Machine learning identifies differences between breast milk and formula in the gut microbiome.

In this study, we analysed differences in the infant gut microbiome between breastfed and formula-fed infants using novel machine learning techniques. Breast milk, rich in bioactive agents, supports microbiota composition and immune development, while formulas aim to replicate its nutritional profile. We applied a methodology combining the DADA2 pipeline for 16S rRNA sequencing with the Recursive Ensemble Feature Selection (REFS) algorithm for biomarker discovery. We analysed three publicly available 16S rRNA datasets: PRJNA633365 (70 stool samples from China), PRJDB7295 (40 stool samples from the Philippines), and PRJNA562650 (40 stool samples from China). The discovery dataset (PRJNA633365) revealed 16 significant taxa out of 1,227, validated across the other two datasets. Next, we compared REFS performance with another feature selection algorithm, SelectKBest. Finally, we conducted a literature review to explore links between identified taxa and medical conditions. Additionally, we used MicrobiomeAnalyst to examine associations with diseases, diet, and lifestyle. Our results show differences in the bacterial composition between breastfed and formula-fed infants, and these findings were validated in two independent datasets. Future research should explore the functional roles of these taxa and consider regional and dietary variability to enhance understanding of microbiome dynamics and long-term health outcomes.