Deodorant could be allowing more harmful bacteria to grow in underarms, research suggests

'When you have all these microbes on your skin, most of them are potentially beneficial, or at least benign'

Deodorant affects how microbiomes work in our bodies, which are the bacteria, viruses and fungi that live inside us and on our skin (Rex features)

Deodorant could do more harm to the body than good, new research has suggested.

The study, published in the Peerj journal, concluded that deodorant affects how microbiomes - bacteria, viruses and fungi that live inside us and on our skin - work in the body, by making potentially dangerous bacteria grow back quicker.

It looked at 17 men and women who regularly used deodorant, antiperspirant, or neither, over a period of eight days.

The researchers specifically focused on the bacteria that grew back under participants' underarms when they did not wear deodorant.

Scientists found deodorants and antiperspirants - which prevent the glands under the arms from producing sweat - change the microbial "community" that live underneath arms, by eliminating some of the good bacteria and allowing more harmful bacteria to grow.

The results of the study showed people who did not use any type of product have more corynebacteria – which is the bacteria that causes body odour - and less staphylococcaceae - a positive bacteria.

Regular deodorant users showed more staphylococcaceae than the other two groups after not using any products, along with some corynebacteria and only five per cent of unidentifiable bacteria.

For those who regularly used antiperspirants, researchers found they had as much staphylococcaceae as those who used deodorant and more than 20 per cent of unidentifiable microbes. After the eight days, most of the microbial communities died off after using antiperspirants again.

Researchers could only say for definite that bacteria grew back faster after people who usually wore deodorant or antiperspirant had stopped using it.

Co-author of the study and evolutionary geneticist at the North Carolina Central University Julie Horvath said the unidentifiable bacteria, which grows on people who regularly use antiperspirant, “may not be anything to worry about”. But, she added, some types of staphylococcaceae can be harmful.

Ms Horvath said: “When you have all these microbes on your skin, most of them are potentially beneficial, or at least benign."