REVIEW ARTICLE
2006 Adis Data Information BV. All rights reserved. Probiotics for Prevention of Recurrent Urinary Tract Infections in Women A Review of the Evidence from Microbiological and Clinical Studies Matthew E. Falagas,1,2 Gregoria I. Betsi,1 Theodoros Tokas1 and Stavros Athanasiou3
1 Alfa Institute of Biomedical Sciences (AIBS), Athens, Greece2 Department of Medicine, Tufts University School of Medicine, Boston, Massachusetts, USA3 First Department of Obstetrics and Gynecology, Athens University School of Medicine,
Contents
Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12531. Literature Search . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12542. Pathophysiology of Recurrent Urinary Tract Infections (UTIs) in Women . . . . . . . . . . . . . . . . . . . . . . . . 12543. Mechanisms of Action of Probiotics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12554. Animal Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12555. Microbiological Studies in Healthy Women . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12566. Clinical and Microbiological Studies in Women with UTIs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12577. Adverse Effects of Probiotics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12598. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1259
Abstract
Recurrent urinary tract infections (UTIs) afflict a great number of women
around the world. The use of probiotics, especially lactobacilli, has been consid-ered for the prevention of UTIs. Since lactobacilli dominate the urogenital flora ofhealthy premenopausal women, it has been suggested that restoration of theurogenital flora, which is dominated by uropathogens, with lactobacilli mayprotect against UTIs. This review is based on a search of PubMed for relevantarticles. Many in vitro studies, animal experiments, microbiological studies inhealthy women, and clinical trials in women with UTIs have been carried out toassess the effectiveness and safety of probiotics for prophylaxis againsturopathogens. Most of them had encouraging findings for some specific strains oflactobacilli. Lactobacillus rhamnosus GR-1 and L. reuteri RC-14 (previouslycalled L. fermentum RC-14) seemed to be the most effective among the studiedlactobacilli for the prevention of UTIs. L. casei shirota and L. crispatus CTV-05have also shown efficacy in some studies. L. rhamnosus GG did not appear to bequite as effective in the prevention of UTIs. The evidence from the availablestudies suggests that probiotics can be beneficial for preventing recurrent UTIs inwomen; they also have a good safety profile. However, further research is needed
to confirm these results before the widespread use of probiotics for this indicationcan be recommended.
Recurrent urinary tract infections (UTIs) are a
‘probiotics’, ‘lactobacillus’, ‘urinary’, ‘urogenic’
common cause of morbidity, especially in postme-
and ‘infections’. We focused on articles regarding in
nopausal and sexually active premenopausal wo-
vitro studies of the effect of probiotics on colonisa-
men. Recurrence occurs in 25–30% of adult women
tion and infection of the urogenital epithelium; ex-
who have a first episode of UTI.[1] The decrease in
periments on probiotics in animals; and studies in-
quality of life of these women and the high health-
vestigating the in vivo effect of intravesical, in-
care cost of treating them have made the prevention
travaginal and oral probiotics on female vaginal
of recurrent UTIs very important. Antibacterials
have been used widely for this purpose, but long--term antimicrobial prophylaxis is associated with
2. Pathophysiology of Recurrent Urinary
increased drug resistance and adverse effects. Thus,
Tract Infections (UTIs) in Women
efforts have been made to discover and develop
The healthy female urogenital flora consists of
many species of micro-organisms, among which
Probiotics are one of these promising alterna-
lactobacilli (especially L. crispatus,[5,6] L. jensenii[5]
tives. They are defined as “live micro-organisms
and L. iners[6,7]) are dominant in healthy preme-
which, when administered in adequate amounts,
nopausal women. Bruce et al.[8] were the first to
confer a health benefit on the host”.[2] There is
show that there is a high prevalence of vaginal
strong evidence that they are effective for the treat-
lactobacilli in women without any history of UTIs.
ment of rotavirus diarrhoea and the prevention of
Lactobacilli and the other microorganisms that dom-
antibacterial-associated diarrhoea in children.[3]
inate the vaginal flora of some healthy women, such
Their usefulness for the prevention of Helicobacter
as Atopobium spp., Megasphaera spp. and Lepto-pylori infections, inflammatory bowel diseases, al-
trichia spp.,[6] produce lactic acid and other sub-
lergy, cancer,[3] respiratory tract infections and other
stances which keep the vaginal pH low and prevent
diseases[4] is still under investigation. Prevention of
the overgrowth of pathogens. Estrogens seem to
recurrent UTIs is a further possible clinical use for
promote the colonisation of the vagina with
probiotics. It should be emphasised that there have
lactobacilli and reduce the vaginal pH, thus control-
been changes to the nomenclature of the various
ling the growth of pathogens.[9] This is thought to be
lactobacilli recently. More specifically, Lactobacil-
one of the main reasons why postmenopausal wo-
lus acidophilus RC-14 and L. fermentum RC-14
men are more susceptible to urogenital infections
studied in The Netherlands and Canada have been
than premenopausal women. Moreover, vaginal
renamed L. reuteri RC-14 and L. casei GR-1, re-
microflora often changes considerably during the
spectively, and L. casei var rhamnosus has been
menstrual cycle, even in women without any epi-
renamed L. rhamnosus GR-1. However, in our re-
view, we use the terms of lactobacillus species as
In patients with UTI, the flora of the urethra and
specified in the publications from which we derived
the vagina are colonised mainly by uropathogens,
especially Escherichia coli and other Enterobacter-iaciae. Uropathogens produce many virulence fac-
1. Literature Search
tors, including adhesins, haemolysin and sider-
We searched PubMed (1950–2005) for publica-
ophores. The ability of uropathogens to cause infec-
tions and relevant references from the initially iden-
tion is associated with their adhesion to urogenital
tified articles. The key words we used included
cells, to each other (autoaggregation) and possibly
2006 Adis Data Information BV. All rights reserved.
to other organisms (coaggregation).[11] Although the
vent the adhesion of uropathogens.[14] It has also
adhesion of the uropathogens on the urogenital epi-
been shown that L. crispatus blocks the adherence
thelium has been demonstrated in many studies, it is
still not yet well understood how they manage to
It is accepted today that there is considerable
survive passage through natural flora.
variation among lactobacillus strains regarding theiradherence to uroepithelium, and inhibition of
3. Mechanisms of Action of Probiotics
uropathogen adherence and growth. Under the con-ditions of an agar overlay inhibition assay, a combi-
In vitro experimentation is useful for clarifying
nation score was allocated to each of 11 tested
the ability of probiotics to inhibit the growth of
lactobacillus strains based on adherence, exclusion
uropathogens. However, the results of such experi-
and inhibition of pathogen growth. L. casei GR-1
ments may or may not be clinically relevant. In vitro
gained the highest score.[16] The production by L.
studies of interactions between micro-organisms
casei GR-1 (and probably other lactobacilli, such as
may be simplified compared with the complexity of
L. acidophilus) of inhibitors against pyelonephrito-
interactions within the human flora. Despite these
genic mutant E. coli strains was proved in another in
limitations, there is sufficient evidence from in vitrovitro study, and this may have clinical implications
studies to elucidate the mechanism of action of
regarding their role in the urogenital microflora.[17]
probiotics in preventing UTIs. Recent in vitro stud-ies have shown that specific lactobacilli strains have
4. Animal Studies
the ability to interfere with the adherence, growthand colonisation of the urogenital human epithelium
Since no ideal animal models exist, where vagi-
by uropathogenic bacteria. This interaction is be-
nal administration of a uropathogen causes UTI,
lieved to be important in the maintenance of a nor-
pathogens are administered intra-urethrally. In
mal urogenital flora and in the prevention of infec-
1985, Reid et al.,[18] using an animal model of fe-
male rats, concluded that L. casei prevented the
According to one study, using glass and sulfonat-
onset of UTIs in 84% of the animals tested. First,
ed polystyrene polymers, both of which are hydro-
they injected bacteria incorporated into agar beads
philic, lactobacilli can be used to coat biomaterial
into the animals’ bladders. The uropathogens stimu-
surfaces, thus decreasing the adhesion of
lated an immune and inflammatory response, there-
uropathogens.[12] Precoating the polymers with
by establishing a persistent adherence of bacteria on
lactobacilli significantly reduced adhesion of staph-
the uroepithelium, and causing a chronic UTI. Sub-
ylococci and E. coli. Another study from The
sequently, L. casei GR-1, isolated from the urethra
Netherlands demonstrated that the L. acidophilus
of a healthy woman, was incorporated into agar
RC-14 biosurfactant ‘surlactin’ inhibited the adhe-
beads and instilled into the rat bladders. In 21 of 25
sion of the majority of bacteria from a urine suspen-
studied animals, no uropathogens were recovered
sion to silicone rubber, 4 hours after urine flow.
from the bladder and kidney tissues up to 60 days
Surlactin was especially effective against Entero-
after instillation. The lactobacilli excluded the
coccus faecalis, E. coli and Staphylococcus epider-
uropathogens from colonising the uroepitheliumwithin 48 hours.[18]
midis.[13] Some years later, a high anti-adhesive,surface-active protein against E. faecalis 1131 was
In 1989, Herthelius and Gorbach[19] established a
purified from L. fermentum RC-14. The structure of
persistent vaginal colonisation with a pyelonephrito-
this protein was identical to that of a collagen-
genic strain of E. coli in four adult monkeys. Repeat-
binding protein from L. reuteri NCIB 11951 and
ed vaginal flushes of lactobacilli or vaginal fluid
was closely homologous with the basic surface pro-
from a healthy monkey were administered for 5–9
tein from L. fermentum BR11. The experiment
days. Vaginal E. coli was eliminated in two of six
showed that this protein of lactobacillus could pre-
experiments where lactobacilli were instilled and in
2006 Adis Data Information BV. All rights reserved.
all eight experiments where vaginal fluid was ad-
studied women were colonised with L. rhamnosus
ministered. In the other four experiments where
lactobacilli were administered, vaginal E. coli was
Cardieux et al.[24] compared the vaginal instilla-
only reduced. This result shows that the entire nor-
tion (immediately after menses) of L. rhamnosus
mal vaginal flora is much more effective in inhib-
GR-1 and L. fermentum RC-14 (109 cfu) with that of
iting the colonisation of the vagina with E. coli than
Lactobacillus GG (109 cfu) in 29 premenopausal
healthy women without urogenital infections. No
In 1996, Silva de Ruiz et al.[20] investigated
adverse effects were reported. L. rhamnosus GR-1/
whether L. fermentum CRL 1058 could control UTIs
L. fermentum RC-14 and Lactobacillus GG were
caused by uropathogenic E. coli in mice treated with
isolated from cultures of vaginal swabs of all wo-
ampicillin. Animals where inoculated intra-urethral-
men in both groups (15 and 14 women, respectively)
ly with agarose beads containing lactobacilli, while
3 days after the instillation of probiotics. However,
ampicillin was administered orally. The ampicillin
L. rhamnosus GR-1/L. fermentum RC-14 and Lacto-
dose used allowed the lactobacilli to persist in the
bacillus GG were isolated from 11/15 (73%) and 3/
urinary tract, leading to the elimination of patho-
14 (21%), respectively, at day 14 (p = 0.009).[24] In a
similar trial, Burton et al.[7] used two techniques
A study by Asahara et al.[21] suggested that L.
(polymerase chain reaction denaturing gradient gel
casei shirota is a strain possibly useful for the pre-
electrophoresis [PCR-DGGE] and randomly ampli-
vention of UTIs. E. coli was administered intra-
fied polymorphic DNA [RAPD] analysis) to detect
urethrally in female mice, causing UTI. L. caseiL. rhamnosus GR-1/L. fermentum RC-14 in the va-
shirota (108 colony-forming units [cfu]) was also
gina at amounts that may not be detectable by cul-
administered intra-urethrally 1 day before and daily
tures. They detected L. rhamnosus GR-1/L. fermen-
after the infection. The growth of E. coli and the
tum RC-14 in 80% of ten healthy premenopausal
inflammatory responses in the urinary tract were
women 1 week after daily vaginal instillation of 109
cfu. L. rhamnosus GR-1 was also detected in 20% of
L. crispatus CTV-05 has also been tested in ani-
mals as a means of protection from urogenital infec-
In another clinical study, Reid et al.[25] compared
tions, as it has been detected in the vagina of many
the oral administration of Lactobacillus GG with L.
healthy women. Patton et al.[22] inserted one capsule
rhamnosus GR-1 and L. fermentum RC-14 in 42
of L. crispatus CTV-05 (108 cfu) intravaginally into
healthy women aged 17–50 years who were free
ten female animals (Macaca) and found that it had
from symptomatic urogenital infections. The wo-
colonised the vaginas of three animals 2 days later.
men were randomly separated into four groups. Groups 1 (n = 10), 2 (n = 12) and 3 (n = 11) received
5. Microbiological Studies in
daily oral capsules of L. rhamnosus GR-1/L. fermen-Healthy Women tum RC-14 at different dosages (8 × 108, 1.6 × 109
The ability of lactobacilli to colonise the vaginal
and 6 × 109 cfu per day, respectively), and group 4
epithelium of healthy women after intravaginal or
(n = 9) received one capsule of Lactobacillus GG
oral administration has been investigated in some
1010 cfu daily. At the start of the study, only 40%
studies. In 2003, Colodner et al.[23] suggested that L.
(17/42) of women had healthy vaginal flora and
rhamnosus GG may not be an effective probiotic
33% (14/42) had asymptomatic bacterial vaginosis.
agent in preventing UTIs. Forty-two post-
Within 28 days, the percentage of women whose
menopausal healthy women were given one to two
vaginal flora converted from abnormal to normal
doses of yogurt containing L. rhamnosus GG (109
was greater for groups 1, 2 and 3 compared with
cfu) daily for 1 month. The cultures of vaginal fluid
group 4 (the difference was statistically significant
specimens showed that only 9.5% (4 of 42) of the
only for group 2; p = 0.017). This study showed that
2006 Adis Data Information BV. All rights reserved.
oral administration of L. rhamnosus GR-1 and L.
lactobacilli and L. fermentum RC-14 was recoveredfrom four.[27]
fermentum RC-14 is associated with greater restora-tion and maintenance of normal vaginal flora than
The ability of L. crispatus CTV-05 to colonise
Lactobacillus GG, and that the required dose of L.
the vagina after vaginal administration has been
rhamnosus GR-1 and L. fermentum RC-14 for this
tested clinically. The subjects in this study had just
effect is more than 8 × 108 cfu of viable lactobacil-
been treated for bacterial vaginosis, and receivedintravaginal L. crispatus CTV-05 or placebo. Thirty
days later, L. crispatus CTV-05 colonised the vagina
The same investigators have also studied the
of 62% of the patients who received it and only 2%
effect of the oral administration of L. rhamnosus
of those who received placebo (p < 0.001).[28]
GR-1 and L. fermentum RC-14 on the vaginal flora,in a randomised, double-blind, placebo-controlledtrial in 64 healthy women (19–46 years old).[26]
6. Clinical and Microbiological Studies in Women with UTIs
Thirty-two women received oral freeze-dried cap-sules of L. rhamnosus GR-1/L. fermentum RC-14(>109 cfu per strain) once daily for 60 days and the
In the first clinical trial of probiotics in women
other 32 received placebo for the same duration.
with UTIs, lactobacilli were given intravesically.
Cultures of vaginal fluid showed a significant in-
Newman[29] was the first who used intravesical
crease in lactobacilli (p = 0.01), a decrease in yeast
lactobacilli in a small number of women for the
(p = 0.01) and a reduction of coliforms (p = 0.001) at
treatment of bladder infections and claimed that this
day 28 in the group receiving the lactobacilli com-
approach was effective. Hagberg et al.[30] instilled L.
pared with placebo-treated women. Significantly
casei GR-1 into the bladder of postmenopausal pa-
fewer coliforms remained in the lactobacilli-treated
tients with recurrent UTIs and found that lactobacilli
group at day 90 (p < 0.01). Moreover, more women
did not adhere to the bladder. They also implanted
in the lactobacillus group reported improvement in
avirulent E. coli strains (6mL of 109 bacilli/mL)from the patients’ own faecal flora intravesically
vaginal health (vaginal itchiness or odour) com-
and found that they colonised the mucosa.
pared with placebo-treated women, although the
Intravaginal administration of lactobacilli met
difference was not statistically significant (p = 0.17).
with more success than intravesical administration.
There were no adverse effects in the probiotic-treat-
During a small, uncontrolled study conducted by
Bruce and Reid[31] in 1988, five women (two of
Another smaller, randomised, double-blind, pla-
whom were postmenopausal) with recurrent UTIs
cebo-controlled clinical trial demonstrating the abil-
were given intravaginal L. casei GR-1 twice weekly.
ity of L. rhamnosus GR-1 and L. fermentum RC-14
L. casei GR-1 colonised the vaginal epithelium and
to colonise the vagina when received orally was
prevented the colonisation of coliform bacteria in
conducted by Morelli et al.[27] Ten healthy women
most women, without affecting enterococcal
received orally either L. rhamnosus GR-1/L. fer-
colonisation, which occurred in two women. No
mentum RC-14 (n = 8) or lactose placebo (n = 2)
adverse effects were mentioned. All studied women
once daily for 14 days. The number of lactobacilli
had significantly more extended infection-free peri-
increased in the vaginas of eight of the ten studied
ods (4 weeks to 6 months) than before treatment (<1
women 14 days later, although the increase was very
month). One patient received a combination of L.
small in three of eight. Genetic typing identified L.fermentum B-54 and L. casei GR-1 after the second
rhamnosus GR-1 and L. fermentum RC-14, respec-
enterococcal infection that occurred during the
tively, in five and two of the studied women. L.
study period. This combination treatment resulted in
rhamnosus GR-1 was also recovered from faecal
an increase in the coloinisation of vaginal epitheli-
samples of all eight women who received the
2006 Adis Data Information BV. All rights reserved.
A trial comparing the risk of recurrence of UTI
Baerheim et al.[35] concluded that it is uncertain
before and after receiving lactobacilli was carried
whether vaginal instillation of lactobacilli decreases
out by Reid et al.[32] in 1992. They treated 41 adult
the incidence of cystitis in women. In a randomised,
women with acute lower UTI with norfloxacin or
double-blind trial, 47 women (aged 18–50 years),
with three or more episodes of distal urinary symp-
for 3 days. UTI recurred in 29% of the norfloxacin-
toms in the previous year (at least one confirmed as
treated group and in 41% of the co-trimoxazole-
UTI) received vaginally L. casei var rhamnosus of
treated group. Women with recurrent UTI then re-
placebo twice weekly. During the next 6 months, the
ceived vaginal suppositories of either L. casei var
incidence rate ratio of lower UTIs between the treat-
rhamnosus GR-1 and L. fermentum B-54 or ster-
ed patients and the placebo group was 1.41 (95% CI
ilised skimmed milk twice weekly for 2 weeks and
0.88, 1.98), a non-statistically significant result.[35]
at the end of each of the next 2 months. The recur-
Besides the intravesical and the intravaginal
rence of UTIs over 6 months decreased to 21% for
route of administration of probiotics, the effective-
those receiving lactobacillus compared with 47%
ness of the oral administration of these agents in
reducing the recurrence of UTIs has also been as-
A case report by Reid et al.[33] further supports
sessed. Tomoda et al.[36] tested Bifidobacterium
the effectiveness of intravaginal lactobacilli as pro-
longum for this purpose and showed that lower UTIs
tection against UTIs. The vagina of a 33-year-old
due to Candida infections were reduced by 70% in
woman with a history of recurrent bladder and vagi-
women receiving oral B. longum.
nal infections was implanted with one gelatin pessa-
Various lactobacilli administered orally have
ry of 0.5g freeze-dried L. casei var rhamnosus GR-1
been also studied. Lactobacillus GG was used in
(>109 viable cells). Although E. faecalis (and no
some studies to test its effect on UTIs, but without
lactobacilli) was the dominant organism in her vagi-
much success. Kontiokari et al.[37] performed a
na at the time of the implantation, 7 weeks after the
randomised clinical trial in 150 women (mean age
pessary insertion, both viable L. casei and L.
30.3 years) who had a UTI caused by E. coli. After
rhamnosus GR-1 were recovered from her vaginal
being treated with antibacterials for the UTI epi-
swabs. She remained free from vaginal and bladder
sode, they were randomly separated into three
symptoms for the 7 weeks of the study and for the
groups. The first group received cranberry-
following 6 months (during which she had two more
lingonberry juice 50mL per day for 6 months, the
second group took a Lactobacillus GG 100mL (4 x
A randomised, double-blind clinical trial, show-
1010 cfu) drink 5 days per week for 1 year, and the
ing a significant impact of intravaginal lactobacilli
third control group received no further treatment.
on recurrence of UTIs, was conducted in 55 preme-
No adverse effects were reported. During 6 months
nopausal women by Reid et al.[34] Twenty-five of
of observation, 8 women (16%) in the cranberry
these women received one vaginal suppository of L.
group, 19 (39%) in the lactobacillus group and 18
rhamnosus GR-1 and L. fermentum B-54 109 cfu per
(36%) in the control group had at least one episode
week and the rest received one vaginal suppository
of UTI. Consequently, recurrence in 6 months was
of a lactobacillus growth factor weekly for 1 year.
significantly less common (p = 0.014) in the cran-
No adverse effects were reported. The UTI rate
berry than in the control group, while lactobacillus
decreased by 73% (from 6 to 1.6 episodes/year; p <
0.001) in the first group and 79% (from 6 to 1.3
In contrast, Kontiokari et al.[38] found a positive
episodes/ year; p < 0.001) in the second.[34]
role for fermented milk products containing probiot-
It should be emphasised that not all clinical stud-
ics, such as L. acidopilus or Lactobacillus GG. They
ies showed a beneficial effect of intravaginal probi-
conducted a case-controlled study in 324 women
otics in preventing the recurrence of UTIs.
(mean age 30.5 years). The patients (n = 139) en-
2006 Adis Data Information BV. All rights reserved.
tered the study 2 weeks after an acute UTI caused by
disease.[40] During the past 30 years, 180 cases of
E. coli; 109 (78%) had more than one UTI episode.
lactobacillaemia and 69 cases of endocarditis due to
The controls (n = 185) had no UTIs during the past 5
lactobacilli have been reported.[41] Gasser[42] report-
years. The questionnaire they completed showed
ed the isolation of L. rhamnosus, L. acidophilus, L.
that frequent consumption of fresh juices, especially
casei and other lactobacilli in patients with endocar-
berry juices, and fermented milk products contain-
ditis. L. rhamnosus was also among other isolates
ing probiotics were more common among controls
than among patients. Specifically, consumption of
Nevertheless, only a few cases have been report-
fermented milk products with probiotics, such as
ed that connect isolated lactobacilli from sites of
Lactobacillus GG or L. acidophilus, more than three
infection with those consumed. Rautio et al.[43] re-
times per week was associated less commonly with
ported the case of a 74-year-old woman who con-
UTIs compared with consumption of these products
sumed about 500mL of dairy drinks with L.
less than once per week (odds ratio [OR] 0.21; 95%
rhamnosus GG daily for 4 months and developed a
liver abscess, an aspirate from which revealed L.
Reid et al.[39] conducted a small, uncontrolled
rhamnosus indistinguishable from GG. Mackay et
trial to assess the efficacy of L. rhamnosus GR-1 and
al.[44] reported the case of a 67-year-old man with a
L. fermentum RC-14 in protecting women against
mild mitral valve regurgitation who consumed cap-
UTIs. Ten women with a recent history of recurrent
sules with L. rhamnosus and L. acidophilus and
urogenital infections who were asymptomatic at the
developed endocarditis after a tooth extraction. L.
start of the study were given orally >109 cfu of
rhamnosus was isolated from blood cultures of this
various strains of L. rhamnosus GR-1 and L. fermen-
patient. Generally, these cases are very rare com-
tum RC-14 twice daily for 14 days. Vaginal cultures,
pared with the increasing consumption of probiotics.
Gram-stain and ribotyping performed 1 week later
An EU workshop concluded that lactic acid bacteria
revealed colonisation of the vagina with L.
are of low risk, with the exception of enterococci.[45]
rhamnosus GR-1 and L. fermentum RC-14 of allpatients.[39] The vaginal flora of six patients, which
8. Conclusion
were considered to be intermediate or indicative ofbacterial vaginosis based on the Nugent score at the
Conclusively, several in vitro and in vivo studies
beginning of the study, was restored to normal 1
support the beneficial effect of some strains of
week after receiving lactobacilli. In addition, all
lactobacilli on the restoration of the vaginal flora
women reported relief from their symptoms of uro-
and the prevention of recurrent UTIs. Most of them
genital infection and had no adverse effects from the
show that L. rhamnosus GR-1 and L. fermentum
RC-14, given either intravaginally or orally, areefficacious. However, their use for the prophylaxisof UTIs is still controversial because only a few
7. Adverse Effects of Probiotics
case-controlled, double-blind clinical trials using
Probiotics are generally considered to be safe.
strains carefully selected according to their laborato-
However, some species of microorganisms that are
ry-proven characteristics have been carried out so
also used as probiotics have recently been isolated
far. More randomised, controlled trials should be
from infection sites, causing some concerns regard-
conducted to confirm the effectiveness of probiotics
ing the safety of these products. Surgical operations,
compared with placebo and antibacterials or other
cancer, diabetes mellitus and long-term antimicrobi-
possible preventive agents. Moreover, although re-
al and immunosuppressive therapy are the most
ported adverse effects are rare to date, further re-search on the safety of probiotics is needed.[2,3,27,46]
common underlying conditions in patients with lac-tobacillus infections. Lactobacillaemia usually oc-
Probiotics are not yet approved for UTIs by sev-
curs in patients with serious and fatal underlying
eral drug licensing organisations, including the US
2006 Adis Data Information BV. All rights reserved.
14. Heineman C, van Hylckama Vlieg JE. Purification and charac-
FDA. L. rhamnosus GR-1 and L. fermentum RC-14
terization of a surface-binding protein from Lactobacillus fer-
are currently available as Omb’e 1 in Austria (by mentum RC-14 that inhibit adhesion of Enterococcus faecalis1131. FEMS Microbiol Lett 2000; 190 (1): 177-80
HSO), and are approved in Malaysia and Singapore
15. Osset J, Bartolome RM, Garcia E, et al. Assessment of the
as PRO-UTIx by Biolife (Australia). They are also
capacity of Lactobacillus to inhibit the growth of uropathogens
sold in Malaysia and Hong-Kong and are expected
and block their adhesion to vaginal epithelial cells. J Infect Dis2001; 183 (3): 485-91
soon to be available worldwide as Urex-cap-5 by
16. Reid G, Cook RL, Bruce AW. Examination of strains of
Urex Biotech Inc. (Canada) and Chr. Hansen (Den-
lactobacilli for properties that may influence bacterial interfer-ence in the urinary tract. J Urol 1987; 138 (2): 330-5
mark). It should emphasised that labelling of the
17. McGroaty JA, Reid G. Detection of lactobacillus substance that
commercial products should mention the strains and
inhibits Escherichia Coli. Can J Microbiol 1998; 34 (8): 974-8
the viability of the probiotics they contain.
18. Reid G, Chan RC, Bruce AW, et al. Prevention of urinary tract
infection in rats with an indigenous Lactobacillus casei strain. Infect Immun 1985; 49 (2): 320-4
Acknowledgements
19. Herthelius M, Gorbach SL. Elimination of vaginal colonisation
with Escherichia coli by administration of indigenous flora.
The authors received no funding for the preparation of this
manuscript and have no potential conflicts of interest directly
20. Silva de Ruiz C, Lopez de Bocanera ME, Nader de Macias ME,
et al. Effect of lactobacilli and antibiotics on E. coli urinaryinfections in mice. Biol Pharm Bull 1996; 19 (1): 88-93
21. Asahara T, Nomoto K, Watanuki M, et al. Antimicrobial activi-
References
ty of intraurethrally administered probiotic Lactobacillus casei
1. Foxman B, Barlow R, D’Arcy H, et al. Urinary tract infection:
in a murine model of Escherichia coli urinary tract infection.
self-reported incidence and associated costs. Ann Epidemiol
Antimicrob Agents Chemother 2001 Jun; 45 (6): 1751-60
22. Patton DL, Cosgrove Sweeney YT, Antonio MA, et al. Lactoba-
2. Reid G, Jass J, Sebulsky T, et al. Potential uses of probiotics in
cillus crispatus capsules: single-use safety study in the Macaca
clinical practice. Clin Microbiol Rev 2003; 16: 658-72
nemestrina model. Sex Transm Dis 2003 Jul; 30 (7): 568-70
3. Senok A, Ismaeel A, Botta G. Probiotics: facts and myths. Clin
23. Colodner R, Edelstein H, Chazan B, et al. Vaginal colonisation
Microbiol Infect Dis 2005; 11 (12): 958-66
by orally administered Lactobacillus rhamnosus GG. Isr Med
4. De Vrese M, Schrezenmeir J. Probiotics and non-intestinal
infectious conditions. Br J Nutr 2002; 88: S59-66
24. Cardieux P, Burton J, Gardiner G, et al. Lactobacillus strains
5. Antonio M, Hawes S, Hillier S. The identification of vaginal
and vaginal ecology. JAMA 2002; 287: 1940-1
Lactobacillus species and the demographic and microbiologic
25. Reid G, Beuerman D, Heinemann C, et al. Probiotic Lactobacil-
characteristics of women colonised by these species. J Infect
lus dose required to restore and maintain a normal vaginal
flora. FEMS Immunol Med Microbiol 2001; 32: 37-41
6. Zhou X, Bent SJ. Characterization of vaginal microbial commu-
26. Reid G, Charbonneau D, Erb J, et al. Oral use of Lactobacillus
nities in adult healthy women using cultivation-independent
rhamnosus GR-1 and L. fermentum RC-14 significantly alters
vaginal flora: randomized, placebo-controlled trial in 64
7. Burton J, Cardieux P, Reid G. Improved understanding of the
healthy women. FEMS Immunol Med Microbiol 2003; 35:
bacterial vaginal microbiota of women before and after probi-
otic instillation. Appl Environ Microbiol 2003; 69: 97-101
27. Morelli L, Zonenenschain D, Del Piano M, et al. Utilization of
8. Bruce AW, Chadwick P, Hassan A, et al. Recurrent urethritis in
the intestinal tract as a delivery system for urogenital probiot-
ics. J Clin Gastroenterol 2004; 38: S107-10
9. Stamm W, Raz R. Factors contributing to susceptibility of
28. Hoesl CE, Altwein JE. The probiotic approach: an alternative
postmenopausal women to recurrent urinary tract infections.
treatment option in urology. Eur Urol 2005; 47: 288-96
29. Newman D. Treatment of cystitis by intravesical injections of
10. Keane F, Ison C, Taylor-Robinson D. A longitudinal study of
lactic bacillus cultures. Lancet 1915; II: 330
the vaginal flora over a menstrual cycle. Int J STD AIDS 1997;
30. Hagberg L, Bruce AW, Reid G, et al. Colonisation of the urinary
tract with live bacteria from the normal fecal and urethral flora
11. Reid G, Sobel J. Bacterial adherence in the pathogenesis of
in patients with recurrent symptomatic urinary tract infections.
urinary tract infection: a review. Rev Infect Dis 1987; 9: 470-
In: Kass EH, Svanborg Eden C, editors. Host-parasite interac-
tions in urinary tract infections. Chicago (IL): University of
12. Hawthorn LA, Reid G. Exclusion of uropathogen adhesion to
polymer surfaces by Lactobacillus acidophilus. J Biomed Ma-
31. Bruce AW, Reid G. Intravaginal instillation of lactobacilli for
prevention of recurrent urinary tract infections. Can J Microbi-
13. Velraeds MM, van de Belt-Gritter B, van der Mei HC, et al.
Interference in initial adhesion of uropathogenic bacteria and
32. Reid G, Bruce AW, Taylor M. Influence of 3-day antimicrobial
yeasts to silicone rubber by a Lactobacillus acidophilus bi-
therapy and Lactobacillus suppositories on recurrence of uri-
osurfactant. J Med Microbiol 1998; 47 (12): 1081-5
nary tract infection. Clin Ther 1992; 14: 11-6
The use of trade names is for product identification purposes only and does not imply endorsement.
2006 Adis Data Information BV. All rights reserved.
33. Reid G, Millsap K, Bruce A. Implantation of Lactobacillus
41. Borriello S, Hammes W, Holzapfel W, et al. Safety of probiotics
casei var rhamnosus into vagina. Lancet 1994; 344: 1229
that contain lactobacilli or bifidobacteria. Clin Infect Dis 2003;
34. Reid G, Bruce AW, Taylor M. Instillation of Lactobacillus and
stimulation of indigenous organisms to prevent recurrence of
42. Gasser F. Safety of lactic acid bacteria and their occurrence in
urinary tract infections. Microecol Ther 1995; 23: 32-45
human clinical infections. Bull Inst Pasteur 1994; 92: 45-67
35. Baerheim A, Larsen E, Digranes A. Vaginal application of
lactobacilli in the prophylaxis of recurrent urinary tract infec-
43. Rautio M, Jousimies-Somer H, Kauma H, et al. Liver abscess
tion in women. Scand J Prim Health Care 1994; 12: 239-43
due to a Lactobacillus rhamnosus strain indistinguishable from
36. Tomoda T, Nakano Y, Kageyama T. Intestinal Candida over-
L. rhamnosus strain GG. Clin Infect Dis 1999; 28: 1159-60
growth and Candida infection in patients with leukemia: effect
44. Mackay A, Taylor M, Kibbler C, et al. Lactobacillus endocardi-
of Bifidobacterium administration. Bifidobacteria Microflora1988; 7: 71-4
tis caused by a probiotic organism. Clin Microbiol Infect 1999;
37. Kontiokari T, Sundqvist K, Nuutinen M, et al. Randomised trial
of cranberry-lingonberry juice and Lactobacillus GG drink for
45. Adams M, Marteau P. On the safety of lactic acid bacteria from
the prevention of urinary tract infections in women. BMJ
food. Int J Food Microbiol 1995; 27: 263-4
46. Andreu A. Lactobacillus as a probiotic for preventing urogenital
38. Kontiokari T, Laitinen J, Jarvi L, et al. Dietary factors protecting
women from urinary tract infection. J Clin Nutr 2003; 77: 600-
infections. Rev Med Microbiol 2004 Jan; 15 (1): 1-6
39. Reid G, Bruce A, Fraser N, et al. Oral probiotics can resolve
urogenital infections. FEMS Immunol Med Microbiol 2001;
Correspondence and offprints: Dr Matthew E. Falagas, Alfa
Institute of Biomedical Sciences (AIBS), 9 Neapoleos Street,
40. Husni R, Gordon S, Washington J, et al. Lactobacillus bacter-
emia and endocarditis: review of 45 cases. Clin Infect Dis1997; 25: 1048-55
2006 Adis Data Information BV. All rights reserved.
The Ne w E n g l a nd Jo u r n a l o f Me d ic i ne Pathophysiology The most frequent form of venous gas embolismis the insidious venous aeroembolism, in which a se-ries of gas bubbles resembling a string of pearls en- GAS EMBOLISM ters the venous system. Rapid entry or large volumesof gas put a strain on the right ventricle because ofCLAUS M. MUTH, M.D., AND ERIK S. SHANK, M.D. the migra
A JOINT DECLARATION BY EUROPEAN ROAD TRANSPORT OPERATORS CONCERNING THE PROFESSIONAL ROUNDTABLE MEETING HELD IN BUDAPEST The organizations from six European countries, representing road transport operators exchanged opinions on the effects, tasks and challenges that have arisen in this sector since the time the European Union was extended. The representatives of the above organization