Fecal Extracts Research Articles

Metabolite quantification of faecal extracts from colorectal cancer patients and healthy controls.

Colorectal cancer (CRC), a primary cause of morbidity and mortality worldwide is expected to rise in the coming years. A better understanding of the metabolic changes taking place during the disease progression is needed for effective improvements of screening strategies and treatments. In the present study, Nuclear Magnetic Resonance (NMR) metabolomics was used to quantify the absolute concentrations of metabolites in faecal extracts from two cohorts of CRC patients and healthy controls. The quantification of over 80 compounds revealed that patients with CRC had increased faecal concentrations of branched chain fatty acids (BCFA), isovalerate and isobutyrate plus valerate and phenylacetate but diminished concentrations of amino acids, sugars, methanol and bile acids (deoxycholate, lithodeoxycholate and cholate). These results suggest that alterations in microbial activity and composition could have triggered an increase in utilisation of host intestinal slough cells and mucins and led to an increase in BCFA, valerate and phenylacetate. Concurrently, a general reduction in the microbial metabolic function may have led to reduced levels of other components (amino acids, sugars and bile acids) normally produced under healthy conditions. This study provides a thorough listing of the most abundant compounds found in human faecal waters and presents a template for absolute quantification of metabolites. The production of BCFA and phenylacetate in colonic carcinogenesis warrants further investigations.

Identification of Glutamic Acid as a Host Marking Pheromone of the African Fruit Fly Species Ceratitis rosa (Diptera: Tephritidae).

Host marking pheromones (HMPs) deposited by female fruit flies deter other females from overexploiting the same fruit for egg laying. Using a bioassay-guided approach, we identified the HMP of the Natal fruit fly species Ceratitis rosa as glutamic acid, 1, from the aqueous fecal matter extract of ovipositing females by liquid chromatography-quadrupole time-of-flight-mass spectrometry (LC-QTOF-MS). Dual choice oviposition assays showed that both the fecal matter extract and 1 significantly reduced oviposition responses in conspecific females of C. rosa. Glutamic acid levels were 10-20 times higher in fecal matter than in the ovipositor or hemolymph extracts of females. Identification of 1 as a host marking pheromone in females of C. rosa improves our understanding of fruit fly chemical ecology and provides evidence that it could be used as a potential component in the integrated management of this fruit fly species.

Intestinal Metabolism and Bioaccumulation of Sucralose In Adipose Tissue In The Rat

ABSTRACTThe aim of this study was to (1) determine if the organochlorine artificial sweetener sucralose is metabolized in rat intestine with repeated dosing and (2) examine whether sucralose might bioaccumulate in rat adipose tissue. Sucralose was administered to 10 rats by gavage daily for 40 days at an average dosage of 80.4 mg/kg/day. The dosages were within the range utilized in historical toxicology studies submitted for regulatory approval in North America, Europe, and Asia. Feces and urine were collected individually from each animal for every 24-hr period during the 40-day dosing period. Analysis of the urine and fecal extracts by ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC–MS/MS) revealed two new biotransformation products that have not previously been reported. These two metabolites are both acetylated forms of sucralose that are less polar and hence more lipophilic than sucralose itself. These metabolites were present in urine and feces throughout the sucralose dosing period and still detected at low levels in the urine 11 days after discontinuation of sucralose administration and 6 days after sucralose was no longer detected in the urine or feces. The finding of acetylated sucralose metabolites in urine and feces do not support early metabolism studies, on which regulatory approval was based, that claimed ingested sucralose is excreted unchanged (i.e. not metabolized). The historical metabolic studies apparently failed to detect these metabolites in part because investigators used a methanol fraction from feces for analysis along with thin layer chromatography and a low-resolution linear radioactivity analyzer. Further, sucralose was found in adipose tissue in rats two weeks after cessation of the 40-day feeding period even though this compound had disappeared from the urine and feces. Thus, depuration of sucralose which accumulated in fatty tissue requires an extended period of time after discontinuation of chemical ingestion. These new findings of metabolism of sucralose in the gastrointestinal tract (GIT) and its accumulation in adipose tissue were not part of the original regulatory decision process for this agent and indicate that it now may be time to revisit the safety and regulatory status of this organochlorine artificial sweetener

NMR-based metabolic profiling of urine, serum, fecal, and pancreatic tissue samples from the Ptf1a-Cre; LSL-KrasG12D transgenic mouse model of pancreatic cancer.

Pancreatic cancer is the third leading cause of cancer deaths in the United States with more than 53,000 expected to be diagnosed with the disease in 2018. The median survival time after diagnosis is four to six months. The poor survival statistics are due in part to the fact that pancreatic cancer is typically asymptomatic until it reaches advanced stages of the disease. Although surgical resection provides the best chance of survival, pancreatic cancer is rarely detected when surgery is still possible due, in part, to lack of effective biomarkers for early detection. The goal of the research reported here was to determine if it was possible to identify metabolic biomarkers for detection of pre-cancerous pancreatic intraepithelial neoplasia (PanIN) that precede pancreatic adenocarcinoma. The transgenic Ptf1a-Cre; LSL-KrasG12D mouse strain was used as a model of pancreatic cancer progression. Nuclear magnetic resonance (NMR) spectroscopy was employed to compare metabolic profiles of urine, sera, fecal extracts, and pancreatic tissue extracts collected from control and study mice aged 5, 11, and 15 months, including 47 mice with tumors. We were able to identify the following potential biomarkers: decreased 3-indoxylsulfate, benzoate and citrate in urine, decreased glucose, choline, and lactate in blood, and decreased phenylalanine and benzoate and increased acetoin in fecal extracts. Potential biomarkers were validated by p-values, PLS-DA VIP scores, and accuracies based on area under ROC curve analyses. Essentially, all of the metabolic profiling changes could be explained as being associated with the consequences of bicarbonate wasting caused by a complete substitution of the normal pancreatic acinar tissue by tissue entirely composed of PanIN. Given the nature of the mouse model used here, our results indicate that it may be possible to use NMR-based metabolic profiling to identify biomarkers for detection of precancerous PanIN that immediately precede pancreatic cancer.

Tissue localization of aggregation pheromones in the American cockroach, Periplaneta americana (Blattodea: Blattidae)

The American cockroach, Periplaneta americana, excretes feces containing aggregation pheromones to attract conspecific individuals. It is thought that these pheromones play an important role in establishing and maintaining colonies. However, despite previous extensive efforts, the aggregation pheromones of P. americana have not been isolated. It is also unclear whether the aggregation pheromones of P. americana are truly biosynthesized by the insect, as most previous experiments extracted chemicals from feces. Here, we investigate the tissue localization of aggregation agents in P. americana. To reduce the effects of diet-derived odorants, we developed a new diet for P. americana consisting of only agar and sugars, and tested the attractiveness of fecal extracts from animals reared on this new diet. Our results show that the aggregation agents of fecal extracts are insect-derived, and the extracts from the midgut evoke stronger behavioral responses than those from other parts of the alimentary tract. This suggests that the midgut may be the production site or the storage organ of the aggregation agents. Thus, our data will facilitate the future identification of the aggregation pheromones of P. americana.

PO-517 Protein profiling in colorectal cancer: from biological mapping to functional validation

IntroductionColorectal cancer (CRC) is one of the most prevalent malignancies and contributes to significant cancer-related deaths worldwide. Despite commonly asymptomatic with 5 year survival rate of 90% at the early stage of disease, extremely low survival rate was reported for late stage diagnosis with metastasis. Therefore, there is an immense urgency for reliable biomarkers to aid in the early diagnosis of CRC and to assist in prognostic stratification. Interrogation on the serum proteome and site-specific secretome may provide an accurate mapping of the circulating and secreted proteins, respectively. Thus, we aim to identify potential protein markers present in human serum, faecal extracts and CRC cells, and to determine its role in CRC.Material and methodsQuantitative proteomics was performed using SWATH-MS analysis on human serum and faecal extracts representing 4 stages of CRC and healthy control. Immuno Blot was conducted to confirm the expression of target proteins in the cell line model for cell manipulation study. Transduction of lentiviral fully sequenced human open reading frames (ORFs) construct into HT29 was carried out with 25 µg/ml Blasticidin S selection for exogenous gene overexpression study. Cell-based assays were performed to evaluate the functional activities and RqPCR for determining the signalling pathway activity.Results and discussionsWe have identified significant upregulation of LRG1 in the sera of CRC patients, particularly in the advanced stage of cancer. The endogenous expression of LRG1 in the CRC cells increased with the advancing stage. Overexpression of LRG1 in HT29 increased cell proliferation by activation of Ki67 mRNA (p<0.01) and cell migration via ZEB1 (p<0.05). The level of TGF-β mRNA was also increased with overexpression of LRG1 (p<0.05).ConclusionIn conclusion, LRG1 is a promising marker for CRC and its overexpression may pose higher risk of metastasis via collective proliferation, migration and invasion possibly through the regulation of TGF-β pathway.

Non-invasive intestinal biomarkers: a new ELISA test for Pancreatitis Associated Protein detection in pig

Feed additives are commonly used to improve pig performance and health, but they need to be tested so new biomarkers for intestinal health, non- or minimally invasive, are under investigations.The quantification of Myeloperoxidase (MPO) and Pancreatitis Associated Protein (PAP) in feces could prove useful to non-invasively monitor intestinal health (Niewold, 2015). MPO is an enzyme that permits to quantify the number of inflammatory cells present in tissues and feces (Prokopowicz et al., 2012) , while PAP is a protein mainly produced in the small intestine with anti-inflammatory and bactericidal activity (Cash et al., 2006; Mukherjee et al., 2014). Because of the lack of a commercial ELISA kit for porcine PAP detection, the main aim of this study was to develop and validate a new sandwich ELISA test for the quantification of PAP in pig fecal samples. Our study consisted of two phases: test development and test validation. During the development phase we used polyclonal antibodies previously immunized from rabbit serum with a pure peptide containing the N-terminus of pig PAP (Soler et al., 2015). The validation of the test was then performed with fecal extraction samples derived from animals with known high or low growth performance.Moreover, the temperature stability of PAP in feces and the optimal extraction method was tested. Even if only preliminary, our results seem to show a fair relationship between fecal consistency, used as health indicator, and PAP fecal concentrations. Furthermore, no relevant differences in PAP concentration after 24h of incubation at 37 °C, 4°C or room temperature were detected.To date, the present results suggest that PAP seems to be exceptionally stable in feces and is a very promising candidate as a non-invasive (fecal) biomarker for intestinal health and growth.

HMGB1 released from intestinal epithelia damaged by cholera toxin adjuvant contributes to activation of mucosal dendritic cells and induction of intestinal cytotoxic T lymphocytes and IgA

Cholera toxin (CT) is a potent mucosal adjuvant and oral administration of ovalbumin (OVA) antigens plus CT induces OVA-specific CD8+ cytotoxic T lymphocytes (CTLs) and IgA production in intestinal mucosa. However, the mechanisms of induction of these immune responses remain unknown. Intestinal OVA-specific CD8+ CTLs were not induced by oral administration of the CT active (CTA) or CT binding (CTB) subunit as an adjuvant and CD11c+ DCs were involved in cross-priming of intestinal CTLs. CD8+CD103+CD11c+CD11b−DCs and DCIR2+CD103+CD11c+CD11b+ DCs were distributed in the intestinal lamina propria and mesenteric lymph nodes, both DC subsets expressed DEC-205, and the expression of co-stimulatory molecules such as CD80 and CD86 was enhanced in both DC subsets after oral administration of intact CT but not the CTA or CTB subunit. Intestinal DCs activated by the oral administration of OVA plus CT cross-presented OVA antigens and DCs that captured OVA antigen through DEC-205, but not DCIR2, could cross-present antigen. We found that oral administration of intact CT, but not the CTA or CTB subunit, enhanced cell death, cytoplasmic expression of high-mobility group box 1 protein (HMGB1) in epithelial cell adhesion molecule (EpCAM)+CD45− intestinal epithelial cells (IECs), and HMGB1 levels in fecal extracts. HMGB1 dose-dependently enhanced the expression of CD80 and CD86 on DCs in vitro, and intravenous or oral administration of glycyrrhizin, an HMGB1 inhibitor, significantly suppressed activation of mucosal DCs and induction of intestinal OVA-specific CTLs and IgA by oral CT administration. These results showed that oral administration of intact CT triggers epithelial cell death in the gut and the release of HMGB1 from damaged IECs, and that the released HMGB1 may mediate activation of mucosal DCs and induction of CTLs and IgA in the intestine.

Enterically Transmitted Non-A, Non-B Hepatitis and the Discovery of Hepatitis E Virus.

The recognition of hepatitis E as a discreet disease entity in the late 1970s followed the development of serological tests for hepatitis A and the discovery that large waterborne outbreaks of hepatitis in India were not caused by hepatitis A virus (HAV). These "enterically transmitted non-A, non-B hepatitis" outbreaks had distinctive epidemiologic features, including the highest attack rates among young adults, little secondary household transmission of infection, and severe disease in pregnant women. The responsible agent, hepatitis E virus (HEV), was identified several years later in extracts of feces from a self-inoculated virologist. Multiple genetically related HEV genotypes are now known to exist, two of which are common in domestic swine herds and the cause of sporadic cases of acute hepatitis in economically well-developed countries. HEV genotypes possess impressive genetic and biologic diversity, and present many unanswered questions concerning their natural host range, potential for zoonotic transmission, and disease pathogenesis.

The pharmacokinetics and metabolism of diclofenac in chimeric humanized and murinized FRG mice.

The pharmacokinetics of diclofenac were investigated following single oral doses of 10mg/kg to chimeric liver humanized and murinized FRG and C57BL/6 mice. In addition, the metabolism and excretion were investigated in chimeric liver humanized and murinized FRG mice. Diclofenac reached maximum blood concentrations of 2.43 ± 0.9µg/mL (n = 3) at 0.25h post-dose with an AUCinf of 3.67µgh/mL and an effective half-life of 0.86h (n = 2). In the murinized animals, maximum blood concentrations were determined as 3.86 ± 2.31µg/mL at 0.25h post-dose with an AUCinf of 4.94 ± 2.93µg h/mL and a half-life of 0.52 ± 0.03h (n = 3). In C57BL/6J mice, mean peak blood concentrations of 2.31 ± 0.53µg/mL were seen 0.25h post-dose with a mean AUCinf of 2.10 ± 0.49µgh/mL and a half-life of 0.51 ± 0.49h (n = 3). Analysis of blood indicated only trace quantities of drug-related material in chimeric humanized and murinized FRG mice. Metabolic profiling of urine, bile and faecal extracts revealed a complex pattern of metabolites for both humanized and murinized animals with, in addition to unchanged parent drug, a variety of hydroxylated and conjugated metabolites detected. The profiles in humanized mice were different to those of both murinized and wild-type animals, e.g., a higher proportion of the dose was detected in the form of acyl glucuronide metabolites and much reduced amounts as taurine conjugates. Comparison of the metabolic profiles obtained from the present study with previously published data from C57BL/6J mice and humans revealed a greater, though not complete, match between chimeric humanized mice and humans, such that the liver humanized FRG model may represent a model for assessing the biotransformation of such compounds in humans.

Co-delivery of mucosa-associated epithelial chemokine (MEC/CCL28) enhances anti-HIV-1 mucosal responses through CCR10 in the context of DNA vaccination

Abstract Mucosal antibody plays a vital role in protection against HIV transmission. Mucosa-associated epithelial chemokine (CCL28) is secreted by mucosal epithelial cells following commensal colonization, and binds CC-chemokine receptor 10 (CCR10), expressed on IgA+ plasma cells. Deletion of CCR10 impairs mucosal IgA production and memory responses. Thus, the CCL28/CCR10 axis is critical for regulating mucosal IgA production and memory immunity. Mice were vaccinated twice with consensus HIV-1 gp160 DNA alone (antigen-only), or antigen and plasmid-encoded CCL28 (pCCL28) via intramuscular injection and in vivo electroporation (EP). pCCL28 increased antigen-specific IgA in fecal extracts (average 36.7ng/ml IgA in the antigen only group compared with 90.9ng/ml in the pCCL28 group). The intestinal compartment from animals co-immunized with pCCL28 harbored a higher frequency of HIV-specific, IgA+ B cells compared to the antigen-alone group (13.1% compared to 5.7%, respectively), and these cells expressed significantly-higher levels of CCR10 than those from mice in the non-adjuvanted group (MFI 413 compared to 181, respectively). Colonization with commensals induces CCL28 secretion by intestinal epithelial cells. Indeed, In vitro experiments with human colonic epithelial cell lines indicate that these organisms increased expression of CCL28 at the transcript and protein level. These studies suggest that electroporated delivery of the mucosal chemokine CCL28, can enhance antigen-specific anti-HIV immunity in the mucosa. Ongoing studies will determine if supplementation of commensal flora during vaccination can enhance CCL28 secretion in vivo and promote retention of vaccine-induced IgA+ B cells at mucosal surfaces.

Methodology challenges in studying human gut microbiota \u2013 effects of collection, storage, DNA extraction and next generation sequencing technologies

The information on microbiota composition in the human gastrointestinal tract predominantly originates from the analyses of human faeces by application of next generation sequencing (NGS). However, the detected composition of the faecal bacterial community can be affected by various factors including experimental design and procedures. This study evaluated the performance of different protocols for collection and storage of faecal samples (native and OMNIgene.GUT system) and bacterial DNA extraction (MP Biomedicals, QIAGEN and MO BIO kits), using two NGS platforms for 16S rRNA gene sequencing (Ilumina MiSeq and Ion Torrent PGM). OMNIgene.GUT proved as a reliable and convenient system for collection and storage of faecal samples although favouring Sutterella genus. MP provided superior DNA yield and quality, MO BIO depleted Gram positive organisms while using QIAGEN with OMNIgene.GUT resulted in greatest variability compared to other two kits. MiSeq and IT platforms in their supplier recommended setups provided comparable reproducibility of donor faecal microbiota. The differences included higher diversity observed with MiSeq and increased capacity of MiSeq to detect Akkermansia muciniphila, [Odoribacteraceae], Erysipelotrichaceae and Ruminococcaceae (primarily Faecalibacterium prausnitzii). The results of our study could assist the investigators using NGS technologies to make informed decisions on appropriate tools for their experimental pipelines.

Development and Validation of an Enzyme Immunoassay for Fecal Dehydroepiandrosterone Sulfate in Japanese Macaques (Macaca fuscata)

Measuring hormonal profiles is important in monitoring stress, physical fitness, and reproductive status in primates. Noninvasive methods have been used to measure several steroid hormones in primates without causing them stress. However, few studies have used feces or urine to measure dehydroepiandrosterone sulfate (DHEAS), an important precursor of sex steroids that has been studied as a biomarker of aging, pregnancy, and stress in humans and nonhuman primates. We developed an enzyme immunoassay to detect DHEAS in the feces of Japanese macaques (Macaca fuscata). Our subjects included eight singly housed Japanese macaques. To validate the assay, we administrated oral DHEA to one male and one female macaque, collected their feces, and measured DHEAS levels over time. Given that DHEAS is related to gonadal steroids and the stress response, we also measured DHEAS concentrations in response to adrenal (adrenocorticotropic hormone [ACTH]) and gonadal (human chorionic gonadotropin [hCG]) stimulation. Our assay successfully detected DHEAS in Japanese macaque feces, and levels of DHEAS were associated with the amount of DHEA ingested. Parallelism and accuracy tests revealed that fecal extracts were reliable measures of DHEAS. Neither ACTH nor hCG challenge appeared to affect DHEAS levels. The method we describe is less expensive than that using the commercially available kits and is applicable to investigations involving aging, stress, and reproduction in Japanese macaques.

Inulin-type fructan improves diabetic phenotype and gut microbiota profiles inrats.

Background & AimsAccumulating research has addressed the linkage between the changes to gut microbiota structure and type 2 diabetes (T2D). Inulin is one type of soluble dietary fiber that can alleviate T2D. As a prebiotic, inulin cannot be digested by humans, but rather is digested by probiotics. However, whether inulin treatment can benefit the entire gut bacteria community remains unknown. In this study, we evaluated the differences in gut microbiota composition among diabetic, inulin-treated diabetic, normal control, and inulin-treated normal control rats.MethodsA diabetic rat model was generated by a high-fat diet and streptozotocin injections (HF/STZ). Inulin was orally administered to normal and diabetic rats. To determine the composition of the gut microbiota, fecal DNA extraction and 16S rRNA gene 454 pyrosequencing were performed.ResultsWe found that inulin treatment reduced fasting blood glucose levels and alleviated glucose intolerance and blood lipid panels in diabetic rats. Additionally, inulin treatment increased the serum glucagon-like peptide-1 (GLP-1) level, reduced serum IL-6 level, Il6 expression in epididymal adipose tissue, and Pepck, G6pc expression in liver of diabetic rats. Pyrophosphate sequencing of the 16s V3–V4 region demonstrated an elevated proportion of Firmicutes and a reduced abundance of Bacteroidetes at the phylogenetic level in diabetic rats compared to normal control rats. The characteristics of the gut microbiota in control and inulin-treated rats were similar. Inulin treatment can normalize the composition of the gut microbiota in diabetic rats. At the family and genus levels, probiotic bacteria Lactobacillus and short-chain fatty acid (SCFA)-producing bacteria Lachnospiraceae, Phascolarctobacterium, and Bacteroides were found to be significantly more abundant in the inulin-treated diabetic group than in the non-treated diabetic group. In addition, inulin-treated rats had a lower abundance of Desulfovibrio, which produce lipopolysaccharide (LPS). The abundance of Lachnospiraceae was negatively correlated with the blood glucose response after a glucose load.ConclusionIn summary, diabetic rats have different gut microbiota from control rats. Inulin treatment can alleviate gut microbiota dysbiosis in T2D model rats. Moreover, inulin treatment enhanced serum GLP-1 level to suppress IL-6 secretion and production and hepatic gluconeogenesis, resulted in moderation of insulin tolerance.

Assessing bat droppings and predatory bird pellets for vector-borne bacteria: molecular evidence of bat-associated Neorickettsia sp. in Europe.

In Europe, several species of bats, owls and kestrels exemplify highly urbanised, flying vertebrates, which may get close to humans or domestic animals. Bat droppings and bird pellets may have epidemiological, as well as diagnostic significance from the point of view of pathogens. In this work 221 bat faecal and 118 bird pellet samples were screened for a broad range of vector-borne bacteria using PCR-based methods. Rickettsia DNA was detected in 13 bat faecal DNA extracts, including the sequence of a rickettsial insect endosymbiont, a novel Rickettsia genotype and Rickettsia helvetica. Faecal samples of the pond bat (Myotis dasycneme) were positive for a Neorickettsia sp. and for haemoplasmas of the haemofelis group. In addition, two bird pellets (collected from a Long-eared Owl, Asio otus, and from a Common Kestrel, Falco tinnunculus) contained the DNA of a Rickettsia sp. and Anaplasma phagocytophilum, respectively. In both of these bird pellets the bones of Microtus arvalis were identified. All samples were negative for Borrelia burgdorferi s.l., Francisella tularensis, Coxiella burnetii and Chlamydiales. In conclusion, bats were shown to pass rickettsia and haemoplasma DNA in their faeces. Molecular evidence is provided for the presence of Neorickettsia sp. in bat faeces in Europe. In the evaluated regions bat faeces and owl/kestrel pellets do not appear to pose epidemiological risk from the point of view of F. tularensis, C. burnetii and Chlamydiales. Testing of bird pellets may provide an alternative approach to trapping for assessing the local occurrence of vector-borne bacteria in small mammals.

Common bed bugs can biosynthesize pheromone components from amino acid precursors in human blood

We have recently shown that the aggregation pheromone of the common bed bug, Cimex lectularius, comprises a six-component blend of dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), (E)-2-hexenal, (E)-2-octenal, 2-hexanone, and histamine. Here, we tested the hypothesis that bed bugs biosynthesize some pheromone components from amino acid precursors in human blood, namely DMDS and DMTS from L-methionine and histamine from histidine. We tested this hypothesis by (i) allowing bed bugs to feed on and metabolize sheep blood enriched with13C-labelled histidine or2H-labelled methionine, (ii) extracting bed bug feces (a source of the aggregation pheromone), and (iii) analyzing feces extracts by GC-MS, HPLC-MS and NMR spectroscopy. The analyses revealed that bed bugs converted2H-methionine to2H-DMDS and2H-DMTS, and13C-histidine to13C-histamine. There is not enough histidine in human blood to account for the amount of histamine that bed bugs produce and excrete with their feces, and only a small proportion of the available13C-histidine was converted to13C-histamine in our study. Therefore, it is likely that bed bugs biosynthesize histamine, and possibly also DMDS and DMTS, primarily de novo.

Faecal Extracts Biomarkers in IBD Patients: Is It Useful?

Faecal Extracts Biomarkers in IBD Patients: Is It Useful?

Preanalytical validation of an in-house radioimmunoassay for measuring calprotectin in feline specimens.

Calprotectin is a marker of inflammatory disorders in people, and serum and fecal calprotectin were shown to be increased in dogs with gastrointestinal inflammation. Biomarkers of gastrointestinal inflammation are currently lacking in cats. The purpose of the study was to analytically validate the canine calprotectin radioimmunoassay for quantification of calprotectin in feline specimens. The immunoassay was analytically validated by determining assay working range, dilutional parallelism, spiking recovery, and intra- and inter-assay variability. Reference intervals for fecal calprotectin were established from healthy cats, and the influence of age, sex, and housing condition on fecal calprotectin was determined. The working range of the assay was 1.5-346.2μg/g of feces and 11.2-8654.4μg/L of serum. Observed-to-expected ratios (O/E) for serial dilutions of fecal extracts ranged from 77.3% to 112.0% (mean: 99.2%) and from 95.7% to 161.4% (mean: 118.5%) for spiking recovery. Intra- and inter-assay coefficients of variation for fecal samples were ≤11.0% and ≤12.8%, respectively. Fecal calprotectin concentrations ranged 1.5-66.5μg/g (3-day sample mean) and 1.5-126.1μg/g (3-day sample maximum). Housing conditions, sex, or age did not affect fecal calprotectin (all P>.05). For serial dilutions of serum samples, O/E ranged from 96.0% to 152.0% (mean: 115.7%). Serum calprotectin concentrations in healthy cats ranged from 108.8 to 255.3μg/L (median: 158.2μg/L). The canine radioimmunoassay for the measurement of calprotectin is analytically sensitive, linear, reproducible, accurate, and sufficiently precise (CVA ≤43.2%) for use with feline feces (with a loss of accuracy at high calprotectin concentrations). The RIs for feline fecal calprotectin are comparable to those established for dogs. Independence of fecal calprotectin from age and sex agrees with findings in dogs.

CCL28-Deficient Mice Have Reduced IgA Antibody-Secreting Cells and an Altered Microbiota in the Colon.

CCL28 induces the migration of IgA Ab-secreting cells (ASCs) via CCR10 and also displays a potent antimicrobial activity in vitro. To explore the role of CCL28 in vivo, we generated CCL28-deficient mice. The mice exhibited a significant reduction and abnormal distribution of IgA ASCs in the lamina propria of the colon. The concentrations of total and Ag-specific IgA in the fecal extracts of CCL28-deficient mice were also drastically reduced. The average amount of IgA secreted by a single IgA ASC derived from the colon was also substantially reduced in CCL28-deficient mice. Furthermore, CCL28 was found to significantly increase the average amount of IgA secreted by a single IgA ASC derived from the colon in vitro. In contrast, the generation of IgA ASCs in Peyer's and cecal patches was not significantly impaired in CCL28-deficient mice. We also found a relative increase in the Class Bacilli in the fecal extracts of CCL28-deficient mice and demonstrated a potent antimicrobial activity of CCL28 against Bacillus cereus and Enterococcus faecalis, both of which belong to Class Bacilli. Thus, CCL28 may also suppress the outgrowth of some bacterial species by its direct antimicrobial activity. Finally, CCL28-deficient mice exhibited a highly aggravated dextran sodium sulfate-induced colitis that was ameliorated by pretreatment with antibiotics. Collectively, CCL28 plays a pivotal role in the homing, distribution, and function of IgA ASCs in the colon and may also affect the intestinal microbiota through its direct antimicrobial activity.

Evaluating Protocols for Porcine Faecal Microbiome Recollection, Storage and DNA Extraction: from the Farm to the Lab.

There is a growing interest in understanding the role of the gut microbiome on productive and meat quality-related traits in livestock species in order to develop new useful tools for improving pig production systems and industry. Faecal samples are analysed as a proxy of gut microbiota and here the selection of suitable protocols for faecal sampling and DNA isolation is a critical first step in order to obtain reliable results, even more to compare results obtained from different studies. The aim of the current study was to establish in a cost-effective way, using automated ribosomal intergenic spacer analysis technique, a protocol for porcine faecal sampling and storage at farm and slaughterhouse and to determine the most efficient microbiota DNA isolation kit among those most widely used. Operational Taxonomic Unit profiles were compared from Iberian pig faecal samples collected from rectum or ground, stored with liquid N2, room temperature or RNAlater, and processed with QIAamp DNA Stool (Qiagen), PowerFecal DNA Isolation (Mobio) or SpeedTools Tissue DNA extraction (Biotools) commercial kits. The results, focused on prokaryote sampling, based on DNA yield and quality, OTU number and Sørensen similarity Indexes, indicate that the recommended protocol for porcine faecal microbiome sampling at farm should include: the collection from porcine rectum to avoid contamination; the storage in liquid N2 or even at room temperature, but not in RNAlater; and the isolation of microbiota DNA using PowerFecal DNA Isolation kit. These conditions provide more reliable DNA samples for further microbiome analysis.