Role of pH in production of hydrogen from carbohydrates by colonic bacterial flora. Studies in vivo and in vitro.

Perman, Jay A.; Modler, Siv; Olson, Alfred C.

doi:10.1172/jci110079

Cited by 191 publications

(68 citation statements)

References 24 publications

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“…Digestive tolerance of maltitol A Ruskone-Fourmestraux et al Prolonged ingestion of slowly absorbed sugars, such as lactose and lactulose, results in changes in the metabolic activity of the colonic flora, especially a fall in breath excretion of H 2 , which increases its ability to ferment the sugar (Florent et al, 1985;Flourié et al, 1993;Launiala, 1968;Perman et al, 1981). As a result, there is efficient fermentation of the chronically ingested unabsorbed sugar, and thus a reduction in its diarrhoeogenic effect (Rambaud & Flourié, 1994).…”

Section: Discussionmentioning

confidence: 99%

“…The capacity to ferment unabsorbable sugars, such as lactose and lactulose, and to reduce their laxative effects can, however, be increased by regular ingestion of these sugars, which results in changes in the metabolic activity of the colonic flora, especially a reduced excretion of hydrogen in the breath (H 2 ) (Florent et al, 1985;Flourié et al, 1993;Launiala, 1968;Perman et al, 1981).…”

Section: Introductionmentioning

confidence: 99%

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A digestive tolerance study of maltitol after occasional and regular consumption in healthy humans

Ruskoné-Fourmestraux

Attar

Chassard³

et al. 2003

Eur J Clin Nutr

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Aim: We aimed to evaluate the gastro-intestinal tolerance to an indigestible bulking sweetener containing sugar alcohol using a double-blind random cross-over study. Method: In order to simulate their usual pattern of consumption, 12 healthy volunteers ingested maltitol or sucrose throughout the day, either occasionally (once a week for each sugar, first period) or regularly (every day for two 9 day periods, second period). In both patterns of consumption, daily sugar doses were increased until diarrhea and=or a grade 3 (ie severe) digestive symptom occurred, at which the dose level was defined as the threshold dose (TD). Results: In the first period (occasional consumption), the mean TD was 92 AE 6 g with maltitol and 106 AE 4 g with sucrose (P ¼ 0.059). The mean intensity of digestive symptoms was 1.1 and 1.3, respectively (P ¼ NS). Diarrhea appeared in six and one subjects respectively (P ¼ 0.035). In the second period (regular consumption), the mean TD was 93 AE 9 g with maltitol and 113 AE 7 g with sucrose (P ¼ 0.008). The mean intensity of digestive symptoms was 1.7 and 1.2, respectively (P ¼ NS). However, diarrhea appeared in eight and three subjects, respectively (P ¼ 0.04). Maltitol and sucrose TDs between the two periods were not different. Conclusions: Under our experimental conditions, in comparison to sucrose: (a) occasional or regular consumption of maltitol is not associated with severe digestive symptoms; (b) in both patterns of maltitol consumption, diarrhea frequency is higher, but it appeared only for very high doses of maltitol, much greater than those currently used; (c) maltitol does not lead to intestinal flora adaptation after a 9 day period of consumption.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A digestive tolerance study of maltitol after occasional and regular consumption in healthy humans

Ruskoné-Fourmestraux

Attar

Chassard³

et al. 2003

Eur J Clin Nutr

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“…Information on the influence ofvarious factors on intracolonic bacterial H2 metabolism primarily has been obtained from in vitro studies of fecal homogenates (14)(15)(16). In all such studies H2 production was assumed to equal the volume of H2 recovered from the gas space of the incubation vessel.…”

Section: Discussionmentioning

confidence: 99%

Factors affecting hydrogen production and consumption by human fecal flora. The critical roles of hydrogen tension and methanogenesis.

Strocchi¹,

Levitt²

1992

J. Clin. Invest.

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We studied the influence of hydrogen tension (PH2) and methanogenesis on H2 production and consumption by human fecal bacteria. Hydrogen consumption varied directly with PH2, and methanogenic feces consumed H2 far more rapidly than did nonmethanogenic feces. At low PH2, H2 production greatly exceeded consumption and there was negligible accumulation of the products of H2 catabolism, methane and sulfide. Thus, incubation at low PH2 allowed the first reported measurements of absolute as opposed to net H2 production. Feces incubated at high and intermediate PH2 had a net H2 production of only 1/900 and 1/64 of absolute production. Glucose fermentation by fecal bacteria yielded an absolute H2 production of 80 ml/g, a value far in excess of that excreted by volunteers ingesting lactulose. We conclude that most H2 produced by colonic bacteria is consumed and methanogenesis and fecal stirring (via its influence on fecal PH2) are critical determinants of H2 consumption and, hence, net H2 production. Study of fecal samples from four subjects with low breath H2 excretion after lactulose showed that absolute H2 production was normal, and the low H2 excretion apparently reflected increased consumption due to rapid methanogenesis (two subjects) and decreased luminal stirring (two subjects). (J. Clin. Invest. 1992. 89:1304-1311

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“…However the accuracy of the H2 breath test in the study of chronic carbohydrate malabsorption is debated (1). Perman et al (7) showed that an 8-d oral administration of lactulose resulted in acidic stools and in a dramatic fall of H2 breath excretion after an oral load of this sugar or of lactose in Received for publication I August 1984. lactase-deficient patients. From stool homogenate incubations with various sugars, these authors concluded that the fall of H2 production was due to an inhibition of bacterial carbohydrate metabolism by the low colonic pH (7).…”

Section: Introductionmentioning

confidence: 99%

“…In the first part of our study, Perman et al (7) protocol design was applied to four normal subjects. Hydrogen breath excretion was found reduced after the 84 lactulose administration; however, fecal pH did not decrease and carbohydrates were not excreted in stools, whereas $-galactosidase fecal output increased significantly.…”

Section: Introductionmentioning

confidence: 99%

Influence of chronic lactulose ingestion on the colonic metabolism of lactulose in man (an in vivo study).

Florent¹,

Flourié²,

Leblond³

et al. 1985

J. Clin. Invest.

241

110

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The effects of a chronic load of nonabsorbable sugars on intracolonic bacterial metabolism of carbohydrates and on H2 breath excretion are disputed. However, most of the discussion relies on indirect evidence or on results of in vitro studies. Thus, we attempted to assess directly and in vivo the effects on intracolonic metabolism of lactulose of a chronic oral load of this nonabsorbable disaccharide. 20 g of lactulose was given orally twice daily during 8 d to eight normal volunteers. In all, breath H2 concentration was measured on days 1 and 8 after ingestion of the morning lactulose dose. In four subjects, stools were collected during 2 d at the beginning and at the end of the lactulose maintenance period to measure fecal pH and daily outputs of carbohydrates and P-galactosidase. The four other subjects were intubated on days 1 and 8 to measure the pH and the concentrations of carbohydrates, lactic acid, and volatile fatty acids (VFA) in the distal ileum and cecal contents.Moreover, '4C-lactulose was added to cold lactulose and "CO2 breath outputs determined. Pulmonary H2 excretion fell from day 1 to day 8 (P < 0.05), whereas '4CO2 excretion increased (P < 0.01). Fecal water pH, lactic acid, and VFA concentrations did not vary between the two stool collection periods. 24-h fecal weight, fecal water, and carbohydrate outputs showed a trend to decrease between days 1 and 2 and days 7-8, whereas jlgalactosidase activity rose markedly (P < 0.01). No significant variations were observed for all parameters measured in ileal fluid. In the cecum, areas under the concentration curves decreased from day 1 to day 8 for lactulose, galactose, and fructose (P < 0.01), while an increase was found for lactic acid (P < 0.001), acetic acid (P < 0.0001), and total VFA (P < 0.001). Cecal fluid pH dropped faster (P < 0.05) and to a lower level (P < 0.05) on day 8 than on day 1. These data clearly show that a chronic load of a nonabsorbable sugar induces changes in colonic bacterial metabolic pathways resulting in a better efficiency of the flora to digest the carbohydrate. Introduction Measurement of pulmonary hydrogen (H2) excretion is widely used to diagnose and quantify carbohydrate malabsorption (1-6). However the accuracy of the H2 breath test in the study of chronic carbohydrate malabsorption is debated (1). Perman et al. (7) showed that an 8-d oral administration of lactulose resulted in acidic stools and in a dramatic fall of H2 breath excretion after an oral load of this sugar or of lactose in lactase-deficient patients. From stool homogenate incubations with various sugars, these authors concluded that the fall of H2 production was due to an inhibition of bacterial carbohydrate metabolism by the low colonic pH (7). Unfortunately, they did not measure stool sugar outputs. If their statement was always true, lactose-H2 breath test could be erroneously normal in lactase-deficient patients ingesting every day large amounts of incompletely absorbed carbohydrates, including lactose itself. This is contradictory to the...

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Role of pH in production of hydrogen from carbohydrates by colonic bacterial flora. Studies in vivo and in vitro.

Cited by 191 publications

References 24 publications

A digestive tolerance study of maltitol after occasional and regular consumption in healthy humans

A digestive tolerance study of maltitol after occasional and regular consumption in healthy humans

Factors affecting hydrogen production and consumption by human fecal flora. The critical roles of hydrogen tension and methanogenesis.

Influence of chronic lactulose ingestion on the colonic metabolism of lactulose in man (an in vivo study).

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