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Y Ghoos

Publications and source records attributed to Y Ghoos.

At least 37 records · Page 2Linked to original sources
PubMed1998

Digestibility of cooked and raw egg protein in humans as assessed by stable isotope techniques.

Egg proteins contribute substantially to the daily nitrogen allowances in Western countries and are generally considered to be highly digestible. However, information is lacking on the true ileal digestibility of either raw or cooked egg protein. The recent availability of stable isotope-labeled egg protein allowed determination of the true ileal digestibility of egg protein by means of noninvasive tracer techniques. Five ileostomy patients were studied, once after ingestion of a test meal consisting of 25 g of cooked 13C- and 15N-labeled egg protein, and once after ingestion of the same test meal in raw form. Ileal effluents and breath samples were collected at regular intervals after consumption of the test meal and analyzed for 15N- and 13C-content, respectively. The true ileal digestibility of cooked and raw egg protein amounted to 90.9 +/- 0.8 and 51.3 +/- 9.8%, respectively. A significant negative correlation (r = -0.92, P < 0.001) was found between the 13C-recovery in breath and the recovery of exogenous N in the ileal effluents. In summary, using the 15N-dilution technique we demonstrated that the assimilation of cooked egg protein is efficient, albeit incomplete, and that the true ileal digestibility of egg protein is significantly enhanced by heat-pretreatment. A simple 13C-breath test technique furthermore proved to be a suitable alternative for the evaluation of the true ileal digestibility of egg protein.

Adult↗
PubMed1998

Lipid digestion in cystic fibrosis: comparison of conventional and high-lipase enzyme therapy using the mixed-triglyceride breath test.

BACKGROUND: Fat maldigestion occurs in most patients with cystic fibrosis. Conventional pancreatic enzyme replacement therapy partially corrects this defect. In this study, the mixed-triglyceride breath test was used to evaluate whether high-lipase enzymes are equivalent to conventional enzymes in improving fat maldigestion in children with cystic fibrosis. METHODS: Fat digestion was studied in 11 patients with a mean age of 10.5 years. The mean intake of conventional enzyme capsules a day was 19. Four 13C mixed-triglyceride tests were performed on separate days and in random order. One test was taken without enzyme substitution, one with three capsules of 8,000 FIP units Creon (pancreatinum, Kali-chemie Pharma, Hannover, Germany) and one with one capsule of 25,000 FIP units. The fourth test was made with 13C octanoic acid to study gastric emptying time. RESULTS: Without enzyme intake, the mean cumulative percentage of 13C dose exhaled after 6 hours was 7.2+/-3.7%. This increased to 14.4+/-4% with intake of conventional pancreatinum and to 14.3+/-5.1% with intake of high-lipase pancreatinum (p = 0.0008 for both; paired t-test). There was no difference between both treatments. Also, the time course of 13C exhalation measured by percentage of 13CO2 exhaled per hour did not differ between enzyme treatments. CONCLUSIONS: The 13C mixed-triglyceride test is noninvasive and documents improved lipid digestion with pancreatic enzyme replacement therapy. If the lipase dose is kept constant, results obtained with high-lipase preparations are equivalent to those obtained with conventional preparations.

Adolescent↗
PubMed1998

Relationship between the results of pre-treatment urea breath test and efficacy of eradication of Helicobacter pylori infection.

AIMS: This study was carried out to evaluate whether the 13C-urea breath test could assess the intragastric Helicobacter pylori load and predict the outcome of infected subjects undergoing short-term triple therapy. METHODS: A total of 108 infected patients underwent upper endoscopy with antral biopsies and histological grading of Helicobacter pylori density. These patients received omeprazole 20 mg b.i.d., clarithromycin 500 mg b.i.d., and amoxycillin 1000 mg b.i.d. or tinidazole 500 mg b.i.d. for one week. 13C-urea breath test (75 mg 13C-urea; results expressed as Delta Over Baseline values at 30') was performed before and after therapy. According to pre-treatment Delta Over Baseline at 30' values, patients were assigned to low (< 16/1000), intermediate (16-35/1000) and high (> 35/1000) Delta Over Baseline at 30' groups. RESULTS: A significant correlation was found between pre-treatment Delta Over Baseline at 30' values and the density of Helicobacter pylori (rs = 0.76). The eradication rates were 82%, 67%, and 17% in the low, intermediate, and high Delta Over Baseline at 30' groups, respectively (p = 0.0001). When classified according to the outcome of therapy, the median pre-treatment Delta Over Baseline at 30' value was 15.7 in eradicated subjects vs 21.6 in non eradicated patients (p = 0.002). In patients who failed eradication, a significant difference was also observed between pre- and post-treatment Delta Over Baseline at 30' values (21.6 vs 15.6, p = 0.019). CONCLUSIONS: The 13C-urea breath test can be used to evaluate the intragastric bacterial load and to predict the outcome of standard eradication treatment.

Adult↗
PubMed1997

Clustering of increased small intestinal permeability in families with Crohn's disease.

BACKGROUND & AIMS: Small intestinal permeability is increased in a proportion of patients with Crohn's disease (CD) and a subset of their healthy relatives. A primary permeability defect was postulated in the pathogenesis of the disease. The aim of this study was to identify a possible genetic pattern in the distribution of CD and/or abnormal permeability. METHODS: Differential urinary excretion of lactulose and mannitol (L/ M) in complete CD families was determined. Controls included healthy families and families with ulcerative colitis. Pedigrees were used to compare the distribution of CD and/or increased permeability. RESULTS: The L/M was significantly increased in patients with CD. Seventeen of 67 first-degree relatives (25%) had a ratio greater than the upper limit (P95 = 0.0170). Permeability results of CD families showed a highly significant familial aggregation. The lack of a genetic pattern in relation with CD and occurrence of disturbed permeability especially within generation, points toward a shared environmental factor. Five of 14 healthy spouses (36%) of patients with CD had also an increased permeability, and prevalence of increased permeability was not higher in families with known familial occurrence (P = 0.85). CONCLUSIONS: This large family study confirms an increased permeability in a subset of healthy relatives of patients with CD. However, the absence of a typical family pattern and the high prevalence in spouses is in favor of a common nongenetic factor or a subclinical disease manifestation.

Adolescent↗
PubMed1997

A new look at dietary carbohydrate: chemistry, physiology and health. Paris Carbohydrate Group.

The current view of dietary carbohydrates as simply providing us with energy is outdated. Because of their varied chemistry and physical form the rate and extent to which the different types are digested in and absorbed from the small intestine varies. This in turn leads to affects on satiety, blood glucose and insulin, protein glycosylation, lipids and bile acids. Some carbohydrates reach the colon where they are fermented and affect many aspects of large bowel function, colonocyte and hepatic metabolism. A new framework for classifying and measuring food carbohydrates is needed to allow a greater understanding of the role of individual species in health and to inform the public of their importance. A classification based primarily on molecular size (degree of polymerisation) into sugars, oligosaccharides and polysaccharides, is suggested, with sub-groups identified by the nature of the monosaccharides. Greater knowledge of the chemical and physical properties of carbohydrates allow a more precise relation with physiology and health to be drawn. The Carbohydrate Group met in Paris in December 1995 at the invitation of Gerard Pascal, Director of CNERNA. Financial support for the meeting was provided by CNERNA.

Carbohydrates↗
PubMed1997

Production of egg proteins, enriched with L-leucine-13C1, for the study of protein assimilation in humans using the breath test technique.

Protein assimilation and metabolism studies are hindered by the lack of an adequate oral tracer, i.e., labeled proteins. We present a new and easily reproducible methodology for producing large amounts of egg proteins labeled with L-leucine-13C1. Laying hens were fed a 0.2% leucine-deficient food supplemented with 0.2% L-leucine-13C1 (99 atom %). At plateau, eggs containing highly enriched proteins were obtained. The 13C content of egg white relative to the total C content was 1.3371 atom %, corresponding to delta = 206%. The overall tracer recovery in egg proteins was high (40.2%), making this method financially attractive as well. Accurately measurable levels of 13CO2 in breath were obtained after ingestion of a physiological load of labeled egg white proteins. Thus, egg proteins with sufficient 13C enrichment and applicable for human protein assimilation and metabolism kinetic studies were produced in an easily reproducible and highly efficient manner.

Adolescent↗
PubMed1997

Helicobacter pylori infection and growth delay in older children.

It is thought that Helicobacter pylori infection may influence growth rate in children. The aim of this study was to evaluate the prevalence of H pylori infection in healthy Italian children, and to look for differences in height between infected and non-infected subjects. Two hundred and sixteen children, aged 3 to 14 years, were tested for H pylori infection by 13C-urea breath test. Centile values for height were calculated. Composite indices for socioeconomic class and household crowding were also determined. Forty nine of 216 children (22.7%) were H pylori positive. The prevalence of infection increased with age. Eight of 49 H pylori positive children (16.3%) were below the 25th centile for height, compared with 13 of 167 H pylori negative children (7.8%). This difference became significant in children aged 8.5 to 14 years; in this group (n = 127), eight of 31 infected children (25.8%) were below the 25th centile for height, compared with eight of 96 non-infected children (8.3%). A significant correlation was found between socioeconomic conditions, household crowding, and H pylori status. By using stepwise logistic regression, only the centile value for height was significantly related to H pylori status in older children. Thus H pylori infection was associated with growth delay in older children, poor socioeconomic conditions, and household overcrowding. This finding is consistent with the hypothesis that H pylori infection is one of the environmental factors capable of affecting growth.

Adolescent↗
PubMed1997

Influence of dietary protein supplements on the formation of bacterial metabolites in the colon.

BACKGROUND: To evaluate the influence of increased dietary protein intake on bacterial colonic metabolism in healthy volunteers. METHODS: Short chain fatty acids, ammonia, and volatile organic compounds in faecal samples, and phenols in the urine of five volunteers were measured after one week of basal nutrient intake and and after one week of a diet supplemented with a protein rich food (Fortimel; Nutricia, Zoetermeer, The Netherlands). Paired t tests and factor analysis were used for statistical analysis. RESULTS: Total energy and resistant carbohydrate intake remained unchanged in each study period. The percentage energy intake delivered as dietary protein, increased significantly (from 15.4% to 23.8%; p = 0.007) during supplement intake. A significant increase in faecal ammonia (p = 0.002), faecal valeric acid (p = 0.02), and urinary p-cresol (p = 0.04) was noted during supplementary protein intake. A total of 120 different volatile compounds were isolated from the faecal samples of which 10 increased significantly during dietary protein supplementation. The change in volatile pattern, especially for S containing metabolites, was clearly shown by a factor analysis model which made a distinction between the two dietary regimens for all volunteers. CONCLUSION: An increase in dietary protein leads to altered products formation by colonic metabolism, mainly reflected by an increase in faecal ammonia, faecal volatile S substances, and urinary p-cresol.

Adult↗
PubMed1997

Breath tests in Helicobacter pylori infection: methodological aspects.

The urea breath test (*C-UBT) is generally considered as a simple, non-invasive and accurate test to demonstrate Helicobacter pylori (Hp) infection. Sensitivity and specificity vary between 95-100%. Some authors even claim that this test should be considered 'gold standard' for the detection of active Hp infection. Although today many centres already use this test in clinical praxis, there exists no uniformity in test protocol. Most modifications recently published in literature, had only minor impact on the accuracy of the test. More important than 'inventing' the n'th *C-UBT, there is a need for a consensus on features such as: which isotope, is a test meal necessary and which one should be used, what is the appropriate urea dose, how many breath samples should be taken and at what time interval, is there a difference between children and adults, what is the most appropriate method to differentiate between buccal and stomach urease activity. Even the expression of the cut-off value has to be defined. Ideally, the answers should result in one *C-UBT which can be used in research and clinical practice. In conclusion, *C-UBT is a simple, non-invasive and accurate test to demonstrate H. pylori infection. To make results comparable there is an absolute need for standardisation in methodology.

Adult↗
PubMed1996

The 13C-octanoic acid breath test: a noninvasive technique to assess gastric emptying in preterm infants.

Gastric emptying (GE) is difficult to evaluate properly in preterm infants because of the lack of safe and reliable noninvasive methods. The 13C-octanoic acid breath test, a noninvasive method to assess GE, was validated in adults. The aim of this study was to adapt the methodology of the 13C-octanoic acid breath test regarding test meal and sampling methods and to define normal values for healthy preterm infants. We tested 11 clinically stable preterm infants who demonstrated normal fetal growth. The infants mean gestational age at birth was 33 weeks, mean birth weight was 1754 g, mean postnatal age at the day of study was 26 days, and mean weight was 2296 g. After a fasting period of 3 h, the subject was fed a test meal with low and stable 13C background activity mixed with 50 microliters of 13C-labeled octanoic acid and 1 g polyethylene glycol 3350. Breath samples were collected using a nasal prong in basal conditions and after the test meal. CO2 production according to weight and age was used in the calculations for 13CO2 enrichment of exhaled air. Results were expressed as percentage of 13C dose excretion per hour and percentage of cumulative 13C after 4h. gastric emptying coefficient (GEC), and gastric half-emptying time (t1/2b). The values for percent of cumulative 13C after 4 h ranged from 30.7 to 52.6% (mean, 40.2%), GEC ranged from 2.7 to 3.4 (mean, 3.0), and the values for t1/2b ranged from 17 to 100 min (mean, 57 min). We conclude that the 13C-octanoic acid breath test can be adapted to preterm infants to allow the study of GE in various conditions.

Breath Tests↗
PubMed1995

The influence of isolated doses of drugs, feeding and colonic bacterial ureolysis on urea breath test results.

BACKGROUND: Aim of this work was to improve standardization of the 13C-urea breath test (13C-UBT) by evaluating the effect of drug administration, feeding and colonic ureolysis on the UBT results. METHODS: Three different studies were performed. First, a 13C-UBT was performed in 41 Helicobacter pylori infected subjects before and after 1 day of therapy with sucralfate (5 g), colloidal bismuth (600 mg), amoxycillin (2.5 g) or omeprazole (40 mg). Second, a 13C-UBT was performed in 10 H. pylori-positive patients after an overnight fast and repeated 2 h after lunch. Finally, a 13C-UBT was carried out in seven healthy volunteers, with breath sampling prolonged to 6 h to investigate colonic bacterial ureolysis. RESULTS: Even a short course of drugs specific for H. pylori may result in a falsely negative 13C-UBT. Feeding does not interfere with the 13C-UBT in infected subjects. No significant 13C-urea breakdown by colonic bacteria is observed during the 13C-UBT when it is prolonged to 6 h. CONCLUSION: The 13C-urea breath test is a sensitive clinical tool for the non-invasive diagnosis of H. pylori infection. It is unaffected by feeding or colonic ureolysis. However, false negative results are likely even after 1 day of therapy with bactericidal, 'cytoprotective' or antisecretory drugs.

Adult↗
PubMed1995

The urea breath test: a non-invasive clinical tool for detecting Helicobacter pylori infection.

The urea breath test exploits the urease enzyme of Helicobacter pylori. The hydrolysis of labelled urea releases labelled carbon dioxide that is excreted in the breath. Distribution of urea throughout the stomach prevents sampling errors and allows for semiquantitative assessment of the extent of Helicobacter pylori infection. The urea breath test is very specific and sensitive and can be proposed as the method of choice for detecting Helicobacter pylori infection in ulcer patients before and after eradicating treatment as well as in epidemiological studies.

Breath Tests↗
PubMed1994

Screening method for the determination of volatiles in biomedical samples by means of an off-line closed-loop trapping system and high-resolution gas chromatography-ion trap detection.

A method is described for the analysis of volatile organic compounds in biological matrices (faeces and urine). The technique is based on off-line preconcentration by means of a closed-loop trapping system followed by high-resolution gas chromatography-ion trap detection (HRGC-ITD) for separation and identification of the compounds. The technique has been validated for pattern recognition in faecal and urine samples from healthy volunteers. It is considered a very promising tool in metabolic research.

Carbohydrates↗
PubMed1994

Increased permeability of macroscopically normal small bowel in Crohn's disease.

To investigate permeability alterations of the macroscopically normal jejunum in Crohn's disease, the permeation of two probes was measured during perfusion of an isolated jejunal segment. The data were compared with the results obtained by the standard per oral test in the same patients. Test probes were PEG-400 and [51Cr]EDTA. Ten normal individuals, 12 patients with Crohn's ileitis or ileocolitis, and seven patients with isolated Crohn's colitis all with normal jejunum on x-ray series were studied. Upon perfusion of the proximal small bowel, the 3-hr [51Cr]EDTA excretion was significantly increased in ileitis patients (P = 0.023) as compared to normals. The excretion exceeded the highest value of normals in eight of 12 ileitis patients. The excretion in Crohn's colitis patients was not significantly increased (P = 0.24) and abnormal excretion was found only in one of the Crohn's colitis patients. PEG-400 permeation during perfusion did not differentiate between the groups, but five of the seven patients with isolated Crohn's colitis had PEG-400 excretion exceeding the highest value in normals. Overall, 13 of the 19 patients had increased permeation of one of the two probes through jejunal mucosa during perfusion. These data suggest that the permeability is increased in the majority of patients even in segments that seem normal on x-ray.

Adult↗
PubMed1994

Test conditions greatly influence permeation of water soluble molecules through the intestinal mucosa: need for standardisation.

Permeability tests are widely used to investigate the pathogenesis of various gastrointestinal diseases including coeliac disease, infectious diarrhoea, and inflammatory bowel disease. In Crohn's disease they are used as activity parameters by some investigators. Lack of standardisation, however, makes it very difficult to compare data reported in different studies. The aim of this study was to gather permeation data in well controlled test conditions to standardise the methods. Nine healthy volunteers each received five consecutive permeability tests by mouth using polyethylene glycol-400 (PEG-400) and 51Cr-EDTA as probe molecules. The probes were dissolved in water, a glucose solution, a starch solution, a hyperosmolar lactulose-mannitol solution, and a liquid meal. A significantly decreased permeation for both probes was found when given with the hyperosmolar solution. The 51Cr-EDTA permeation was also decreased with water. The permeability index, 51Cr-EDTA/PEG-400, corrected for influencing factors, confirmed that the lactulose-mannitol solution and plain water yield lower values of macro-molecule permeation than starch, glucose or liquid meal. Hyperosmolarity was clearly accompanied by a decrease in permeability probably caused by reversed solvent drag. Interindividual variability of probe permeation and permeability index is very low with a standard liquid meal. It is proposed that for permeability studies a standard liquid meal is always used.

Adult↗
PubMed1993

Metabolism of erythritol in humans: comparison with glucose and lactitol.

The metabolism of erythritol was assessed in six normal volunteers by measuring the amount of 13CO2 excretion and H2 excretion in breath, and erythritol in urine after intake of 25 g 13C-labelled erythritol. The results were compared with the same variables obtained after intake of 25 g 13C-labelled glucose and 13C-labelled lactitol. In addition, the H2 production by faecal flora supplemented with small amounts of erythritol, glucose and lactitol was measured in vitro, as an index of bacterial metabolism of non-absorbed substrate. In contrast to the results obtained after intake of glucose and lactitol, no increase in breath 13CO2 and H2 was observed after intake of erythritol, and erythritol was nearly completely recovered in urine. The in vitro experiments showed that no H2 was formed by faecal flora from erythritol as compared with glucose and lactitol. It is concluded that erythritol is a substrate that is readily absorbed, and undergoes no metabolism by the host. If part of it escapes absorption, it is not metabolized by faecal flora.

Adult↗
PubMed1992

Effects of acarbose on starch hydrolysis. Study in healthy subjects, ileostomy patients, and in vitro.

The effect of acarbose on hydrolysis of a pure starch meal was investigated in normal subjects and ileostomy patients by means of 13CO2 breath tests and blood glucose levels as parameters of absorption, and of H2 breath tests, serum acetate levels, and ileal loss of carbohydrate as parameters of malabsorption. Additional information on the effect of acarbose on alpha-amylase activity was obtained by in vitro experiments. Acarbose (200 and 400 mg) significantly delayed starch absorption. Serum acetate was found to be a less sensitive marker of malabsorption than breath H2 excretion. After intake of 50 g starch plus 400 mg acarbose, 23-71% of the starch load was lost in the ileostomy effluent, for a large part as starch. This suggests that acarbose considerably inhibits alpha-amylase, and not only brush-border enzymes. In vitro experiments confirm that an inhibition of two thirds of alpha-amylase activity can be expected from pharmacologically used doses of acarbose.

Acarbose↗