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Urinary tract infections cranberry juice, underwear, and probiotics in the 21st century.

There is a substantial gap between the viewpoint of urologists and the rest of society regarding UTIs. Urologists spend little time and effort thinking about UTIs. In contrast, UTIs are a major issue for many women. There is substantial concern about "natural compounds" and probiotics that allow women to take charge of their health care. It is easy to understand this concern because UTIs are common, costly, and cause considerable morbidity.

Clothing↗

Probiotics and prevention of atopic disease: 4-year follow-up of a randomised placebo-controlled trial.

Perinatal administration of the probiotic Lactobacillus rhamnosus strain GG (ATCC 53103), reduces incidence of atopic eczema in at-risk children during the first 2 years of life (infancy). We have therefore assessed persistence of the potential to prevent atopic eczema at 4 years. Atopic disease was diagnosed on the basis of a questionnaire and a clinical examination. 14 of 53 children receiving lactobacillus had developed atopic eczema, compared with 25 of 54 receiving placebo (relative risk 0.57, 95% CI 0.33-0.97). Skin prick test reactivity was the same in both groups: ten of 50 children previously given lactobacillus compared with nine of 50 given placebo tested positive. Our results suggest that the preventive effect of lactobacillus GG on atopic eczema extends beyond infancy.

Child, Preschool↗

Encapsulation of probiotic bacteria with alginate-starch and evaluation of survival in simulated gastrointestinal conditions and in yoghurt.

A modified method using calcium alginate for the microencapsulation of probiotic bacteria is reported in this study. Incorporation of Hi-Maize starch (a prebiotic) improved encapsulation of viable bacteria as compared to when the bacteria were encapsulated without the starch. Inclusion of glycerol (a cryo-protectant) with alginate mix increased the survival of bacteria when frozen at -20 degrees C. The acidification kinetics of encapsulated bacteria showed that the rate of acid produced was lower than that of free cultures. The encapsulated bacteria, however, did not demonstrate a significant increase in survival when subjected to in vitro high acid and bile salt conditions. A preliminary study was carried out in order to monitor the effects of encapsulation on the survival of Lactobacillus acidophilus and Bifidobacterium spp. in yoghurt over a period of 8 weeks. This study showed that the survival of encapsulated cultures of L. acidophilus and Bifidobacterium spp. showed a decline in viable count of about 0.5 log over a period of 8 weeks while there was a decline of about 1 log in cultures which were incorporated as free cells in yoghurt. The encapsulation method used in this study did not result in uniform bead size, and hence additional experiments need to be designed using uniform bead size in order to assess the role of different encapsulation parameters, such as bead size and alginate concentration, in providing protection to the bacteria.

Alginates↗

Comparison of selective media for the recovery and enumeration of probiotic yeasts from animal feed.

Six selective media (acidified malt extract agar, CHROMagar Candida, dichloran rose bengal chloramphenicol, molybdate, oxytetracycline glucose yeast extract and Petrifilm Yeast and Mould agar) were examined for the recovery of three yeasts commonly used in animal feeds as probiotic additives (Candida pintolopesii, C. saitoana and Saccharomyces cerevisiae). The highest recovery was obtained on oxytetracycline glucose yeast extract agar, although this was susceptible to overgrowth by moulds. CHROMagar Candida also gave good recovery and species were easily discriminated by the differential colour formation of colonies.

Animal Feed↗

Some probiotic properties of yeast isolates from infant faeces and Feta cheese.

Yeast isolates from infant faeces and Feta cheese were characterized to species level by phenotypic criteria, Randomly Amplified Polymorphic DNA (RAPD)-PCR and mitochondrial DNA (mt-DNA) restriction analysis. Results suggested that there is a good agreement between phenotypic characterization of yeasts and RAPD-PCR at species level; in addition, RAPD-PCR as well as mt-DNA restriction analysis provided good discrimination at strain level. Some technological and probiotic properties of selected strains were also investigated. The test strains exhibited lipolytic and proteolytic activities. They also tolerated low pH and survived satisfactory in gastric juice in vitro as well as in the presence of bile. In general, the isolates from faeces were more resistant to low pH and bile than those from Feta cheese. Selected strains could be used as starter supplements for industrial fermentations.

Cheese↗

Identification and antibiotic susceptibility of bacterial isolates from probiotic products.

In the present study, a total of 55 European probiotic products were evaluated with regard to the identity and the antibiotic resistance of the bacterial isolates recovered from these products. Bacterial isolation from 30 dried food supplements and 25 dairy products, yielded a total of 268 bacterial isolates selected from several selective media. Counts of food supplements showed bacterial recovery in 19 (63%) of the dried food supplements ranging from 10(3) to 10(6) CFU/g, whereas all dairy products yielded growth in the range of 10(5)-10(9) CFU/ml. After identification of the isolates using whole-cell protein profiling, mislabeling was noted in 47% of the food supplements and 40% of the dairy products. In six food supplements, Enterococcus faecium was isolated whereas only two of those products claim this species on their label. Using the disc diffusion method, antibiotic resistance among 187 isolates was detected against kanamycin (79% of the isolates), vancomycin (65%), tetracycline (26%), penicillinG (23%), erythromycin (16%) and chloramphenicol (11%). Overall, 68.4% of the isolates showed resistance against multiple antibiotics including intrinsic resistances. Initially, 38% of the isolated enterococci was classified as vancomycin resistant using the disc diffusion method, whereas additional broth dilution and PCR assays clearly showed that all E. faecium isolates were in fact vancomycin susceptible.

Anti-Bacterial Agents↗

Synthesis and utilisation of folate by yoghurt starter cultures and probiotic bacteria.

Thirty-two bacterial isolates from species commonly used in yoghurts and fermented milks were examined for their ability to synthesise or utilise folate during fermentation of skim milk. The organisms examined included the traditional yoghurt starter cultures, Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus, and probiotic lactobacilli, bifidobacteria, and Enterococcus faecium. Folate was synthesised by S. thermophilus, bifidobacteria, and E. faecium. S. thermophilus was the dominant producer, elevating folate levels in skim milk from 11.5 ng g(-1) to between 40 and 50 ng g(-1). Generally, lactobacilli depleted the available folate in the skim milk. Fermentations with mixed cultures showed that folate production and utilisation by the cultures was additive. Fermentations using a combination of Bifidobacterium animalis and S. thermophilus resulted in a six-fold increase in folate concentration. Although increased folate levels in yoghurts and fermented milks are possible through judicious selection of inoculum species, the folate levels remain relatively low in terms of recommended daily allowance.

Bifidobacterium↗

Evaluation of the effect of malt, wheat and barley extracts on the viability of potentially probiotic lactic acid bacteria under acidic conditions.

In this work, the effect of cereal extracts, used as delivery vehicles for potentially probiotic lactic acid bacteria (LAB), on the acid tolerance of the cells was evaluated under conditions that simulate the gastric tract. More specifically, the effect of malt, barley and wheat extracts on the viability of Lactobacillus plantarum, Lactobacillus acidophilus and Lactobacillus reuteri during exposure for 4 h in a phosphate buffer acidified at pH 2.5 was investigated. In the absence of cereal extracts all strains demonstrated a significant reduction in their cell population, particularly L. plantarum. The viability of L. plantarum was improved by approximately 4 log(10) cycles in the presence of malt and 3 log(10) cycles in the presence of wheat and barley. The survival of L. acidophilus and L. reuteri was increased by more than 1.5 and 0.7 log(10) cycle, respectively, upon addition of cereal extracts. In order to evaluate the contribution of the cereal constituents on cell survival, the individual effect of glucose, maltose and free amino nitrogen (FAN), which were added at concentrations that correlated to the reducing sugar and FAN content of the cereal extracts, was examined. The viability of L. plantarum was progressively improved as the maltose or glucose concentration increased; an increase by approximately 2 log(10) cycles was observed in the presence of 8.33 g/l sugar. The survival of L. acidophilus increased by more than 1 log(10) cycle, even at very low concentrations of maltose and glucose (e.g., 0.67 g/l), while L. reuteri stability was enhanced in the presence of maltose but no appreciable effect was demonstrated in the presence of glucose. Sugar analysis indicated that glycolysis was inhibited in all cases. Addition of tryptone and yeast extract, used as sources of FAN, enhanced L. acidophilus acid tolerance, but did not affect L. reuteri and L. plantarum. The results presented in this study indicate that malt, wheat and barley extracts exhibit a significant protective effect on the viability of L. plantarum, L. acidophilus and L. reuteri under acidic conditions, which could be mainly attributed to the amount of sugar present in the cereal extracts.

Analysis of Variance↗

Specific identification of certain probiotic Lactobacillus rhamnosus strains with PCR primers based on phage-related sequences.

PCR primers derived from Lactobacillus rhamnosus phage Lc-Nu genome were used to screen the presence of phage-related sequences in Lb. rhamnosus strains. Several primer pairs derived from structural and replication gene regions of phage Lc-Nu amplified PCR products of expected sizes from bacterial strains revealing phage-related sequences in 10 of 11 Lb. rhamnosus strains. Strain-specific PCR primers for three probiotic Lb. rhamnosus strains were derived from these phage-related sequences for identification and detection purposes. Specificity of these primers was tested against 11 Lb. rhamnosus strains and over 40 other bacterial strains.

Bacteriophages↗

Adhesion of some probiotic and dairy Lactobacillus strains to Caco-2 cell cultures.

The adhesion of 12 different Lactobacillus strains was studied using Caco-2 cell line as an in vitro model for intestinal epithelium. Some of the strains tested have been used as probiotics, and most of them are used in the dairy and food industry. Human and bovine enterotoxigenic Escherichia coli strains were used as positive and negative control, respectively. Bacterial adhesion to Caco-2 cell cultures was quantitated using radiolabelled bacteria. The adherence of bacteria was also observed microscopically after Gram staining. Viability of bacteria prior to adhesion was verified using flow cytometry. Among the tested strains, L. casei (Fyos) was the most adhesive strain and L. casei var. rhamnosus (Lactophilus) was the least adhesive strain, approximately 14 and 3% of the added bacteria adhered to Caco-2 cell cultures, respectively. The corresponding values for positive and negative control E. coli strains were 14 and 4%, respectively. The Lactobacillus strains tested could not be divided into distinctly adhesive or non-adhesive strains, since there was a continuation of adhesion rates. The four most adhesive strains were L. casei (Fyos), L. acidophilus 1 (LC1), L. rhamnosus LC-705 and Lactobacillus GG (ATCC 53103). No significant differences in the percentage adhesion were observed between these strains. Adhesion of all the strains was dependent on the number of bacteria used, since an approximately constant number of Caco-2 cells was used, indicating that the Caco-2 cell binding sites were not saturated. Viability of bacteria was high since approximately 90% of the bacteria were viable with the exception of L. acidophilus 1 which was 74% viable. Microscopic evaluations agreed with the radiolabelled binding as evidenced by observing more bacteria in Gram-stained preparations of good adhering strains compared to poorly adhering strains.

Animals↗

Overview of gut flora and probiotics.

Scientific developments in recent years have opened new frontiers and enable a better understanding of the gastrointestinal tract (GIT) as a complex and delicately balanced ecosystem. This paper focuses on more recent information related to the microbial population of the GIT and its functional role in human physiology and health. Special attention is also given to modern approaches for improving or stabilising the intestinal system and its functioning by the deliberate application of viable microbial cultures, so-called 'probiotics', selected for special functional properties.

Bacterial Physiological Phenomena↗

Survival of a probiotic, Lactobacillus casei strain Shirota, in the gastrointestinal tract: selective isolation from faeces and identification using monoclonal antibodies.

Lactobacillus casei strain Shirota (LCS) is a probiotic bacterium used in the production of fermented milk products and lactic acid bacteria preparations. To investigate the survival of LCS in the gastrointestinal tract, we have developed a selective medium and specific monoclonal antibodies to isolate and identify this strain. Selective LLV agar medium was prepared by modifying LBS medium, a selective medium for lactobacilli, through the replacement of glucose with lactitol as a carbon source and vancomycin as a selective antibiotic. Culture in LLV agar medium followed by ELISA using monoclonal antibodies specific for LCS was able to detect the organism in faeces. Using this method, we studied the faecal recovery of LCS in individuals who drank 125 ml of fermented milk which contained 10(10) live LCS for 3 days. The mean recovery was about 10(7) live bacteria per gram of faeces, indicating that LCS survived transit through the gastrointestinal tract after ingestion of the fermented milk.

Adult↗

Immunonutrition: role of biosurfactants, fiber, and probiotic bacteria.

Phospholipids constitute an important part of cellular membranes, and membrane fluidity and permeability are dependent on the fatty acid composition of the phospholipid. The composition, which changes with aging and disease is, to a large degree, influenced by nutrient supply. Phospholipids have been effective in protecting cellular membranes such as those of the gastrointestinal tract to an extent not much different from that observed with external supply of established mucosa-protective drugs such as misoprostol and sucralfate. Polar lipids have also been shown to be effective in preventing microbial translocation. The effect is further potentiated by an external supply of probiotic fibers such as pectin, guar gum, and oat gum. These and many other fibers also have documented strong mucosa preventive effects. Prebiotic bacteria such as Lactobacillus plantarum have demonstrated a strong ability to preserve food and prevent spoilage. In addition, L. plantarum seems to not only preserve key nutrients such as omega-3 fatty acids, but also increases its content during storage conditions. L. plantarum alone or in combination with various fibers has demonstrated a strong ability to reduce and eliminate potentially pathogenic microorganisms both in vitro and in vivo. It has recently been shown that L. plantarum possesses the ability to adhere to and colonize intestinal mucosa. It seems unique among the lactobacilli for L. plantarum to use mannose-specific adhesins, uncommon among gram-positive, but common among gram-negative bacteria, which makes it possible that L. plantarum competes with gram-negative other potential pathogens for receptor sites at the mucosal cell surfaces. Additionally, L. plantarum seems to be effective in eliminating nitrate and producing nitric oxide. These functions of L. plantarum are among the reasons why it has been used in combination with various fibers and polar lipids to recondition the gastrointestinal mucosa. For the purpose of a L. plantarum-containing formula being produced and tried, a treatment policy is regarded as an extension of the immunonutrition program and called ecoimmunonutrition.

Bacteria↗

Functionality of probiotics and intestinal lactobacilli: light in the intestinal tract tunnel.

The commercial interest in functional foods that contain live microorganisms, also termed probiotics, is paralleled by increasing scientific attention to their functionality in the digestive tract. Most studies are focused on intestinal Lactobacillus species, which are part of the natural gastro-intestinal microbiota, and include analysis of colonisation factors and other interactions with the host, the design of novel or improved strains with specific health benefits, and the application of sophisticated molecular tools to determine their fate and activity in situ.

Genetic Techniques↗

Immune enhancement in rainbow trout (Oncorhynchus mykiss) by potential probiotic bacteria (Lactobacillus rhamnosus).

The present study assessed the immune enhancement of fish by a lactic acid bacterium (LAB) Lactobacillus rhamnosus (ATCC 53103). The bacterium was administered orally at five different doses 7.9 x 10(4) (LAB4), 2.1 x 10(6) (LAB6), 2.8 x 10(8) (LAB8), 1.9 x 10(10) (LAB10) and 9.7 x 10(10) (LAB11) CFU/g feed to rainbow trout for two weeks and the feed was changed to un-supplemented diet. From the onset of feeding supplemented diets at 1, 2, 3 and 4 weeks, blood and mucus samples were taken. During the LAB feeding period L. rhamnosus persisted in the fish intestine and in the tank water in high numbers. However, L. rhamnosus disappeared from the intestine, skin mucus and tank water within one week after the change to the non-supplemented feed. In comparison to untreated control fish, respiratory burst activity of blood cells was raised significantly in the LAB4 treated group on week 2. Serum-mediated killing of Escherichia coli was increased significantly in group LAB6 on week 2. Serum immunoglobulin levels were significantly raised only in LAB8 group on week 1 and in LAB4 and LAB8 at the end of the trial. The results show that rainbow trout immune parameters were enhanced by using probiotic bacteria.

Analysis of Variance↗

The role of probiotic bacteria in cancer prevention.

Colorectal cancer is one of the most important causes of cancer morbidity and mortality in western countries [1]. A myriad of healthful effects have been attributed to the probiotic lactic acid bacteria; perhaps the most controversial remains that of anticancer activity. There is no direct experimental evidence for cancer suppression in humans as a result of consumption of lactic cultures in fermented or unfermented dairy products. However, there is a wealth of indirect evidence, based largely on laboratory studies, in the literature and this will be summarised in the present paper.

Animals↗

Using probiotics and prebiotics to improve gut health.

Recent molecular-based investigations have confirmed the species diversity and metabolic complexity of the human gut microbiota. It is also increasingly clear that the human gut microbiota plays a crucial role in host health, both as a source of infection and environmental insult and, conversely, in protection against disease and maintenance of gut function. Although little is known about the health impact of the dominant groups of gut bacteria it is generally accepted that bifidobacteria and lactobacilli are important components of what might be termed the beneficial gut microbiota. The microbiota management tools of probiotics, prebiotics and synbiotics have been developed and, indeed, commercialized over the past few decades with the expressed purpose of increasing numbers of bifidobacteria and/or lactobacilli within the gastrointestinal tract.

Animals↗