Clinical Significance of Nitric Oxide Measurement in Assessing the State of The Small Intestinal Mucosa in Children with Intestinal Malabsorption Syndrome

Abstract

Betel Intestinal malabsorption syndrome (IMS) in children is a clinically heterogeneous condition that may result from functional and enzymatic disorders, inflammatory processes, and structural changes in the small intestinal mucosa. It is therefore important to search for non-invasive biomarkers that can help assess the activity of the pathological process and distinguish between the inflammatory and functional-enzymatic components of intestinal damage. One such potential marker is nitric oxide (NO), which regulates microcirculation, intestinal motility, and mucus secretion, and maintains the epithelial barrier.

                 Aim of the study — to summarize current scientific data on the physiological role of nitric oxide and its diagnostic value in assessing the state of the small intestinal mucosa in children with intestinal malabsorption syndrome, and to determine the prospects for the practical application of this approach in pediatrics.

                 Materials and methods. An analytical review of the literature was conducted in the PubMed, Scopus, and eLibrary databases for the period from 1994 to 2025. Search queries included the following keywords and their combinations: “nitric oxide”, “nitric oxide synthase”, “intestinal mucosa”, “intestinal permeability”, “malabsorption syndrome”, “fecal nitric oxide”, “exhaled nitric oxide”, and “children”, as well as the corresponding Russian-language terms. Of the 62 publications initially identified, 28 were included in the analysis after the exclusion of duplicates and irrelevant sources.

                 Results. The literature analysis showed that nitric oxide (NO) plays a fundamental role in maintaining normal homeostasis of the intestinal mucosa. Epithelial inflammation is accompanied by activation of inducible NO synthase (iNOS), which leads to a significant increase in NO synthesis and changes in the levels of its stable metabolites, nitrites and nitrates. These metabolites are important markers of the inflammatory process. Increased NO production and iNOS activation are characteristic of inflammatory bowel diseases, celiac disease, and other enteropathies.

                 The assessment of fecal and serum NO metabolites, as well as direct measurement of NO concentrations in biological media, is regarded as a promising non-invasive or minimally invasive approach to evaluating inflammatory activity. However, data on the diagnostic value of these parameters in children with intestinal malabsorption syndrome (IMS) remain insufficient and require further investigation.

                 Conclusion. Measurement of nitric oxide metabolites is a promising method for the non-invasive assessment of the small intestinal mucosa in children with IMS. At present, this method should be regarded as an additional diagnostic tool that does not replace standard clinical, laboratory, endoscopic, and histological examinations. Further prospective clinical studies are needed to establish its diagnostic capabilities, define reference values, and determine its place in the diagnostic algorithm for children.

Keywords:

Nitric oxide, NO synthase, intestinal malabsorption syndrome

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