Sodium chloride transport of normal and dietary enlarged rat cecum in vitro

Sodium chloride transport across isolated cecum mucosa was investigated in normal rats and rats with adaptive cecum growth induced by dietary polyethylene glycol (PEG). The normal cecum absorbed CI in excess of Na with a small short-circuit current (Isc). Dietary adaptation led to large equivalent increments of Na and Cl net absorption without adequate Ise change. Inhibitor studies (mucosal amiloride 10(-3) and 10(-4) M; mucosal 4,4-diisolhiocyanatostilbene-2,2-disulfonic acid 5 x 10(-5) M;serosal furosemide 10(-3) M;serosal ouabain 10(-3) M) suggested that normal cecal NaCl absorption involves electroneutral Na/N and Cl/HCO3 exchange at the apical and Na-K-ATPase-mediated exit across the basolateral cell membrane. Dietary adaptation stimulates the loosely coupled antiports and possibly activates a small serosally located NaCl cotransport. Comparative histology showed flattening of all tissue layers and widening of crypts in PEG animals. Crypt widening may facilitate ion access to underutilized transport sites and, at least in part, explain the increased absorption of the enlarged cecum

Absorptive transport of amino acids by the rat colon.

The capacity of the colon to absorb microbially produced amino acids (AAs) and the underlying mechanisms of AA transport are incompletely defined. We measured the profile of 16 fecal AAs along the rat ceco-colonic axis and compared unidirectional absorptive AA fluxes across mucosal tissues isolated from the rat jejunum, cecum, and proximal colon using an Ussing chamber approach, in conjunction with 1H-NMR and ultra-performance liquid chromatography-mass spectrometry chemical analyses. Passage of stool from cecum to midcolon was associated with segment-specific changes in fecal AA composition and a decrease in total AA content. Simultaneous measurement of up to 16 AA fluxes under native luminal conditions, with correction for endogenous AA release, demonstrated absorptive transfer of AAs across the cecum and proximal colon at rates comparable (30-80%) to those across the jejunum, with significant Na+-dependent and H+-stimulated components. Expression profiling of 30 major AA transporter genes by quantitative PCR revealed comparatively high levels of transcripts for 20 AA transporters in the cecum and/or colon, with the levels of 12 exceeding those in the small intestine. Our results suggest a more detailed model of major apical and basolateral AA transporters in rat colonocytes and provide evidence for a previously unappreciated transfer of AAs across the colonic epithelium that could link the prodigious metabolic capacities of the luminal microbiota, the colonocytes, and the body tissues.NEW & NOTEWORTHY This study provides evidence for a previously unappreciated transfer of microbially generated amino acids across the colonic epithelium under physiological conditions that could link the prodigious metabolic capacities of the luminal microbiota, the colonocytes, and the body tissues. The segment-specific expression of at least 20 amino acid transporter genes along the colon provides a detailed mechanistic basis for uniport, heteroexchange, Na+-cotransport, and H+-cotransport components of colonic amino acid absorption

Dietary Uncoupling of Gut Microbiota and Energy Harvesting from Obesity and Glucose Tolerance in Mice

The authors gratefully acknowledge Doctoral Training Partnership funding from the BBSRC (M.J.D.) and funding from the Scottish Government (P.J.M., A.W.R., and A.W.W.). We also thank the Centre for Genome-Enabled Biology and Medicine for help with next-generation sequencing and Karen Garden and the Rowett’s Analytical Services for SCFA analysis. SUPPLEMENTAL INFORMATION Supplemental Information includes four figures and two tables and can be found with this article online at https://doi.org/10.1016/j.celrep.2017.10.056.Peer reviewedPublisher PD

Campylobacter jejuni colonization promotes the translocation of Escherichia coli to extra-intestinal organs and disturbs the short-chain fatty acids profiles in the chicken gut

For a long time Campylobacter was only considered as a commensal microorganism in avian hosts restricted to the ceca, without any pathogenic features. The precise reasons for the symptomless chicken carriers are still unknown, but investigations of the gastrointestinal ecology of broiler chickens may improve our understanding of the microbial interactions with the host. Therefore, the current studies were conducted to investigate the effects of Campylobacter jejuni colonization on Escherichia coli translocation and on the metabolic end products (short-chain fatty acids, SCFAs). Following oral infection of 14 day old broiler chickens with 1 × 108 CFU of Campylobacter jejuni NCTC 12744 in two independent animal trials, it was found that C. jejuni heavily colonized the intestine and disseminate to extra-intestinal organs. Moreover, in both animal trials, the findings revealed that C. jejuni promoted the translocation of E. coli with a higher number encountered in the spleen and liver at 14 days post infection (dpi). In addition, Campylobacter affected the microbial fermentation in the gastrointestinal tract of broilers by reducing the amount of propionate, isovalerate, and isobutyrate in the cecal digesta of the infected birds at 2 dpi and, at 7 and 14 dpi, butyrate, isobutyrate, and isovalerate were also decreased. However, in the jejunum, the C. jejuni infection lowered only butyrate concentrations at 14 dpi. These data indicated that C. jejuni may utilize SCFAs as carbon sources to promote its colonization in the chicken gut, suggesting that Campylobacter cannot only alter gut colonization dynamics but might also influence physiological processes due to altered microbial metabolite profiles. Finally, the results demonstrated that C. jejuni can cross the intestinal epithelial barrier and facilitates the translocation of Campylobacter itself as well as of other enteric microorganisms such as E. coli to extra-intestinal organs of infected birds. Altogether, our findings suggest that the Campylobacter carrier state in chicken is characterised by multiple changes in the intestinal barrier function, which supports multiplication and survival within the host

Effects of Single-Dose Prucalopride on Intestinal Hypomotility in Horses: Preliminary Observations

Abnormalities of gastrointestinal motility are often a challenge in horses; however, the use of prokinetic drugs in such conditions must be firmly established yet. For this reason we carried out a preliminary study on the effects of prucalopride on intestinal motor activity of horses with gut hypomotility. The effect of prucalopride per os by oral dose syringe (2 mg/100 kg body weight) was assessed by abdominal ultrasound (evaluating duodenal, cecal, and colonic motor activity) in six horses with gut hypomotility. After administration of prucalopride, a significant increase of contractile activity was found in the duodenum at 30 minutes (p = 0.0005), 60 minutes (p = 0.01) and 90 minutes (p = 0.01), whereas in the cecum and in the left colon the increase was only present at 60 minutes (p = 0.03, and p = 0.02, respectively). No changes from baseline heart and respiratory rate or behavior side effects were observed after administration of the drug and throughout the observation period. Prucalopride may be a useful adjunct to the therapeutic armamentary for treating hypomotile upper gut conditions of horses. Dosing information is however needed to establish its actual clinical efficacy and its proper effects on the large bowel in these animals

Effect of probiotic inocula on the population density of lactic acid bacteria and enteric pathogens in the intestine of weaning piglets

Because antibiotic resistance occurs in bacteria at an alarming rate, significant research has been focused on finding alternative treatments which do not involve the use of antibiotics. The promotion of beneficial gut bacteria can increase the resistance of animals to possible intestinal infections. Probiotics can be administered to humans or animals, offering preventive benefits of protecting the host from various types of intestinal diseases, providing positive effects on digestive processes and stimulating influence on the growth of organism, strengthening the barrier function of the gut microbiota and/or non-specific enhancement of the immune system. A study was designed to screen potential probiotic Bifidobacterium spp. strains with the ability to multiply in the intestine of weaned piglets and then to assess their health promoting effects when challenged with two enteric pathogens. Three series of trials were conducted with 60 weaning pigs fed one of 12 different Bifidobacterium spp. strains either once or twice a day. The most effective probiotic treatment (Bifidobacterium animalis subsp. lactis, strain Ra 18, at a dose of 1011cfu twice a day) was then challenged in two series of experiments with the enteric pathogens, Salmonella enterica serovar typhimurium and E. coli K88. Bifidobacterium animalis subsp. lactis strain Ra 18 significantly increased (p<0.01) the number of viable bifidobacteria in the cecum contents. When it was challenged with Salmonella, Ra 18 reduced excretion of this pathogen with the faeces. On the whole, supplementation with Ra 18 had a positive effect on the growth performance of pigs except after challenge with E. coli K88 where pigs susceptible to ETEC adhesion were lighter than pigs not susceptible