Oral Health and Gut-Targeted Microbial Marker Changes Associated with Prolonged Hospitalization in Cardiac Patients: An Integrative Risk Analysis

Prolonged hospitalization in cardiac patients is associated with increased morbidity and healthcare resource utilization, yet early biological factors linked to extended length of stay remain insufficiently defined. This study aimed to explore an integrative framework combining oral health parameters and targeted gut microbial markers to identify factors associated with prolonged hospitalization in cardiac patients. A comparative observational design was applied, including patients with short-term hospitalization (1–4 days) and prolonged hospitalization (≥25 days). Oral health status was evaluated using a standardized dental protocol at admission and longitudinally in patients with prolonged hospitalization. Targeted qRT-PCR-based quantification of selected gut bacterial markers was performed at admission and reassessed after one and two weeks. Temporal changes were calculated relative to baseline, and multivariate logistic regression models adjusted for age, sex, and major cardiac diagnoses were used to explore associations with prolonged hospitalization. Short-term hospitalized patients (n = 27) exhibited minimal oral health variation (+2%) and stable marker profiles. In contrast, patients with prolonged hospitalization (n = 30 for oral health; n = 18 for microbial markers) showed progressive changes over time. Oral health impairment increased by 3% after one week and 16% after two weeks, while targeted microbial marker variation showed modest directional changes. Integrative models combining oral health parameters and targeted microbial markers suggested potential complementary information alongside clinical variables, within the limits of an exploratory framework and limited sample size. These findings support the relevance of multidomain clinical and biological monitoring in the early identification of patients at risk for prolonged hospitalization.