Gut Microbiome in Children with Bronchial Asthma Against the Background of Mycoplasma and Chlamydial Infection: Features and Clinical Significance

Asthma is the most common chronic inflammatory disease of the airways, characterized by episodes of obstruction. The aim of the study is to assess the state of the gut microbiome in children with bronchial asthma and to investigate its interaction with Chlamydia pneumoniae and Mycoplasma pneumoniae infections in the course of the disease. Materials and methods. All patients were examined at the Department of Pediatric Allergology of the Tashkent Medical Academy. The study included 14 children with severe, 23 with moderate, and 31 with mild forms of BA. Age distribution: 7–10 years – 23 children (34%), 11–14 years – 20 children (30%), 15–17 years – 25 children (36%). Duration of the disease: 1–3 years — 34 children (50%), 3–6 years — 34 children (50%). Gender distribution: 43 boys (63%) and 25 girls (36%). Results. All children with BA experienced breathing difficulties, mainly at night. In 82.3% of cases, bronchial asthma attacks (shortness of breath, dry cough) occurred 1–3 times per month, lasting 5–10 minutes. In patients infected with M. pneumoniae and C. pneumoniae, significant alterations in the gut microbiota were observed. These changes manifested as a decrease in beneficial bacteria — Bifidobacterium and Lactobacillus. In infected children, the number of Bifidobacterium decreased by an average of 48% (p<0.05), while Lactobacillus decreased by 42% (p<0.01). Additionally, an increase in conditionally pathogenic bacteria — Escherichia coli, Clostridium, and Bacteroides — was detected: Clostridium increased by 35% (p<0.01), Bacteroides by 29% (p<0.05), and E. coli by 33% (p<0.01). These infectious agents contribute to the development of dysbiosis, characterized by a reduction in beneficial microorganisms (Bifidobacterium, Lactobacillus) and an increase in conditionally pathogenic bacteria (Escherichia coli, Clostridium, Bacteroides). Such changes are associated with an enhanced systemic inflammatory response and a higher susceptibility to allergic reactions, which aggravate the clinical course of the disease. Conclusion: Mycoplasma pneumoniae and Chlamydia pneumoniae significantly affect the composition of the gut microbiome in children with bronchial asthma. These infectious agents contribute to the development of dysbiosis, characterized by a decrease in beneficial microorganisms (such as Bifidobacterium and Lactobacillus) and an increase in conditionally pathogenic microorganisms (such as Escherichia coli, Clostridium, and Bacteroides). These alterations in the intestinal microbiota are associated with enhanced systemic inflammatory processes and increased susceptibility to allergic reactions, which in turn aggravate the clinical course of the disease.