Jejunal Aspirates Research Articles

Diagnosis of small intestinal bacterial overgrowth in patients with cirrhosis of the liver: poor performance of the glucose breath hydrogen test

Background/Aims: Small intestinal bacterial overgrowth is known to occur in association with cirrhosis of the liver and studies are needed to assess its patho-physiological role. The glucose breath hydrogen test as an indirect test for small intestinal bacterial overgrowth has been applied to patients with cirrhosis but has not yet been validated against quantitative culture of jejunal secretion in this particular patient population. Methods: Forty patients with cirrhosis underwent glucose breath hydrogen test and jejunoscopy. Jejunal secretions were cultivated quantitatively for aerobe and anaerobe microorganisms. Results: Small intestinal bacterial overgrowth was detected by culture of jejunal aspirates in 73% of patients, being associated with age and the administration of acid-suppressive therapy. The glucose breath hydrogen test correlated poorly with culture results, sensitivity and specificity ranging from 27%–52% and 36%–80%, respectively. Conclusions: In patients with cirrhosis, the glucose breath hydrogen test correlates poorly with the diagnostic gold standard for small intestinal bacterial overgrowth. Until other non-invasive tests have been validated, studies addressing the role of small intestinal bacterial overgrowth in patients with cirrhosis should resort to microbiological culture of jejunal secretions.

Comparison of duodenal with jejunal biopsy and aspirate in chronic human immunodeficiency virus–related diarrhea

Objectives: In human immunodeficiency virus (HIV)-infected patients with chronic unexplained diarrhea, upper endoscopy with small bowel biopsy and aspirate is often performed to identify treatable pathogens. The purpose of this study was to compare the diagnostic yield of duodenal with jejunal biopsy and aspirate. Methods: All HIV-infected patients with chronic unexplained diarrhea who were evaluated by upper endoscopy at Bellevue Hospital Center between January 1992 and January 1997 were identified. Data were collected by reviewing patient charts, endoscopy reports, and pathology records. Results: During the 5-yr study period, 442 patients underwent upper endoscopy with sampling of the duodenum (N = 173) or jejunum (N = 269). A pathogen was identified in 123 patients (27.8%). Microsporidia was the most common organism detected (12.2%). The diagnostic yield of jejunal biopsy and aspirate was significantly higher than that obtained from the duodenum (32.3% vs 20.8%, p = 0.009). Small bowel aspirates detected a pathogen in only 1.8% of patients evaluated, and there was no difference in the yield of duodenal and jejunal aspirates (1.3% vs 2.1%, p = 0.7). Patients with a CD4 count of < 100 cells/mm 3 were significantly more likely to have a pathogen identified than those with higher CD4 counts (38.8% vs 7.1%, p < 0.0001). Conclusions: Upper endoscopy with small bowel biopsy and aspirate identifies a pathogen in 27.8% of individuals with HIV-related chronic unexplained diarrhea. In this patient population, jejunal biopsies acquired by enteroscopy are superior to those obtained from the duodenum. Small bowel aspirates are of little value in the workup of chronic HIV-related diarrhea.

Nutritional status of gastric cancer patients after total gastrectomy.

A number of causes of malnutrition after total gastrectomy have been proposed. The purpose of this study was to assess nutritional status and to determine the cause of malnutrition after total gastrectomy. We studied 20 gastric cancer patients who had undergone total gastrectomy and immunochemotherapy and 6 normal controls. Nutritional status was assessed by dietary history, anthropometric methods, and serologic measurements. Malabsorption tests included the fecal fat excretion test, D-xylose absorption test, glucose tolerance test, vitamin B12 absorption test using dual isotopes, bacterial culture of jejunal aspirates, and jejunal biopsy. Weight loss was compared to the preoperative status in all patients (average 15%: 59.0 +/- 9.9 vs. 50.2 +/- 7.8 kg, preoperatively vs. postoperatively). Average daily calorie intake was 1586.2 kcal, which is lower than the normal intake of Korean adults (1838 kcal). Malnutrition of skeletal and visceral protein was not found. There was, however, severe fat malnutrition and a deficit of body fat. Postoperatively the body mass index was considerably lower than that preoperatively (22.2 +/- 0.4 vs. 18.9 +/- 0.4 kg/m2; preoperatively vs. postoperatively). With malabsorption tests, the daily excreted amount of fecal fat was 28.6 +/- 3.4 g (mean +/- SD) in patients and 6.9 +/- 0.2 g in controls. There was no significant malabsorption of carbohydrates. In 64.3% (9/14) of patients, vitamin B12 absorption was abnormal; and the serum concentration of vitamin B12, which was significantly related to malabsorption of this vitamin, was lower than normal in 73.7% (14/19). Bacterial overgrowth was not found, and there were no abnormal histologic findings in the jejunal mucosa. These results suggest that poor oral intake and fat malabsorption following total gastrectomy cause malnutrition and that fat malabsorption may be related to relative pancreatic insufficiency.

Development of malabsorption and nutritional complications in simian immunodeficiency virus-infected rhesus macaques

To assess the development and cause of malabsorption in rhesus macaques following experimental simian immunodeficiency virus (SIV) infection and to evaluate its impact on nutritional status. Clinical malabsorption tests and serial jejunal aspirates and biopsies were obtained from nine SIV-infected and three uninfected animals prior to infection and at 1, 2, 4, 8, 12, 24, 40 and 52 weeks postinoculation. Malabsorption was measured by sucrose breath hydrogen (H2) analysis and blood assay of D-xylose. Digestive enzyme activity was determined in jejunal mucosal homogenates. Bacterial and protozoal flora were determined in jejunal aspirates. Nutritional assessment was evaluated using specific blood micronutrient values. Cellular targets of SIV in the jejunum were determined by combined in situ hybridization and immunohistochemistry. Eight out of nine SIV-infected monkeys, including asymptomatic animals, exhibited malabsorption by either increased breath H2 and/or decreased blood D-xylose. All animals that died of AIDS had diarrhea, D-xylose malabsorption and decreased sucrase activity. Significant changes in nutritional status were associated with malabsorption. Bacterial overgrowth was not considered to be a cause of malabsorption. Histopathological biopsy findings included dilated villus lacteals, excessive cellular debris, lymphoplasmocytic infiltrates and cytoplasmic vacuoles in crypt epithelial cells. SIV-infected T cells and macrophages were detected as early as 1 week postinoculation. SIV-associated malabsorption can occur prior to clinical complications of disease. Severe intestinal complications are associated with malabsorption and malnutrition in the terminal stages of AIDS. The high proportion of macaques experiencing malabsorption without detectable pathogens, suggests an enteropathogenic role for SIV.

Microbiological evaluation of jejunal aspirates and faecal samples after oral administration of bifidobacteria and lactic acid bacteria

A double-blind placebo controlled investigation was carried out to study the effect of peroral colonization. Human volunteers were given mixtures of bifidobacteria and lactic acid bacteria. Measurements were made over a 1 week treatment period and for another week after the end of the treatment. Two different bacteriological preparations were used, one consisted of Enterococcus faecium and Bifidobacterium longum (a total of 6.4 x 10(8) cfu d-1); the other consisted of Lactobacillus acidophilus, Bif. bifidum, Lact. delbrueckii ssp. bulgaricus, and Streptococcus thermophilus (a total of 9 x 10(9) cfu d-1). Together with a placebo preparation, they were given to 24 healthy controls (eight in each group). Microbiological examinations of jejunal aspirates showed that viable counts of most species were below the detection limit. However, the test preparation containing Ent. faecium and Bif. longum significantly reduced the anaerobe: aerobe ratio in faeces by a factor of three during treatment (P = 0.03), and increased it by a factor of 30 during the following week (P < 0.02). This study shows that peroral administration of certain bacterial cultures may affect the distal intestinal microflora.

Diarrhoea associated with cyanobacterium-like bodies: a new coccidian enteritis of man

Faecal excretion of cysts known as cyanobacterium-like bodies (CLB) is associated with a diarrhoeal illness, which is often prolonged and severe. It is seen mainly in travellers and immunocompromised patients. Recently these cysts have been shown to be coccidian oocysts. We describe three patients who developed diarrhoea while travelling abroad. Stool samples from all three patients contained CLB. Jejunal aspirates from two patients also yielded CLB. Conventional histology of jejunal biopsy specimens confirmed that two patients had enteritis. Electromicroscopy of the same biopsy specimens revealed intraepithelial coccidia. These findings suggest that the small bowel is the site of infection of this new coccidian disease.

Pancreatic insufficiency

To investigate the course of postprandial lipid solubilization in nine patients with chronic, alcoholic pancreatitis, luminal contents were aspirated from the proximal part of the jejunum for 180 min after a meal containing 1.5% fat. Six of the patients had pancreatic insufficiency, whereas three patients were without insufficiency. pH was measured continuously at two sites: at the level of the papilla of Vater and the aspiration site. The fraction of bile acids in the micellar phase of the jejunal aspirates correlated positively to both pH in the aspirates (p less than 0.05) and the fraction of fat solubilized (p less than 0.02). pH was below 4.0 for a longer period of time in the patients with insufficiency, compared to the patients without. However, pH fluctuated rapidly, and there was no correlation between the continuously measured values at the aspiration site and values in the aspirates. Lipid solubilization was not correlated to the lipase activity in the aspirates. We conclude that acidic bile acid precipitation most likely plays a dominant role in the pathophysiology of pancreatic steatorrhea although the methods available are too crude to disclose the precise course of events.

The diagnosis of small bowel bacterial overgrowth: Reliability of jejunal culture and inadequacy of breath hydrogen testing

The reliability of a single jejunal culture in the diagnosis of small bowel bacterial overgrowth has recently been questioned. Seventy-seven patients thought to have bacterial overgrowth, defined as a jejunal culture yielding at least 106 organisms per milliliter of aspirate, took part in the study. Bacterial overgrowth was found in 74% of the patients with predisposing conditions and in 32% of those with no clear causes of bacterial colonization. The intestinal juice of some patients was taken at two different levels of the proximal jejunum, using both the closed-and open-tube systems. Highly significant correlations (r8 = 0.90, p < 0.001) were found between the numbers of bacteria per milliliter at the 2 jejunal levels and between the numbers of bacteria per milliliter of jejunal aspirate obtained from the closed and open tubes (r8 = 0.84, p < 0.001). Compared with the jejunal culture, the gas chromatography of volatile fatty acids in jejunal aspirate and the glucose-and lactulose-hydrogen breath tests showed sensitivities of 56%, 62%, and 68% and specificities of 100%, 83%, and 44%, respectively. This work demonstrates the reliability of jejunal cultures and the inadequacy of breath hydrogen testing in the prediction of positive jejunal cultures. When results of testing for volatile fatty acids in jejunal aspirates are positive, this always indicates the presence of bacterial overgrowth; thus, this procedure would avoid the more complicated, time-consuming, and costly bacteriological analysis of jejunal samples.

Small intestinal bacterial overgrowth in patients with chronic lymphocytic leukaemia.

As part of a study to assess the possible contribution of lymphoid infiltration of the gastrointestinal mucosa to occult blood loss or malabsorption 20 patients with chronic lymphocytic leukaemia (CLL) had a lactulose hydrogen breath test. In 10 cases (50%) a small intestinal peak was detected, suggesting small bowel bacterial overgrowth, and this was confirmed in seven patients by the positive culture of jejunal aspirate. Of the patients with a positive hydrogen breath test, radiological examination showed a duodenal diverticulum in two but no anatomical abnormalities in the other cases. There was no evidence of achlorhydria and transit times were normal. There was no difference in the incidence of hypogammaglobulinaemia among those patients with evidence of small intestinal bacterial overgrowth and those without. Seven patients with a positive hydrogen breath test, however, had undetectable secretory piece in their jejunal aspirates whereas this was present in all patients with a normal breath test who had local immunoglobulin concentrations measured (p less than 0.05), indicating that the small intestinal bacterial overgrowth may be due to impaired local immunity.

IMMUNISATION OF VOLUNTEERS WITH A SYNTHETIC PEPTIDE VACCINE FOR ENTEROTOXIGENIC ESCHERICHIA COLI

A completely synthetically produced peptide vaccine, consisting of the 18-aminoacid Escherichia coli heat-stable toxin and the 26-aminoacid epitope of the heat-labile toxin B subunit, was given orally to thirteen volunteers. It raised antitoxin titres to both toxin components four-fold in serum samples and seven-fold in jejunal aspirates over preimmunisation control titres. Jejunal aspirates taken after immunisation from vaccinees, but not controls, neutralised the secretory activity of both toxins in appropriate biological assays. These findings show that synthetically produced vaccines are immunogenic in human beings. The peptide used is a promising vaccine for diarrhoeal disease caused by enterotoxigenic strains of E coli.

Mucosal antitoxin response in volunteers to immunization with a synthetic peptide of Escherichia coli heat-stable enterotoxin.

Peroral immunization of volunteers on four weekly occasions with 750 micrograms of a conjugate containing 3,000 antigen units of a synthetically produced peptide of hyperantigenic Escherichia coli heat-stable (ST) toxin, conjugated with the heat-labile toxin B subunit as a carrier, raised serum immunoglobulin G antitoxin titers to ST by fourfold and intestinal immunoglobulin A antitoxin titers to ST by sevenfold over control values at five weeks postimmunization. The ability of jejunal aspirates from the immunized volunteers to neutralize ST in the suckling mouse assay correlated with the intestinal immunoglobulin A ST antitoxin response determined by enzyme-linked immunosorbent assay.

Effects of Pectin and Wheat Bran on Intraluminal Pancreatic Enzyme Activities and on Fat Absorption As Examined with the Triolein Breath Test in Patients with Pancreatic Insufficiency

In totally pancreatectomized patients breath 14CO2 excretion after ingestion of 14C-labeled triolein was significantly increased by a granulated pancreatic enzyme preparation and was reduced when pectin was added to the enzyme supplement. In the same patients pectin reduced trypsin, lipase, and amylase activities of jejunal aspirates after a test meal supplemented with pancreatic enzyme substitution, which was shown to give good enzyme activities in the intestine. In patients with chronic pancreatitis, breath 14CO2 excretion was reduced by wheat bran, which also caused a reduction in lipase and amylase activities of duodenal aspirates after a test meal. The findings demonstrate the efficiency of treatment with a granulated pancreatic enzyme preparation in restoring intraluminal enzyme activities and fat absorption in patients with pancreatic insufficiency. They also show that pectin and wheat bran may induce fat malabsorption and inhibit digestive enzyme activities in vivo.

Dysfunction of the continent ileostomy: clinical features and bacteriology.

The pathogenesis and treatment of dysfunction of the continent ileostomy was investigated in 12 patients, five of whom had asymptomatic malabsorption and seven of whom had acute complaints. The number of anaerobic bacteria in jejunal aspirates was increased in patients with pouch malfunction (range 10(3) to 10(8)/g aspirate), but the microbiology of ileal effluent and the morphology of the ileal mucosa could not be correlated with dysfunction. Bile acid breath tests and lactose tolerance tests were not, however, reliable indicators of jejunal bacterial overgrowth. The symptoms, the malabsorption, and the number of jejunal and ileal anaerobic bacteria decreased in patients during treatment with metronidazole, implicating overgrowth of anaerobic bacterial flora in the pathogenesis of the syndrome.

Chromatographic analysis of sugars in physiological fluids by postcolumn reaction with cuprammonium: A new and highly sensitive method

A new highly sensitive method of high-performance liquid chromatographic analysis has been used to separate mono-, di-, and oligosaccharides present in jejunal aspirates from experimentally perfused animals. The sugars in the column eluant are detected at 280 to 310 nm after reaction with cuprammonium. No reaction coil is required between the column and uv detector because the reaction is virtually instantaneous. This technique is more sensitive than differential refractometry, so that it is possible to detect 2.5 nmol (450 ng) of glucose routinely, compared to a minimum detection limit of 100 nmol (18 μg) using a commercial refractive index detector. Using a suitable postcolumn pump, the technique is not sensitive to changes in solvent composition, as with gradient elution, and is applicable to analysis of other cis-cis glycols.

The antibody response to bacterial gastroenteritis in serum and secretions: Labroody, J. T., Davidson, G. P., Shearman, D. J. C. and Rowley, D. (1980). Clinical and Experimental Immunology, 41, 290

The antibody responses to bacterial gastroenteritis in jejunal aspirates and sera from sixteen adults and nine children were examined using a radioimmunoassay. Twelve adults served as controls. A clear antibody response was apparent in both intestinal aspirates and sera. While the absolute concentrations of antibody were much higher in sera, the proportion of immunoglobulin committed to specific antibodies was similar in both the intestinal fluids and sera. The antibody responses in the intestine and in the serum were very similar in the group as a whole, but they varied widely in individual subjects. Over a period of 1 month intestinal antibody levels in adults remained constant but in children they showed a decrease. In two subjects high levels of intestinal antibody were still apparent after 1 year. The organism responsible for the infection was still present in the gut of five subjects 1 month after clinical recovery from infection in the presence of local antibody. The relevance of these results and their implications for further study of the immune response to bacterial gastroenteritis are discussed.

A study of malabsorption in intestinal tuberculosis: stagnant loop syndrome

A study was carried out in the patients with intestinal tuberculosis and obstruction requiring surgery to determine the pathogenesis of malabsorption in this condition. Fifteen of the 20 patients studied had malabsorption, nine of 17 (53%) had intestinal bacterial overgrowth and 10 of 16 (62.6%) had free bile acids in their jejunal aspirates. In a comparable group of nontuberculus intestinal obstruction requiring surgery, six of seven (85.7%) had malabsorption, and four of five (80%) had both the bacterial overgrowth as well as bile salt deconjugation. Among a group of 10 patients with intestinal tuberculosis without significant obstruction, four were found to have malabsorption but only one had evidence of bacterial overgrowth and bile salt deconjugation. In contrast, only one of the 10 patients with extraintestinal tuberculosis and none of the 12 healthy, normal subjects had malabsorption. None had bacterial overgrowth or bile salt deconjugation in either group. Resection of the obstructing lesion corrected the malabsorption as well as the bacterial overgrowth and the bile salt deconjugation in all four patients tested with intestinal tuberculosis. Malabsorption in intestinal tuberculosis thus appears to be associated with obstruction rather than with the tuberculous process. Demonstration of bacterial overgrowth and bile salt deconjugation in the upper small intestine of patients with intestinal tuberculosis with obstruction and malabsorption indicate the presence of a stagnant loop syndrome.

Mechanism of malabsorption in giardiasis: a study of bacterial flora and bile salt deconjugation in upper jejunum.

Sixty-three unselected cases of giardiasis, with no evidence of other systemic disease, were screened for evidence of steatorrhoea. No patient had any evidence of protein-energy malnutrition. Seventeen (27%) of the cases had steatorrhoea; three (17-8%) of the 17 patients having steatorrhoea also had D-xylose malabsorption. Vitamin B12 absorption was normal in all. Bacterial culture and qualitative analysis of bile salt in jejunal fluid was carried out in all the 17 cases having steatorrhoea as well as 13 cases with normal absorptive parameters (eight cases of irritable bowel syndrome and five cases of giardia infection) who served as controls. All the patients showing bacterial overgrowth had free bile acids in their duodenal aspirate. Free bile acids could also be detected in jejunal aspirates of five of the seven patients having no bacterial overgrowth. Two control cases of giardia infection with normal small bowel function and sterile duodenal aspirate showed evidence of bile salt deconjugation. The significance of these findings is discussed in relation to the pathogenesis of steatorrhoea in patients with giardiasis. The possible role of giardia in bile salt deconjugation is suggested.

Fat Digestion after Jejunoileal Bypass Operation for Obesity

Fat digestion in the upper jejunum was studied in 12 obese patients treated by jejunoileal bypass including either 37.5 cm jejunum and 12.5 cm ileum or 12.5 cm jejunum and 37.5 cm ileum. Jejunum was intubated and a test meal ingested before and 1-2 months after operation. Jejunal aspirates were heated immediately to destroy lipase, pooled and assayed for dilution marker, bile acids and total fat. Lipolytic products were determined by thin-layer chromatography and densitometry. The micellar phase was achieved by ultracentrifugation and analysed for total fat. Results. Bile acid concentration and lipolysis decreased after both bypass operations. In accordance with this, micellar solubilization of fat was impaired after operation. Bile acid concentration and micellar solubilization were lower after bypass with a long, than after bypass with a short, ileal loop. Absorption of fat in the duodenum and upper jejunum did not change significantly after any of the operations. Conclusions. Jejunoileal bypass impairs fat digestion, but this does nto contribute significantly to the fat malabsorption after operation.

Evidence for the absorption of bile acids in the proximal small intestine of normo- and hyperlipidaemic subjects.

Bile acid composition was determined in duodenal and jejunal aspirates obtained under fasting conditions in normolipidaemic controls and in patients with the type IIa and type IV lipoprotein patterns. In 17 out of the 22 subjects studied, the duodenal as compared with the jejunal aspirates contained proportionally more CD (chenodeoxycholic acid) than C (cholic acid). The two types of aspirates also differed slightly with regard to the D (deoxycholic acid): CD ratio, which was higher in samples drawn from the jejunum. These findings, compatible with an absorpiton of about 30% of CD in the upper small intestine, were approximately the same in all groups of patients. As evidenced by additional experiments in two subjects, an oral intake of cream does not significantly influence the absorption of CD in the upper small intestine.

Contamination of the Small Intestine by Enterotoxigenic Coliform Bacteria among the Rural Population of Haiti

Coliform bacteria were isolated by either aerobic or anaerobic culture techniques from aspirates of the proximal small intestine of 4 of 5 Haitians with tropical sprue, but not from any of 10 well nourished Haitians who had milder gastrointestinal complaints and abnormalities. Klebsiella (Klebsiella pneumoniae and Klebsiella ozaenae) was cultured from the jejunal aspirates of 2 sprue patients and Escherichiae coli from the other 2. Fifteen colonies of coliform bacteria cultured from each aspirate were specifically identified by their biotype. In three instances, every colony in each aspirate was the same; In three instances, every colony in each aspirate was the same; in the fourth aspirate, two biotypes of E. coli were present, one of which grew under both aerobic and anaerobic culture conditions and another which grew only under anaerobic conditions on initial isolation. A randomly selected strain of each of the five coliform biotypes isolated was examined for enterotoxigenicity by determining the effect of variously prepared cell-free preparations on water transport in the rat jejunum using standard marker perfusion techniques. Every strain tested was toxigenic; one produced only a heat-stable toxin, one produced a heat-labile toxin only, and three elaborated both forms of enterotoxin. These observations indicate that most Haitians with tropical sprue have colonization of the proximal small intestine by a specific strain of enterotoxigenic coliform bacteria, but such is not the case among Haitians who have milder intestinal abnormalities.