Characterization of microbial communities from rumen and large intestine of lactating creole goats grazing in arid plant communities.

Arid plant communities provide variable diets that can affect digestive microbial communities of free-foraging ruminants. Thus, we used next-generation sequencing of 16S and 18S rDNA to characterize microbial communities in the rumen (regurgitated digesta) and large intestine (faeces) and diet composition of lactating creole goats from five flocks grazing in native plant communities in the Sonoran Desert in the rainy season. The bacterial communities in the rumen and large intestine of the five flocks had similar alpha diversity (Chao1, Shannon, and Simpson indices). However, bacterial community compositions were different: a bacterial community dominated by Proteobacteria in the rumen transitioned to a community dominated by Firmicutes in the large intestine. Bacterial communities of rumen were similar across flocks; similarly occurred with large-intestine communities. Archaea had a minimum presence in the goat digestive tract. We detected phylum Basidiomycota, Ascomycota, and Apicomplexa as the main fungi and protozoa. Analyses suggested different diet compositions; forbs and grasses composed the bulk of plants in the rumen and forbs and shrubs in faeces. Therefore, lactating goats consuming different diets in the Sonoran Desert in the rainy season share a similar core bacterial community in the rumen and another in the large intestine and present low archaeal communities.

Effects of differing withdrawal times from ractopamine hydrochloride on residue concentrations of beef muscle, adipose tissue, rendered tallow, and large intestine.

Ractopamine hydrochloride (RAC) is a beta-agonist approved by the U.S. Food and Drug Administration (FDA) as a medicated feed ingredient for cattle during the final days of finishing to improve feed efficiency and growth. Maximum residue limits and U.S. FDA residue tolerances for target tissues have defined management practices around RAC usage in the U.S. However, many countries have adopted zero tolerance policies and testing of off-target tissues, presenting a major challenge for international export. Therefore, the objective this study was to determine the necessary withdrawal time among cattle group-fed RAC to achieve residue concentrations below tolerance levels in muscle and off-target tissues. Specifically, both total and parent RAC residues were quantified in muscle, adipose tissue, rendered tallow, and large intestines from animals group-fed RAC and subjected to withdrawal 2, 4, or 7 days before harvest. Ractopamine (parent and total) residues were below the assay limit of detection (< 0.12 ng/g) in all muscle and adipose tissue samples from animals in control groups (no RAC). However, RAC residues were detectable, but below the limit of quantitation, in 40% of tallow and 17% of large intestine samples from control animals. As expected, mean RAC residue concentrations in muscle, adipose tissue, and large intestine samples decreased (P < 0.05) as the RAC withdrawal duration (days) was extended. Irrespective of RAC withdrawal duration, mean parent RAC residue concentrations in muscle, adipose tissue, and large intestine ranged from 0.33 to 0.76 ng/g, 0.16 to 0.26 ng/g, 3.97 to 7.44 ng/g, respectively and all tallow samples were > 0.14 ng/g (detectable but below the limit of quantitation). Results of this study provide a baseline for the development of management protocol recommendations associated with withdrawal following group-feeding of RAC to beef cattle in countries that allow RAC use and intend to export to global markets which may be subject to zero tolerance policies and off-target tissue testing.

Distribution of aquaporins and sodium transporters in the gastrointestinal tract of a desert hare, Lepus yarkandensis.

Lepus yarkandensis is a desert hare of the Tarim Basin in western China, and it has strong adaptability to arid environments. Aquaporins (AQPs) are a family of water channel proteins that facilitate transmembrane water transport. Gastrointestinal tract AQPs are involved in fluid absorption in the small intestine and colon. This study aimed to determine the distribution of AQPs and sodium transporters in the gastrointestinal tract of L. yarkandensis and to compare the expression of these proteins with that in Oryctolagus cuniculus. Immunohistochemistry was performed to analyse the cellular distribution of these proteins, and the acquired images were analysed with IpWin32 software. Our results revealed that AQP1 was located in the colonic epithelium, central lacteal cells, fundic gland parietal cells, and capillary endothelial cells; AQP3 was located in the colonic epithelium, small intestinal villus epithelium, gastric pit and fundic gland; AQP4 was located in the fundic gland, small intestinal gland and colonic epithelium; and epithelial sodium channel (ENaC) and Na+-K+-ATPase were located in the epithelial cells, respectively. The higher expression levels of AQP1, AQP3, ENaC and Na+-K+-ATPase in the colon of L. yarkandensis compared to those in O. cuniculus suggested that L. yarkandensis has a higher capacity for faecal dehydration.

"Bowel on the Bench": Proof of Concept of a Three-Stage, In Vitro Fermentation Model of the Equine Large Intestine.

The intestinal microbiota of the horse, an animal of huge economic and social importance worldwide, is essential to the health of the animal. Understanding the intestinal ecosystem and its dynamic interaction with diet and dietary supplements currently requires the use of experimental animals, with consequent welfare and financial constraints. Here, we describe the development and assessment, using multiple analytical platforms, of a three-vessel, continuous-flow, in vitro model of the equine hindgut. After inoculation of the model with fresh horse feces, the bacterial communities established in each vessel had a taxonomic distribution similar to that of the source animal. Short-chain fatty acid (SCFA) and branched-chain fatty acid (BCFA) production within the model at steady state was consistent with the expected bacterial function, although higher concentrations of some SCFA/BCFA relative to those in the ex vivo gut content were apparent. We demonstrate the intermodel repeatability and the ability of the model to capture some aspects of individual variation in bacterial community profiles. The findings of this proof-of-concept study, including recognition of the limitions of the model, support its future development as a tool for investigating the impact of disease, nutrition, dietary supplementation, and medication on the equine intestinal microbiota.IMPORTANCE The equine gut model that we have developed and describe has the potential to facilitate the exploration of how the equine gut microbiota is affected by diet, disease, and medication. It is a convenient, cost-effective, and welfare-friendly alternative to in vivo research models.

Modifications of cholera toxin subunit B binding to human large intestinal epithelium. An immunohistochemical study.

Binding of cholera toxin subunit B (CTB) to its receptor and toxin transport into the intestinal epithelial cells are the causative events for the potentially lethal disease cholera. The five sugar mono-sialo ganglioside GM1 is the cell surface receptor for cholera toxin B-subunit. CTB binding was determined by use of immobilized GM1 to microtiter plates and by immunohistochemistry. Sections from the human colon and the human soft palate were incubated with FITC-conjugated CTB and with anti-MUC2. Both the luminal surface of the intestine and the secretory goblet cells exhibited strong binding. Addition of simple carbohydrates and milk to the incubation medium showed that a combination of lactose and non-fat dry milk was potent inhibitors of toxin- and mucin binding. Both CTB and ant-MUC2 stained to the cytoplasm (mucin granules) in the goblet cells from the human soft palate. In the colon CTB stained the entire cytoplasm of the goblet cells while anti-MUC2 detected only the supranuclear region of some cells, suggesting carbohydrate heterogeneity between goblet cell mucin granules in different regions of the human body. Both CTB- and MUC2 binding were inhibited when GM1 was added to the incubation medium. It is proposed that the human colonic goblet cells play a role in the secretory diarrhea in patients with cholera and that milk might have a prophylactic or therapeutic application in the management of cholera.

Effect of fulvic and humic acids on copper and zinc homeostasis in rats.

The objective of this study was to investigate the effects of fulvic acid (FA) and humic acid (HA), the two main compounds of humic substances (HSs), on copper (Cu) and zinc (Zn) homeostasis. Seventy-two male Wistar rats were randomly divided into nine experimental groups. The control diet (AIN-93G formula) and the diets supplemented with 0.1%, 0.2%, 0.4% and 0.8% FA or HA were fed for 26 days. Cu and Zn concentrations of the large intestinal content (LIC), liver, kidney, femur and hair were determined. FA and HA did not influence significantly the Cu or Zn contents of the experimental diets, the rats' feed intake, weight gain and the feed to gain ratio. Both FA and HA decreased the Cu concentrations of the LIC significantly and in a dose-related manner; however the absorption-stimulating effect of HA was more pronounced. FA increased the Cu content of the liver, but neither FA nor HA had a dose-dependent effect on it. FA or HA supplementations had no significant effect on the Cu concentration of the kidney. At the concentrations used, dietary FA or HA supplementations are not promising growth promoters. FA influences the Cu homeostasis unlike HA, because FA not only stimulates Cu absorption, but the extra quantity of absorbed Cu is retained in the organism. The stimulatory effect of HA on Zn absorption may not be manifested in Cu and Zn homeostasis, because of the tight connection of these microelements to FA and HA, which prevents the transmission of Zn from the ZnHA complex to the organs. As regards the effect of FA and HA on Cu and Zn homeostasis, both FA and HA stimulated the absorption of these microelements, but only FA increased the retention of Cu (in the liver) and Zn (in the kidney).

Effect of fulvic and humic acids on iron and manganese homeostasis in rats.

The objective of this study was to investigate the effects of fulvic acid (FA) and humic acid (HA) as the two main compounds of humic substances, separately on Fe and Mn homeostasis. Seventy-two male Wistar rats were randomly divided into 9 experimental groups. The control diet (AIN-93G formula) and diets supplemented with 0.1%, 0.2%, 0.4% and 0.8% HA or FA were fed for 26 days. Fe and Mn concentrations of the large intestinal content, liver, kidney, femur and hair were determined. No significant differences were observed in the production parameters. The effects of FA and HA on iron homeostasis were significantly different. FA proved to be a good iron source, and slightly increased the iron content of liver and kidney, but - up to a dietary iron level of 52.7 mg/kg - it did not influence the efficiency of iron absorption. Above a dietary iron level of 52.7 mg/kg down-regulation of Fe absorption can be assumed. HA significantly stimulated the iron uptake and there was no down-regulation of Fe absorption up to 0.8% dietary HA supplementation level (61.5 mg Fe/kg diet). In the HA groups the iron content of the liver and kidney decreased significantly, suggesting that in spite of the better Fe absorption, the HA-Fe complex does not provide iron to the investigated organs. Neither FA nor HA supplementation influenced the Fe content of the femur and hair and slightly decreased the Mn concentration in the large intestinal content. This effect was significant (with a 22.7% Mn concentration decrease) only at the HA supplementation rate of 0.8%. Neither FA nor HA influenced significantly the Mn concentrations of the liver, kidney and femur. The Mn concentration of the hair in rats receiving FA- or HA-supplemented diets was higher than in the control rats; however, this result needs further confirmation.

Immunohistochemical study of mucins in human intestinal spirochetosis.

Most patients with human intestinal spirochetosis (HIS; a colorectal bacterial infection caused by Brachyspira species) seem asymptomatic, and its pathogenicity remains unclear. Recently, alterations in mucin expression were reported in animal Brachyspira infection. The present question was "Is mucin expression altered in HIS?" Using antibodies for MUCs 1, 2, 4, 5AC, and 6, we immunohistochemically compared 215 specimens from 83 histology-confirmed HIS cases with 106 specimens from 26 non-HIS cases. Positive staining (which included even focal positive staining) was rated "high (+)" or "low (+)." Results were analyzed for 4 categories of lesions, and associations between MUC expression and spirochetal presence were also analyzed. In the "specimens without polyps or adenocarcinoma" category, high (+) MUC2 positivity was more frequent in HIS than in control. In the hyperplasia/serrated polyp category, in HIS (versus control), the MUC5AC positivity rate was lower, whereas high (+) MUC4 positivity was more frequent. In the conventional adenoma category, in HIS (versus control), the MUC1 positivity rate was lower, whereas both high (+) MUC2 positivity and high (+) MUC5AC positivity were less frequent. In the adenocarcinoma category, high (+) MUC2 positivity was more frequent in HIS than in control. Among the above mucins, only MUC1 positivity was significantly associated with an absence of the so-called fringe formation, an absence of spiral organisms within mucus, and an absence of strong immunopositive materials within the epithelial layer and within the subepithelial layer. The results suggest that Brachyspira infection or a related change in the microbiome may alter the large intestine mucin expression profile in humans.

The Synaptojanins in the murine small and large intestine.

The expression of the phosphoinositides phosphatases Synaptojanins (Synjs) 1 and 2 has been shown in brain and in some peripheral tissues, but their expression in the intestine has not been reported. Herein we show that the small and large intestine express Synj1 and Synj2. Their mRNA levels, measured by RT-PCR, are not affected by development in the small intestine but in the colon they increase with age. Immunostaining assays reveal that both Synjs localize at the apical domain of the epithelial cells and at the lamina propria at sites also expressing the neuron marker calretinin. Synj2 staining at the lamina propria is fainter than that of Synj1. In colonocytes Synjs are at the apical membrane and cytosolic membrane vesicles. Synj2 is also at the mitochondria. Western blots reveal that the intestinal mucosa expresses at least two Synj1 (170- and 139-kDa) and two Synj2 (160- and 148-kDa) isoforms. The observations suggest that Synj1-170, Synj2-160, and Synj2-148 in colonocytes, might participate in processes that take place mainly at the apical domain of the epithelial cells whereas Synj1-139 in those at the enteric nervous system. Experimental colitis augments the mRNA abundance of both Synjs in colon but only Synj2 mRNA levels are increased in colon tumors. In conclusion, as far as we know, this is the first report showing expression, location and isoforms of Synj1 and Synj2 in the small and large intestine and that they might participate in intestinal pathology.

Isolation and Identification of Conventional Dendritic Cell Subsets from the Intestine of Mice and Men.

The identification of conventional dendritic cells (cDCs) in the intestinal mucosa has been hampered by the difficulties associated with isolating cells from the intestine and by the fact that overlapping markers have made it complicated to discriminate them accurately from other intestinal mononuclear phagocytes such as macrophages (MFs). Here we detail the protocols we have developed to isolate live leukocytes from both murine and human small and large intestines and describe reliable strategies which can be used to identify bona fide cDCs in such preparations.

Metabolic and Microbial Modulation of the Large Intestine Ecosystem by Non-Absorbed Diet Phenolic Compounds: A Review.

Phenolic compounds represent a diverse group of phytochemicals whose intake is associated with a wide spectrum of health benefits. As consequence of their low bioavailability, most of them reach the large intestine where, mediated by the action of local microbiota, a series of related microbial metabolites are accumulated. In the present review, gut microbial transformations of non-absorbed phenolic compounds are summarized. Several studies have reached a general consensus that unbalanced diets are associated with undesirable changes in gut metabolism that could be detrimental to intestinal health. In terms of explaining the possible effects of non-absorbed phenolic compounds, we have also gathered information regarded their influence on the local metabolism. For this purpose, a number of issues are discussed. Firstly, we consider the possible implications of phenolic compounds in the metabolism of colonic products, such as short chain fatty acids (SCFA), sterols (cholesterol and bile acids), and microbial products of non-absorbed proteins. Due to their being recognized as affective antioxidant and anti-inflammatory agents, the ability of phenolic compounds to counteract or suppress pro-oxidant and/or pro-inflammatory responses, triggered by bowel diseases, is also presented. The modulation of gut microbiota through dietetic maneuvers including phenolic compounds is also commented on. Although the available data seems to assume positive effects in terms of gut health protection, it is still insufficient for solid conclusions to be extracted, basically due to the lack of human trials to confirm the results obtained by the in vitro and animal studies. We consider that more emphasis should be focused on the study of phenolic compounds, particularly in their microbial metabolites, and their power to influence different aspects of gut health.

Enterohemorrhagic Escherichia coli senses low biotin status in the large intestine for colonization and infection.

Enterohemorrhagic Escherichia coli (EHEC) is an important foodborne pathogen that infects humans by colonizing the large intestine. Here we identify a virulence-regulating pathway in which the biotin protein ligase BirA signals to the global regulator Fur, which in turn activates LEE (locus of enterocyte effacement) genes to promote EHEC adherence in the low-biotin large intestine. LEE genes are repressed in the high-biotin small intestine, thus preventing adherence and ensuring selective colonization of the large intestine. The presence of this pathway in all nine EHEC serotypes tested indicates that it is an important evolutionary strategy for EHEC. The pathway is incomplete in closely related small-intestinal enteropathogenic E. coli due to the lack of the Fur response to BirA. Mice fed with a biotin-rich diet show significantly reduced EHEC adherence, indicating that biotin might be useful to prevent EHEC infection in humans.

Dose-dependent uptake of 3'-deoxy-3'-[(18) F]fluorothymidine by the bowel after total-body irradiation.

PURPOSE: The aim of this study is to non-invasively assess early, irradiation-induced normal tissue alterations via metabolic imaging with 3'-deoxy-3'-[(18) F]fluorothymidine ([(18) F]FLT). PROCEDURES: Twenty-nine male C57BL/6 mice were investigated by [(18) F]FLT positron emission tomography for 7 days after total body irradiation (1, 4, and 8 Gy) versus 'sham' irradiation (0 Gy). Target/background ratios were determined. The imaging results were validated by histology and immunohistochemistry (Thymidine kinase 1, Ki-67). RESULTS: [(18) F]FLT demonstrated a dose-dependent intestinal accumulation post irradiation. Mean target/background ratio (±standard error) 0 Gy: 1.4 (0.2), 1 Gy: 1.7 (0.1), 4 Gy: 3.1 (0.3), 8 Gy: 4.2 (0.6). Receiver operating characteristic analysis (area under the curve, p value): 0 vs. 1 Gy: 0.81, 0.049; 0 vs. 4 Gy: 1.0, 0.0016; and 0 vs. 8 Gy: 1.0, 0.0020. Immunohistochemistry confirmed the results. CONCLUSIONS: [(18) F]FLT seems to provide dose-dependent information on radiation-induced proliferation in the bowel. This opens the perspective for monitoring therapy-related side-effects as well as assessing, e.g., radiation accident victims.

Growth, acid production and bacteriocin production by probiotic candidates under simulated colonic conditions.

AIMS: The aim of this study is to evaluate the capacity of three bacteriocin producers, namely Lactococcus lactis subsp. lactis biovar diacetylactis UL719 (nisin Z producer), L. lactis ATCC 11454 (nisin A producer) and Pediococcus acidilactici UL5 (pediocin PA-1 producer), and to grow and produce their active bacteriocins in Macfarlane broth, which mimics the nutrient composition encountered in the human large intestine. METHODS AND RESULTS: The three bacteriocin-producing strains were grown in Macfarlane broth and in De Man-Rogosa-Sharpe (MRS) broth. For each strain, the bacterial count, pH drop and production of organic acids and bacteriocins were measured for different period of time. The ability of the probiotic candidates to inhibit Listeria ivanovii HPB 28 in co-culture in Macfarlane broth was also examined. Lactococcus lactis subsp. lactis biovar diacetylactis UL719, L. lactis ATCC 11454 and Ped. acidilactici UL5 were able to grow and produce their bacteriocins in MRS broth and in Macfarlane broth. Each of the three candidates inhibited L. ivanovii HPB 28, and this inhibition activity was correlated with bacteriocin production. The role of bacteriocin production in the inhibition of L. ivanovii in Macfarlane broth was confirmed for Ped. acidilactici UL5 using a pediocin nonproducer mutant. CONCLUSIONS: The data provide some evidence that these bacteria can produce bacteriocins in a complex medium with carbon source similar to those found in the colon. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrates the capacity of lactic acid bacteria to produce their bacteriocins in a medium simulating the nutrient composition of the large intestine.

[Experimental study on functional connection between the lung and large intestine meridians in the rat: cross-talk between the lung and large intestine meridians].

OBJECTIVE: According to the theory of traditional Chinese medicine about "close association between the lung and the large intestine", the present study was designed to investigate the functional relationship between the Lung and Large Intestine Meridians and the colorectum by using electrophysiological methods. METHODS: A total of 40 SD rats were used in the present study. Under anesthesia, the cardiopulmonary branch of the left sympathetic nerve (CPSN) was separated for recording the electrical activities with a pair of platinum wire electrodes. Intra-colorectal pressure was recorded using a water-balloon inserted into the anus and connected to a pressure-transducer for observing rectocolonic pressure changes (mobility). Electroacupuncture (EA) stimulation was applied to bilateral "Taiyuan" (LU 9)- "Jingqu" (LU 8) of the Lung Meridian, "Yangxi" (LI 5)-"Pianli" (LI 6) of the Large Intestine Meridian, and "Shangjuxu" (ST 37)-"Zusanli" (ST 36) of the Stomach Meridian, respectively. Colorectal distension (CRD, visceral pain stimulation, 60 mmHg and 80 mmHg) was performed using an air-balloon for observing its influence on EA stimulation of LU 9- LU 8 induced changes of electrical activities of CPSN. RESULTS: Under anesthesia conditions, no spontaneous electrical activities of the CPSN were found in rats. After EA stimulation (3 times of the threshold intensity) of the bilateral "Taiyuan" (LU 9)- "Jingqu" (LU 8) of the Lung Meridian, and "Yangxi" (LI 5)-"Pianli" (LI 6) of the Large Intestine Meridian, the evoked discharge numbers of the cardiopulmonary sympathetic nerve were (11.26 +/- 2.34) and (10.73 +/- 2.62) spikes, respectively, without significant differences between the two groups (P > 0.05). Compared with pre-stimulation, the colorectal motility (amplitudes of the intra-colorectal pressure waves) was obviously increased following EA stimulation of LU 9-LU 8 of the Lung Meridian, LI 5-LI 6 of the Large Intestine Meridian and "Shangjuxu" (ST 37)-"Zusanli" (ST 36) , Lower-Ho (Sea) acupoints of the Large Intestine Meridian (P < 0.05). After CRD stimulation at 60 mmHg and 80 mmHg, the LU 9- LU 8-stimulation evoked discharge rates of CPSN were reduced by 43.46% and 67.42%, respectively. CONCLUSION: EA stimulation of LU 9- LU 8 of the Lung Meridian and LI 5-LI 6 of the Large Intestine Meridian can activate discharges of CPSN, and increase the colorectal motility in the rat. CRD stimulation inhibits the activated effect of EA on electrical activities of CPSN. These results show a functional communication or cross-talk between the lung and the colorectum.

Immunohistochemical study of arginase 1 and 2 in various tissues of rats.

Arginase 1 and arginase 2 catalyze the hydrolysis of arginine to ornithine and urea. The localization of these enzymes was studied in various tissues in Sprague-Dawley rats by immunohistochemistry and Western blotting. Western blot analysis showed that both arginase 1 and 2 were differentially expressed in the various organs examined. Arginase 1 was expressed at high levels in the liver, at moderate levels in the pancreas, and at low levels in the cerebrum, cerebellum, spinal cord, stomach, small and large intestines, kidneys, lungs, and spleen. The levels of arginase 2 immunoreactivity were high in the kidneys and pancreas, and moderate in the cerebrum, spinal cord, stomach, small intestine, large intestine, and lungs; the levels were very low in the liver and spleen compared with that in the cerebellum. Immunohistochemical analysis largely confirmed the results of the Western blot analysis. These findings indicate that the levels of arginase 1 and 2 varied among organs, suggesting that the arginase isoforms may play organ-specific roles in the urea cycle.

Expression of SOCS1-7 and CIS mRNA in porcine tissues.

The Suppressor Of Cytokine Signaling (SOCS) proteins are key physiological regulators of the immune system. Little is known about tissue expression of SOCS and data in pigs are extremely scarce. In order to further study SOCS in pigs, preliminary data must be collected. In the current report, we first identified the three most suitable reference genes in ten porcine tissues. The beta-2-microglobulin (B2MI) reference gene was most often particularly suitable in our conditions. Then, using three reference genes we determined the mRNA expression of SOCS1-7 and CIS in every selected tissue. Constitutive mRNA expression was identified for all the members of the SOCS family in the ten tissues. Interestingly, the constitutive mRNA expression of SOCS1, SOCS3, SOCS7 and CIS was rather heterogeneous between tissues while for SOCS2, SOCS4, SOCS5 and SOCS6 differences of expression were less obvious. Highest CIS and SOCS mRNA expressions were observed in large intestine (SOCS1, SOCS3, SOCS4, SOCS6, and CIS), small intestine (SOCS1, SOCS4, SOCS6, and CIS), spleen (SOCS2, SOCS3, SOCS5, SOCS7, and CIS), trachea (SOCS3) and thymus (SOCS1, SOCS2, SOCS4, SOCS7, and CIS). These data will help for further studies about the role of SOCS proteins in the control of porcine innate and adaptive responses.

Somatostatin, substance P and calcitonin gene-related peptide-positive intramural nerve structures of the human large intestine affected by carcinoma.

The aim of this study was to investigate the arrangement and chemical coding of enteric nerve structures in the human large intestine affected by cancer. Tissue samples comprising all layers of the intestinal wall were collected during surgery form both morphologically unchanged and pathologically altered segments of the intestine (n=15), and fixed by immersion in buffered paraformaldehyde solution. The cryostat sections were processed for double-labelling immunofluorescence to study the distribution of the intramural nerve structures (visualized with antibodies against protein gene-product 9.5) and their chemical coding using antibodies against somatostatin (SOM), substance P (SP) and calcitonin gene-related peptide (CGRP). The microscopic observations revealed distinct morphological differences in the enteric nerve system structure between the region adjacent to the cancer invaded area and the intact part of the intestine. In general, infiltration of the cancer tissue resulted in the gradual (depending on the grade of invasion) first decomposition and reduction to final partial or complete destruction and absence of the neuronal elements. A comparative analysis of immunohistochemically labeled sections (from the unchanged and pathologically altered areas) revealed a statistically significant decrease in the number of CGRP-positive neurons and nerve fibres in both submucous and myenteric plexuses in the transitional zone between morphologically unchanged and cancer-invaded areas. In this zone, a decrease was also observed in the density of SP-positive nerve fibres in all intramural plexuses. Conversely, the investigations demonstrated statistically insignificant differences in number of SP- and SOM-positive neurons and a similar density of SOM-positive nerve fibres in the plexuses of the intact and pathologically changed areas. The differentiation between the potential adaptive changes in ENS or destruction of its elements by cancer invasion should be a subject of further investigations.

Relative contribution of small and large intestine to deglycosylation and absorption of flavonoids from Chrysanthemun morifolium extract.

The flower of Chrysanthemum morifolium Ramat (CM) is an established part of traditional Chinese medicine (TCM). Luteolin and apigenin flavonoids are the effective components of the CM extract (CME); however, they exist in the orally consumed CME as glycosides. The present study was carried out to determine the relative contribution of the small and large intestine to the deglycosylation and absorption of flavonoids from CME using a rat model system. The distribution of luteolin and apigenin in rat gastrointestinal (GI) luminal contents, tissues, and plasmas was assessed after the oral administration of CME. The hydrolysis and absorption of CME flavonoids in different rat GI segments were further evaluated by using in situ ligated models and cell-free extracts prepared from rat GI segments. The results demonstrated that after the oral administration of CME, the magnitude of deglycosylation in rats was surprisingly high (about 30%) in the stomach and upper intestine within the first 5 min after ingestion, and early absorption in the plasma was detected. The results from site-limited administration revealed that the stomach was the initial hydrolysis site, while the duodenum was the first effective absorption site for CME flavonoids. Diminishing microbial flora in the jejunum had no significant effect on the hydrolysis of the flavonoids from CME, but the cell-free extracts prepared from rat GI segments demonstrated a strong ability to hydrolyze. Taken together, our findings suggest that enteric disposition contributes to the pharmacokinetics of luteolin and apigenin after oral administration of CME. Moreover, the upper digestive tract plays a key role in the hydrolysis and absorption of flavonoids in CME.

Structural differences among alkali-soluble arabinoxylans from maize (Zea mays), rice (Oryza sativa), and wheat (Triticum aestivum) brans influence human fecal fermentation profiles.

Human fecal fermentation profiles of maize, rice, and wheat bran and their dietary fiber fractions released by alkaline-hydrogen peroxide treatment (principally arabinoxylan) were obtained with the aim of identifying and characterizing fractions associated with high production of short chain fatty acids and a linear fermentation profile for possible application as a slowly fermentable dietary fiber. The alkali-soluble fraction from maize bran resulted in the highest short chain fatty acid production among all samples tested, and was linear over the 24 h fermentation period. Size-exclusion chromatography and (1)H NMR suggested that higher molecular weight and uniquely substituted arabinose side chains may contribute to these properties. Monosaccharide disappearance data suggest that maize and rice bran arabinoxylans are fermented by a debranching mechanism, while wheat bran arabinoxylans likely contain large unsubstituted xylose regions that are fermented preferentially, followed by poor fermentation of the remaining, highly branched oligosaccharides.