Sobrecrecimiento bacteriano intestinal / Small intestinal bacterial overgrowth. An update

Small intestinal bacterial overgrowth (SIBO) is characterized by nutrient malabsorption, associated with an excessive number of bacteria in the proximal small intestine. Unfortunately, the diagnosis of bacterial overgrowth presents several difficulties and limitations, and as yet there is not a widespread agreement on the best diagnostic test. SIBO occurs when there are alterations in intestinal anatomy, gastrointestinal motility, or a lack of gastric acid secretion. The true association between SIBO and irritable bowel syndrome and celiac disease remains uncertain. The treatment usually consists in the eradication of bacterial overgrowth with repeated courses of antimicrobials, nutritional support and when it is possible, the correction of underlying predisposing conditions.

[Small intestinal bacterial overgrowth. An update]. / Sobrecrecimiento bacteriano intestinal.

Small intestinal bacterial overgrowth (SIBO) is characterized by nutrient malabsorption, associated with an excessive number of bacteria in the proximal small intestine. Unfortunately, the diagnosis of bacterial overgrowth presents several difficulties and limitations, and as yet there is not a widespread agreement on the best diagnostic test. SIBO occurs when there are alterations in intestinal anatomy, gastrointestinal motility, or a lack of gastric acid secretion. The true association between SIBO and irritable bowel syndrome and celiac disease remains uncertain. The treatment usually consists in the eradication of bacterial overgrowth with repeated courses of antimicrobials, nutritional support and when it is possible, the correction of underlying predisposing conditions.

Nutritional impact and ultrastructural intestinal alterations in severe infections due to enteropathogenic Escherichia coli strains in infants.

OBJECTIVE: Enteropathogenic Escherichia coli (EPEC) strains are able to adhere to human intestinal tissue inducing a typical lesion causing dissolution of the brush border membrane and loss of microvillus structure at sites of bacterial attachment. The presence of these lesions can provoke perpetuation of diarrhea associated with malabsorption of the nutrients and nutritional aggravation. In this paper we report the nutritional impact of severe EPEC gastroenteritis in infants in a small bowel ultrastructural study. METHODS AND RESULTS: Two infants aged 3 months and one 4 month old infant with profuse watery diarrhea lasting less than 6 days were studied. After rehydration therapy, the patients were fed a cow's milk formula and since food intolerance was diagnosed, a protein-hydrolisate, lactose-free formula was introduced. This dietary modification was successful, diarrhea ceased, the patients were discharged and followed up for 30 days. The following EPEC strains were identified in the stools and in the jejunal secretion: O111ab:H2, O119:H6 and O18ab:H14. A small bowel biopsy was performed and the electron microscopic study revealed bacteria tightly adhered to the apical portion of the enterocyte and effacement of the microvilli. These lesions were more prominent in the areas where bacteria were present. CONCLUSION: The patients underwent an acute nutritional aggravation due to food intolerance, but the introduction of a protein-hydrolisate, lactose-free formula, allowed prompt cessation of diarrhea and nutritional recovery.

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.