No abstract

Considering the effects of some fermentation products on intestinal morphology and finction, these variations may be relevant to the pathogenesis of colorectal diseases.

Lanreotide is safe and well tolerated in patients with carcinoid tumors. It seems to have both symptomatic and antitumoral effects in this setting.

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

In order to assess the relationship between methane (CH4) producing status and the breath excretion of hydrogen (H2) in healthy subjects, breath CH4 and H2 were simultaneously measured for 14 hours after oral ingestion of 10 g lactulose in 65 young volunteers. Forty were breath CH4 producers and 25 were not. Statistically significant differences were observed between both groups, with lower values for CH4 producers recorded for the foliowing parameters: fasting basal value of breath H2 (8.1 (4.9) v 5-2 (3.7) ppm, p<005), mouth-to-caecum transit time (68 (24) The hydrogen (H2) and methane (CH4) produced in the human body derive entirely from colonic anaerobic bacterial fermentation. While most of these gases are consumed on site or excreted in flatus, the part expelled by the lungs can be easily collected and measured by endexpiratory sampling.'2 H2 production increases when a fermentable carbohydrate is incompletely absorbed in the small intestine, forming the basis for the use of the H2 breath test. This non-invasive procedure has been extensively used in clinical practice3'" and pharmacological studies'2 to measure mouth-to-caecum transit time. It has also been proposed as a semi quantitative method for evaluating intestinal malabsorption of carbohydrates.'314 The recent development of a simple gas analyser not only offers the opportunity to measure breath H2 but breath CH4 as well. Although the substrates for CH4 production are not yet fully identified,2 '5 it has been shown that in Caucasian adults, only 30%-50% are breath CH4 producers, whereas 90%-98% excrete breath H2.'622 In most previously published investigations, however, little attention has been paid to the relationship between breath CH4 producing status and the H2 excretion profile after lactulose administration. In a previous study evaluating starch malabsorption of pasta,23 we observed different patterns of H2 production according to breath CH4 producing status, a finding which has also been described in preliminary studies by other authors. 16 20 24 This prompted us to prospectively assess the relationship between breath CH4 producing status and the breath excretion of H2 in healthy subjects. Methods SUBJECTSSixty five subjects (32 men, 33 women) ranging from 19 to 30 years (mean 22 4 (2)) were selected from a population of healthy volunteers without known disease and free from gastrointestinal symptoms as previously tested in our laboratory. In addition, their breath CH4 producing status was already known. Forty were breath CH4 producers as defined below. Their breath samples were compared with those of 25 healthy controls who were breath CH4 non-producers. All volunteers were French born Caucasians of similar ethnic origin. As enemas, laxatives, and antibiotics can affect the colonic microflora and, hence, the production of intestinal gas,25 any individual receiving these treatments within three months before the study was excluded. All subjects gave their informed consent to the study protocol which had been approved by the Ethics ...

No abstract

Objective: To assess the effects of drug-induced changes in mean transit time (MTT) on the activity of human fecal¯ora in vitro. Methods: The activity of fecal¯ora was estimated by the ability of a fecal inoculum to ferment a substrate (beet ®ber) in vitro in a batch system for 24 h. The inoculum was collected from 8 healthy volunteers studied during three 3-week randomized periods, who received a controlled diet alone (control period) or the same diet with either cisapride or loperamide. Cisapride and loperamide were adjusted in order to halve and double MTT measured during the control period. At the end of each period, the percentage disappearance of the initial added substrate and the concentration and the pro®le of short-chain fatty acids (SCFAs), were determined. Results: In the control period, the pH of the inoculum and SCFA concentration were inversely related to MTT (P 0.0001). Individual SCFA production was also signi®cantly related to MTT (P`0.01). Cisapride-reduced transit time was associated with a signi®cant rise in the concentrations of total SCFAs (P`0.05), propionic and butyric acids (P`0.05) and the percentage substrate disappearance (P`0.05). Inverse relations were observed during the loperamide period. Moreover, MTT was inversely related to the percentage substrate disappearance (P`0.001), SCFA production (P`0.001) and butyrate production (P`0.0005). Conclusion: Changes in MTT alter bacterial activity and modify the bacterial pathways affecting the proportion of individual SCFAs. Sponsorship:

Six healthy young men were studied by indirect calorimetry for 6 h after eating a meal composed of glucose or manioc starch (equivalent to 50 g dextrose). Blood was drawn every 30 min for 6 h to measure plasma glucose, free fatty acid (FFA), and insulin concentrations. The glycemic index of the starch was 57%. Plasma insulin and glucose concentrations were significantly higher from 150 to 210 min and FFA concentrations remained significantly lower from 210 to 360 min after starch than after glucose. Carbohydrate oxidation rose from a similar initial concentration for glucose and starch, to a constant concentration until 200 min before becoming significantly higher for the starch load until the end of the test. Total glucose oxidation was significantly higher with starch. Total fat oxidation did not differ after the two loads. A negative correlation was found between glucose oxidation and plasma FFA concentrations. Use of low-glycemic-index carbohydrates increases carbohydrate oxidation because of lower plasma FFA concentrations and fat oxidation.