Alterations of the gut microbiota and their clinical associations in AIDS patients with Talaromyces marneffei co-infection

Background Talaromyces marneffei is a life-threatening opportunistic pathogen in patients with advanced HIV infection. Whether T. marneffei co-infection is associated with alterations in gut microbiota in patients with AIDS remains insufficiently understood. Methods We conducted a cross-sectional study including 99 patients with AIDS, comprising 65 with T. marneffei co-infection and 34 without T. marneffei infection. Fecal microbiota was profiled by 16S rDNA sequencing of the V3–V4 region. Alpha diversity, beta diversity, differential taxa, and correlations with clinical indicators were analyzed. Results Patients with T. marneffei co-infection had lower CD4 and CD8 T-cell counts and higher HIV RNA levels than those without co-infection. No significant difference in overall gut microbial community structure was observed between groups (ANOSIM, P  = 0.686), although several genera differed significantly in relative abundance. Gemmiger , Enterocloster , Schaalia , and Clostridioides were enriched in the co-infection group, whereas Agathobacter and Dialister were enriched in the non-co-infection group. In addition, Clostridioides, Anaerotignum , and Streptococcu s showed positive correlations with HIV RNA, and Dialister showed a positive correlation with CD4 T-cell counts. Conclusions In patients with AIDS, T. marneffei co-infection is associated with genus-level changes in gut microbiota and with clinical indicators of HIV disease severity. These findings provide preliminary evidence for a link between opportunistic fungal infection and gut microbial alterations in AIDS.