Faecal Microbiota Composition Varies between Patients with Breast Cancer and Healthy Women: A Comparative Case-Control Study

Christine Bobin-Dubigeon,Françoise Le Vacon,Jean-Marie Bard,Sébastien Leuillet,Hassane Nazih,Thomas Carton,Catherine Michel,Huyen Trang Luu,Sidonie N Lavergne

doi:10.3390/nu13082705

Abstract

The intestinal microbiota plays an essential role in many diseases, such as obesity, irritable bowel disease (IBD), and cancer. This study aimed to characterize the faecal microbiota from early-stage breast cancer (BC) patients and healthy controls. Faeces from newly diagnosed breast cancer patients, mainly for an invasive carcinoma of no specific type (HR+ and HER2−), before any therapeutic treatment and healthy controls were collected for metabarcoding analyses. We show that the Shannon index, used as an index of diversity, was statistically lower in the BC group compared to that of controls. This work highlights a reduction of microbial diversity, a relative enrichment in Firmicutes, as well as a depletion in Bacteroidetes in patients diagnosed with early BC compared to those of healthy women. A tendency towards a decreased relative abundance of Odoribacter sp., Butyricimonas sp., and Coprococcus sp. was observed. This preliminary study suggests that breast cancer patients may differ from healthy subjects in their intestinal bacterial composition.

Highlights

Breast cancer (BC) is the most commonly diagnosed solid organ cancer in women worldwide
The recent investigations of the influence of the gut microbiota on human health, in particular on metabolism and nutrient absorption in the digestive tract, as well as on many diseases, raise the question of whether this community is involved in the aetiology of cancer [3], especially in BC
We demonstrated in our previous study that a high abundance and relative proportion of some bacterial groups such as Clostridium cluster XIVa, Clostridium cluster IV, Faecalibacterium prausnitzii, and Blautia sp. was associated with a more severe clinical stage in BC patients [10]

Summary

Introduction

Breast cancer (BC) is the most commonly diagnosed solid organ cancer in women worldwide. The recent investigations of the influence of the gut microbiota on human health, in particular on metabolism and nutrient absorption in the digestive tract, as well as on many diseases (e.g., obesity, diabetes, and allergies), raise the question of whether this community is involved in the aetiology of cancer [3], especially in BC. Answering this question could lead to new preventative strategies for this pathology. These results are compatible with the findings of epidemiological studies that suggest an association between microbial dysbiosis due to antibiotic therapy and an increased incidence in breast carcinoma [3,9]

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Conclusion