Consuming natural yoghurt on a daily basis may reduce the risk of breast cancer, according to a new study which says the probiotic supplement may help replace harmful inflammation-causing bacteria with beneficial microbes present in the food.

Researchers, including those from Lancaster University in the UK, said their idea -- as yet unproven -- is supported by the available evidence that bacterial induced inflammation is linked to cancer.

According to the study, published in the journal Medical Hypothesis, bacteria induced inflammation in breast ducts disturbs undeveloped cells, or stem cells, waiting to mature into specialised ones, and may be a cause of breast cancer.

"There is a simple, inexpensive potential preventive remedy, which is for women to consume natural yoghurt on a daily basis," said study co-author Auday Marwaha from Lancaster University.

According to the research team, the lactose fermenting beneficial bacteria, or microflora, commonly found in yoghurt, is similar to those found in the breasts of mothers who have breastfed.

"We now know that breast milk is not sterile and that lactation alters the microflora of the breast," said Rachael Rigby, study co-author from Lancaster University.

"Lactose fermenting bacteria are commonly found in milk and are likely to occupy the breast ducts of women during lactation and for an unknown period after lactation," she added.

The researchers believe these bacteria in the breast may be protective since earlier studies had reported that each year of breast feeding reduced the risk of breast cancer by nearly 5 per cent.

A similar effect seen in yoghurt, the scientists said, may be due to the displacement of harmful bacteria by beneficial bacteria.

"The stem cells which divide to replenish the lining of the breast ducts are influenced by the microflora, and certain components of the microflora have been shown in other organs, such as the colon and stomach, to increase the risk of cancer development," the researchers noted.

"Therefore a similar scenario is likely to be occurring in the breast, whereby resident microflora impact on stem cell division and influence cancer risk," they concluded.