First look at breast microbiota raises tantalizing questions

Mar 24, 2014

The female breast contains a unique population of microbes relative to the rest of the body, according to the first-ever study of the breast microbiome. That study sought to lay the groundwork for understanding how this bacterial community contributes to health and disease, says first author Camilla Urbaniak, a PhD student at the University of Western Ontario. The research was published ahead of print in Applied and Environmental Microbiology.

"Proteobacteria was the dominant phylum in healthy breast tissue," says Urbaniak, noting that it is found only in small proportions at other sites in the body. That may reflect the fact that breast tissue produces high concentrations of fatty acids, and these bacteria are fatty acid metabolizers. Proteobacteria is also the predominant phylum in human milk.

"The fact that beneficial bacteria, such as Lactobacillus and Bifidobacteria, were also detected makes us wonder whether their presence might be protective for both mother and child," says principal investigator Gregor Reid of the University of Western Ontario. Breast milk is one of the initial sources of gastrointestinal (GI) bacteria for newborns, and their GI microbiota are different if they are formula fed, says Urbaniak.

Conversely, Escherichia and Bacillus predominated in cancerous breasts.

"Strains of Escherichia have been shown to have mutagenic and carcinogenic activity in the gut and the bladder," says Urbaniak.

In the study, the investigators collected from 81 women. Ten of these had undergone , and their breast microbiota served as controls. The remaining women had had benign or cancerous tumors. The tissue collected from these women was taken from about five centimeters from the tumor, from what is known as "normal adjacent" tissue. Bacterial censuses were taken using a molecular technique known as 16S ribosomal sequencing, and with cultures.

Studies of the microbiome in other parts of the body, most notably the gastrointestinal tract, have shown that certain changes in bacterial populations can lead to a variety of ills, from obvious gastrointestinal conditions such as inflammatory bowel disease to those more unexpected, such as diabetes, obesity, cancer and even neurological conditions.

"Future studies will examine how this breast microbiome is established, why no infections accompany colonization, despite the fact that some of these bacteria cause infections elsewhere in the body, what impact these organisms have on the host, and whether external factors such as diet, antibiotics, and illness affect this , and what consequences that has for women and their offspring," says Urbaniak.

The manuscript can be found online at http://aem.asm.org/content/early/2014/03/03/AEM.00242-14.full.pdf+html. The final version of the article is scheduled for the May 2014 issue of Applied and Environmental Microbiology.

Explore further: More than just bacteria: The importance of microbial diversity in gut health and disease

add to favorites email to friend print save as pdf

Related Stories

Human breast milk microbiome changes over time

Jan 28, 2013

(HealthDay)—The microbiome of breast milk is influenced by many factors, including maternal weight and how the baby was delivered, according to research published in the American Journal of Clinical Nu ...

Recommended for you

Scientists see how plants optimize their repair

3 hours ago

Researchers led by a Washington State University biologist have found the optimal mechanism by which plants heal the botanical equivalent of a bad sunburn. Their work, published in the Proceedings of the Na ...

Structure of an iron-transport protein revealed

9 hours ago

For the first time, the three dimensional structure of the protein that is essential for iron import into cells, has been elucidated. Biochemists of the University of Zurich have paved the way towards a better ...

Over-organizing repair cells set the stage for fibrosis

9 hours ago

The excessive activity of repair cells in the early stages of tissue recovery sets the stage for fibrosis by priming the activation of an important growth factor, according to a study in The Journal of Ce ...

User comments : 0