Gallensäuren sind steroidale Verbindungen, die ein wichtiges Endprodukt des CholesterinMetabolismus darstellen. Als zentrale Bestandteile des Fettstoffwechsels sind Gallensäuren essentiell für die ...Resorption von Lipiden, lipidlöslichen Vitaminen und Steroiden. Dabei bilden sie Mizellen aus, welche die lipophilen Substanzen einschließen und resorbierbar machen . Seit einigen Jahren werden Gallensäuren immer häufiger mit verschiedenen Krankheiten, unter anderem entzündliche Darmkrankheiten (IBD), Cholestase, Fettleibigkeit, Typ‐2‐Diabetes und Krebs assoziiert.
Da moderne Messmethoden im Bereich der quantitativen Gallensäureanalytik meist nur eine geringe Anzahl an Gallensäuren inkludieren oder zeitaufwändig sind, wurde im ersten Teil dieser Arbeit eine robuste und schnelle Messmethode entwickelt, um 45 Gallensäuren qualitativ und quantitativ zu erfassen. Darunter befanden sich 2 humane primäre, 2 murine primäre, 26 sekundäre unkonjugierte, 8 Taurin‐konjugierte und 7 Glycin‐konjugierte Gallensäuren. Zur Bestimmung wurde die Ultrahochleistungsflüssigkeitschromatographie mit der hochauflösenden Tandem‐Massen spektrometrie gekoppelt und als Trennmaterial ein reversed phase C18‐Material verwendet. Dadurch konnte eine Trennung der 45 Gallensäuren, innerhalb von 22 Minuten ermöglicht werden.
Als Nachweis einer erfolgreichen Methodenentwicklung wurde eine ausführliche Validierung in humanen Faeces durchgeführt. Dabei wurden die Parameter Wiederfindung, Extraktionsverlust, Mess‐, Wiederholungs‐ und Methodenpräzision, Linearität, Selektivität sowie Nachweis‐ und Bestimmungsgrenze berücksichtigt. Als Ausgangsmaterial für die Ermittlung des linearen Arbeitsbereiches, Selektivität und Nachweis‐ sowie Bestimmungsgrenze war es notwendig, eine analytfreie Faeces‐Matrix herzustellen. Diese konnte durch Einwirken von Aktivkohle auf dem fäkalen Matrix‐Extrakt gewonnen werden, da endogene Gallensäuren gebunden und entfernt werden.
Im zweiten Teil der Arbeit wurde die entwickelte und validierte Messmethode auf biologische Matrices tierischen Ursprungs angewendet, um das Gallensäureprofil verschiedener Tierarten, wie Rind, Schwein, Lamm und Geflügel, in unterschiedlichen Geweben zu analysieren. Dafür wurden verschiedene Kompartimente des enterohepatischen und systemischen Kreislaufs untersucht. Es konnten unterschiedlich dominierende Gallensäuren bei verschiedenen Tierspezies festgestellt werden, was auf einen unterschiedlichen Gallensäure‐Metabolismus hinweist. In Geflügel konnte Chenodesoxycholsäure als dominierende Gallensäure ausgemacht werden, die hauptsächlich an Taurin gebunden war, während in Rindern die Gallensäuren Cholsäure und Desoxycholsäure primär vorlagen. In Schweinen überwiegen die Gallensäuren Hyodesoxycholsäure und Chenodesoxycholsäure, die hauptsächlich an Glycin konjugiert vorliegen.
Des Weiteren wurden Gallensäuren in einer Studie mit Morbus Crohn‐Patienten bestimmt, um das Gallensäureprofil der Patienten nach einer hämatopoetischen Stammzelltransplantation zu untersuchen. Zudem wurde das Gallensäureprofil in keimfreien IL‐10‐/‐ Mäusen als humanisiertes Modell nach einer Stuhltransplantation von erkrankten Patienten analysiert. Da die Mäuse im Vergleich zum Menschen eine geringere Varianz in den Gallensäurekonzentrationen aufwiesen, wurden die Vorteile der Verwendung eines Mausmodells verdeutlicht. Insbesondere bei den Mäusen konnten unterschiedliche Gallensäureprofile bei entzündeten und nichtentzündeten Phänotypen ermittelt werden. Dabei lieferten Taurin‐konjugierte Gallensäuren einen Hinweis auf Entzündungen im Wirt, was Aussagen über den Entzündungsstatus ermöglichen kann.
Background: It is estimated that over 4.8 million deaths can be attributed to cardiometabolic diseases among adults ages 25-64 in the US from 1990-2017, making it the number one cause of death for ...several years. With this growing prevalence of cardiometabolic (CM) disease risk, it is of grave importance to better understand the etiology of these diseases as CM disease risk is associated with cardiovascular diseases, diabetes and some cancers . The gut microbiome has been indicated as influencing CM risk; however, the pathway by which this occurs is unknown. Methods: Fecal samples from 561 participants across three sites (Ghana: 195, South Africa:175 and United States:190) underwent 16S analysis. Fecal SCFAs including acetate, propionate and butyrate were also measured. Weight, height and blood pressure were measured using the same model scales and monitors across all three sites. Multivariate analyses and general linear models were used to evaluate associations. Results: CM risk was highest in US men and women and lowest in Ghanaian men and women. Correspondingly, gut microbiome diversity (both alpha and beta diversity) was significantly lower in the US when compared to South Africa and Ghana. Surprisingly, gut microbiome diversity did not significantly differ between obese and non-obese groups. However, there were 9 exact seuqence variants (ESVs) that significantly differed by obesity status including ESVs from the Enterobacteriaceae and Clostridiaceae families. ESVs from the Clostridiales order were negatively correlated with total fecal SCFAs levels. There were several country-level differences based on the functional annotation pathways, however differences were largely driven by the differences among the Ghanaian participants when compared to the US (p<0.05) and South African participants (p<0.05). Conclusions: Many of the health outcome and microbiome differences identified in this analysis were driven by site. It is possible that the gut microbiome, with short chain fatty acids (SCFAs) acting as mediators, could be a novel method of intervening in the growing prevalence of CM disease.
Investigations involving human faeces and faecal sludge are of great importance for urban sanitation, such as operation and maintenance of sewer systems, or implementation of faecal sludge ...management. However, working with real faecal matter is difficult as it not only involves working with a pathogenic, malodorous material but also individual faeces and faecal sludge samples are highly variable, making it difficult to execute repeatable experiments. Synthetic faeces and faecal sludge can provide consistently reproducible substrate and alleviate these challenges. A critical literature review of simulants developed for various wastewater and faecal sludge related research is provided. Most individual studies sought to develop a simulant representative of specific physical, chemical, or thermal properties depending on their research objectives. Based on the review, a suitable simulant can be chosen and used or further developed according to the research needs. As an example, the authors present such a modification for the development of a simulant that can be used for investigating the motion (movement, settling and sedimentation) of faeces and their physical and biological disintegration in sewers and in on-site sanitation systems.
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•We review synthetic human faeces and faecal sludge for sanitation related research.•Making use of these simulants can make research more reproducible and safer.•Simulants represent specific properties depending on the research objectives.•Simulants can be modified to meet emerging research needs. We give an example.•Characterization of faeces and faecal sludge is needed to validate simulants.
A practical handbook on fecal microbiota transplantation (FMT) for physicians, nurses, physician assistants, students, residents, and fellows,
The 6 Ds of Fecal Microbiota Transplantation: A Primer ...from Decision to Discharge and Beyond
provides a clinical framework to understand and administer this treatment as safely and effectively as possible.
FMT has emerged as a promising treatment for C. difficile infection (CDI), and there is a major need for educational resources on the topic. Drs. Jessica Allegretti, Zain Kassam, and their expert contributors are leaders in the field and have collectively cared for thousands of patients suffering from recurrent CDI who have benefitted from FMT.
This guide provides practical tools, clinical pearls, and answers to frequently asked questions. Beginning with introductory information on the microbiome and exploring the history of FMT,
The 6 Ds of Fecal Microbiota Transplantation
outlines a step-by-step checklist for administering FMT:
Decision: Who is the right CDI patient to receive FMT? What clinical questions should you ask patients in your FMT clinical assessment?
Donor: How do you select and screen a donor for FMT?
Discussion: What are the risks, benefits, and alternatives that need to be discussed with patients?
Delivery: What is the best delivery method for FMT-colonoscopy, nasogastric tube, enema, or capsules?
Discharge and follow-up: What is the ideal post-FMT care? How should you council patients following FMT?
Discovery: What are the most promising emerging clinical applications for FMT? What is the evidence for FMT in obesity, autism, irritable bowel syndrome, inflammatory bowel disease, antibiotic resistant bacteria, and liver disease?
Arming healthcare professionals with the ability to answer questions from patients regarding FMT and the microbiome,
The 6 Ds of Fecal Microbiota Transplantation
provides a pragmatic guide for this exciting treatment.
Although severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA was detected in faeces of patients with COVID-19, the activity and infectivity of the virus in the GI tract during disease ...course is largely unknown. We investigated temporal transcriptional activity of SARS-CoV-2 and its association with longitudinal faecal microbiome alterations in patients with COVID-19.
We performed RNA shotgun metagenomics sequencing on serial faecal viral extractions from 15 hospitalised patients with COVID-19. Sequencing coverage of the SARS-CoV-2 genome was quantified. We assessed faecal microbiome composition and microbiome functionality in association with signatures of faecal SARS-CoV-2 infectivity.
Seven (46.7%) of 15 patients with COVID-19 had stool positivity for SARS-CoV-2 by viral RNA metagenomic sequencing. Even in the absence of GI manifestations, all seven patients showed strikingly higher coverage (p=0.0261) and density (p=0.0094) of the 3' vs 5' end of SARS-CoV-2 genome in their faecal viral metagenome profile. Faecal viral metagenome of three patients continued to display active viral infection signature (higher 3' vs 5' end coverage) up to 6 days after clearance of SARS-CoV-2 from respiratory samples. Faecal samples with signature of high SARS-CoV-2 infectivity had higher abundances of bacterial species
,
,
,
, and higher functional capacity for nucleotide de novo biosynthesis, amino acid biosynthesis and glycolysis, whereas faecal samples with signature of low-to-none SARS-CoV-2 infectivity had higher abundances of short-chain fatty acid producing bacteria,
,
,
and
.
This pilot study provides evidence for active and prolonged 'quiescent' GI infection even in the absence of GI manifestations and after recovery from respiratory infection of SARS-CoV-2. Gut microbiota of patients with active SARS-CoV-2 GI infection was characterised by enrichment of opportunistic pathogens, loss of salutary bacteria and increased functional capacity for nucleotide and amino acid biosynthesis and carbohydrate metabolism.
In a phase 1 clinical study, coadministration of the adsorbent-based DAV132 product together with the fluoroquinolone antibiotic moxifloxacin, while not affecting the plasma concentrations of the ...antibiotic, reduced by >99% exposure of the intestinal microbiota to the moxifloxacin.
Abstract
Background
Antibiotics are life-saving drugs but severely affect the gut microbiome with short-term consequences including diarrhea and selection of antibiotic-resistant bacteria. Long-term links to allergy and obesity are also suggested. We devised a product, DAV132, and previously showed its ability to deliver a powerful adsorbent, activated charcoal, in the late ileum of human volunteers.
Methods
We performed a randomized controlled trial in 28 human volunteers treated with a 5-day clinical regimen of the fluoroquinolone antibiotic moxifloxacin in 2 parallel groups, with or without DAV132 coadministration. Two control goups of 8 volunteers each receiving DAV132 alone, or a nonactive substitute, were added.
Results
The coadministration of DAV132 decreased free moxifloxacin fecal concentrations by 99%, while plasmatic levels were unaffected. Shotgun quantitative metagenomics showed that the richness and composition of the intestinal microbiota were largely preserved in subjects co-treated with DAV132 in addition to moxifloxacin. No adverse effect was observed. In addition, DAV132 efficiently adsorbed a wide range of clinically relevant antibiotics ex vivo.
Conclusions
DAV132 was highly effective to protect the gut microbiome of moxifloxacin-treated healthy volunteers and may constitute a clinical breakthrough by preventing adverse health consequences of a wide range of antibiotic treatments.
Clinical Trials Registration
NCT02176005.
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