Abstract 3062: Modifiable factors and gut microbiome alteration among colorectal cancer patients

Abstract

Abstract Background: Previous study have indicated an association of microbial dysbiosis with stages of colorectal cancer (CRC). Meanwhile, higher microbial stochasticity has been introduced as the Anna Karenina principle (AKP) effect, which originates from the opening line of Leo Tolstoy and is translated in the microbiome as “all healthy microbiomes are similar; each dysbiotic microbiome is dysbiotic in its own way”. Here, we aim to elucidate the effect of modifiable factors on microbiome stochasticity related to dysbiosis in CRC. Methods: Fecal samples from 331 CRC patients, were collected prior to their surgery at Seoul National University Hospital. Bacteria that were enriched in early- and late-stage CRC groups were identified by linear discrimination analysis effect size (LEfSE) method, which was then used to calculate microbial dysbiosis index (MDI). The association of dietary choices with microbiome variability was addressed using the LEfSE analysis. The difference of intra-sample similarity index among lifestyle factors and metabolic diseases was tested to examine the AKP effect. A tree-based analysis of food choices was constructed. We then applied Procrustes framework to analyze the shape of dietary diversity and microbiome. Results: The LEfSE identified Leuconostoc, Oxalobacter, Acidaminococcus, and Methanobrevibacter were enriched in early-stage CRC, whereas Bacteroides, Fusobacterium, Lachnoanaerobaculum, Clostridium, and Granulicatella were enriched in late-stage CRC patients. The MDI derived from these bacteria had 64.2% predictive ability for CRC stages, with sensitivity and specificity of 61% and 69%, respectively. The AKP effect was found for history of smoking, alcohol consumption, and diabetes, whereas obesity and hypertension showed anti-AKP effect. For dietary choices, the hierarchical tree of foods and nutrients did not shape the microbial between-sample diversity. Additionally, high MDI was related with a high intake of pizza/hamburger, poultry, and light-vegetable combination. Conclusion: Our study contributed to current evidence of the microbiome structure and dysbiosis at different stages of CRC. Furthermore, history of smoking, alcohol consumption, and diabetes showed AKP effect in CRC patients. Non-significant association between dietary choices and microbiome diversity supported a small variation of microbiome profiles explained by dietary intake at the population level. Citation Format: Tung Hoang, Min Jung Kim, Ji Won Park, Seung-Yong Jeong, Jeeyoo Lee, Aesun Shin. Modifiable factors and gut microbiome alteration among colorectal cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3062.