BACKGROUND: Mechanistic data indicate the benefit of short-chain fatty acids (SCFA) produced by gut microbial fermentation of fiber on colorectal cancer, but direct epidemiologic evidence is limited. A recent study identified SNPs for two SCFA traits (fecal propionate and butyrate-producing microbiome pathway PWY-5022) in Europeans and showed metabolic benefits. METHODS: We conducted a two-sample Mendelian randomization analysis of the genetic instruments for the two SCFA traits (three SNPs for fecal propionate and nine for PWY-5022) in relation to colorectal cancer risk in three large European genetic consortia of 58,131 colorectal cancer cases and 67,347 controls. We estimated the risk of overall colorectal cancer and conducted subgroup analyses by sex, age, and anatomic subsites of colorectal cancer. RESULTS: We did not observe strong evidence for an association of the genetic predictors for fecal propionate levels and the abundance of PWY-5022 with the risk of overall colorectal cancer, colorectal cancer by sex, or early-onset colorectal cancer (diagnosed at <50 years), with no evidence of heterogeneity or pleiotropy. When assessed by tumor subsites, we found weak evidence for an association between PWY-5022 and risk of rectal cancer (OR per 1-SD, 0.95; 95% confidence intervals, 0.91-0.99; P = 0.03) but it did not surpass multiple testing of subgroup analysis. CONCLUSIONS: Genetic instruments for fecal propionate levels and the abundance of PWY-5022 were not associated with colorectal cancer risk. IMPACT: Fecal propionate and PWY-5022 may not have a substantial influence on colorectal cancer risk. Future research is warranted to comprehensively investigate the effects of SCFA-producing bacteria and SCFAs on colorectal cancer risk.

• MeSH
• butyráty * analýza   metabolismus   MeSH
• feces * chemie   mikrobiologie   MeSH
• kolorektální nádory * epidemiologie   genetika   metabolismus   MeSH
• kyseliny mastné těkavé analýza   genetika   metabolismus   MeSH
• lidé MeSH
• mendelovská randomizace MeSH
• propionáty * analýza   metabolismus   MeSH
• riziko MeSH
• střevní mikroflóra * genetika   fyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Geografické názvy
• Evropa MeSH

Kalprotektin se nachází v tělesných tekutinách v koncentracích odpovídajících stupni zánětu. Ve stolici je jeho hladina 6× vyšší než v krvi. Fekální kalprotektin je obrazem intenzity střevního zánětu.

Calprotectin is found in bodily fluids at concentrations proportional to the degree of inflammation, in feces at levels roughly 6× higher than in the blood. Fecal calprotectin reflects intestinal inflammation.

• MeSH
• biologické markery MeSH
• dítě MeSH
• dospělí MeSH
• feces chemie   MeSH
• idiopatické střevní záněty * diagnóza   MeSH
• leukocytární L1-antigenní komplex * analýza   MeSH
• lidé MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé MeSH

Quantitative PCR (qPCR) has become a frequently employed direct method for the detection and quantification of Mycobacterium avium subsp. paratuberculosis (MAP). The quantity of MAP determined by qPCR, however, may be affected by the type of qPCR quantification standard used (PCR product, plasmid, genomic DNA) and the way in which standard DNA quantity is determined (absorbance, fluorescence). In practice, this can be reflected in the inability to properly compare quantitative data from the same qPCR assays in different laboratories. Thus, the aim of this study was to prepare a prototype of an international MAP reference standard, which could be used to calibrate routinely used qPCR quantification standards in various laboratories to promote clinical data comparability. Considering stability, storage and shipment issues, a lyophilised fecal suspension artificially contaminated with a MAP reference strain was chosen as the most suitable form of the standard. The effect of five types of lyophilisation matrices on standard stability was monitored on 2-weeks interval basis for 4 months by F57 qPCR. The lyophilisation matrix with 10% skimmed milk provided the best recovery and stability in time and was thus selected for subsequent comparative testing of the standard involving six diagnostic and research laboratories, where DNA isolation and qPCR assay procedures were performed with the parallel use of the identical supplied genomic DNA solution. Furthermore, the effect of storage conditions on the standard stability was tested for at least 6 months. The storage at room temperature in the dark and under light, at + 4 °C, - 20 °C and - 80 °C showed no significant changes in the stability, and also no substantial changes in MAP viability were found using phage amplification assay. The prepared MAP quantification standard provided homogeneous and reproducible results demonstrating its suitability for utilisation as an international reference qPCR standard.

• MeSH
• DNA bakterií klasifikace   genetika   MeSH
• feces chemie   mikrobiologie   MeSH
• kvantitativní polymerázová řetězová reakce normy   MeSH
• lyofilizace MeSH
• Mycobacterium avium subsp. paratuberculosis klasifikace   genetika   izolace a purifikace   MeSH
• nemoci skotu diagnóza   MeSH
• paratuberkulóza diagnóza   mikrobiologie   MeSH
• referenční standardy MeSH
• senzitivita a specificita MeSH
• skot MeSH
• zvířata MeSH
• Check Tag
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

An aberrant immune response developed early in life may trigger inflammatory bowel disease (IBD) and food allergies (e.g., celiac disease). Fecal levels of immune markers categorize an inflammatory response (e.g., food allergy, autoimmune) paralleled with the initial microbial colonization. The immunoaffinity assays are routinely applied to quantify circulating immune protein markers in blood/serum. However, a reliable, multiplex assay to quantify fecal levels of immune proteins is unavailable. We developed mass spectrometry assays to simultaneously quantify fecal calprotectin, myeloperoxidase, eosinophil-derived neurotoxin, eosinophil cationic protein, alpha-1-antitrypsin 1, and adaptive immunity effectors in 134 neonatal stool swabs. We optimized extraction and proteolytic protocol and validated the multiplex assay in terms of linearity of response (> 100; typically 0.04 to 14.77 µg/mg of total protein), coefficient of determination (R2; > 0.99), the limit of detection (LOD; 0.003 to 0.04 µg/mg of total protein), the limit of quantification (LOQ; 0.009 to 0.122 µg/mg of total protein) and robustness. The median CV of intra- and interday precision was 9.8% and 14.1%, respectively. We quantified breast milk-derived IGHA2 to differentiate meconium from feces samples and to detect the first food intake. An early life profiling of immune markers reflects disrupted intestinal homeostasis, and it is perhaps suitable for pre-symptomatic interception of IBD and food allergies.

• MeSH
• biologické markery metabolismus   MeSH
• chemické techniky analytické metody   MeSH
• feces chemie   MeSH
• hmotnostní spektrometrie metody   MeSH
• idiopatické střevní záněty etiologie   metabolismus   MeSH
• lidé MeSH
• novorozenec MeSH
• odběr biologického vzorku metody   MeSH
• potravinová alergie etiologie   metabolismus   MeSH
• zánět diagnóza   mikrobiologie   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• novorozenec MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: Unconjugated hyperbilirubinemia, a feature of neonatal jaundice or Crigler-Najjar syndrome, can lead to neurotoxicity and even death. We previously demonstrated that unconjugated bilirubin (UCB) can be eliminated via transintestinal excretion in Gunn rats, a model of unconjugated hyperbilirubinemia, and that this is stimulated by enhancing fecal fatty acid excretion. Since transintestinal excretion also occurs for cholesterol (TICE), we hypothesized that increasing fecal cholesterol excretion and/or TICE could also enhance fecal UCB disposal and subsequently lower plasma UCB concentrations. METHODS: To determine whether increasing fecal cholesterol excretion could ameliorate unconjugated hyperbilirubinemia, we treated hyperbilirubinemic Gunn rats with ezetimibe (EZE), an intestinal cholesterol absorption inhibitor, and/or a liver X receptor (LXR) and farnesoid X receptor (FXR) agonist (T0901317 (T09) and obeticholic acid (OCA), respectively), known to stimulate TICE. RESULTS: We found that EZE treatment alone or in combination with T09 or OCA increased fecal cholesterol disposal but did not lower plasma UCB levels. CONCLUSIONS: These findings do not support a link between the regulation of transintestinal excretion of cholesterol and bilirubin. Furthermore, induction of fecal cholesterol excretion is not a potential therapy for unconjugated hyperbilirubinemia. IMPACT: Increasing fecal cholesterol excretion is not effective to treat unconjugated hyperbilirubinemia. This is the first time a potential relation between transintestinal excretion of cholesterol and unconjugated bilirubin is investigated. Transintestinal excretion of cholesterol and unconjugated bilirubin do not seem to be quantitatively linked. Unlike intestinal fatty acids, cholesterol cannot "capture" unconjugated bilirubin to increase its excretion. These results add to our understanding of ways to improve and factors regulating unconjugated bilirubin disposal in hyperbilirubinemic conditions.

• MeSH
• bilirubin chemie   MeSH
• cholesterol metabolismus   MeSH
• Criglerův-Najjarův syndrom metabolismus   terapie   MeSH
• dietní tuky farmakokinetika   MeSH
• ezetimib farmakologie   terapeutické užití   MeSH
• feces chemie   MeSH
• fluorované uhlovodíky farmakologie   terapeutické užití   MeSH
• haptoglobiny analýza   MeSH
• hyperbilirubinemie terapie   MeSH
• jaterní receptor X metabolismus   MeSH
• krysa rodu rattus MeSH
• kyselina chenodeoxycholová analogy a deriváty   farmakologie   terapeutické užití   MeSH
• lipidy krev   MeSH
• náhodné rozdělení MeSH
• potkani Gunn MeSH
• PPAR delta metabolismus   MeSH
• receptory cytoplazmatické a nukleární metabolismus   MeSH
• střeva účinky léků   metabolismus   MeSH
• sulfonamidy farmakologie   terapeutické užití   MeSH
• žluč chemie   MeSH
• žlučové kyseliny a soli metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Preanalytické a analytické aspekty kvantitativní metody stanovení hemoglobinu ve stolici mají podstatný význam na vyhodnocení testu, jehož pozitivita je indikací ke kolonoskopii při screeningu kolorektálních nádorů. Požadavky na kvalitu laboratorní analýzy vyžadují podle normy ČSN EN ISO 15189, aby byla hodnocena variabilita ve všech fázích procesu zkoušky. Preanalytickým aspektem je odběr a transport vzorku zahrnující odběrovou kazetu (množství stolice, objem a složení extrakčního pufru), konzistenci stolice, stabilitu vzorku (doba a teplota transportu). Analytickým aspektem je především variabilita imunochemické technologie, rozdílné protilátky, pufry, standardy a kalibrace analyzátorů. Harmonizace a standardizace stanovení hemoglobinu ve vzorcích stolice je tématem pracovní skupiny IFCC - WG-FIT (Working Group for Fecal Immunochemical Testing).

Preanalytical and analytical aspects of the quantitative method for the determination of haemoglobin in stool are essential for the evaluation of the test, the positivity of which is an indication for colonoscopy in the screening of colorectal tumors. The quality requirements for laboratory analysis require, according to standard ISO 15189, that variability be assessed at all stages of the test process. The pre-analytical aspect is the collection and transport of the sample including the collection cassette (amount of stool, volume and composition of the extraction buffer), stool consistency, stability of the sample (time and temperature of transport). The analytical aspect is mainly the variability of immunochemical technology, different antibodies, buffers, standards and calibration of analysers. Harmonization and standardization of hemoglobin determination in stool samples is the topic of the IFCC Working Group for Faecal Immunochemical Testing (WG-FIT).

• Klíčová slova
• imunochemický test na okultní krvácení,
• MeSH
• feces chemie   MeSH
• hemoglobiny * analýza   MeSH
• imunochemie metody   MeSH
• kolorektální nádory * prevence a kontrola   MeSH
• lidé MeSH
• okultní krev MeSH
• plošný screening MeSH
• Check Tag
• lidé MeSH

Quantitative faecal immunochemical tests for haemoglobin (FIT) are being used increasingly around the world in colorectal cancer screening programmes, and in patients presenting with lower bowel symptoms to determine who should proceed to further bowel visualisation investigations, usually colonoscopy. The clinical utility of FIT is well reported. There are a number of analytical challenges including pre-analytical variation, difficulty setting up external quality assessment schemes, access to third party internal quality control material and a lack of standardisation or harmonisation of FIT methods. Here we report the work of the International Federation of Clinical Chemistry FIT Working Group. We provide an overview of the main pre-analytical variables; discuss different approaches to external quality assurance of FIT; propose a solution to third party internal quality assurance materials and summarise the challenges of standardisation and harmonisation of FIT.

• MeSH
• časná detekce nádoru MeSH
• feces chemie   MeSH
• hemoglobiny analýza   MeSH
• kolonoskopie MeSH
• kolorektální nádory * diagnóza   MeSH
• lidé MeSH
• okultní krev * MeSH
• plošný screening MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Úvod: Cílem studie bylo porovnat koncentraci lepku ve stolici pomocí měření z lepku odvozených imunogenních peptidů (GIP – gluten-related immunogenic peptides) s koncentrací protilátek proti tkáňové transglutamináze ve třídě IgA (anti-tTG IgA) v krvi u dětí s nově diagnostikovanou celiakií. Metody: Studie se zúčastnily děti, kterým byla na našem pracovišti diagnostikována od května 2018 do května 2020 celiakie a splnily podmínky studie. Při stanovení diagnózy jsme kromě anti-tTG IgA v krvi změřili GIP ve stolici. Tato vyšetření jsme zopakovali i při následné klinické kontrole. Obě metody – stanovení protilátek anti-tTG IgA v krvi i GIP ve stolici pomocí protilátky G12 – byly hodnoceny pomocí ELISA testu. Hodnoty jsme porovnali co do vztahu k příslušným horním hranicím normy. Výsledky: Studie se zúčastnilo 29 dětí (18 dívek) ve věku 2–15 let. U všech byly vstupní hodnoty GIP nad normu 0,15 μg/g (průměr 4,21; medián 3,29; standardní odchylka [SD] 3,7). Při kontrolním vyšetření (průměrně 4 měsíce od zahájení diety) byly koncentrace GIP u všech dětí až na tři (10,3 %) pod normu (průměr 0,29; medián 0,12; SD 0,73). V případě anti-tTG IgA byla jejich hodnota před zahájením diety průměrně 164 U/ml, s mediánem 195, SD 49, při horní hranici normy 9,9 U/ml. Při kontrolním odběru byly hodnoty anti-tTG IgA u všech dětí až na jedno nižší, ale pouze u deseti z nich (34,5 %) byly hodnoty v normě (průměr 27,9; medián 12,0; SD 38,9). Všechny děti deklarovaly striktní dodržování bezlepkové diety. Diskuze: Podle hodnocení koncentrace GIP ve stolici je adherence dětí s nově diagnostikovanou celiakií k bezlepkové dietě velmi dobrá, lepší než běžně literárně udávaná. Závěr: Hodnocení GIP ve stolici může být citlivějším ukazatelem dodržování bezlepkové diety zejména v prvních měsících od stanovaní diagnózy než anti-tTG IgA, u kterých je popsán výrazně pomalejší pokles do normy po zahájení bezlepkové diety.

Objectives and study: To compare the values of gluten-related immunogenic peptides (GIP) in stool and anti-tissue transglutaminase IgA antibodies (anti-tTG IgA) in blood in children newly diagnosed with coeliac disease (CD). Methods: All children (2–15 y) newly diagnosed with CD between May 2018 and May 2020 at our clinic who complied with the inclusion criteria were invited to join the prospective study. During workup for CD, a stool sample to measure GIP was taken together with a blood sample to measure anti-tTG IgA. All newly diagnosed children were invited 4 months later for a check-up. Children and their caregivers were asked about known non-compliance with the gluten-free diet (GFD), a blood sample was taken to measure the anti-tTG IgA, and a stool sample was collected to measure GIP. Blood was evaluated for anti-tTG IgA by ELISA, and the stool was tested by quantitative Sandwich ELISA designed to detect and quantify GIP using the G12 antibody. Values of GIP and anti-tTG IgA were compared in terms of their relation to the upper limit of normal (ULN) of the particular method. Results: 29 children (18 girls) were enrolled in the study. The values of GIP in stool at the time of diagnosis were above the ULN (0.15 μg/g) in all children. Average 4.21, median 3.29, standard deviation (SD) 3.7. After the four months, all but three (89.7%) had values of GIP in the reference range. Average 0.29, median 0.12, SD 0.73. Similarly, anti-tTG IgA values were above the ULN (9.9 U/mL) at the time of diagnosis in all children. Average 164, median 195, SD 49. Although the anti-tTG IgA levels were lower at check-up in all but one child, only 10 (34.5%) showed values within the normal range, with an average of 27.9, median 12.0, and SD 38.9. All children declared strict adherence to GFD. Discussion: Using the GIP concentration in stool, adherence to GFD in our cohort of children is very good, better than that described in literature. Conclusion: Measuring GIP in stool could prove a more sensitive indicator of adherence to GFD in the early months after the diagnosis of CD when anti-tTG IgA are still elevated above the ULN due to their well-described gradual decrease after GFD initiation.

• MeSH
• adherence a compliance při léčbě * MeSH
• celiakie * dietoterapie   MeSH
• dítě MeSH
• feces chemie   MeSH
• gluteny analýza   MeSH
• klinická studie jako téma MeSH
• lidé MeSH
• mladiství MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH

Based on the assumption that dietary and faecal nitrogen correlate, the number of studies using faecal samples collected in the wild to understand diet selection by wild herbivores and other ecological patterns has been growing during the last years, especially due to the recent development of cheap tools for analysis of nutrients like Near-Infrared Reflectance Spectroscopy (NIRS). Within the annual reproductive cycle, cervids (members of the family Cervidae) face strong seasonal variations in nutritional demands, different for hinds (gestation and lactation) and stags (antler growth) and reflected in differential patterns of seasonal diet selection. In this study we aimed to quantify how pasture availability, season and individual factors like sex, age, reproductive status, body mass and body condition affect faecal nutrients in captive red deer with the goal of understanding how these factors may influence the interpretation of results from samples obtained in the wild with little or no information about the animals who dropped those faeces. We used NIRS for analysing nitrogen, neutral and acid detergent fibres in faeces. The relative influence of some individual factors like pregnancy was low (around 4%), while age and weight may induce a variability up to 18%. The presence or absence of pasture contributed to a variability around 13%, while the season contributed to an average variability around 17% (and up to 21% in certain situations). This high variability in faecal nutrients was observed in a controlled setting with captive animals and controlled diets. Thus, in natural situations we suspect that there would be even greater variation. According to the results, we recommend that preliminary research with captive animals of the species of interest should be conducted before collecting samples in the wild, which should help in the interpretation of results.

• MeSH
• feces chemie   MeSH
• fyziologie výživy zvířat * MeSH
• věkové faktory MeSH
• vysoká zvěř * MeSH
• živiny analýza   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Španělsko MeSH

The acquisition of the infant gut microbiota is key to establishing a host-microbiota symbiosis. Microbially produced metabolites tightly interact with the immune system, and the fermentation-derived short-chain fatty acid butyrate is considered an important mediator linked to chronic diseases later in life. The intestinal butyrate-forming bacterial population is taxonomically and functionally diverse and includes endospore formers with high transmission potential. Succession, and contribution of butyrate-producing taxa during infant gut microbiota development have been little investigated. We determined the abundance of major butyrate-forming groups and fermentation metabolites in faeces, isolated, cultivated and characterized the heat-resistant cell population, which included endospores, and compared butyrate formation efficiency of representative taxa in batch cultures. The endospore community contributed about 0.001% to total cells, and was mainly composed of the pioneer butyrate-producing Clostridium sensu stricto. We observed an increase in abundance of Faecalibacterium prausnitzii, butyrate-producing Lachnospiraceae and faecal butyrate levels with age that is likely explained by higher butyrate production capacity of contributing taxa compared with Clostridium sensu stricto. Our data suggest that a successional arrangement and an overall increase in abundance of butyrate forming populations occur during the first year of life, which is associated with an increase of intestinal butyrate formation capacity.

• MeSH
• Bacteria klasifikace   genetika   izolace a purifikace   metabolismus   MeSH
• butyráty metabolismus   MeSH
• feces chemie   mikrobiologie   MeSH
• fermentace MeSH
• kojenec MeSH
• kyseliny mastné těkavé metabolismus   MeSH
• lidé MeSH
• spory bakteriální klasifikace   genetika   izolace a purifikace   metabolismus   MeSH
• střeva růst a vývoj   mikrobiologie   MeSH
• střevní mikroflóra fyziologie   MeSH
• Check Tag
• kojenec MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH