A cross-sectional study of salivary and gut microbiomes in hemodialysis patients with heart failure with preserved ejection fraction.

Salivary microbial community structure was significantly distinct and effectively distinguished MHD patients from healthy controls.

• Alpha diversity and beta diversity analyses revealed a distinct salivary microbial structure in MHD groups versus controls (P < 0.05)
• The study used 16S rRNA gene sequencing on salivary and fecal samples
• Total sample size was n=88, comprising HFpEF (n=30), NHF (n=30), and CON (n=28) groups
• The salivary microbiome differences were described as more pronounced than gut microbiome differences

Overall gut microbial community structure showed no significant separation between MHD groups and healthy controls.

• Beta diversity analysis of gut microbiome showed no significant separation between groups
• This contrasted with the salivary microbiome, which did show significant structural differences
• Both salivary and fecal microbiomes were analyzed using 16S rRNA gene sequencing in the same cross-sectional cohort

Both MHD groups (HFpEF and NHF) showed depletion of salivary Veillonella compared to healthy controls.

• Genus-level analysis identified Veillonella as depleted in the salivary microbiome of both MHD groups relative to CON
• This depletion was shared across both MHD groups regardless of heart failure status
• Findings were derived from 16S rRNA gene sequencing with genus-level compositional analysis

Both MHD groups showed depletion of gut Faecalibacterium compared to healthy controls.

• Genus-level analysis identified Faecalibacterium as depleted in the gut microbiome of both HFpEF and NHF groups compared to CON
• This depletion was shared across both MHD groups regardless of heart failure status
• Faecalibacterium is a known butyrate-producing genus frequently reported as depleted in various disease states

LEfSe analysis identified salivary Anaerocolumna as a candidate microbial feature enriched in the HFpEF group specifically.

• Linear discriminant analysis Effect Size (LEfSe) analysis was used to identify discriminating taxa
• Salivary Anaerocolumna was highlighted as a 'promising candidate feature associated with the HFpEF group'
• This feature distinguished HFpEF from both the NHF and CON groups
• The authors described this as 'preliminary evidence' positioning the oral microbiome for further investigation in this high-risk population

The study design was cross-sectional with three groups: MHD patients with HFpEF, MHD patients without HF, and healthy controls.

• Total n=88 participants across three groups: HFpEF (n=30), NHF (n=30), and CON (n=28)
• Both salivary and fecal (gut) microbiomes were characterized for each participant
• Microbial profiling was performed using 16S rRNA gene sequencing
• Analyses included microbial community structure, composition, alpha diversity, beta diversity, and LEfSe