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Biomedical subjects

D J Jenkins

Publications and source records attributed to D J Jenkins.

At least 253 records · Page 14Linked to original sources
PubMed1976

Breath-hydrogen test for small-intestinal bacterial colonisation.

Breath-hydrogen production after oral glucose administration was examined in patients suspected of having small-intestinal colonisation and compared with the 14C-glycine-cholate breath test (14C-G.C.) and with bacteriological examination of the small intestine. Of 17 patients, 12 had bacteriological evidence of small-intestinal colonisation. Each breath test showed 8 of the 12 patients to be colonised, but only 5 patients gave positive results with both tests. Nevertheless, using both tests only 1 patients out of 12 with small-intestinal colonisation would have been missed. There were no false-positive results in the 5 bacteriologically normal patients when the breath-hydrogen test was used. It is concluded that simultaneous use of these two relatively simple breath tests may improve the indirect diagnosis of small-intestinal colonisation.

Bacteria↗
PubMed1976

Breath hydrogen in hyposucrasia.

A simple and reliable test for the diagnosis of hyposucrasia is required, since this may be an unsuspected cause of long-standing gastrointestinal disorder. Furthermore little has been done to define the epidemiology of this condition, possibly because of the limitations of multiple blood-sampling. Breath hydrogen (H2) production after lactose ingestion is a reliable test for hypolactasia, and has now been measured after sucrose ingestion in eleven patients with various gastrointestinal symptoms. Six who had normal sucrase activity on jejunal biopsy produced no H2 after taking 50 g of sucrose. No H2 was produced in three patients with borderline hyposucrasia, either after 50 g sucrose or when retested using 100 g sucrose (two patients). However, the two patients with low jejunal sucrase activity showed rises of breath H2, after only 25 g glucose. Breath H2 measurement is a simple, accurate, and non-invasive test for diagnosing gastrointestinal symptoms due to hyposucrasia.

Breath Tests↗
PubMed1976

A simple method of measuring breath hydrogen in carbohydrate malabsorption by end-expiratory sampling.

1. A simple method is described for measuring the hydrogen concentration in alveolar air by end-expiratory sampling, by using a modified Haldane-Priestley tube and gas chromatography. Hydrogen was generated in vivo by ingestion of the non-absorbable sugar lactulose. 2. Alveolar hydrogen concentration showed a highly significant correlation with hydrogen production measured either by a rebreathing technique or by a total collection procedure. 3. The coefficient of variation of the end-expiratory method, assessed by comparing sixty-one paired results, was 11-6%. The coefficient of variation in ten measurements in one subject at 1 min intervals was 17-6%.

Carbohydrate Metabolism↗
PubMed1976

Bacteria, diet, and large bowel cancer.

The influence of various dietary supplements on the fecal bacteria was studied. Substances were chosen for study because they were known to influence body metabolism or had been implicated in the various hypotheses as the cause of large bowel cancer. No alteration in the fecal flora was demonstrated. The implications of these findings are discussed in the light of other investigations with special reference to our theory concerning the cause of large bowel cancer.

Adult↗
PubMed1976

Changes in fecal composition and colonic function due to cereal fiber.

The effect on colonic function of adding wheat fiber for 3 weeks to the metabolically-controlled diets of six healthy volunteers has been studied. Increasing dietary fiber intake from 17 to 45 g/day increased fecal weight from 79 +/- 6.6 g/day to 228 +/- 29.9 g/day and shortened mean transit time, measured by a continuous marker method, from 57.8 +/- 8.3 hr to 40.3 +/- 8.9 hr. The increase in fecal weight was largely due to water. Fiber caused a dilution of fecal marker and an increase in fecal fat, nitrogen, and calcium output. Fecal sodium, potassium, and chloride showed only small changes but volatile fatty acid output increased significantly without concentrations changing. Fecal bile acid output increased from 199 +/- 46 mg/day to 279 +/- 46 mg/day. These changes are discussed in light of current views of the role of dietary fiber in protecting against colon cancer.

Adult↗
PubMed1976

The influence of a diet rich in wheat fibre on the human faecal flora.

The effect on the faecal flora of adding wheat fibre to a controlled diet in four healthy volunteers for a 3-week period has been observed. No change in the concentration of the bacteria in the bacterial groups counted was found, although there was a slight increase in total output associated with increased faecal weight. The predominant organisms in all subjects were non-sporing anaerobes, but the dominant species in each subject was different and was unaffected by changing the diet. Similarly, the concentration of faecal beta-glucuronidase detected in two subjects was unaltered and the concentration of clostridia able to dehydrogenate the steroid nucleus found in one subject was unaltered. It is suggested that the faecal microflora is not primarily controlled by the presence of undigested food residues in the large bowel.

Adult↗
PubMed1976

Measurement of the mean transit time of dietary residue through the human gut.

A new method is described for measuring the mean transit time (MTT) of digesta through the human gut in which a constant amount of marker (radio-opaque pellets) is fed to subjects with each meal over a period of weeks, and its excretion measured in the stools. The MTT measured by this method (MTT-C) has been compared with MTT measured by giving single doses of similar markers to the same subjects (MTT-S) and with the 80% transit time (80% TT). Mean values on three dietary regimes for the MTT-C (54.2 h +/- 2.5) and MTT-S (54.2 +/- 2.6) were lower than that for 80% TT (63.1 +/- 3.0). The average MTT-C in a group of six healthy young men on an ad libitum diet was 2-3 days (range 0-7-4-0). When additional dietary fibre was added to a standard diet the average MTT-C fell (in all of five subjects) from 2-4 to 1-6 days. A continuous record of MTT-C is obtained by this new method which shows wide variations from week to week even on controlled dietary intakes. Using the single dose technique, evidence is produced which suggests that the MTT-S is a more accurate and reproducible method than the 80% TT.

Contrast Media↗
PubMed1976

The relation of impaired vitamin A and E tolerance to fat absorption in biliary diversion.

Eleven patients have been studied after cholecystectomy with exploration of the common bile duct (CBD) and insertion of a T tube for free biliary drainage. Prior to clamping the T tube no significant rise was seen above fasting serum vitamin A and E, or serum triglyceride levels after 6 of the patients had been given these substances in a liquid test meal. In addition no rise in fasting vitamin E levels was seen after 3 subjects had been loaded for 4 days with 0.5 g DL alpha-tocopherol acetate/day. Faecal fat collections performed on 9 subjects indicated that over 70% of the ingested fat was absorbed. All these findings returned to normal when the T tube was clamped and the intraluminal flow of bile re-established. We conclude that deficiency of bile may allow the absorption of fat in the absence of fat soluble vitamins.

Bile↗