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Surface features of small-intestinal mucosa in childhood diarrheal disorders
1Department of Child Health, Queen's University of Belfast, Northern Ireland.
Insights
Scanning electron microscopy revealed bacterial colonization on the jejunal mucosa in children with chronic nonspecific diarrhea (CNSD). This finding, linked to microvillar damage, suggests bacteria may contribute to pediatric gastrointestinal disorders.
Area of Science:
- Pediatric Gastroenterology
- Microbiology
- Electron Microscopy
Background:
- The pathophysiology of pediatric diarrhea, particularly chronic nonspecific diarrhea (CNSD), remains incompletely understood.
- Standard light microscopy often yields normal results in CNSD cases, limiting diagnostic insights.
Purpose of the Study:
- To investigate the jejunal mucosal surface in children with CNSD using scanning electron microscopy (SEM).
- To compare SEM findings in CNSD with those in children having other gastrointestinal diseases and healthy controls.
Main Methods:
- Jejunal biopsy specimens were examined using scanning electron microscopy (SEM).
- SEM findings were compared across groups: CNSD (n=9), other GI diseases (n=21), and healthy controls (n=11).
- Light microscopy was also performed for comparison.
Main Results:
- SEM revealed bacterial colonization, primarily coccoid forms, on the jejunal mucosa in 100% of CNSD cases.
- This colonization was associated with loss of glycocalyx and microvillar clumping.
- Bacterial colonization was also observed in 89% of children with other GI disorders, but less frequently in healthy children.
- SEM provided distinct surface morphology information not visible with light microscopy.
Conclusions:
- Bacterial colonization of the small intestine is prevalent in children with various gastrointestinal diseases, including CNSD.
- SEM of jejunal biopsies offers valuable diagnostic information for pediatric chronic diarrhea, potentially aiding treatment strategies.
- The findings suggest a role for bacterial colonization in the pathogenesis of certain pediatric gastrointestinal conditions.
Abstract:
The pathophysiology of diarrhea, especially in the otherwise healthy child, is still poorly understood. The aim of this study was to use the scanning electron microscope (SEM) to examine the surface of the jejunal mucosa of children with chronic nonspecific diarrhea (CNSD) (n = 9) and to compare the findings with specimens obtained from children with (n = 21) and without (n = 11) other gastrointestinal diseases. Light microscopy of the specimens from children with CNSD was normal. However, SEM showed the presence of bacterial colonization with predominantly coccoid organisms in 100% of cases. This colonization was associated with loss of glycocalyx and clumping of the microvilli. The children with celiac disease (n = 9) all showed characteristic appearances with light microscopy, but only one had bacterial colonization on SEM. The surface features of specimens from children with other gastrointestinal disorders (food intolerance, postenteritis syndrome, protracted diarrhea of infancy, and immune deficiency states) were very similar to those from the CNSD group. Bacteria were visible on 89% of specimens, and in half of these cases the organisms were bacilli. SEM of specimens from children with no gastrointestinal disease (ages 11-107 months) suggested an increased density of villi/unit area with advancing age. Bacteria were present in only two cases and did not include bacilli. The findings suggest that bacterial colonization of the surface of the small intestine is common in children with several gastrointestinal diseases and may play a part in their pathogenesis. Routine SEM examination of jejunal biopsies provides information not available from standard light microscopy, which may be relevant to the treatment of children with chronic diarrhea.