Colonic content: effect of diet, meals, and defecation

This is the peer reviewed version of the following article: Bendezú, Á., Mego, M., Monclús, E., Merino, X., Accarino, A., Malagelada, J., Navazo, I., Azpiroz, F. Colonic content: effect of diet, meals, and defecation. "Neurogastroenterology and motility", Febrer 2017, vol. 29, núm. 2, which has been published in final form at [http://onlinelibrary.wiley.com.recursos.biblioteca.upc.edu/doi/10.1111/nmo.12930/full]. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.The metabolic activity of colonic microbiota is influenced by diet; however, the relationship between metabolism and colonic content is not known. Our aim was to determine the effect of meals, defecation, and diet on colonic content. Methods: In 10 healthy subjects, two abdominal MRI scans were acquired during fasting, 1 week apart, and after 3 days on low- and high-residue diets, respectively. With each diet, daily fecal output and the number of daytime anal gas evacuations were measured. On the first study day, a second scan was acquired 4 hours after a test meal (n=6) or after 4 hours with nil ingestion (n=4). On the second study day, a scan was also acquired after a spontaneous bowel movement. Results: On the low-residue diet, daily fecal volume averaged 145 ± 15 mL; subjects passed 10.6 ± 1.6 daytime anal gas evacuations and, by the third day, non-gaseous colonic content was 479 ± 36 mL. The high-residue diet increased the three parameters to 16.5 ± 2.9 anal gas evacuations, 223 ± 19 mL fecal output, and 616 ± 55 mL non-gaseous colonic content (P<.05 vs low-residue diet for all). On the low-residue diet, non-gaseous content in the right colon had increased by 41 ± 11 mL, 4 hours after the test meal, whereas no significant change was observed after 4-hour fast (-15 ± 8 mL; P=.006 vs fed). Defecation significantly reduced the non-gaseous content in distal colonic segments. Conclusion & inferences: Colonic content exhibits physiologic variations with an approximate 1/3 daily turnover produced by meals and defecation, superimposed over diet-related day-to-day variations.Peer ReviewedPostprint (author's final draft

Fisiología y fisiopatología de la distensión abdominal : gas intestinal /

Premi Extraordinari de Doctorat concedit pels programes de doctorat de la UAB per curs acadèmic 2017-2018Los trabajos que componen esta tesis doctoral están enfocados al estudio de la fisiología del gas intestinal. En nuestro primer trabajo determinamos el volumen de gas intestinal producido tras una comida rica en residuos fermentables como las alubias, con y sin lavado intestinal. Observamos una gran diferencia entre el volumen de gas intestinal evacuado con y sin lavado, sin lavado sólo se evacuaron una cuarta parte del volumen total producido, demostrando que la homeostasis del gas intestinal es un proceso altamente dinámico, donde una gran proporción del gas producido por la fermentación bacteriana de los residuos de la comida se absorbe rápidamente a la sangre y/o se metaboliza por microorganismos que consumen gas, y sólo una proporción relativamente modesta se elimina por el ano. Siguiendo en la línea del efecto de la dieta sobre la producción de gas intestinal, en el segundo trabajo realizamos varios experimentos combinando dieta alta y baja en residuos fermentables, con ayunas y tras una comida rica en residuos fermentables. Observamos un incremento en el volumen de gas intestinal producido en los experimentos con una precarga alta en residuos fermentables, con respecto a una precarga baja en residuos fermentables ambos en ayunas, demostrando que los residuos preexistentes en el colon producto de comidas previas ejercen efecto en la producción del gas intestinal. Tras una comida alta en residuos fermentables, en ambas precargas demostramos un incremento notable en la producción de gas intestinal, lo que es esperado. No obstante la producción de gas intestinal no fue tan diferente como se cabría esperar para las diferentes precargas, sugiriendo que la fermentación bacteriana es un proceso saturable. Nuestros resultados demuestran que la actividad metabólica de la microbiota intestinal aumenta notablemente durante las primeras horas tras la ingesta de sustratos fermentables no absorbibles, pero esta actividad persiste horas más tarde, aunque a un nivel más bajo que en la fase temprana, es decir la producción de gas intestinal en respuesta a una comida depende del contenido de residuos en el colon derivado de las comidas previas; ambos efectos son sumativos. Una proporción substancial de sujetos con trastornos intestinales funcionales, incluso en la población general, se quejan de síntomas que son comúnmente atribuidos al gas, tales como, distensión y flatulencia. Los nuevos conocimientos arrojados por los estudios presentes pueden ayudar a clarificar la dinámica del gas intestinal en relación a estos síntomas, tomando en consideración diferentes factores que pueden influir en la homeostasis del gas intestinal y tolerancia, tales como motilidad intestinal, tránsito, sensibilidad y actividad microbiotaThe works of this thesis are focused on the study of the physiology of intestinal gas. In our first experiment, we determine the volume of intestinal gas produced after a flatulogenic test meal, with and without wash-out. Observed a great difference between the volume of intestinal gas evacuated with and without wash-out, only a quarter of the total volume produced were evacuated. Our data indicate that intestinal gas homeostasis is a highly dynamic process. A large proportion of the gas produced by bacterial fermentation of meal residues appears to be rapidly absorbed into the blood and/or metabolized by gas-consuming microorganisms, and only a relatively modest proportion eliminated per anus. Following the line, in the second experiment the intestinal gas production was measured after 1 day low-flatulogenic diet and fast or test meal; or 1 day high-flatulogenic diet and fast or test meal. We observed an increase in the volume of intestinal gas produced in the experiments with high preload respect to a low preload both in fasting, showing that preexisting residues on colon exert effect in the production of intestinal gas. After a test meal in both preload demonstrate a great increase in gas production, what is expected, but the gas production rate after the test meal with the high-flatulogenic preload was not higher than with the low-flatulogenic preload, suggesting that gas production may be a saturable process. Show, that the metabolic activity of intestinal microbiota markedly increases during the first few hours after ingestion of non-absorbable, fermentable substrates, but this activity still persists hours later, albeit at a lower level than in the early phase, and demonstrates summation effects of fermentable foodstuffs on gas production. A substantial proportion of subjects with functional gut disorders, or even in the general population, complain of symptoms that are commonly attributed to gas, like distension and bloating. This new knowledge should contribute to elucidating the dynamic complex of the intestinal gas in relationship with these symptoms, take into consideration different factors that may influence gas homeostasis and tolerance, such as intestinal motility, transit, sensitivity,and microbiota activity

Quantitative GC–TCD Measurements of Major Flatus Components: A Preliminary Analysis of the Diet Effect

The impact of diet and digestive disorders in flatus composition remains largely unexplored. This is partially due to the lack of standardized sampling collection methods, and the easy atmospheric contamination. This paper describes a method to quantitatively determine the major gases in flatus and their application in a nutritional intervention. We describe how to direct sample flatus into Tedlar bags, and simultaneous analysis by gas chromatography–thermal conductivity detection (GC–TCD). Results are analyzed by univariate hypothesis testing and by multilevel principal component analysis. The reported methodology allows simultaneous determination of the five major gases with root mean measurement errors of 0.8% for oxygen (O2), 0.9% for nitrogen (N2), 0.14% for carbon dioxide (CO2), 0.11% for methane (CH4), and 0.26% for hydrogen (H2). The atmospheric contamination was limited to 0.86 (95% CI: [0.7–1.0])% for oxygen and 3.4 (95% CI: [1.4–5.3])% for nitrogen. As an illustration, the method has been successfully applied to measure the response to a nutritional intervention in a reduced crossover study in healthy subjects. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

Semi-automatic colonic content analysis for diagnostic

The analysis of the morphology and content of the gut is necessary in order to understand metabolic and functional gut activity and for diagnostic purposes. Magnetic resonance imaging (MRI) has become an important modality technique since it is able to visualize soft tissues using no ionizing radiation, and hence removes the need for any contrast agents. In the last few years, MRI of gastrointestinal function has advanced substantially, although scarcely any publication has been devoted to the analysis of the colon content. This paper presents a semi-automatic segmentation tool for the quantitative assessment of the unprepared colon from MRI images. This application has allowed for the analysis of the colon content in various clinical experiments. The results of the assessment have contributed to a better understanding of the functionality of the colon under different diet conditions. The last experiment carried out by medical doctors showed a marked influence of diet on colonic content, accounting for about 30% of the volume variations.Peer ReviewedPostprint (published version

Clinical significance of small bowel manometry patterns suggestive of intestinal obstruction

Constipation; Intestinal manometry; Intestinal neuropathyRestrenyiment; Manometria intestinal; Neuropatia intestinalEstreñimiento; Manometría intestinal; Neuropatía intestinalIntroduction Minute rhythm and prolonged simultaneous contractions are patterns of postprandial small bowel contractile activity that historically have been considered as suggestive of mechanical intestinal obstruction; however, these patterns have been also encountered in patients with motility-like symptoms in the absence of bowel obstruction. The objective of this study was to determine the current diagnostic outcome of patients with these intestinal manometry patterns. Methods Retrospective study of patients with chronic digestive symptoms evaluated by intestinal manometry at our center between 2010 and 2018. Results The minute rhythm (MRP) or prolonged simultaneous contractions (PSC) postprandial patterns were detected in 61 of 488 patients (55 MRP and 6 PSC). Clinical work-up detected a previously non-diagnosed partial mechanical obstruction of the distal intestine in 10 (16%) and a systemic disorder causing intestinal neuropathy in 32 (53%). In the remaining 19 patients (31%, all with MRP), the origin of the contractile pattern was undetermined, but in 16, substantial fecal retention was detected within 7 days of the manometric procedure by abdominal imaging, and in 6 of them colonic cleansing completely normalized intestinal motility on a second manometry performed within 39 ± 30 days. Conclusion and Inference Currently, the most frequent origin of MRP and PSC encountered on small bowel manometry is intestinal neuropathy, while a previously undetected mechanical obstruction is rare. Still, in a substantial proportion of patients, no underlying disease can be identified, and in them, colonic fecal retention might play a role, because in a subgroup of these patients, manometry normalized after colonic cleansing. Hence, colonic preparation may be considered prior to intestinal manometry.This work was supported by the Instituto de Salud Carlos III and co-financed by the European Union (FEDER/FSE) [PI17/01794]; Spanish Ministry of Economy and Competitiveness (Dirección General de Investigación Científica y Técnica) [SAF 2016-76648-R]; Ciberehd is funded by the Instituto de Salud Carlos III. LA was supported by the Instituto de Salud Carlos III (CM20/00182)

Clinical significance of small bowel manometry patterns suggestive of intestinal obstruction

Minute rhythm and prolonged simultaneous contractions are patterns of postprandial small bowel contractile activity that historically have been considered as suggestive of mechanical intestinal obstruction; however, these patterns have been also encountered in patients with motility-like symptoms in the absence of bowel obstruction. The objective of this study was to determine the current diagnostic outcome of patients with these intestinal manometry patterns. Retrospective study of patients with chronic digestive symptoms evaluated by intestinal manometry at our center between 2010 and 2018. The minute rhythm (MRP) or prolonged simultaneous contractions (PSC) postprandial patterns were detected in 61 of 488 patients (55 MRP and 6 PSC). Clinical work-up detected a previously non-diagnosed partial mechanical obstruction of the distal intestine in 10 (16%) and a systemic disorder causing intestinal neuropathy in 32 (53%). In the remaining 19 patients (31%, all with MRP), the origin of the contractile pattern was undetermined, but in 16, substantial fecal retention was detected within 7 days of the manometric procedure by abdominal imaging, and in 6 of them colonic cleansing completely normalized intestinal motility on a second manometry performed within 39 ± 30 days. Currently, the most frequent origin of MRP and PSC encountered on small bowel manometry is intestinal neuropathy, while a previously undetected mechanical obstruction is rare. Still, in a substantial proportion of patients, no underlying disease can be identified, and in them, colonic fecal retention might play a role, because in a subgroup of these patients, manometry normalized after colonic cleansing. Hence, colonic preparation may be considered prior to intestinal manometry. Minute rhythm (or clustered contractions) in postprandial small bowel manometry can be produced by intestinal neuropathy or mechanical occlusion, but in some patients, the minute rhythm pattern is associated with colonic fecal retention, and resolves after colonic cleansing. Hence, colonic preparation may be considered prior to intestinal manometry

Significado del patrón ritmo minuto en período postprandial en la manometría gastrointestinal

Objetivo: Determinar el significado del patrón ritmo minuto postprandial. Métodos: Se revisaron manometrías para el análisis de las alteraciones manométricas y posterior correlación con la clínica. Resultados: Los diagnósticos fueron: Trastorno motor 69, ritmo minuto 52, normales: 161. Clínicamente la presencia de crisis suboclusivas fue más frecuente en pacientes con ritmo minuto y trastorno motor que en pacientes con manometría normal, en cambio la alteración del ritmo deposicional fue más frecuente en pacientes con manometría normal. El dolor abdominal fue similar en todos. Conclusión: El ritmo minuto en ausencia de oclusión se podría considerar criterio de alteración neuropático.Objectiu: Determinar el significat del patró ritme minut postprandial. Mètodes: Es van revisar manometrías per a l'anàlisi de les alteracions manomètriques i posterior correlació amb la clínica. Resultats: Els diagnòstics van ser: Trastorn motor 69, ritme minut 52, normals: 161. Clínicament la presència de crisis suboclusivas va ser més freqüent en pacients amb ritme minut i trastorn motor que en pacients amb manometria normal, en canvi l'alteració del ritme deposicional va ser més freqüent en pacients amb manometria normal. El dolor abdominal va ser similar en tots. Conclusió: El ritme minut en absència d'oclusió es podria considerar criteri d'alteració neuropàtic

High Resolution Esophageal Manometry in Patients with Chagas Disease : A Cross-Sectional Evaluation

Gastrointestinal involvement affects 30-40% of the patients with chronic Chagas disease. Esophageal symptoms appear once the structural damage is established. Little is known about the usefulness of high resolution manometry to early identification of esophageal involvement. We performed a cross-sectional study at the Vall d'Hebron University Hospital (Barcelona, Spain) between May 2011 and April 2012. Consecutive patients diagnosed with Chagas disease in the chronic phase were offered to participate. All patients underwent a structured questionnaire about digestive symptoms, a barium esophagogram (Rezende classification) and an esophageal high resolution manometry (HRM). A control group of patients with heartburn who underwent an esophageal HRM in our hospital was selected. 62 out of 73 patients that were included in the study fulfilled the study protocol. The median age of the Chagas disease group (CG) was 37 (IQR 32-45) years, and 42 (67.7%) patients were female. Twenty-seven (43.5%) patients had esophageal symptoms, heartburn being the most frequent. Esophagogram was abnormal in 5 (8.77%). The esophageal HRM in the CG showed a pathological motility pattern in 14 patients (22.6%). All of them had minor disorders of the peristalsis (13 with ineffective esophageal motility and 1 with fragmented peristalsis). Hypotonic lower esophageal sphincter was found more frequently in the CG than in the control group (21% vs 3.3%; p<0.01). Upper esophageal sphincter was hypertonic in 22 (35.5%) and hypotonic in 1 patient. When comparing specific manometric parameters or patterns in the CG according to the presence of symptoms or esophagogram no statistically significant association were seen, except for distal latency. The esophageal involvement measured by HRM in patients with chronic Chagas disease in our cohort is 22.6%. All the patients with esophageal alterations had minor disorders of the peristalsis. Symptoms and esophagogram results did not correlate with the HRM results. Chagas disease is a parasitic disease mainly transmitted to humans by blood-sucking insects. The disease was endemic in Latin America, but it is now a global disease due to migratory movements. The disease can affect the heart and the digestive system (mainly esophagus and colon). Classically, esophageal assessment in Chagas disease is performed by X-ray and self-reported symptoms. However, they lack accuracy and detect only advanced stage of the disease. Recently, new tools, such as esophageal high resolution manometry, provide more detailed information about the motility disorders of the esophagus. We assessed the esophageal involvement in patients with Chagas disease by means of high resolution manometry and compared the findings with the X-ray and self-reported symptoms. We found a low rate of mild severity motility disorders. We did not find an association between X-ray assessment and symptoms with the high resolution manometry findings. The assessment of esophageal involvement in patients with Chagas disease may benefit from early diagnosis by high resolution manometry, although more research is needed

Effects of prebiotics vs a diet low in FODMAPS in patients with functional gut disorder

Prebiotics and diets low in fermentable oligo-, di-, mono-saccharides and polyols (low-FODMAP diet) might reduce symptoms in patients with functional gastrointestinal disorders, despite reports that some nonabsorbable, fermentable meal products (prebiotics) provide substrates for colonic bacteria and thereby increase gas production. We performed a randomized, parallel, double-blind study of patients with functional gastrointestinal disorders with flatulence. We compared the effects of a prebiotic supplement (2.8 g/d Bimuno containing 1.37 g beta-galactooligosaccharide) plus a placebo (Mediterranean-type diet; prebiotic group, n = 19) vs a placebo supplement (2.8 g xylose) plus a diet low in FODMAP (low-FODMAP group, n = 21) for 4 weeks; patients were then followed for 2 weeks. The primary outcome was effects on composition of the fecal microbiota, analyzed by 16S sequencing. Secondary outcomes were intestinal gas production and digestive sensations. After 4 weeks, we observed opposite effects on microbiota in each group, particularly in relation to the abundance of Bifidobacterium sequences (increase in the prebiotic group and decrease in the low-FODMAP group; P = .042), and Bilophila wadsworthia (decrease in the prebiotic group and increase in the low-FODMAP group; P = .050). After 4 weeks, both groups had statistically significant reductions in all symptom scores, except reductions in flatulence and borborygmi were not significant in the prebiotic group. Although the decrease in symptoms persisted for 2 weeks after patients discontinued prebiotic supplementation, symptoms reappeared immediately after patients discontinued the low-FODMAP diet. Intermittent prebiotic administration might therefore be an alternative to dietary restrictions for patients with functional gut symptoms. ClinicalTrials.gov no.: NCT02210572

European Registry on Helicobacter pylori Management: Effectiveness of First and Second-Line Treatment in Spain

The management of Helicobacter pylori infection has to rely on previous local effectiveness due to the geographical variability of antibiotic resistance. The aim of this study was to evaluate the effectiveness of first and second-line H. pylori treatment in Spain, where the empirical prescription is recommended. A multicentre prospective non-interventional registry of the clinical practice of European gastroenterologists concerning H. pylori infection (Hp-EuReg) was developed, including patients from 2013 until June 2019. Effectiveness was evaluated descriptively and through a multivariate analysis concerning age, gender, presence of ulcer, proton-pump inhibitor (PPI) dose, therapy duration and compliance. Overall, 53 Spanish hospitals were included, and 10,267 patients received a first-line therapy. The best results were obtained with the 10-day bismuth single-capsule therapy (95% cure rate by intention-to-treat) and with both the 14-day bismuth-clarithromycin quadruple (PPI-bismuth-clarithromycin-amoxicillin, 91%) and the 14-day non-bismuth quadruple concomitant (PPI-clarithromycin-amoxicillin-metronidazole, 92%) therapies. Second-line therapies were prescribed to 2448 patients, with most-effective therapies being the triple quinolone (PPI-amoxicillin-levofloxacin/moxifloxacin) and the bismuth-levofloxacin quadruple schemes (PPI-bismuth-levofloxacin-amoxicillin) prescribed for 14 days (92%, 89% and 90% effectiveness, respectively), and the bismuth single-capsule (10 days, 88.5%). Compliance, longer duration and higher acid inhibition were associated with higher effectiveness. "Optimized" H. pylori therapies achieve over 90% success in Spain