A MICROSCOPIC VIEW OF THIS CHAPTER
• Microbes also live in the urogenital tract.
• Probiotics support health in the urogenital tract.
• Use of probiotics can help fight yeast overgrowth.
• Vaginal bacteriosis is caused by overgrowth of bad microbes.
• Probiotics may help prevent and treat urinary tract infections.
• Oral and intravaginal administration of probiotics supports the urogenital tract.
The microflora that exists in our body does not just live in the gastro-intestinal tract. Microbes can move from place to place, and the microflora in our body will move from the mouth, throughout the intestinal tract and into the urogenital (urethra and bladder) tract. Some microbes also live on your skin. The microflora needs no passport. There are no borders between these areas of the body. The movement of microbes is unrestricted. Of note, their movement does not happen at great lengths, as each species has a preferred location to live in the body. An example is Bifidobacteria’s preference to colonize in the large intestine.
You can find microbes in the mouth, intestinal tract, urethra, vagina and on the skin. The urogenital tract consists of the urethra and bladder (and vagina in females). The urogenital tract is normally sterile with the exception of the vagina and the distal first centimeter of the urethra. This small population of microbes in the urogenital tract may not compare to the large numbers found in the intestines, but its influence on the body’s health is almost as important.
How do Lactobacilli promote a healthy urogenital tract? These organisms lower the pH of the vagina to 4 or 5, which inhibits the growth of bad microbes. If conditions change, such as an increase in stress or the use of antibiotics, the presence of Lactobacilli declines. If there is a loss in the number of Lactobacilli in the urogenital tract, the defenses available to fight bad microbes are decreased. Where do these bad microbes come from? The origin of the bad microbes in urinary tract infections and bacterial vaginosis commonly comes from fecal flora.
Bad microbes that can thrive in a urogenital tract that lacks Lactobacilli include Candida albicans, Streptococci and E. coli. When conditions are favorable toward these bad microbes, they flourish, causing disease or illness in the urogential tract. Such diseases include Candida infections (yeast infection), bacteria vaginosis and urinary tract infections. Urogenital infections are a problem shared worldwide. They are the most common reason for a woman to decide to visit a gynecologist or urologist.
Research has discovered that the presence of certain probiotics appears to lessen the severity of some of these urogenital illnesses. Lactobacilli are thought to play a major role in the health of the urogenital tract.
THE VAGINA
The vagina, also called the birth canal, is a thin-walled tube about 8 to 10 centimeters long. It lies between the bladder and rectum. It extends from the cervix, the opening to the uterus, to the outside of the body. The vagina provides a passageway for the delivery of an infant and for menstrual flow to leave the body. As the vagina is a passageway between the outside environment and the body, it is a common place to find microbes. In close proximity to the anus, the vagina can easily be infected with bacteria from the large intestine. Bad microbes from feces can easily find their way over to the vagina.
Various members of the Lactobacillus family love to live in the vagina. Certain Bifidobacteria also live in the vagina, although everyone is different. We have different genes, different fingerprints and different microflora. There is no one dominant probiotic species in a healthy vagina. The dominant species of bacteria in one woman’s vagina may be different than the next. However, we do know that Lactobacilli are common in all healthy vaginas, and they have a protective effect against the colonization and overgrowth of bad microbes.
Some studies have tried to identify which species are commonly found in healthy vaginal microflora. Both Bifidobacteria and Lactobacilli species are present. Four species—Bifidobacterium bifidum, B. breve, B. adolescentis and B. longum—are thought to be the dominant Bifidobacteria in the vaginal microflora. Little research has been done in the area of Bifidobacteria and the vagina, but as these species are also common in the large intestine, it is not surprising that they are found inhabiting the vagina as well.
Lactobacilli have long been considered the protective microbes of the vagina. An investigation of 19 healthy women discovered that Lactobacillus gasseri was the dominant Lactobacilli in their vaginas. However, there is no consensus among experts that this species is the most important or universally dominant vaginal probiotic. Lactobacillus crispatus, Lactobacillus jensenii and Lactobacillus vaginalis have also been identified as important species in the vagina. Natural differences from human to human likely explain the conflicting results as to which probiotic species is the most dominant in the vagina.
With no consensus on which Lactobacilli are most dominant, a group of scientists sought to discover which species of Lactobacilli were most effective. Lactobacillus acidophillus CRL 1259 and Lactobacillus paracasei CRL 1289 were found to inhibit bad microbes, such as Staphylococcus aureus, from attaching to the lining of the vagina. More strains are likely to be found to offer similar protective effects against vaginal infections. Lactobacilli play an important role in maintaining urogential health.
How does oral supplementation of probiotics affect the vagina? The vagina is not part of the gastrointestinal tract. Probiotics move from the rectum to the vagina and/or cause changes in the body that promote probiotic growth in the vagina. Oral probiotic supplementation positively changes the diversity of microbes in the vagina. Probiotics are also available as suppositories, which work very well; however, research does not support this method as a superior administration route to oral supplementation.
YEAST INFECTIONS
In a healthy vagina, probiotics are dominant. They are present in large, healthy colonies. They stimulate the immune system and create an environment that inhibits the growth of bad microbes. However, there are many conditions that can tip the balance: stress, antibiotic use, consuming foods that contain antibiotics, environmental changes and infection. By altering the balance of microflora in the vagina, bad microbes can flourish. The result is an infection, inflammation or other illness. Candida overgrowth and bacteria vaginosis are both examples of illnesses that can arise when the delicate balance of microbes in the vagina is altered and bad microbes flourish.
It is estimated that 70% of the female population has suffered from Candida-related symptoms at some point in their lives. An overgrowth of Candida is called Candidiasis. Candida is a yeast that lives in us and on us as part of our body’s normal collection of microbes. In a normal digestive tract, about 90% of the body’s Candida live in the mouth and colon. Candida albicans is most often the species of Candida found on the skin and in the vagina of humans. The stomach, small and large intestine are hostile to Candida growth, so not much is found there. As such, Candida overgrowth is commonly only seen on the skin or in the vagina.
A Candida infection is also called a yeast infection.
A yeast infection is a horrible experience. Symptoms of a yeast infection include itching, burning, redness and irritation of the vaginal area. Severe yeast infections may cause swelling of the vulva. In some cases women experience painful and/or frequent urination, which is caused by inflammation of the urinary opening. Excessive vaginal discharge, which is thicker than normal, appears whiter, curd-like and looks similar to cottage cheese, will be apparent in women experiencing vaginal yeast infections.
About 70% of females have experienced a yeast overgrowth.
The vagina may increase mucus production and encourage candida overgrowth as a reaction to contact alergens land circulating food allergens. For example, a milk allergy commonly triggers inflammation and Candida overgrowth in both children and adults. Yeast overgrowth can be a nuisance. There is no way to eliminate all of the yeast in your body. All you can hope is to find a balance in which yeast grows at a controlled rate below levels that cause symptoms. Probiotics can help you find this balance.
Conditions that promote yeast overgrowth: environmental changes, stress, using antibiotics, bacterial infection and eating allergenic foods.
Yeast in Men?
Yeast overgrowth is not isolated in women. Men can suffer symptoms of yeast overgrowth. It is more common than you may think. Men may be troubled by yeast overgrowth on their penis or on the skin around the anus and groin. This is more commonly known as “jock itch.” Sexual intercourse can transfer yeast from a man to a woman. Both partners should consider probiotic treatment.
Antibiotic use changes the bacteria in the vagina and thus promotes the growth of Candida. Antibiotic use reduces the presence of all bacteria, including the beneficial probiotics in the vagina such as Lactobacillus. Antibiotic use causes the vaginal probiotic population to shrink. Then the pH of the vagina increases, due to no lactic acid coming from Lactobacilli to keep it low, and Candida is no longer restricted. Candida can colonize and flourish in such an environment.
How do Lactobacilli inhibit and control Candida? According to laboratory studies, Lactobacilli reduces the ability of Candida albicans to attach to the cells that line the vagina (vaginal epithelium), thus restricting its ability to colonize in the vagina.
The birth control pill also alters the vaginal environment. Many women use the birth control pill. It inhibits ovulation by altering hormone levels in the body. The use of birth control pills has been strongly linked to the development of Candidiasis. The birth control pill can disrupt the delicate balance of bacteria in the body, and allow yeast to grow. Probiotics have the ability to prevent yeast’s ability to grow. As such, probiotics offer women, particularly those on birth control pills or using antibiotics, a defense against Candida.
Many species of probiotics are known to inhibit Candida albicans growth in the vagina. In particular, Lactobacillus acidophilus, Lactobacillus rhamnosus GR-1 and Lactobacillus fermentum RC-14 taken orally or intravaginally are strains that can effectively fight against Candida. The use of Lactobacilli species to combat Candida is a good choice for women. More research is still needed in this area. In the meantime, the use of probiotics should be considered by women with frequent recurrences of Candida infections, as probiotics offer many immune health benefits—and adverse reactions from probiotics are very rare, unlike commonly prescribed antifungal agents.
BACTERIAL VAGINOSIS
Bacterial vaginosis is a condition in which the number of Lactobacilli in the vagina decrease and an overgrowth of bad microbes occurs. Bacterial vaginosis has been associated with various gynecological and obstetric complications as discussed in Chapter 7.
Bacterial vaginosis is commonly treated with antibiotics. As such, it has an extremely high recurrence rate. This may be because antibiotics do not help the underlying problem of bacterial vaginosis—an imbalance of microbes in the vagina. Antibiotics do not just kill bad bacteria, including Gardnerella vaginalis, a common cause of bacterial vaginosis; they also kill all of the bacteria in the body, including probiotics. The result is similar to an empty parking lot. After antibiotic use, the lot is empty and it is a race between all microbes to grab a parking spot. By repopulating the parking lot with probiotics as soon as possible, there are fewer spots open for pathogenic microbes. Antibiotic treatment of bacterial vaginosis does not help establish healthy microbes in the vagina. Consuming probiotics during and after antibiotic use decreases the risk of bad microbes growing in the body and causing disease. The use of high-potency probiotics during and after antibiotic use offers the most beneficial effects. Women with bacterial vaginosis using antibiotic therapy can benefit from probiotic use.
By repopulating the parking lot with probiotics as soon as possible, there are fewer spots for bad microbes.
Scientists have been studying the characteristics of probiotic strains that naturally live in a healthy urogential tract. Probiotics that are effective in preventing bacterial infections have the following characteristics:
• They prevent the growth of bad microbes.
• They can produce acid and hydrogen peroxide.
• They can attach to the cells of the vagina (vaginal epithelial cells).
• Strains thought to offer these characteristics include: L. acidophilus 61701 and L. acidophilus 48101, as well as L. crispatus 55730 and L. delbrueckii 65407. Lactobacillus rhamnosus is thought to offer the best potential against bacterial vaginosis. Lactobacilli are particularly effective at preventing bacterial vaginosis.
In a human clinical trial, 10 billion (1010) colony-forming units of L. rhamnosus were given orally to 10 women daily for two weeks. The women were suffering from abnormal flora in their vagina. The majority of the women complained of pains, frequent urination and vaginal irritation prior to the study. Within one week of probiotic introduction into their daily routine, the women reported a disappearance of their symptoms. Most exciting was the follow-up reports from the women; they had a healthy vaginal flora for several months following supplementation. Probiotics can help you rebalance your vaginal flora and the effects last for a few months. This is great news for women who suffer from recurrent vaginal infections.
Combinations of probiotics are also effective. Lactobacillus rhamnosus in combination with Lactobacillus fermentum has positive effects on the vaginal tract. In a study of 42 females with bacterial vaginosis, a daily oral dose of one billion (109) colony-forming units of L. rhamnosus and L. fermentum for one month treated 70% of the cases. There were no reported side effects in this study. The researchers also tested L. rhamnosus GG in this trial, but it did not have any effect on the bacterial vaginosis.
What is the best probiotic combination to fight bacterial vaginosis? To date, there are no conclusions as to the perfect mix of probiotic strains to cure bacterial vaginosis; however, it appears that Lactobacilli offers the best effects and is a potential treatment. The evidence strongly associates a healthy vaginal microflora with a reduced risk of developing bacterial vaginosis. Probiotics may be a good way to prevent bacterial vaginosis.
PREBIOTICS FOR VAGINAL HEALTH
Prebiotics beneficially affect you by stimulating the growth and activity of probiotics. As such, prebiotics may help increase the probiotic populations in the vagina and help prevent or treat yeast infections or bacterial vaginosis.
Specific research has investigated whether prebiotics selectively promote the growth of probiotics in the vaginal tract without promoting the growth of bad microbes in the vagina. Of 17 Lactobacilli strains found in healthy vaginas, three that were deemed dominant were selected for a prebiotic study. Four prebiotics were tested, including two fructooligosaccharides (FOS) and two glucooligosaccharides (GOS). Two of the prebiotics (FOS Actilight DP3 and alpha-1,4 GOS DP) were only used by the Lactobacilli strains. Common bad microbes in the vagina were unable to metabolize these prebiotics. Therefore, prebiotics do help good microbes grow and do not stimulate the growth of bad microbes. Prebiotics are a way to help the vagina stay healthy.
URINARY TRACT INFECTIONS
Traditionally, probiotics are used to improve gastrointestinal health; however, the urogenital tract also has microbes, and disturbance of this microflora may lead to urinary tract infections.
Infections of the urinary tract are the second most common type of infection in the body. Women are especially prone to urinary tract infections for reasons that are not yet well understood. One woman in five develops a urinary tract infection during her lifetime. In men, urinary tract infections are not as common as in women, but they can be very serious when they do occur.
How does a urinary tract infection occur? Normally, urine is sterile (free of bacteria, viruses and fungi). An infection occurs when microorganisms, usually bacteria from the digestive tract, cling to the opening of the urethra and begin to multiply. The urethra is the tube that carries urine from the bladder to outside the body. An infection limited to the urethra is called urethritis. However, bacteria can move up the urethra and infect the bladder. A bladder infection is called cystitis. This type of infection is of concern, for if it is not treated promptly, the bacteria colonizing in the bladder can move up the ureters into the kidneys and result in a kidney infection. A kidney infection is called pyelonephritis.
Urinary tract infections account for about 8.3 million doctor visits each year.
Microorganisms that commonly cause a urinary tract infection include Chlamydia, Mycoplasma, Gardnerella vaginalis and most frequently E. coli. Unlike E. coli, whose source tends to be feces, Chlamydia and Mycoplasma are sexually transmitted, and these infections require treatment of both partners.
Luckily, the urinary system is structured in a way that helps ward off infections by bacteria. The natural downward flow of urine makes it hard for bacterial to move up the tract. Urine indirectly washes bacteria in the urinary tract out of the body. Also, the ureters and bladder normally prevent urine from backing up toward the kidneys. In men, the prostate gland produces secretions that slow bacterial growth. In both sexes, immune defenses along the lining of the urinary tract prevent infection. Probiotics increase these immune defenses and guard the lining of the urinary tract. Probiotics help reduce the risk of infection.
The Urinary Tract
The urinary tract is made up of the kidneys, ureters, urinary bladder and the urethra. The kidneys filter the blood and continually make urine, which is carried by the ureters to the bladder, where it is stored until it is convenient to release it. The average adult passes about a quart and a half of urine each day and the volume formed at night is about half that formed in the daytime. The urethra is a thin-walled tube that carries urine by peristalsis from the bladder to the outside of the body. The length and relative function of the urethra differs among men and women. In females, the urethra is about three to four centimeters long and its external end is in front of the vaginal opening. In males, the urethra is about 20 centimeters long and not only carries urine but also carries sperm.
There is a high incidence of urogenital infections of bacterial origin among the world’s female population during their reproductive years.
Recurrent urinary tract infections bother a great number of women around the world. Although this area has been rarely investigated, probiotics that produce hydrogen peroxide appear to reduce the risk of urinary tract infections. In particular, the use of Lactobacilli has been considered for the prevention of urinary tract infections. Lactobacilli are the dominant species in the urogenital tract of healthy premenopausal women. As such, supplementing with Lactobacilli probiotics may protect against urinary tract infections.
Many studies (in vitro, animal experiments, microbiological studies, clinical trials) have looked at the ability of probiotics to help fight bad microbes that cause urinary tract infections. Most of the studies have produced encouraging findings. Lactobacillus rhamnosus and L. reuteri seem to be the most effective at preventing urinary tract infections among the studied species of Lactobacilli. Most studies used oral supplementation; however, vaginal insertion may also offer positive effects. A study noted that vaginal insertion of probiotic suppositories containing L. rhamnosus or L. fermentum decreased the rates of urinary tract infection by up to 75% with no adverse effects reported. Other probiotics, including L. casei Shirota and L. crispatus have also shown efficacy in some studies. L. rhamnosus GG did not appear to be quite as effective. The evidence from the available studies suggests that probiotics can prevent recurrent urinary tract infections in women.
L. rhamnosus, L. reuteri and L. fermentum, L. casei Shirota and L. crispatus are good species to consider when choosing a probiotic to fight urogential infections. Of note, other Lactobacilli species are probably effective in fighting urogenital infections as they boost immunity and inhibit the growth of bad microbes throughout the body.
SUMMARY
Just as the microflora of the intestinal tract plays a role in health, the microflora of the urogenital tract also plays an important role in health. Preliminary research in this area suggests that probiotics are vital in maintaining a healthy urogenital tract. Growth of bad microbes can result in Candida infections, urinary tract infections and bacterial vaginosis. Keeping a healthy population of probiotics in the urogenital tract can help prevent these illnesses. Supplementation both orally and vaginally shows promise as treatments for infections of the urogential tract caused by bad microbe overgrowth. Probiotics present in the rectum are capable of translocating to the urogenital tract to elicit beneficial effects. The research in this area is still young in its development. How probiotics cause their positive effects is not known for certain; however, the mechanisms are likely to be similar to those seen in the intestinal tract. Some species have been shown to offer specific benefits to the host. Lactobacilli are likely to emerge as an effective species for vaginal health. Future research is required to determine which probiotic species combinations are most effective against urogenital infections.
