Genetic evidence strengthens the bidirectional connection between gut microbiota and Shigella infection: insights from a two-sample Mendelian randomization study

In recent investigations, substantial strides have been made in the precise modulation of the gut microbiota to prevent and treat a myriad of diseases. Simultaneously, the pressing issue of widespread antibiotic resistance and multidrug resistance resulting from infections demands urgent attention. Several studies suggest that the antagonistic influence of the gut microbiota could serve as a novel avenue for impeding the colonization of pathogenic microorganisms or treating infections. However, conventional research methodologies encounter inherent challenges in identifying antagonistic microbial agents against , necessitating a comprehensive and in-depth analysis of the causal relationship between infections and the gut microbiota. Utilizing the aggregated summary statistics from Genome-Wide Association Studies (GWAS), we conducted Mendelian Randomization (MR) analyses encompassing 18,340 participants to explore the interplay between the gut microbiota and infections. This investigation also involved 83 cases of infection patients and 336,396 control subjects. In the positive strand of our findings, we initially performed a preliminary analysis using the Inverse Variance Weighting (IVW) method. Subsequently, we undertook sensitivity analyses to assess the robustness of the results, addressing confounding factors' influence. This involved employing the Leave-One-Out method and scrutinizing funnel plots to ensure the reliability of the MR analysis outcomes. Conclusively, a reverse MR analysis was carried out, employing the Wald ratio method due to the exposure of individual Single Nucleotide Polymorphisms (SNPs). This was undertaken to explore the plausible associations between infections and genetically predicted compositions of the gut microbiota. In this study, we employed 2,818 SNPs associated with 211 species of gut microbiota as instrumental variables (IVs). Through IVW analysis, our positive MR findings revealed a significant negative correlation between the occurrence of infections and the phylum Tenericutes (OR: 0.18, 95% CI: 0.04-0.74, = 0.02), class Mollicutes (OR: 0.18, 95% CI: 0.04-0.74, p = 0.02), genus (OR: 0.16, 95% CI: 0.04-0.63, = 0.01), genus (OR: 0.39, 95% CI: 0.16-0.93, = 0.03), and genus (OR: 0.44, 95% CI: 0.23-0.87, = 0.02). Conversely, a positive correlation was observed between the occurrence of infections and genus (OR: 10.16, 95% CI: 1.87-55.13, = 0.01) and genus (OR: 12.24, 95% CI: 1.71-87.34, = 0.01). In sensitivity analyses, ut