A Study on the Correlation Between intestinal flora Characteristics and Serum Zinc and Iron Levels in Paediatric Patients with Mycoplasma pneumoniae pneumonia

Objective This study aimed to investigate the correlation between intestinal flora characteristics and serum zinc and iron levels in paediatric patients with M. pneumoniae pneumonia (MPP). Methods Faecal and serum samples were collected from 30 children with M. pneumoniae pneumonia (MPP group), 30 children with non-M. pneumoniae pneumonia (NMP group), and 30 healthy children (N group) who met the study criteria and were treated at our hospital between November 2024 and March 2025. These samples underwent 16S rRNA sequencing and trace element detection analyses. Results Alpha diversity showed no significant differences ( P  > 0.05). Beta diversity analysis revealed significant intergroup differences ( P  < 0.05). At the phylum level, all three groups were dominated by Firmicutes , Bacteroidetes , Actinobacteria , and Proteobacteria . The MPP group exhibited the lowest abundance of Firmicutes and the highest abundance of Bacteroidetes . At the genus level, the MPP group showed higher abundances of Bacteroides , Enterococcus , and Escherichia-Shigella compared to the control group. Analysis of intestinal flora differences revealed that the abundances of Prevotella and Lachnoclostridium in the MPP group were higher than those in both the NMP and N groups, whereas the abundance of Enterococcus was higher than that in the N group ( P  < 0.05). The NMP group exhibited higher abundances of Eubacterium , Anaerostipes , and Collinsella than the MPP and N groups ( P  < 0.05). The N group demonstrated higher abundances of Roseburia , Lachnospiraceae , and Subdoligranulum than the MPP and NMP groups ( P  < 0.05). Blood zinc and iron levels were lower in the MPP group than in the NMP and N groups. The heatmap of intestinal flora correlations with clinical parameters showed positive associations between Faecalibacterium , Parabacteroides , and Blautia with blood zinc and iron levels. Among these, the correlation between Parabacteroides and blood zinc levels was statistically significant (r = 0.370, P  < 0.05). Escherichia-Shigella and Intestinibacter showed negative correlations with serum zinc and iron levels. Conclusion Paediatric patients with MPP exhibit disrupted intestinal flora composition alongside reduced serum zinc and iron levels, with specific bacterial genera correlating with alterations in serum zinc and iron concentrations.