36.4%, P < 0.001, respectively) and reduced the impact of pregnancy on insulin resistance but did not change glucose tolerance. In nonpregnant HFD-fed mice, OCA ameliorated weight gain, reduced mRNA expression of inflammatory markers in white adipose tissue, and reduced plasma glucagon-like peptide 1 concentrations (by 62.7%, P < 0.01). However, these effects were not evident in pregnant mice. OCA administration can normalize plasma cholesterol levels in a mouse model of GDM. However, the absence of several of the effects of OCA in pregnant mice indicates that the agonistic action of OCA is not sufficient to overcome many metabolic consequences of the pregnancy-associated reduction in FXR activity.
Scott AJ, Alexander JL, Merrifield CA, et al., 2019, International Cancer Microbiome Consortium consensus statement on the role of the human microbiome in carcinogenesis, Gut, Vol: 68, Pages: 1624-1632, ISSN: 0017-5749
Objective In this consensus statement, an international panel of experts deliver their opinions on key questions regarding the contribution of the human microbiome to carcinogenesis.Design International experts in oncology and/or microbiome research were approached by personal communication to form a panel. A structured, iterative, methodology based around a 1-day roundtable discussion was employed to derive expert consensus on key questions in microbiome-oncology research.Results Some 18 experts convened for the roundtable discussion and five key questions were identified regarding: (1) the relevance of dysbiosis/an altered gut microbiome to carcinogenesis; (2) potential mechanisms of microbiota-induced carcinogenesis; (3) conceptual frameworks describing how the human microbiome may drive carcinogenesis; (4) causation versus association; and (5) future directions for research in the field.The panel considered that, despite mechanistic and supporting evidence from animal and human studies, there is currently no direct evidence that the human commensal microbiome is a key determinant in the aetiopathogenesis of cancer. The panel cited the lack of large longitudinal, cohort studies as a principal deciding factor and agreed that this should be a future research priority. However, while acknowledging gaps in the evidence, expert opinion was that the microbiome, alongside environmental factors and an epigenetically/genetically vulnerable host, represents one apex of a tripartite, multidirectional interactome that drives carcinogenesis.Conclusion Data from longitudinal cohort studies are needed to confirm the role of the human microbiome as a key driver in the aetiopathogenesis of cancer.
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