Effect of Garambullo (Myrtillocactus geometrizans) Consumption on the Intestinal Microbiota Profile in an Early-Phase Rat Model of Colon Cancer

Bioactive compounds in food contribute to reducing the risk of developing colon cancer by modulating the gut microbiota. We have recently demonstrated that garambullo (<i>Myrtillocactus geometrizans</i>), an endemic fruit of Mexico rich in bioactive compounds, attenuates aberrant crypt foci in an animal model. However, its potential to modulate the gut microbiota is unknown. The main objective of this study was to evaluate whether its consumption modulates colon carcinogenesis by altering the microbiota in an in vivo model induced by azoxymethane and dextran sulfate sodium (AOM/DSS). Fecal samples were collected from twelve male Sprague-Dawley rats and analyzed for microbiota composition after 0, 8, and 16 weeks of treatment with saline (control), AOM/DSS, garambullo (G), or residue of garambullo (RG) with AOM/DSS (G+AOM/DSS and RG+AOM/DSS, respectively). Characterization of the microbiome was based on the conserved region of the 16S rRNA V3-V4 gene, and analyzed by the ZymoBIOMICS' Targeted Metagenomics Sequencing (Zymo Research) service. In an animal model induced with AOM/DSS for 8 weeks, consumption of G and its residue increased the bacterial genera <i>Shuttleworthiia</i>, <i>Subdoligranulum</i>, <i>Lactobacillus</i>, <i>Faecalibacterium</i>, and <i>Alloprevotella</i> (<i>p</i> < 0.05). Consumption of G and its residue allowed the proliferation of bacteria that produce short-chain fatty acids and are associated with protective mechanisms of the colon.