Document resource
Background Traditional Chinese Medicine (TCM) proposes that individuals may experience suboptimal health even in the absence of overt disease. Based on physiological patterns and symptoms, individuals are classified into a balanced constitution (NBC) or eight unbalanced body constitution types. Emerging studies suggest that gut microbiome composition may relate to these constitution-associated physiological patterns. However, most studies classify individuals based on a primary constitution despite the frequent occurrence of multi-constitution profiles, which may confound microbiome associations. This study aimed to characterize the distribution of single TCM body constitution types in a healthy Singapore adult population and examine their associations with gut microbiome composition.Methods Healthy community-dwelling adults (n=800), aged ≥21 years, without chronic disease, gastrointestinal disorders, smoking history, or recent antibiotic use were recruited through AMILI’s ‘Poop Saves Lives’ campaign (2010–2024) with IRB approval (2020/0501). TCM body constitution was assessed using the validated Constitution in Chinese Medicine Questionnaire, restricting analysis to individuals with a single constitution. Stool microbial DNA underwent shotgun metagenomic sequencing and taxonomic profiling using the BioBakery pipeline. Alpha and beta diversity and differential abundance analysis (MaAsLin2) were performed in R comparing each unbalanced type against NBC while adjusting for age, BMI, gender, and race.Results Among 800 healthy participants, 61% exhibited a single TCM body constitution, with NBC being most prevalent. Gut microbial community structure differed modestly across constitution types based on Bray–Curtis β-diversity (PERMANOVA p=0.045), whereas α-diversity indices did not differ significantly. After adjustment for demographic covariates, differential abundance analysis identified several constitution-associated taxa (IDDF2026-ABS-0289 Figure 1). Klebsiella (including Klebsiella pneumoniae) and Megasphaera sp. NM10 were enriched in Qi-deficiency constitution (QIDC), while Schaalia spp. were enriched in Qi-stagnation constitution (QSBC) (q<0.05). In contrast, blood-stasis constitution (BSBC) showed reduced abundance of the butyrate-producing bacterium Agathobaculum, including Agathobaculum butyriciproducens (q<0.05). Hierarchical clustering of MaAsLin2 effect-size profiles suggested three constitution-related differential abundance patterns, with QIDC clustering closely with QSBC, while BSBC exhibited a distinct microbial profile. Conclusions In conclusion, TCM body constitution types showed modest differences in gut microbiome composition among healthy adults, suggesting a potential microbial basis for constitution-related physiological variation.Abstract IDDF2026-ABS-0289 Figure 1