Researchers at the Chicago based Rush University Medical Centre have received $750,000 in funding from the US Department of Defence to study microbial cells in the human gut and the mechanism by which they can influence health and disease.
The researcher team, led by gastroenterologist Dr Ece Mutlu, said that it hoped to determine whether gastrointestinal microbiota has the potential to explain rises in breast cancer incidence.
According to Mutlu, this is the first time a study has hypothesized that intestinal bacteria and bacterial metabolism could represent a transferable genetic and environmental risk factor affecting susceptibility to breast cancer.
Indirect evidence
She told NutraIngredientsUSA.com that while there is no direct evidence from previous research to suggest gut microflora can influence breast cancer risk, there is a lot of indirect data.
“We know high fat foods change bacterial composition in the intestines and a high fat diet is a risk factor for breast cancer.
No one knows how high fat causes breast cancer and we postulate that the effects of high fat may be through alterations in bacterial metabolism by either affecting exposure to carcinogens or the amount of estrogen exposure," said Mutlu.
Lending the hypothesis further credence, she said, is the generally accepted view that bacteria can affect bile circulation, which regulates estrogen absorption, and that bacteria can directly metabolize female hormones as well.
Human microbiome
The study is part of a wider project aimed at understanding how changes in bacterial genomes, known as the human microbiome, can be correlated with changes in human health, according to the scientists.
The researchers said that breast cancer susceptibility genes explain less that five to 10 per cent of total breast cancer cases related to familiar factors, and they postulate that the gut microbiome passed on from mother to child may be another familiar factor previously never taken into account in the genetic risk models for the disease.
Probiotic potential
The project aims to map out the composition of gut microorganisms and the team claim that if they are able to find the microbes responsible for certain diseases it could influence potential treatments or diagnostic tools.
The project could generate exciting results for the probiotics and/or prebiotics and functional food industry, according to Mutlu.
“If we can identify a set of bacteria associated with breast cancer or a set of bacteria that appears to be protective from breast cancer, then we can try to manipulate the GI bacteria either with new probiotics/prebiotics or other functional foods,” she said.
Human study
The researchers are currently recruiting study participants who are female, 30 years of age or older, and newly diagnosed with breast cancer before any treatment has begun.
Clinical data from the participant’s medical records will be taken, and prior to a patient receiving any cancer-related therapy, biopsies of the colon and stool specimens will be taken, added the researchers.
The team said that they will use a technology for genomic sequencing called Multitag Pyrosequencing (MTPS) that will allow them to identify 50,000 or 60,000 microbes per sample.
Mutlu added that animal studies are set to be part of the research project as well but funding needs to be secured in this regard.
This article was amended from the one originally published on 2 November on NutraIngredientsUSA.com to include the comments from the study's lead researcher, Dr Ece Mutlu.