Machine Learning-Driven Detection of Colorectal Neoplasia from 16S rRNA Gut Microbiome Profiles: A Compositional Approach
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Abstract
The early detection of colorectal cancer (CRC) and advanced adenomas through non-invasive methods remains limited due to the lack of sensitivity of traditional fecal-based techniques. In order to solve this challenge, 16S rRNA gene amplicon sequencing data derived from 59 stool samples were analyzed using optimized machine learning classifiers using compositional data analysis techniques. CLR transformations were applied on 208 genera to overcome issues of compositionality and sparseness. With respect to 5-fold stratified cross-validation, the Random Forest algorithm proved to be superior, exhibiting an average AUC of 0.81 ± 0.15 in binary CRC classification as well as an average accuracy of 0.67 ± 0.08 for multi-class classification. The predictive models suggested an ecological dichotomy, where the oral pathogens, Fusobacterium and Parvimonas, were found significantly abundant in CRC patients compared to healthy controls, while the protective and beneficial bacteria producing butyrate, Roseburia and Faecalibacterium, showed progressive reduction from adenoma to carcinoma. The stability of feature selection was determined using a Jaccard index of more than 0.80. This suggests the development of a reliable computational framework for improving diagnostic accuracy. Nevertheless, the clinical relevance of these results awaits confirmation in large-scale studies.
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