Hormone pills designed to make menopause easier also make women more resistant to painful urine infections, according to a new study.

Researchers found that women who take menopausal hormone therapy - also known as HRT - are less likely to suffer from painful urinary tract infections (UTIs) because they have more good-bacteria in their system, scientists have found.

Between 50 and 60 per cent of women experience UTIs during their lifetime and are eight times more likely to get infected than men.

Assistant Professor Nicole De Nisco, of the University of Texas, said: "As far as we know, this is the first focused analysis of the bacteria in the urogenital tract of postmenopausal women, and the results indicate that oestrogen use is associated with high levels of Lactobacilli in the urine, which could possibly offer some protection against infection.

"However, this is a small study and needs to be repeated with a larger group of women.”

Urine naturally contains a variety of bacteria, fungi and viruses, which are mostly harmless or even helpful to our digestion.

Lactobacillus are rod-shaped bacteria which are known to play a “protective role” against infections in the vagina.

The research team collected and analysed bacteria DNA from the urine of 75 postmenopausal women who attended a clinic in Dallas, Texas.

Women were split into three groups, 25 who had never had a UTI, 25 who had a history of UTIs but were not infected, and 25 who had a history and were infected.

Dr De Nisco said: “The DNA analysis showed two things. Firstly, women who have recurrent infections have fewer types of bacteria in their urine than women who do not have infections.

“Secondly, 34 of the women were taking Menopausal Hormone Therapy, and they tended to have more Lactobacillus-type bacteria in their urine, which may imply that the oestrogen in MHT supports the growth of Lactobacillus in the urogenital tract.”

Menopause marks the end of a woman's menstrual cycle, at which point the ovaries stop producing oestrogen.

The number of infection-resistant bacteria also depended on what type of hormone therapy the women used, researchers found.

Dr De Nisco said: “We also found that women who were taking MHT via patches or orally had more Lactobacillus than women taking MHT via vaginal cream.”

Menopause, which normally happens to women in their 50s, can have many

different symptoms such as hot flushes, weight gain and vaginal dryness.

A probiotic to be taken alongside MHT could be developed to stop women relying on antibiotics, although this still needs to be tested.

Dr De Nisco said: “We now need to look more closely at whether managing the bacterial content of the urogenital system might affect susceptibility to infection.

“Additional studies need to be performed to determine a causal link between oestrogen therapy, Lactobacillus colonisation and prevention of UTI.

“Possible future applications may include administering probiotic vaginal pessaries to women at risk of infection. and perhaps prescribing oestrogen

therapy.”

The findings support previous research which found women who have less natural oestrogen tend to have more infections.

Dr De Nisco said: “However it's too early to bring these into clinical practice.We know that oestrogen therapy is not recommended for all women going through menopause, and the optimal formulations of probiotic pessaries need to be developed and their use in women with UTI would need to be tested".

This is the next step in our research."