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Gut Oct 1987Evidence for the occurrence of microbial breakdown of carbohydrate in the human colon has been sought by measuring short chain fatty acid (SCFA) concentrations in the...
Evidence for the occurrence of microbial breakdown of carbohydrate in the human colon has been sought by measuring short chain fatty acid (SCFA) concentrations in the contents of all regions of the large intestine and in portal, hepatic and peripheral venous blood obtained at autopsy of sudden death victims within four hours of death. Total SCFA concentration (mmol/kg) was low in the terminal ileum at 13 +/- 6 but high in all regions of the colon ranging from 131 +/- 9 in the caecum to 80 +/- 11 in the descending colon. The presence of branched chain fatty acids was also noted. A significant trend from high to low concentrations was found on passing distally from caecum to descending colon. pH also changed with region from 5.6 +/- 0.2 in the caecum to 6.6 +/- 0.1 in the descending colon. pH and SCFA concentrations were inversely related. Total SCFA (mumol/l) in blood was, portal 375 +/- 70, hepatic 148 +/- 42 and peripheral 79 +/- 22. In all samples acetate was the principal anion but molar ratios of the three principal SCFA changed on going from colonic contents to portal blood to hepatic vein indicating greater uptake of butyrate by the colonic epithelium and propionate by the liver. These data indicate that substantial carbohydrate, and possibly protein, fermentation is occurring in the human large intestine, principally in the caecum and ascending colon and that the large bowel may have a greater role to play in digestion than has previously been ascribed to it.
Topics: Acetates; Acetic Acid; Animals; Butyrates; Butyric Acid; Fatty Acids; Female; Fermentation; Gastrointestinal Contents; Hepatic Veins; Humans; Hydrogen-Ion Concentration; Intestine, Large; Male; Portal Vein; Propionates; Swine
PubMed: 3678950
DOI: 10.1136/gut.28.10.1221 -
Case Reports in Gastroenterology 2022Colonic intramural hematoma is a rare condition and its endoscopic and radiological findings remain poorly described. An 82-year-old woman was hospitalized with a...
Colonic intramural hematoma is a rare condition and its endoscopic and radiological findings remain poorly described. An 82-year-old woman was hospitalized with a diagnosis of acute cerebral infarction. She immediately received anticoagulant therapy with argatroban for 1 week. With the appearance 4 days later of hematochezia, she was found to have severe anemia. Following insertion of the colonoscope, a large submucosal hematoma was shown to be present in the descending colon, with the mucosa shown to be necrotic and the residual mucosa around the hematoma shown to be yellowish. Computed tomography revealed a hyperdense mass in the descending colon. Laparoscopic colectomy was performed for the lesion diagnosed as intramural hematoma. Pathologically, it was a hematoma located in the subserosal layer involving full-thickness hemorrhage. To our knowledge, this report represents a valuable addition to the literature describing a case of colonic intramural hematoma whose diagnosis was effectively established by the combined use of CS and CT.
PubMed: 35814795
DOI: 10.1159/000524793 -
Case Reports in Gastroenterology 2020Ischaemic colitis (IC) is the most frequent form of ischaemia of the digestive tract. Due to the worldwide increasing use of medications, there is a growing interest in...
Ischaemic colitis (IC) is the most frequent form of ischaemia of the digestive tract. Due to the worldwide increasing use of medications, there is a growing interest in drug-induced IC. This study reports a rare case of IC directly due to amoxicillin-clavulanate intake. The objective of the study was to describe the evolution of this novel manifestation. An 18-year-old man, non-smoker, with an insignificant medical history, presented with diarrhoea and cramping abdominal pain that started the day following the end of a 10-day amoxicillin-clavulanate course for recent upper respiratory tract infection. Stool cultures including toxin testing were negative. Colonoscopy documented an erosive-ulcerative colitis of the sigmoid and the descending colon. Histological examination of the colon biopsies revealed an IC with focal pseudomembranous areas in the descending-sigmoid colon. Thrombophilia screening tests were negative. The patient was discharged from the hospital without symptoms, and another colonoscopy was performed 3 weeks after the previous one, which documented normal endoscopic and histological findings. Amoxicillin-clavulanate IC is a very rare condition and should be suspected once infectious diseases, vascular/haemodynamic causes and a prothrombotic/hypercoagulable state have been excluded. Immediate discontinuation of the antibiotic leads to rapid disease remission.
PubMed: 32508555
DOI: 10.1159/000507014 -
World Journal of Gastroenterology Jan 2020Obesity is a risk factor for colorectal cancer, yet metabolic distinctions between healthy right and left colon tissue, before cancer is diagnosed, remains largely...
BACKGROUND
Obesity is a risk factor for colorectal cancer, yet metabolic distinctions between healthy right and left colon tissue, before cancer is diagnosed, remains largely unknown. This study compared right-ascending and left-descending colon tissue metabolomes to identify differences from the stool metabolome in normal weight, overweight, and obese adults.
AIM
To examine right and left colon tissue metabolites according to body mass index that may serve as mechanistic targets for interventions and biomarkers for colon cancer risk.
METHODS
Global, non-targeted metabolomics was applied to assess right-ascending and left-descending colon tissue collected from healthy adults undergoing screening colonoscopies to test the hypothesis that BMI differentially impacts colon tissue metabolite profiles. The colon tissue and stool metabolome of healthy adults ( 24) was analyzed for metabolite signatures and metabolic pathway networks implicated in progression of colorectal cancer.
RESULTS
Ascending and descending colon contained 504 host, food, and microbiota-derived metabolites from normal weight, overweight and obese adults grouped according to body mass index. Amino acids, lipids, and nucleotides were among the chemical types that further differentiated from the stool metabolite profiles. Normal weight adults had 46 significantly different metabolites between ascending and descending colon tissue locations, whereas there were 37 metabolite differences in overweight and 28 metabolite differences for obese adults ( < 0.05). Obese adults had trimethylamine N-oxide, endocannabinoids and monoacylglycerols with different relative abundances identified between ascending and descending colon. Primary and secondary bile acids, vitamins, and fatty acids also showed marked relative abundance differences in colon tissue from overweight/obese adults.
CONCLUSION
There were metabolite profile differences between right-ascending and left-descending colon tissue in healthy adults. Colon lipids and other metabolites in obese and overweight adults were distinguished from normal weight participants and associated with gut inflammation, nutrient absorption, and products of microbiota metabolism.
Topics: Adult; Biomarkers, Tumor; Body Mass Index; Colon, Ascending; Colon, Descending; Colorectal Neoplasms; Feces; Female; Gastrointestinal Microbiome; Healthy Volunteers; Humans; Ideal Body Weight; Intestinal Absorption; Lipid Metabolism; Lipids; Male; Metabolome; Middle Aged; Obesity; Overweight; Risk Factors
PubMed: 31988593
DOI: 10.3748/wjg.v26.i3.335 -
European Journal of Pharmacology Sep 2023Capsaicin and allyl isothiocyanate (AITC) activate transient receptor potential (TRP) vanilloid-1 (TRPV1) and TRP ankyrin-1 (TRPA1), respectively. TRPV1 and TRPA1...
Capsaicin and allyl isothiocyanate (AITC) activate transient receptor potential (TRP) vanilloid-1 (TRPV1) and TRP ankyrin-1 (TRPA1), respectively. TRPV1 and TRPA1 expression have been identified in the gastrointestinal (GI) tract. GI mucosal functions remain largely undefined for TRPV1 and TRPA1 with side-dependence and regional differences in signalling unclear. Here we investigated TRPV1- and TRPA1-induced vectorial ion transport as changes in short-circuit current (ΔI), in defined segments of mouse colon mucosa (ascending, transverse and descending) under voltage-clamp conditions in Ussing chambers. Drugs were applied basolaterally (bl) or apically (ap). Capsaicin responses were biphasic, with primary secretory and secondary anti-secretory phases, observed with bl application only, which predominated in descending colon. AITC responses were monophasic and secretory, with ΔI dependent on colonic region (ascending vs. descending) and sidedness (bl vs. ap). Aprepitant (neurokinin-1 (NK1) antagonist, bl) and tetrodotoxin (Na channel blocker, bl) significantly inhibited capsaicin primary responses in descending colon, while GW627368 (EP4 receptor antagonist, bl) and piroxicam (cyclooxygenase inhibitor, bl) inhibited AITC responses in ascending and descending colonic mucosae. Antagonism of the calcitonin gene-related peptide (CGRP) receptor had no effect on mucosal TRPV1 signalling, while tetrodotoxin and antagonists of the 5-hydroxytryptamine-3 and 4 receptors, CGRP receptor, and EP1/2/3 receptors had no effect on mucosal TRPA1 signalling. Our data demonstrates the regional-specificity and side-dependence of colonic TRPV1 and TRPA1 signalling, with involvement of submucosal neurons and mediation by epithelial NK1 receptor activation for TRPV1, and endogenous prostaglandins and EP4 receptor activation for TRPA1 mucosal responses.
Topics: Mice; Animals; Transient Receptor Potential Channels; TRPA1 Cation Channel; Capsaicin; Tetrodotoxin; Colon; Mucous Membrane; TRPV Cation Channels
PubMed: 37394028
DOI: 10.1016/j.ejphar.2023.175897