CLINICAL AND MICROBIOLOGICAL CHARACTERISTICS OF THE INTESTINAL MICROBIOTA IN CHILDREN WITH BRONCHIAL ASTHMA ASSOCIATED WITH MYCOPLASMA PNEUMONIAE AND CHLAMYDIA PNEUMONIAE

Abstract

Objective  To study the clinical and microbiological alterations of the intestinal microbiota in children with bronchial asthma associated with Mycoplasma pneumoniae and Chlamydia pneumoniae infections, and to determine their correlation with disease severity. Materials and Methods. From 2023 to 2025, 78 children aged 7–15 years with bronchial asthma were observed at the Department of Pediatric Allergology, Tashkent Medical Academy. Patients were distributed according to asthma severity: mild — 41 children, moderate — 23 children, and severe — 14 children. A control group consisted of 42 healthy children. All subjects underwent serological testing (for antibodies to M. pneumoniae and C. pneumoniae), spirometry, and microbiological analysis of intestinal flora. Results and Discussion. Infections caused by Mycoplasma pneumoniae and Chlamydia pneumoniae were found to exacerbate the clinical course of bronchial asthma in children. These infections lead to significant dysbiosis of the intestinal microbiota, characterized by a decrease in beneficial bacteria (Bifidobacterium, Lactobacillus) and an increase in opportunistic microorganisms (Escherichia coli, Clostridium, Bacteroides). The imbalance in the intestinal microbiome correlated with disease severity. In children with severe asthma, the level of beneficial bacteria decreased by 45–55%, while opportunistic flora increased by 30–40% compared to the control group. Additionally, elevated levels of pro-inflammatory cytokines (IL-4, TNF-α) and immunoglobulin E (IgE) were observed, indicating an intensified immune response and persistent airway inflammation. Conclusion. Mycoplasma pneumoniae and Chlamydia pneumoniae infections aggravate the course of bronchial asthma in children and induce intestinal dysbiosis. The reduction of beneficial bacteria and the overgrowth of conditionally pathogenic flora are associated with more severe forms of asthma. Alterations in the intestinal microbiota modulate immune activity by increasing IL-4, TNF-α, and IgE levels, which enhance inflammation and allergic reactivity. Early detection of dysbiosis and the inclusion of probiotic therapy in complex treatment regimens may improve the clinical course of bronchial asthma in children.