Skip to content

 A study found that a combination of cranberry supplement (120 mg cranberries, with a minimum proanthocyanidin content of 32mg), the probiotic Lactobacillus rhamnosus, and vitamin C (750 mg) three times a day was enough to prevent the recurrence of urinary tract infections (UTIs) for the majority of women in this small (36 patient) study. At 6 months there was a 61% success rate. No side effects were reported.

These are wonderful results, but why aren't more studies also being done on the effective product D-Mannose? The one study (see post) that I found looking at D-Mannose found an 85% success rate at 6 months. It is especially effective against E.coli, which is the cause of the majority of UTIs. But the great news is that finally women have some effective and safe treatments to try, and the wonderful possibility of getting off the vicious cycle of repeated courses of antibiotics. The article abstract from Pubmed.gov (National Library of Medicine):

Effectiveness of a Combination of Cranberries, Lactobacillus rhamnosus, and Vitamin C for the Management of Recurrent Urinary Tract Infections in Women: Results of a Pilot Study.

Urinary tract infections (UTIs) are common in women and many patients with recurrent UTIs do not eradicate the condition albeit being treated with multiple courses of antibiotics. The use of nutritional supplements might reduce the risk of recurrent UTIs. However, the role of supplements taken as single agents appears to be limited. We hypothesized that a combination of cranberries, Lactobacillus rhamnosus, and vitamin C might produce a clinical benefit due to their additive or synergistic effects. We prospectively enrolled 42 consecutive women with recurrent UTIs treated with 120mg cranberries (minimum proanthocyanidin content: 32mg), 1 billion heat-killed L. rhamnosus SGL06, and 750mg vitamin C thrice daily for 20 consecutive days. Patients were advised to stop taking these supplements for 10 d and then to repeat the whole cycle three times. Patients were contacted three mo and six mo following the end of the administration of these supplements and evaluated with a semistructured interview and urinalysis. Responders were defined as the absence of symptoms and negative urinalysis or urine culture. Follow-up data were available for 36 patients. Overall, 26 (72.2%) and 22 patients (61.1%) were responders at the 3-mo and 6-month follow-up. No major side effects were recorded. The administration of cranberries, L. rhamnosus, and vitamin C might represent a safe and effective option in women with recurrent UTIs.

PATIENT SUMMARY: We evaluated the effectiveness of cranberries, Lactobacillus rhamnosus, and vitamin C thrice daily for 20 consecutive d monthly for 3 mo for the management of recurrent urinary tract infections in women. Our results show that this approach might represent a safe and effective option.

 This new research suggests possible future treatments in treating urinary tract infections (UTIs) by manipulating the person's diet and so influencing gut microbes and urinary pH (how acidic is the urine). These possible future treatments are different than what others are looking for, which are bacteria (probiotics) that one can take to prevent or treat UTIs. (Earlier posts on treating UTIs are here and here,)

The researchers found that during UTIs, humans secrete siderocalin which helps the body fight infection by depriving bacteria of iron (a mineral necessary for bacterial growth), and that samples that were less acidic, and closer to the neutral pH of pure water, showed higher activity of the protein siderocalin and were better at restricting bacterial growth than the more acidic samples. The researchers found that the presence of small metabolites called aromatics, which vary depending on a person's diet, also contributed to variations in bacterial growth. Samples that restricted bacterial growth had more aromatic compounds, and urine that permitted bacterial growth had fewer. Stay tuned for follow-up research. 

One of the researchers, Dr. Jeffrey P. Henderson, pointed out that physicians already know how to raise urinary pH with things like calcium supplements, and alkalizing agents are already used in the U.K. as over-the-counter UTI treatments. But knowing how to encourage the metabolites is trickier, but will involve dietary changes. Some good food sources include those rich in antioxidants: coffee, tea, colorful berries, cranberries, and red wine.From Science Daily:

A person's diet, acidity of urine may affect susceptibility to UTIs

The acidity of urine -- as well as the presence of small molecules related to diet -- may influence how well bacteria can grow in the urinary tract, a new study shows. The research may have implications for treating urinary tract infections, which are among the most common bacterial infections worldwide. Urinary tract infections (UTIs) often are caused by a strain of bacteria called Escherichia coli (E. coli), and doctors long have relied on antibiotics to kill the microbes. But increasing bacterial resistance to these drugs is leading researchers to look for alternative treatment strategies.

"Many physicians can tell you that they see patients who are particularly susceptible to urinary tract infections," said senior author Jeffrey P. Henderson​, MD, PhD,...With this in mind, Henderson and his team, including first author Robin R. Shields-Cutler, a graduate student in Henderson's lab, were interested in studying how the body naturally fights bacterial infections. They cultured E. coli in urine samples from healthy volunteers and noted major differences in how well individual urine samples could harness a key immune protein to limit bacterial growth. "We could divide these urine samples into two groups based on whether they permitted or restricted bacterial growth," Henderson said. "Then we asked, what is special about the urine samples that restricted growth?"

The urine samples that prevented bacterial growth supported more activity of this key protein, which the body makes naturally in response to infection, than the samples that permitted bacteria to grow easily. The protein is called siderocalin, and past research has suggested that it helps the body fight infection by depriving bacteria of iron, a mineral necessary for bacterial growth. Their data led the researchers to ask if any characteristics of their healthy volunteers were associated with the effectiveness of siderocalin.

"Age and sex did not turn out to be major players," Shields-Cutler said. "Of all the factors we measured, the only one that was really different between the two groups was pH -- how acidic or basic the urine was."Henderson said that conventional wisdom in medicine favors the idea that acidic urine is better for restricting bacterial growth. But their results were surprising because samples that were less acidic, closer to the neutral pH of pure water, showed higher activity of the protein siderocalin and were better at restricting bacterial growth than the more acidic samples.

Importantly, the researchers also showed that they could encourage or discourage bacterial growth in urine simply by adjusting the pH, a finding that could have implications for how patients with UTIs are treated."Physicians are very good at manipulating urinary pH," said Henderson, who treats patients with UTIs. "If you take Tums, for example, it makes the urine less acidic. But pH is not the whole story here. Urine is a destination for much of the body's waste in the form of small molecules. It's an incredibly complex medium that is changed by diet, individual genetics and many other factors."

After analyzing thousands of compounds in the samples, the researchers determined that the presence of small metabolites called aromatics, which vary depending on a person's diet, also contributed to variations in bacterial growth. Samples that restricted bacterial growth had more aromatic compounds, and urine that permitted bacterial growth had fewer.

Henderson and his colleagues suspect that at least some of these aromatics are good iron binders, helping deprive the bacteria of iron. And perhaps surprisingly, these molecules are not produced by human cells, but by a person's gut microbes as they process food in the diet."Our study suggests that the body's immune system harnesses dietary plant compounds to prevent bacterial growth," Henderson said. "We identified a list of compounds of interest, and many of these are associated with specific dietary components and with gut microbes."

Indeed, their results implicate cranberries among other possible dietary interventions. Shield-Cutler noted that many studies already have investigated extracts or juices from cranberries as UTI treatments but the results of such investigations have not been consistent.

Image result for pills wikipedia My last post was about a recent Medscape article discussing whether probiotics can be used to treat urinary tract infections (UTIs) (answer: probiotics are promising, but too little is known right now to recommend any). Two alternative treatments that the article did not discuss were drinking cranberry juice or taking cranberry supplements (studies are currently mixed regarding their effectiveness in UTIs - possibly due to varying cranberry products and doses used) and taking D-mannose supplements (whether as a powder or pill).

D-mannose is recommended on alternative medical sites as an effective treatment for UTIs caused by E.coli, including recurrent UTIs. Studies show that up to 90% of UTIs are caused by E. coli.The majority of both males and females writing comments about UTI treatments on these sites and for D-mannose product reviews (on Amazon) rave about D-mannose as the only treatment that worked for them after suffering from recurrent UTIs (antibiotics typically did not work well for them). D-mannose is a naturally occurring sugar found in a number of fruits, especially cranberries and blueberries. D-mannose is effective because it attaches to E. coli bacteria, and prevents them from attaching to the walls of the urinary tract. (Researchers write that D-mannose "inhibits bacterial adhesion to uroepithelial cells.") Persons taking D-mannose are also advised to drink plenty of water, which then flushes out the bacteria.

The typical dose of D-mannose for UTI treatment is 500 mg, in capsule or powder form, taken in a glass of water or juice, every few hours for five days (perhaps 5 or 6 tablets a day). Then continue taking for a few days after all symptoms go away to make sure all the bacteria are flushed out of the urinary tract. Many long-term recurrent UTI sufferers continue taking D-mannose at lower doses to prevent the UTIs from recurring. There are no known side-effects. D-mannose is easily found at stores such as Whole Foods and online (Amazon).

After doing a D-mannose and urinary tract infection search using PubMed (from Medline, the National Institute of Health), I found that currently there is only one published study looking at the use of D-Mannose in urinary tract infections.

The 2014 study by B. Kranjcec, D. Papes, and S. Altarac looked at the effectiveness of D-mannose powder for recurring urinary tract infections in women. 308 women with a history of recurrent UTIs were first treated with an antibiotic (ciprofloxacin) for an UTI, and then were randomly assigned to one of 3 groups for 6 months. The 3 groups were: D-mannose (2 g of D-mannose in 200 ml water daily), or prophylactic antibiotics (50 mg Nitrofurantoin daily) or a control group that didn't take anything (no prophylaxis). Results were that 98 patients (31.8%) had a recurrent UTI. Of those 98, 14.6% (15 women) were in the D-mannose group, 20.4% (21 women) in the Nitrofurantoin antibiotic group, and 60.8%  (62 women) in the no treatment (no prophylaxis) group. In other words, the D-mannose group did the best in preventing recurrences, even better than the antibiotic. From World Journal of Urology:

D-mannose powder for prophylaxis of recurrent urinary tract infections in women: a randomized clinical trial.

Overall 98 patients (31.8%) had recurrent UTI: 15 (14.6) in the D-mannose group, 21 (20.4) in Nitrofurantoin group, and 62 (60.8) in no prophylaxis group, with the rate significantly higher in no prophylaxis group compared to active groups (P < 0.001). Patients in D-mannose group and Nitrofurantoin group had a significantly lower risk of recurrent UTI episode during prophylactic therapy compared to patients in no prophylaxis group (RR 0.239 and 0.335, P < 0.0001). In active groups, 17.9% of patients reported side effects but they were mild and did not require stopping the prophylaxis. Patients in D-mannose group had a significantly lower risk of side effects compared to patients in Nitrofurantoin group (RR 0.276, P < 0.0001), but the clinical importance of this finding is low because Nitrofurantoin was well tolerated.