Estrobolome: Microbiome, estrogen and cancer

A reader asked me to do a research dive and post on Estrobolome. This is likely a new word for most of my readers as it was for myself.

” estrobolome, the gut bacterial genes capable of metabolizing estrogens in both healthy individuals and in women diagnosed with estrogen-driven breast cancer ” [2016]

or a more technical definition

 “the aggregate of enteric bacterial genes whose products are capable of metabolizing estrogens”  [2011]

This visual may put things is a clearer perspective: [2016 src]

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“Recent research suggests that the microbiota of women with breast cancer differs from that of healthy women, indicating that certain bacteria may be associated with cancer development and with different responses to therapy.”[2018]


The differences of genes determine what happens with estrogens.

  • “In the human GI tract, the BG gene is well represented in the bacterial phyla Bacteroidetes and Firmicutes whereas gus is more common in Firmicutes” [2012]

The technical details are  ß-glucuronidase and/or ß-galactosidase +, on which we have some basic taxonomy information [2012]

Genus ß-glucuronidase ß-galactosidase
Collinsella +
Edwardsiella +
Alistipes + +
Bacteroides + +
Bifidobacterium + +
Citrobacter + +
Clostridium + +
Dermabacter + +
Escherichia + +
Faecalibacterium + +
Lactobacillus + +
Marvinbryantia + +
Propionibacterium + +
Roseburia + +
Tannerella + +
Actinomyces +
Alistipes +
Anaerostipes +
Bacteroides +
Barnesiella +
Bifidobacterium +
Blautia +
Butyricicoccus +
Butyrivibrio +
Catenibacterium +
Cedecea +
Cetobacterium +
Citrobacter +
Clostridium +
Collinsella +
Coprobacillus +
Coprococcus +
Dorea +
Dysgonomonas +
Enterobacter +
Enterococcus +
Eubacterium +
Fusobacterium +
Hafnia +
Holdemania +
Klebsiella +
Lactobacillus +
Megamonas +
Mitsuokella +
Odoribacter +
Paenibacillus +
Parabacteroides +
Paraprevotella +
Pediococcus +
Porphyromonas +
Prevotella +
Pseudoflavonifractor +
Roseburia +
Ruminococcus +
Staphylococcus +
Streptococcus +
Subdoligranulum +
Turicibacter +
Weissella +
Yokenella +

I will be adding this information to analysis underexp


Additional Literature

  • “Relative abundances of the order Clostridiales and the genus Bacteroideswere directly and inversely related with the ratio estrogen metabolites to estrogen parents, respectively.” [2014]
  • ” However, Methylobacterium radiotolerans was the most significantly enriched and the most prevalent (100% of samples) in tumor tissues, and Sphingomonas yanoikuyae(95% of samples) in paired normal tissues. ” [2014]
  • ” Authors only found higher abundance of Escherichia coli in [cancer] cases compared with healthy controls. [2014]
  • “Absolute numbers of Bifidobacterium and Blautia, and proportion of F Prausnitzii and Blautia were significantly different according to clinical stages [of cancer]. Women with grade III had increased absolute numbers of Blautia sp. compared to women with grade I.
    Significant differences were also found in the absolute numbers of total bacteria and some bacterial groups (F prausnitziiFirmicutesBlautia and Egerthella), according to BMI.” [2015]
  • “Relative abundance of several taxa differed between cases and control: case patients had higher levels of ClostridiaceaeFaecalibacterium, and Ruminococcaceae; and lower levels of Dorea and Lachnospiraceae. ” [2015]

We are still in hypothesis land

” In conclusion, links between the microbiome and estrogen-driven breast cancer are growing, and we hope that research will identify specific characteristics of the gut microbiome that can be used to develop novel approaches for breast cancer risk assessment, prevention, and treatment.” [2016]

Bottom Line

The concept of microbiome influencing estrogen and possibly many cancers seems to be growing in popularity with researchers.  The microbiome shifts for different cancers are likely to be different and is a topic that is likely worth returning to in a year when the body of research would be  far greater.