"We have read for you": the role of probiotics in women with recurrent urinary tract infections.
I have read lately a review entitled "The role of probiotics in women with recurrent urinary tract infections", written by researchers Turgay Akgül and Tolga Karakan.
Urinary tract infections (UTIs) are the most frequent bacterial infections. One of the most complex and unpleasant problems of UTIs in women is the tendency to relapse. We talk about relapsing UTI when there are 3 episodes over 12 months or 2 episodes over 6 months.
Antibiotics use in UTIs treatment or in prophylaxis damages the normal intestinal and vaginal microbiota and creates antibiotic resistance.
Increasingly frequent resistance to antibiotics and a greater patients awareness has led in recent years to prefer new prevention strategies and alternative approaches to antibiotic therapies especially in case of recurrent urinary tract infections.
Among the most effective strategies, together with D-Mannose, probiotics represent the most promising approach.
The probiotic term is formed by the Latin "pro" (in favor) and the Greek term "bios" (life). The concept of probiotic was first introduced by Elie Metchnikoff, who noted that microbes in the digestive system, could make positive contributions, especially in digestive system diseases.
The World Health Organization has defined probiotics as "useful living microorganisms that have a positive effect on a person's health and physiology if taken in sufficient quantities".
Probiotics can be found in food and food supplements (capsules, tablets and powder).
Microbiome structure (the set of bacteria present in the human organism) has been the subject of immense interest in recent years. Various studies have been conducted on the potential roles played by microbial structures in different diseases.
Although there are sufficient studies in the literature about skin, mouth, vagina and intestine microbiome, the urinary microbiome (UM) has not been sufficiently studied. The reason for this is that until recently, it was believed that urine in healthy individuals was sterile.
Thanks to rRNA 16S sequencing and advanced urine quantitative culture (EQUC) techniques developed in recent years, aerobic and anaerobic bacteria that colonize the normal flora of the urinary system have been detected. These play an important role for the health and balance of the urinary system. In urinary microbiomes studies, the degree of concentration of bacteria living in the urinary tract, may vary according to sex, collecting urine method and used technique to study the UM. In general, Lactobacillus and Streptococcus are the most frequently detected species. Both microorganisms have protective roles against pathogens that colonize the urogenital region.
When examining the vaginal flora, it is known that Lactobacillus spp. microorganisms are the dominant bacteria and form a good bacterial flora with antimicrobial activity. Inadequate approaches to genitourinary infections and continuous relapses lead to a prevalence of coliform uropathogens on lactobacilli.
There is a clear and consolidated relationship between vaginal flora and urogenital infections. In fact, most of the vagina microorganisms come from the gastrointestinal tract. Numerous scientific studies have shown how the regulation of gastrointestinal and vaginal flora with probiotic support can prevent genitourinary infections.
Probiotics work by acidifying the vaginal environment, creating a protective film on the mucosa, inhibiting pathogens adhesion, producing substances such as vitamins and immunomodulators and carrying out synergistic activity with the host's immune system.
Some species of lactobacilli produce hydrogen peroxide and biosurfactants that acidify the vaginal mucosa. All these properties make lactobacilli be the probiotic selected agents for uroginecological infections prophylaxis and contrast.
Lactobacilli can prevent adherence, growth and colonization of uropathogenic bacteria. It has been shown that healthy biological populations of Lactobacillus species have a strong inhibitory effect on E. coli.
Most recurrent UTIs in women are caused by the pathogen E. coli. The antibiotics used in the treatment of these infections reduce the number of lactobacilli, which form a natural defensive barrier in the urinary system, also causing in many cases, antibiotic resistance.
In one study, researchers from Dr. Zucotti's team stated that probiotics could be a good alternative to antibiotic therapy due to their ability to bind to uroepithelial cells and inhibit pathogenic growth and biosurfactant secretion. The same researchers pointed out that the oral intake of lactobacilli and the consequent intestinal colonization can also bring these bacteria into the urinary tract.
Clinical studies have shown that oral administration of lactobacilli can also reach the vaginal environment. In many studies, capsules containing L. rhamnosus and L. fermentes were administered orally at 10*9 CFU once or twice a day. In these studies, the authors found that orally administered capsules can regulate vaginal flora and can be effective on recurrent UTIs. It has also been emphasized that oral probiotics may be more comfortable for patients than vaginal administration and that compliance (adherence to therapy) significantly improves.
Recently, two double-blind placebo-controlled randomized clinical trials have been published that investigate the effects of probiotics on inhibiting recurrent UTIs.
In the first one, Dr. Beerepoot's team demonstrated that supplementation with 480 mg of L. rhamnosus GR-1 and L. reuteri RC-14 significantly reduced the average number of relapses in patients with uncomplicated UTI compared to the control group. Furthermore, antibiotic resistance was significantly reduced in the probiotic group compared to the control group.
In the second one, Dr. Stapleton's group studied 100 premenopausal women who had experienced bacterial cystitis at least once in the last 12 months. Patients, after one episode of cystitis, were divided into two groups.
The first group was treated with placebo. The second one was subjected to vaginal application of lactobacilli for 10 weeks, specifically Lactobacillus crispatus (10*8 CFU/mL). This study results showed that recurrent vaginal and urinary infections incidence in patients treated with intravaginal Lactobacillus decreased significantly compared to the placebo group.
In literature studies on probiotic use in UTI, the duration of probiotic use varies from 5 days to 12 months and doses vary between 10*4 CFU and 10*10 CFU.
We therefore have clinical evidence that a balance of gastrointestinal and vaginal flora is very important both for prevention and management of recurrent urinary tract infections. The supplementation of probiotics and prebiotics is therefore an effective and safe strategy without side effects in familiar people with urogenital problems.
Obstetrician Sara Furno