Effect of a lacto-ovo vegetarian diet on fasting small intestinal motility.

BACKGROUND: Changes in diet can alter gastric and small intestinal (SI) motility. The effects of a vegetarian diet on fasting SI motility are unknown. METHODS: Manometric studies were performed in 9 lacto-ovo vegetarians (7 women) and 9 omnivores (7 women) of similar age and body mass index. On each study day, manometry was used to assess SI motility for 5 h, or 3 complete cycles of the interdigestive motor complex (IDMC). Lacto-ovo vegetarians were studied once: omnivores were studied twice, on their usual diet, and after consuming a 14-day lacto-ovo vegetarian diet. Diet diaries were kept for 5 days prior to each manometric study. Data were analysed for dietary composition and for cycle length and duration of each phase (I, II and III) of the IDMC. RESULTS: Dietary intake did not differ between chronic vegetarians and chronic omnivores apart from a trend to higher fibre intake (29 +/- 3 versus 20 +/- 3 g/day; P = 0.058). Omnivores eating a vegetarian diet showed a trend to decreased alcohol consumption (P = 0.068), but did not increase their fibre intake (20 +/- 3 versus 21 +/- 3 g/day). Neither cycle length nor duration of each IDMC phase differed between chronic vegetarians and chronic omnivores. After 14 days of a vegetarian diet, omnivores had a reduction in cycle length (128 +/- 19 versus 86 +/- 12 min; P = 0.02), with a non-significant reduction of Phase II (99 +/- 20 versus 50 +/- 8 min: P = 0.066). CONCLUSIONS: A chronic vegetarian diet has no major effect on fasting SI motility; but acute dietary change may alter the cycle length and component phases of the IDMC.

Delayed gastric emptying in ventilated critically ill patients: measurement by 13 C-octanoic acid breath test.

OBJECTIVE: To measure gastric emptying in ventilated critically ill patients with a new noninvasive breath test. DESIGN: Single-center, open study. SETTING: Combined medical and surgical intensive care unit of a university hospital. SUBJECTS: Thirty unselected mechanically ventilated critically ill patients receiving gastric feeding and 22 healthy volunteers. INTERVENTIONS: None. PATIENTS: After 4 hrs without feeding, intragastric infusion of 100 mL of a liquid meal (Ensure) labeled with 100 microL 13C-octanoic acid. End-expiratory breath samples were collected into evacuated tubes from the respirator circuit every 5 mins for the first hour, then every 15 mins for 3 hrs. End-expiratory breath samples were also collected from volunteers studied supine after an overnight fast following an identical infusion via a nasogastric tube. Breath 13CO2 was measured with an isotope ratio mass spectrometer. MEASUREMENTS AND MAIN RESULTS: Performance of the breath test posed no difficulty or interference with patient care. The CO2 level was >1% in 1297/1300 breath samples, indicating satisfactory end-expiratory timing. Data are median and interquartile range. Gastric emptying was slower in patients compared with volunteers: gastric emptying coefficient 2.93 (2.17-3.39) vs. 3.58 (3.18-3.79), p <.001 and gastric half emptying time, derived from the area under the 13CO2 curve, 155 min (130-220) vs. 133 min (120-145), p <.008. Fourteen of the 30 patients had a gastric emptying coefficient <95% of all volunteers and 11 had a gastric half emptying time longer than 95% of all volunteers. The Acute Physiology and Chronic Health Evaluation (APACHE II) score (median 22, range 13-43) either at admission or on the day of the study did not correlate with gastric emptying coefficient. CONCLUSION: Gastric emptying of a calorie-dense liquid meal is slow in 40% to 45% of unselected mechanically ventilated patients in a combined medical and surgical intensive care unit. The 13C-octanoic acid breath test is a novel and useful bedside technique to measure gastric emptying in these patients.

Evaluation of miniature manometric techniques for the measurement of esophageal body pressure waves.

BACKGROUND AND AIMS: Perfused miniature manometric assemblies with lumina of 0.4-0.5 mm i.d. have been developed. Reduced luminal size offers the advantages of reduced assembly bulk and increased assembly complexity with greater numbers of lumina and lower manometric infusion volumes because of a slower perfusion rate. This study investigated the recording fidelity of miniature manometric assemblies in the measurement of esophageal peristalsis. METHODS: Four miniature manometric assemblies, each containing manometric lumina of either 0.4 or 0.5 mm i.d., were evaluated at 100 and 180 cm lengths. The fidelity of miniature manometric luminal recordings were evaluated in vivo during esophageal peristalsis by using a simultaneous comparison with the standard lumina and an intraluminal strain gauge. RESULTS: During esophageal peristalsis, miniature manometric lumina recorded the peak amplitude of pressure waves, with an accuracy at perfusion rates of 0.04 mL/min (0.4 mm, i.d.) and 0.15 mL/min (0.5 mm, i.d.). CONCLUSION: Miniature manometric assemblies of lengths that are practical for use in humans are suitable for recording esophageal peristalsis.

Assays for total and antigen-specific polymeric IgA in serum based on binding to secretory component.

Binding assays with secretory component (SC) were used to detect polymeric IgA antibody to E. coli lipopolysaccharide and to estimate total polymeric IgA in sera from 14 patients with alcoholic liver disease and eight normal controls. Radioiodinated human SC was shown to bind to polymeric IgA and IgM but not to monomeric IgA, secretory IgA or IgG. Serum aliquots (0.5 ml) were totally depleted of IgM using 2 ml anti-IgM affinity columns and the effluent sera were titrated in microtitre plates coated with lipopolysaccharide, the binding of polymeric IgA being detected by adding 10 ng radiolabelled SC. Total polymeric IgA was measured via its capacity to inhibit the binding of 5 ng labelled SC to IgM coated wells, quantitation being achieved by comparison with the inhibition produced by purified polymeric IgA. Total lipopolysaccharide-specific IgA antibody was detected by ELISA in sera from both patients and controls, 1185 +/- 793 and 56 +/- 19 U/100 microliters (mean +/- SD), respectively; but polymeric IgA antibody was detected only in patients' sera (131 +/- 214 U/100 microliters). The concentration of total polymeric IgA was higher in patients' sera than in control sera (488 +/- 333 and less than 120 micrograms/ml respectively).