American Association for Cancer Research
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Figure S2 from Diet Alters Entero-Mammary Signaling to Regulate the Breast Microbiome and Tumorigenesis

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posted on 2023-03-31, 04:25 authored by David R. Soto-Pantoja, Mohamed Gaber, Alana A. Arnone, Steven M. Bronson, Nildris Cruz-Diaz, Adam S. Wilson, Kenysha Y.J. Clear, Manuel U. Ramirez, Gregory L. Kucera, Edward A. Levine, Sophie A. Lelièvre, Lesley Chaboub, Akiko Chiba, Hariom Yadav, Pierre-Alexandre Vidi, Katherine L. Cook

A. Uninfected 4T1 tumor volume from mice treated 1 x weekly control diet-derived fecal transplant. B. Uninfected 4T1 tumor volume from mice treated 1 x weekly lard diet-derived fecal transplant. C. Tumor volume over time of uninfected 4T1 cells mixed with control diet-derived fecal conditioned media infected RAW 264.7 (macrophage) cells. D. Tumor volume over time of uninfected 4T1 cells mixed with lard diet-derived fecal conditioned media infected RAW 264.7 (macrophage) cells. E. Tumor proliferation as determined by Ki67 immunoreactivity. F. Gram-positive bacteria content in 4T1 breast tumors. G. LPS positive bacteria content in 4T1 tumors. H. Infiltrating tumor-associated macrophage content in 4T1 tumors was determined by F4/80 immunoreactivity. n=5-6.*p<0.05


Chronic Disease Research Fund

American Cancer Society Research Scholar

Komen Foundation

American Institute for Cancer Research


Department of Defense Breast Cancer Research Program

National Cancer Center's Comprehensive Cancer



Obesity and poor diet often go hand-in-hand, altering metabolic signaling and thereby impacting breast cancer risk and outcomes. We have recently demonstrated that dietary patterns modulate mammary microbiota populations. An important and largely open question is whether the microbiome of the gut and mammary gland mediates the dietary effects on breast cancer. To address this, we performed fecal transplants between mice on control or high-fat diets (HFD) and recorded mammary tumor outcomes in a chemical carcinogenesis model. HFD induced protumorigenic effects, which could be mimicked in animals fed a control diet by transplanting HFD-derived microbiota. Fecal transplants altered both the gut and mammary tumor microbiota populations, suggesting a link between the gut and breast microbiomes. HFD increased serum levels of bacterial lipopolysaccharide (LPS), and control diet–derived fecal transplant reduced LPS bioavailability in HFD-fed animals. In vitro models of the normal breast epithelium showed that LPS disrupts tight junctions (TJ) and compromises epithelial permeability. In mice, HFD or fecal transplant from animals on HFD reduced expression of TJ-associated genes in the gut and mammary gland. Furthermore, infecting breast cancer cells with an HFD-derived microbiome increased proliferation, implicating tumor-associated bacteria in cancer signaling. In a double-blind placebo-controlled clinical trial of patients with breast cancer administered fish oil supplements before primary tumor resection, dietary intervention modulated the microbiota in tumors and normal breast tissue. This study demonstrates a link between the gut and breast that mediates the effect of diet on cancer. This study demonstrates that diet shifts the microbiome in the gut and the breast tumor microenvironment to affect tumorigenesis, and oral dietary interventions can modulate the tumor microbiota in patients with breast cancer.