Small intestinal mucosal pattern of Myanmar children.

BACKGROUND: Little is known about the small intestinal mucosal pattern of Myanmar children. METHODS: Duodenal, jejunal and ileal mucosal specimens obtained from children within 6 h of death were examined under a dissecting microscope with the objective of determining villus pattern in relation to site within the small intestine and then correlated with age. RESULTS: Abnormalities in the small intestinal mucosa were detected at a very young age. In children under 1 year of age, the changes are more marked proximally and become less marked distally, perhaps reflecting exposure to the causative agent(s) in early life. Presumably these agents are ingested orally and inactivated progressively. The pattern in older children reflects more severe changes in the ileum. CONCLUSIONS: It is postulated that frequent intestinal infections or small bowel bacterial contamination could lead to damage of the intestinal mucosa.

Screening for colorectal cancer: what is the most cost-effective approach?

In Western countries, including Australia, colorectal cancer is the leading cause of cancer mortality in nonsmokers. Development of most colorectal cancers can be prevented by adenoma removal. The current screening strategies of faecal occult blood testing (FOBT), flexible sigmoidoscopy combined with FOBT and colonoscopy are all cost effective. In clinical practice, a range of options should be offered to allow for individual patients' preferences. A public education program is essential to the success of any screening strategy.

Small intestinal mucosal immunity and morphometry in luminal overgrowth of indigenous gut flora.

OBJECTIVE: The aim of this study was to investigate the separate effects of indigenous oropharyngeal- and colonic-type flora on small intestinal mucosal immunity and morphometry in small intestinal bacterial overgrowth (SIBO). METHODS: A duodenal aspirate and random biopsies of underlying mucosa were obtained from 52 adult subjects (age range, 18-90 yr; median, 60 yr) without disorders that may otherwise disturb small intestinal histology or mucosal immunity. Villus height, crypt depth, villus/crypt ratios, counts of intraepithelial lymphocytes (IELs) and lamina propria total mononuclear cells, IgA, IgM, and IgG plasma cells, mast cells, and B and T lymphocytes were determined in relation to the presence or absence of SIBO and the nature of the overgrowth flora in all subjects. CD4+ve and CD8+ve T-cell counts were determined in 24 subjects. RESULTS: SIBO was present in 26 of 52 (50%) subjects. Overgrowth flora included colonic-type bacteria in 20 subjects and oropharyngeal-type flora alone in 6 subjects. Lamina propria IgA plasma cell counts were significantly increased in subjects with SIBO, irrespective of whether the overgrowth flora comprised oropharyngeal-type flora alone or included colonic-type bacteria. Neither villus height, crypt depth, villus/crypt ratios, nor total or other mononuclear cell counts in lamina propria differed significantly between subjects with and without SIBO, irrespective of the nature of the overgrowth flora. IEL counts were significantly higher than in culture-negative subjects only when the overgrowth flora included colonic-type bacteria. Even then, IEL counts were within a range currently considered normal. A significant, inverse correlation between advancing age and IEL counts became apparent after adjusting for the effect of SIBO of colonic-type flora. CONCLUSIONS: SIBO of oropharyngeal- and colonic-type flora are associated with differing disturbances of local duodenal mucosa. Nonetheless, these would not be readily apparent during routine histological assessment. Old age independently influences duodenal IEL counts.

Evaluation of the rice breath hydrogen test for small intestinal bacterial overgrowth.

OBJECTIVES: The aims of this study were 1) to document the sensitivity, specificity, and predictive values of the rice breath hydrogen test for small intestinal bacterial overgrowth; 2) to determine the possible influence of concurrent gastric bacterial overgrowth and gastroduodenal pH on the efficacy of this test; and 3) to investigate whether reliability is limited by an inability of small intestinal luminal flora to ferment rice or its product of hydrolysis, maltose. METHODS: Twenty adult subjects were investigated with microbiological culture of proximal small intestinal aspirate and a 3-g/kg rice breath hydrogen test. Gastroduodenal pH, the presence or absence of gastric bacterial overgrowth, and the in vitro capability of small intestinal luminal flora to ferment rice and maltose, its product of hydrolysis, were determined. RESULTS: Sensitivity of the rice breath hydrogen test for small intestinal bacterial overgrowth was 33% and remained low even when subjects with small intestinal overgrowth with oropharyngeal-type (38%) and colonic-type flora (20%) and those with concurrent small intestinal and gastric bacterial overgrowth (40%) were considered separately. Sensitivity remained suboptimal despite favorable gastroduodenal luminal pH and documented ability of bacterial isolates to ferment rice and maltose in vitro. Specificity of the rice breath hydrogen test for small intestinal bacterial overgrowth was 91%. Positive predictive value, negative predictive value, and predictive accuracy were 75%, 63%, and 65%, respectively. CONCLUSIONS: Clinical value of the rice breath hydrogen test for detecting small intestinal bacterial overgrowth is limited. The rice breath hydrogen test is not a suitable alternative to small intestinal intubation and culture of secretions for the detection of small intestinal bacterial overgrowth.

Heartburn: community perceptions.

BACKGROUND AND AIMS: To determine the prevalence of heartburn in the Australian community, and document factors precipitating it and medications used in treatment. METHODS: Telephone interviews with 1200 individuals aged 18 years or more were conducted one weekend in 1996. Each respondent was asked four questions about heartburn, its severity, factors causing it and current therapy. RESULTS: Fifty-six per cent of respondents reported that they had suffered from heartburn at some time in the past and 37% had symptoms at least once every 4-6 months. The frequency of heartburn increased with age and was more common in men (40.7%) than women (32.6%). There was no difference in frequency between city and rural dwellers, or between white- and blue-collar workers. Almost half the individuals experienced mild pain or discomfort, one-third had moderate discomfort and 15% reported severe pain or discomfort. Women were more likely to report greater problems than men. Aggravating factors included spicy foods, greasy/rich foods, stress, alcohol, overeating, pregnancy, smoking, food allergy and coffee. More than half the respondents relied on antacids to control symptoms, 20% used prescription medications and a similar number did not use any medication. CONCLUSION: Heartburn is common in the Australian community and sufferers attribute symptoms to various lifestyle events, including diet and stress. Antacid usage is the commonest mode of therapy.

Investigation of small-intestinal transit time in normal and malnourished children.

We aimed to establish whether there was a variation in orocecal transit time (OCTT) in Myanmar children and whether shortened transit time correlated with malnutrition. OCTT was measured in 90 healthy Myanmar children aged 1-5 years, using the hydrogen breath test (10g in 10% aqueous solution). The relationships between OCTT, sex, age, and malnutrition status were assessed. OCTT for 1 to 5-year old children was 90.2 +/- 20min (mean +/- SD). There was no significant difference in mean OCTT between boys and girls, breast-fed and weaned children, malnourished and non-malnourished children. There was also no difference between age groups (1-2 years, 2-3 years, 3-4 years, and 4-5 years), and no correlation was found between age and orocecal transit time. The assessment of OCTT using the lactulose breath hydrogen test was found to be feasible and acceptable in the field setting. The OCTT of Myanmar children with rice as a staple food is similar to that of children from developed countries having a different diet, and no shortening of transit time was demonstrated in children with malnutrition.

Ineffectiveness of breath methane excretion as a diagnostic test for lactose malabsorption.

BACKGROUND: In clinical and field conditions, breath gas analysis has been widely used in evaluating carbohydrate digestion. A field study was performed to determine the prevalence of lactose malabsorption in Myanmar children and to evaluate the possibility of using breath methane excretion to indicate lactose malabsorption in a field situation. METHODS: The study population consisted of 118 children aged 1 to 12 years. A hydrogen breath test after a lactose meal (2 g/kg, maximum 50 g) was used as a standard test. RESULTS: Lactose malabsorption was detected in 16.7% of children aged 1 to 2.9 years, with the prevalence increasing with age from 40.5% of those aged 3 to 5.9 years to 88.5% of those aged 6 to 8.9 years and reaching 91.7% in those aged 9 to 11.9 years. Lactose malabsorption was more prevalent when children were weaned before 4 months of age (87.2 vs. 41.1%; p < 0.01). Compared with lactose-tolerant children, those with lactose malabsorption had significantly higher concentrations of breath hydrogen excretion 60 minutes after the lactose test meal. Breath methane excretion was also significantly higher in samples at 120 minutes in children with lactose malabsorption. Breath methane excretion of greater than or equal to 2 parts per million at 180 minutes as a diagnostic test for lactose malabsorption had a sensitivity of 61.5% and a specificity of 84.6%. CONCLUSION: The breath methane test for lactose malabsorption has a lower sensitivity and specificity than the breath hydrogen test and therefore does not replace the lactose breath hydrogen test.

Serum immunoglobulin and soluble IL-2 receptor levels in small intestinal overgrowth with indigenous gut flora.

Murine studies have demonstrated that the presence of indigenous gut flora is crucial for the induction of systemic immune hyporesponsiveness to antigens initially encountered within the gastrointestinal lumen. This study investigated whether increased titers of such flora, as occur in human small intestinal bacterial overgrowth, may be associated with increased suppression of systemic immune responsiveness and the possible relation between systemic and mucosal immunity in this setting. Serum total immunoglobulin (Ig), immunoglobulin subclass, and soluble interleukin-2 receptor levels and lamina propria IgA plasma cell counts were determined in 50 consecutive subjects with (N = 30) and without (N = 20) small intestinal bacterial overgrowth. Luminal IgA levels were measured in 35 of these subjects. Serum concentrations of IgG3, but not of other immunoglobulin isotypes or soluble interleukin-2 receptors, were significantly reduced in subjects with bacterial overgrowth (P < 0.0005). Small intestinal lamina propria IgA plasma cell counts (P < 0.0005) and luminal IgA concentrations (P = 0.001) were significantly increased in this group. Serum IgG3 levels were significantly inversely correlated with luminal IgA levels (P < 0.01) and fell below the lower limit of normal (0.41 g/liter) in 17/30 (56.7%) subjects with bacterial overgrowth compared to 1/20 (5.0%) subjects without (P < 0.0005). These findings document an association between small intestinal bacterial overgrowth with indigenous gut flora and reduced serum IgG3 reactivity in humans, possibly via an interaction with mucosa-related immunoregulatory mechanisms. The possibility of underlying small intestinal bacterial overgrowth should be considered in patients with serum IgG3 deficiency, especially those with compatible symptoms and/or known predisposition.

Lansoprazole quadruple therapy is effective in curing Helicobacter pylori infection.

BACKGROUND: Quadruple therapy using omeprazole combined with classic bismuth triple therapy has been advocated as optimal therapy for the cure of Helicobacter pylori (H. pylori) infection. We investigated the efficacy of substituting lansoprazole for omeprazole in proton pump quadruple therapy. MATERIALS AND METHODS: In a prospective open study, 219 consecutive patients, with either peptic ulcer disease or biopsy-proven H. pylori-associated gastritis, received seven days of lansoprazole, bismuth, tetracycline and metronidazole after three days of lansoprazole pretreatment. Cure of infection was judged by 14C urea breath test at six weeks after completion of therapy. RESULTS: On an intention to treat basis, 198 of the 219 patients (90%) were confirmed to be cured of H. pylori infection. Compliance was excellent and minimal side effects reported. CONCLUSION: Lansoprazole-based quadruple therapy achieves a very high cure rate in an unselected population of either peptic ulcer patients or those with H. pylori-associated gastritis. Recommended regimens should achieve at least 90% cure of infection. Lansoprazole quadruple therapy is effective and compares favorably with other H. pylori treatment regimens.

Interleukin-6 and small intestinal luminal immunoglobulins.

Our aim was to determine the relationships between interleukin-6 and immunoglobulin levels within small intestinal luminal secretions. Twenty adult subjects with small intestinal bacterial overgrowth (N = 13), irritable bowel syndrome (N = 4), and nonulcer dyspepsia (N = 3) underwent endoscopic aspiration of secretions from the small intestinal mucosal surface for assessment of IL-6, IgA1, IgA2, IgM, IgG1, IgG2, IgG3, and IgG4 concentrations. Serum immunoglobulin concentrations and small intestinal histology were also determined. IgA2 and IgG3 were the predominant IgA and IgG subclasses in luminal secretions in 19/20 (95%) and 20/20 (100%) subjects, respectively. IgA1 and IgG1 predominated in serum in all subjects. No subject had villous atrophy. Luminal IL-6 concentrations correlated significantly with luminal IgA2, IgM, and IgG3 concentrations but not with IgA1 or any other IgG subclass levels. Conversely, luminal IL-6 or immunoglobulin concentrations did not correlate significantly with levels of any immunoglobulin isotype in serum. These observations suggest that important relationships exist between local IL-6 and IgA2, IgM, and IgG3 responses in human small intestinal luminal secretions. Local investigation is mandatory when assessing intestinal immune activity.

Flatus emission patterns and fibre intake.

Knowledge of the normal range of flatus emissions and their relationship to diet, particularly fibre, would be helpful in managing patients who complain of excessive flatus or abdominal distention. Sixty men and 60 women aged between 17 and 67 kept a three-day daily record, including one week-end day, of their flatus emissions, dietary fibre intake and beer consumption. Daily flatus emissions averaged 12.7 (range to 2-53) for men and 7.1 (range 1-32) for women. Fibre intake averaged 28+/-13 g for men and 24+/-3 g for women. Flatus emissions significantly correlated with dietary fibre intake (p<.001). There was a correlation between increased aroma of flatus emissions and beer intake in men and men recorded more aromatic flatus than women. This study of 120 normal individuals eating their choice of foods provides a basis to judge degrees of abnormality in patients complaining of excessive flatus.

Luminal antigliadin antibodies in small intestinal bacterial overgrowth.

OBJECTIVE: Elevated antigliadin antibody levels in small intestinal luminal secretions of subjects with normal or only mildly abnormal small intestinal histology are considered indicative of "latent" or "potential" celiac disease. The purpose of this study was to determine whether small intestinal bacterial overgrowth (SIBO) might provide an alternative explanation for positive luminal antigliadin antibodies in such subjects. METHODS: Twenty-six adult subjects without predisposition to disturbed mucosal immunity were investigated with culture of small intestinal luminal secretions. Luminal total IgA and IgA-antigliadin antibody concentrations were measured by radial immunodiffusion and indirect enzyme immunoassay, respectively. Local mucosal counts of IgA-plasma cells were determined by immunohistochemistry. Small intestinal histology and intraepithelial lymphocyte counts were assessed by light microscopy. Corresponding serum antigliadin antibody concentrations were determined. RESULTS: SIBO was present in 17/26 (65.4%) subjects. No subject with SIBO had villous atrophy. Luminal total IgA concentrations (p < 0.0005), mucosal IgA-plasma cell counts (p < 0.01), and intraepithelial lymphocyte counts (p < 0.01) were significantly increased in subjects with SIBO. Luminal IgA-antigliadin antibodies were detected in 6/17 (35.3%) subjects with SIBO and 0/9 (0%) subjects without SIBO. Luminal IgA-antigliadin antibody concentrations correlated significantly with luminal total IgA levels (p < 0.01) but not with serum values (p < 0.1). Serum IgG-antigliadin antibody concentrations were elevated in 2/6 (33.3%) subjects with SIBO and positive luminal antigliadin antibodies. CONCLUSIONS: SIBO may be an alternative explanation to "latent" or "potential" celiac disease for positive luminal antigliadin antibodies in subjects with either normal or only mildly abnormal small intestinal histology, even when serum antigliadin antibody concentrations are elevated. Positive luminal antigliadin antibodies in SIBO probably occur as epiphenomena in the context of a graded mucosal immune response to local bacterial antigens.

Luminal bacteria and small-intestinal permeability.

BACKGROUND: The influence of luminal bacteria on small-intestinal permeability has not been fully assessed. This study addressed this issue. METHODS: Thirty-four subjects (mean age 64 years; range 22-95 years) were investigated for possible small-intestinal bacterial overgrowth (SIBO) with culture of a small-intestinal aspirate. A lactulose/mannitol small-intestinal permeability test was performed, small-intestinal histology assessed and serum vitamin B12 concentrations measured in all subjects. Permeability was also assessed in a control group of 34 asymptomatic volunteers. RESULTS: Urinary lactulose/mannitol ratios were significantly increased in subjects with SIBO with colonic-type flora (P < 0.0005), even in the absence of villous atrophy. Urinary lactulose/mannitol ratios were increased in this group due to significantly increased urinary lactulose concentrations (P < 0.0005) rather than reduced urinary mannitol levels, after correcting for inter-subject variations in renal function. Counts of intraepithelial lymphocytes of CD8 phenotype were significantly increased in this group (P = 0.003). Although a significant correlation was found between intraepithelial lymphocyte counts and small-intestinal permeability overall (P < 0.002), these counts were not significantly different in subjects with SIBO with colonic-type flora whose permeability values were < or = > 0.028, the upper limit of normal in asymptomatic controls. Serum vitamin B12 concentrations did not differ significantly between groups (P > 0.5). Ageing did not independently influence small-intestinal permeability (P > 0.5). CONCLUSIONS: Small-intestinal permeability is increased in subjects with SIBO with colonic-type bacteria. This effect is independent of ageing and not mediated by vitamin B12 deficiency. Although counts of intraepithelial lymphocytes of CD8 phenotype are increased in this disorder, it is also unlikely that these cells play an important causative role in this process. Routine light microscopic assessment underestimates the prevalence of small-intestinal functional disturbance in this disorder.