Are you getting recurrent UTIs? Your estrogen levels may be to blame

US study finds a very strong association between beneficial bacteria in the bladder and the use of estrogen hormone therapy in postmenopausal women. ‘Estrogen supplementation can certainly break the cycle of recurrent infections. Focus on preventives,’ says gynaecologist Dr Amrinder Bajaj

The researchers found robust correlations between so-called “good” bacteria and urinary estrogens in post-menopausal women without a history of UTIs. (Photo: Getty Images/Thinkstock)

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Why are older women more prone to urinary tract infections (UTIs)? Turns out their falling estrogen levels are to blame. Researchers at the University of Texas at Dallas have identified specific bacteria in the bladder that may indicate which postmenopausal women are more susceptible to recurrent urinary tract infections (UTIs), and found that estrogen may play a role in reducing that susceptibility. “We found a very strong association between beneficial bacteria in the bladder and the use of estrogen hormone therapy in postmenopausal women,” said Dr Nicole De Nisco, assistant professor of biological sciences in the School of Natural Sciences and Mathematics. “Estrogen is important not just in regulating reproductive processes but also in shaping the chemical environment of the entire body. When you lose that hormone, you lose all the benefits that it provides.”

The study confirms what we have known for some time now, according to gynaecologist Dr Amrinder Bajaj, Senior Consultant, FMRI (Fortis Memorial Research Institute) Gurgaon. “Under the influence of estrogen, the vagina remains elastic, moist and multi-layered. But as estrogen levels dip, it thins down and dries up. Lactobacillus, a type of good bacteria, is abundantly present in the vagina before menopause. The vaginal walls release a type of glucose called glycogen. Lactobacilli ferment the glycogen, producing lactic acid, which in turn prevents other kinds of bacteria from growing and blocks pathogens. Many other research studies have shown how reduced levels of estrogen during menopause lead to lower levels of lactobacilli and an elevated pH. This altered ecosystem is a breeding ground for microbes. In fact, a research from Sweden in 2013 had shown how estrogen acts on the epithelium in a way that the gaps between the cells lining the bladder lumen are healed. In other words, estrogen glues them together. This makes it more difficult for bacteria to break this protecting shield and reach the underlying cells,” says she.

Dr Bajaj also says how postmenopausal women become more susceptible to contamination. “As estrogen levels continue to reduce, the muscles in the bladder and pelvic floor weaken, causing urinary incontinence, or uncontrolled leakage of urine from the bladder. Remember the posterior wall of the urinary bladder is adjacent to the posterior of the vagina, making post-menopausal women that much more prone to picking up an infection. Contamination occurs when bacteria from the surrounding area, including the rectum and vagina, enter the urethra, which is the tube through which urine exits the body. Being sexually active may also increase the likelihood of contracting a UTI,” she explains.

While antibiotics are prescribed for the UTIs, Dr Bajaj recommends a preventive protocol like applying estrogen cream long-term as recommended by a gynaecologist. “The estrogen levels may never come back to what they were but supplementation can certainly break the cycle of recurrent infections,” she says.

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The researchers found robust correlations between so-called “good” bacteria and urinary estrogens in post-menopausal women without a history of UTIs. More than 50 per cent women suffer from UTI in their lifetimes. Age is one of the strongest associated risk factors.

The research team tested 75 postmenopausal women, who fell into three groups: Those who did not have a history of UTIs, those who have recurrent UTIs and were experiencing one at the time of testing and those who have recurrent UTIs but were not experiencing one at the time of testing. “What we found is that those women who are in between infections — those with a history of recurrent UTIs but currently UTI negative — had a microbiome that was full of microorganisms capable of causing disease of the urinary tract while having fewer good bacteria,” Dr Nisco said.

In contrast, many of the women who were taking estrogen therapy did not have the “bad” bacteria in their bladders. Researchers said the greater amount of estrogen found in the urine correlated with a predominance of good bacteria, such as Lactobacilli, in the microbiome. The researchers also found that microbiomes of the women with recurrent UTIs contained more antibiotic resistance genes than those in women with no history of UTI. Antibiotic resistance genes can be exchanged between cells, allowing resistance to spread rapidly through a population of bacteria and thus making infections more difficult to treat.

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While antibiotics have been somewhat effective in fighting disease-causing bacteria, Dr Nisco said the prescribing of antibiotics when they are not needed — which is accelerating antibiotic resistance — is one of the biggest hurdles in treating UTIs. “We just can’t throw antibiotics at this problem or else we will never break the cycle of recurrent infections,” De Nisco said. “We need to start thinking about out-of-the-box therapies that don’t rely so heavily on antibiotics. Rather, we can use things such as estrogen or maybe we give a combined therapy of estrogen and a probiotic.”

De Nisco said the new information can perhaps guide the development of new screening and prevention tools. She is studying whole-cell vaccines and believes other solutions can be developed.