Gut Microbiota Profiling by 16S rRNA Sequencing in Children with Mild or Intermittent Asthma: A Pilot Study in Alessandria, Italy

Asthma is one of the most common chronic diseases in childhood, and the gut microbiota is increasingly recognized as a key player in its pathogenesis through the gut-lung axis. This pilot, cross-sectional study analyzed the intestinal microbiota of 20 children (6-9 years) with intermittent or mild persistent asthma, in the absence of a healthy control group. Stool samples were processed with 16S rRNA sequencing (Illumina iSeq100, V3-V6 regions) and analyzed with MicrobAT-SmartSeq software. Contrary to most literature, no enrichment of <i>Proteobacteria</i> was detected, and <i>Faecalibacterium</i> was not reduced but emerged as the most abundant genus. Higher adherence to the Mediterranean diet correlated with greater microbial richness, while asthma phenotypes showed no major taxonomic differences. Pharmacological treatments modulated microbial profiles: leukotriene antagonists correlated with protective taxa, whereas inhaled corticosteroids and bronchodilators were linked to reduced beneficial functions. These findings highlight an overall eubiotic microbiota in asthmatic schoolchildren and call for larger, controlled studies to confirm these novel observations.