- April 10, 2014 at 4:53 pm #118051
dvjorgeParticipantTopics: 283Replies: 1368
Candida albicans is the most important Candida species causing vulvovaginal candidiasis (VVC). VVC has significant medical and economical impact on women’s health and wellbeing. While current antifungal treatment is reasonably effective, supportive and preventive measures such as application of probiotics are required to reduce the incidence of VVC. We investigated the potential of the probiotics Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 towards control of C. albicans. In vitro experiments demonstrated that lactic acid at low pH plays a major role in suppressing fungal growth. Viability staining following cocultures with lactobacilli revealed that C. albicans cells lost metabolic activity and eventually were killed. Transcriptome analyses showed increased expression of stress-related genes and lower expression of genes involved in fluconazole resistance, which might explain the increased eradication of Candida in a previous clinical study on conjoint probiotic therapy. Our results provide insights on the impact of probiotics on C. albicans survival.
The protective effect of Lactobacillus casei, L. acidophilus, L. delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus administered orally against an infection with Candida albicans in a corticoid immunosuppression model was studied. Balb/c mice were infected intraperitoneally with C. albicans (5 × 107 cells/mouse) on the third day post‐corticoid inoculation. At 24 h after infection, 1.2 × 109 cells/day/mouse of the bacteria under study were administered orally to the test animals for 2 days. The number of C. albicans colony‐forming units in liver, spleen and kidney was determined at 4–5 day intervals for 17 days. During the same period, the influence of the oral administration of the above bacteria on the immune response of non‐infected corticoid‐treated mice was also studied. The phagocytic capacity of peritoneal macrophages was determined by in vitro assays, the humoral immune response by the number of plaque‐forming cells and T‐lymphocyte activity by the delayed hypersensitivity response for sheep red blood cell antigen. Oral administration of L. casei and L. bulgaricus in corticoid‐immunosuppressed animals was demonstrated to give protection against C. albicans infection. This was due to a significant increase in the specific and non‐specific immune response, which reached higher values than the non‐immunosuppressed controls. L. acidophilus proved to be less effective at protection, although it reverts corticoid immunosuppression, reaching values similar to those of the normal controls. S. thermophilus was ineffective for protection, and it did not favour enhancement of the immune response, which was only slightly higher than that of the suppression controls. The authors believe that the oral administration of certain lactic acid bacteria may be extremely useful as support therapy for the control of infections produced by opportunistic microorganisms. It could affect the immunosuppression that occurs in tumour processes or other immunodeficiencies but never in autoimmune pathological events.
Inhibition of Candida albicans by Lactobacillus acidophilus: evidence for the involvement of a peroxidase system.
Fitzsimmons N1, Berry DR.
A range of cultures of Lactobacillus acidophilus was isolated from patients using oral, vaginal and endocervical swabs. These were investigated for their ability to (1) inhibit the growth of Candida albicans, and (2) generate peroxidase, hydrogen peroxide and hypothiocyanite. Inhibition of Candida albicans and hydrogen peroxide production was detected in nine out of twelve strains whereas peroxidase production was only detected in three out of twelve strains, all from oral swabs. Hypothiocyanite production was detected in two strains and it was only detected in these strains after growth in MRS medium in aerobic conditions.
The in vitro activity of vaginal Lactobacillus with probiotic properties against Candida.
Strus M1, Kucharska A, Kukla G, Brzychczy-Włoch M, Maresz K, Heczko PB.
Lactobacilli, the predominant vaginal microorganisms in healthy premenopausal women, control other members of the vaginal microflora and thus protect against bacterial vaginosis and urinary tract infections. It has been claimed that some lactobacilli are also protective against Candida vaginitis. Little is known, however, about the mechanisms by which these lactobacilli can control vaginal populations of Candida and prevent vaginitis. To address this question, vaginal Lactobacillus strains with known antagonistic properties against bacteria were tested for their cell surface properties, adhesion to vaginal cell lines in vitro and antagonistic activities against Candida. A small proportion of the lactobacilli tested adhered strongly to cultured vaginal epithelial cells and inhibited growth of Candida albicans but not of C. pseudotropicalis. This anticandidal activity was in some Lactobacillus strains related to hydrogen peroxide (H2O2) production, but catalase treatment did not suppress this activity in other Lactobacillus strains, suggesting alternative mechanism(s). Moreover, tested vaginal Candida strains were resistant to relatively high concentrations of H2O2 that markedly exceeded those produced by even the most active Lactobacillus strains.
Urogenital infections affect millions of people every year worldwide. The treatment of these diseases usually requires the use of antimicrobial agents, and more recently, the use of probiotic lactic acid bacteria (LAB) cultures for the management of vaginal infections has been extensively studied. In this work, 11 vaginal lactobacilli isolates, previously obtained from healthy patients, were studied to screen microorganisms with probiotic properties against Candida spp. The LAB were tested for their ability of auto-aggregation, coaggregation with C. albicans, C. glabrata, C. krusei, and C. tropicalis, adhesion to Caco-2 epithelial cells and production of lactic acid and hydrogen peroxide (H2O2). All lactobacilli isolates tested were able to auto-aggregate (ranging from 25.3% to 75.4% assessed at 4 hours of incubation) and to co-aggregate with the four Candida species into different degrees; among them L. crispatus showed the highest scores of coaggregation. The highest amount of lactic acid was produced by L. salivarius (13.9 g/l), followed by L. johnsonii (6.5 g/l), L. acidophilus (5.5 g/l), and L. jensenii (5.4 g/l). All isolates produced H2O2 , but the highest levels (3 -10 mg/l) were observed for L. acidophilus, L. crispatus, L. gasseri, L. johnsonii, and L. vaginalis. Only L. agilis, L. jensenii, L. johnsonii and L. ruminus were able to adhere to epithelial Caco-2 cells. Among the isolates evaluated, L agilis, L. jensenii, L. johnsonii, and L. ruminus exhibited simultaneously several desirable properties as potential probiotic strains justifying future studies to evaluate their technological properties in different pharmaceutical preparations for human use.
Ecology of Candida albicans gut colonization: inhibition of Candida adhesion, colonization, and dissemination from the gastrointestinal tract by bacterial antagonism.
Kennedy MJ, Volz PA.
Antibiotic-treated and untreated Syrian hamsters were inoculated intragastrically with Candida albicans to determine whether C. albicans could opportunistically colonize the gastrointestinal tract and disseminate to visceral organs. Antibiotic treatment decreased the total population levels of the indigenous bacterial flora and predisposed hamsters to gastrointestinal overgrowth and subsequent systemic dissemination by C. albicans in 86% of the animals. Both control hamsters not given antibiotics and antibiotic-treated animals reconventionalized with an indigenous microflora showed significantly lower gut populations of C. albicans, and C. albicans organisms were cultured from the visceral organs of 0 and 10% of the animals, respectively. Conversely, non-antibiotic-treated hamsters inoculated repeatedly with C. albicans had high numbers of C. albicans in the gut, and viable C. albicans was recovered from the visceral organs of 53% of the animals. Examination of the mucosal surfaces from test and control animals indicated further that animals which contained a complex indigenous microflora had significantly lower numbers of C. albicans associated with their gut walls than did antibiotic-treated animals. The ability of C. albicans to associate with intestinal mucosal surfaces also was tested by an in vitro adhesion assay. The results indicate that the indigenous microflora reduced the mucosal association of C. albicans by forming a dense layer of bacteria in the mucus gel, out-competing yeast cells for adhesion sites, and producing inhibitor substances (possibly volatile fatty acids, secondary bile acids, or both) that reduced C. albicans adhesion. It is suggested, therefore, that the indigenous intestinal microflora suppresses C. albicans colonization and dissemination from the gut by inhibiting Candida-mucosal association and reducing C. albicans population levels in the gut.
Candida albicans is an opportunistic dimorphic fungus that inhabits various host mucosal sites. Conversion from the yeast to the hyphal form has been associated with increased virulence and mucosal invasiveness. C. albicans morphogenesis is regulated by multiple signals and signaling pathways. However, signals that control morphogenesis in vivo are unknown. We investigated the effects of host long chain fatty acids, eicosanoids, and bacterial short chain fatty acids on control of germination. None of the C18 or C20 fatty acids tested had an effect on enhancing germ tube formation (arachidonic acid, oleic acid, linolenic acid, or γ-linolenic acid). Among the different eicosanoids, both prostaglandin E2 and thromboxane B2 significantly enhanced serum-induced germination by C. albicans. Addition of antiprostaglandin or antithromboxane antibodies to serum alone inhibited germ tube formation by almost 30%, while control antibody had no effect, indicating that these eicosanoids are major morphogenic factors in the serum. Since these molecules also bind to albumin, this may also explain the hyphal transforming activity in serum that associates with albumin. Interestingly, short chain fatty acids (butyric acid), the product of lactic acid bacteria (LAB), inhibited germination. In addition, LAB culture supernatants as well as live LAB also inhibited C. albicans morphogenesis. Overall, these results indicate that fatty acid metabolites and fatty acid pathways can up-regulate and down-regulate germination in C. albicans.
Candida albicans is a normal member of the gastrointestinal (GI) tract microbiota of healthy humans, but during host immunosuppression or alterations in the bacterial microbiota, C. albicans can disseminate and cause life-threatening illness. The bacterial microbiome of the GI tract, including lactic acid bacteria (LAB), plays a vital role in preventing fungal invasion. However, little is known about the role of C. albicans in shaping the bacterial microbiota during antibiotic recovery. We investigated the fungal burdens in the GI tracts of germfree mice and mice with a disturbed microbiome to demonstrate the role of the microbiota in preventing C. albicans colonization. Histological analysis demonstrated that colonization with C. albicans during antibiotic treatment does not trigger overt inflammation in the murine cecum. Bacterial diversity is reduced long term following cefoperazone treatment, but the presence of C. albicans during antibiotic recovery promoted the recovery of bacterial diversity. Cefoperazone diminishes Bacteroidetes populations long term in the ceca of mice, but the presence of C. albicans during cefoperazone recovery promoted Bacteroidetes population recovery. However, the presence of C. albicans resulted in a long-term reduction in Lactobacillus spp. and promoted Enterococcus faecalis populations. Previous studies have focused on the ability of bacteria to alter C. albicans; this study addresses the ability of C. albicans to alter the bacterial microbiota during nonpathogenic colonization.
Two strains of Lactobacillus crispatus (15L08 and 21L07) and one strain of Lactobacillus jensenii (5L08) were selected from amongst 100 isolates from the vaginas of healthy premenopausal women for properties relevant to mucosal colonization and the production of H2O2 and/or bacteriocin-like compound. All three strains self-aggregated and adhered to vaginal epithelial cells, displacing well-known vaginal pathogens, such as Gardnerella vaginalis and Candida albicans. Lactobacillus crispatus 15L08 was characterized as a potential H2O2 producer. A high level of bacteriocin-like compound was synthesized by L. jensenii 5L08, with a bactericidal mode of action for G. vaginalis, C. albicans and Escherichia coli. However, H2O2-dependent activity alone was not sufficient to inhibit the growth of C. albicans. Simultaneous actions of H2O2 and bacteriocin-like compound produced by lactobacilli may be important for antagonizing pathogenic bacteria. These strains of lactobacilli may be excellent candidates for eventual use as probiotics to restore the normal microbial communities in the vaginal ecosystem.
Vulvovaginal candidiasis (VVC) is a common infection affecting the quality of life of many women. Probiotics have been investigated as possible agents for the prevention of recurrences of VVC. We reviewed the available literature. In some studies the development of VVC was associated with either a low number of lactobacilli in the vagina or with the presence of H2O2-non-producing vaginal lactobacilli, although there are a few studies not supporting these statements. In addition, in vitro studies have shown that lactobacilli can inhibit the growth of Candida albicans and/or its adherence on the vaginal epithelium. The results of some clinical trials support the effectiveness of lactobacilli, especially Lactobacillus acidophilus, Lactobacillus rhamnosus GR-1 and Lactobacillus fermentum RC-14, administered either orally or intravaginally in colonizing the vagina and/or preventing the colonization and infection of the vagina by C. albicansApril 10, 2014 at 5:58 pm #118057
rasterParticipantTopics: 104Replies: 6837
This is why everyone should take probiotics imho…
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