Association between socio-economic status and intestinal microbiota composition in patients with colorectal adenomas

Intestinal flora dysbiosis is closely linked to colorectal cancer development, yet the influence of socioeconomic status (SES) on the intestinal microbiota of patients with colorectal adenomas (CRA, a pre-cancerous lesion) remains unclear. This study aimed to investigate the associations between SES and the composition as well as relative abundance of the intestinal microecosystem in CRA patients. This cross-sectional study recruited 92 CRA patients from March 2021 to March 2022 at Tianjin Nankai Hospital, Tianjin, China. Data collection included personal history questionnaires (to capture SES-related indicators) and fresh stool samples (for microbiota analysis). Latent class analysis (LCA) was utilized to categorize participants into distinct subgroups based on SES, which was defined by four key indicators: occupation, educational attainment, household income, and residential address. Beta (β)-diversity of the gut microbiota was evaluated using principal coordinate analysis (PCoA). Generalized linear models (GLMs) were employed to explore the associations between SES subgroups, alpha (α)-diversity indices, and the relative abundance of specific gut microbial taxa. A significant difference in gut microbiota α-diversity was observed between high and low SES groups (Chao1 index, P = 0.047), whereas no disparity in β-diversity was detected. Compared to lower SES participants, those with higher SES exhibited a nominally reduced relative abundance of Actinobacteria (β = -0.889, 95% CI: -1.630 to -0.148, P = 0.019; q = 0.076), a phylum with both beneficial (e.g., antibiotic production) and pathogenic species. In contrast, higher SES was associated with greater relative abundance of Lachnospira (β = 0.475, 95% CI: 0.027 to 0.924, P = 0.038; q = 0.277) and Coprococcus (β = 0.565, 95% CI: 0.066 to 1.064, P = 0.027; q = 0.277), two fiber-fermenting, short-chain fatty acid–producing genera implicated in maintaining intestinal health. However, none of these associations remained statistically significant after multiple-testing correction. Our study suggests a potential association between SES and gut microbiota in CRA patients: high SES may correlate with a microbial profile potentially favorable for colorectal health (enriched beneficial genera including Lachnospira and Coprococcus). These observations may inform future interventions aimed at reducing intestinal microecological disparities in low-SES subgroups. However, none of the taxon-level associations remained statistically significant after false discovery rate correction; therefore, these findings should be considered exploratory. Further large-scale prospective studies are warranted to validate these preliminary associations and clarify the underlying mechanisms. Trial registration and ethics approval: The trial registration number of this study is ChiCTR2100046390. This study was approved by the Ethics Committee of Tianjin Nankai Hospital (No. NKYY_YXKT_IRB_2021_048_01). All procedures involving human participants were conducted in accordance with the ethical standards of the institutional research committee and with the Declaration of Helsinki (as revised in 2013). Written informed consent was obtained from all participants prior to enrollment. Clinical trial number: not applicable. This study did not involve a clinical trial. “PERMANOVA18” refers to the statistical method and its corresponding reference, not a clinical trial registration number.