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PubMed2005

Activation of CD1d-independent NK1.1+ T cells in the large intestine by Lactobacilli.

Among digestive organs, the liver and the large intestine are abundant in T cells expressing NK1.1. NK1.1+ T cells in the liver are mostly CD1d-dependent whereas those in the large intestine are CD1d-independent. In this study, we investigated the effects of Lactobacilli on NK1.1+ T cells in the digestive organs of mice. C57BL/6 mice were orally given a dietary supplement prepared from mixed cultures of eight strains of Lactobacilli. Oral administration of Lactobacilli to mice resulted in the selective expansion of NK1.1+ T cells in the large intestine. These colon NK1.1+ T cells activated by Lactobacilli were found to express IFN-gamma mRNA. The level of IFN-gamma in the serum was also elevated by the administration of Lactobacilli. Our results suggest that Lactobacilli selectively activate CD1d-independent NK1.1+ T cells in the large intestine to produce IFN-gamma and therefore modulate Th1 immune responses.

Animals↗
PubMed2003

Reduced experimental autoimmune encephalomyelitis after intranasal and oral administration of recombinant lactobacilli expressing myelin antigens.

Oral administration of autoantigens is a safe and convenient way to induce peripheral T-cell tolerance in autoimmune diseases like multiple sclerosis (MS). To increase the efficacy of oral tolerance induction and obviate the need for large-scale purification of human myelin proteins, we use genetically modified lactobacilli expressing myelin antigens. A panel of recombinant lactobacilli was constructed producing myelin proteins and peptides, including human and guinea pig myelin basic protein (MBP) and proteolipid protein peptide 139-151 (PLP(139-151)). In this study we examined whether these Lactobacillus recombinants are able to induce oral and intranasal tolerance in an animal model for multiple sclerosis, experimental autoimmune encephalomyelitis (EAE). Lewis rats received soluble cell extracts of Lactobacillus transformants intranasally three times prior to induction of EAE. For the induction of oral tolerance, rats were fed live transformed lactobacilli for 20 days. Ten days after the first oral administration EAE was induced. Intranasal administration of extracts containing guinea pig MBP (gpMBP) or MBP(72-85) significantly inhibited EAE in Lewis rats. Extracts of control transformants did not reduce EAE. Live lactobacilli expressing guinea pig MBP(72-85) fused to the marker enzyme beta-glucuronidase (beta-gluc) were also able to significantly reduce disease when administered orally. In conclusion, these experiments provide proof of principle that lactobacilli expressing myelin antigens reduce EAE after mucosal (intranasal and oral) administration. This novel method of mucosal tolerance induction by mucosal administration of recombinant lactobacilli expressing relevant autoantigens could find applications in autoimmune disease in general, such as multiple sclerosis, rheumatoid arthritis and uveitis.

Administration, Intranasal↗
PubMed1996

Genetics of lactobacilli in food fermentations.

Lactobacilli play a substantial role in food biotechnology and influence our quality of life by their fermentative and probiotic properties. Despite their obvious importance in fermentation ecology and biotechnology only recent years have brought some insight into the genetics of lactobacilli. These genetic investigations allow the elucidation of traits determinative for competitiveness and ecology and thus product safety and quality. They have concentrated only on a small selection of lactobacilli whereas others are hardly touched or remained recalcitrant to genetic analysis and manipulation. The knowledge gained on the biochemistry, physiology, ecology and especially genetics is a prerequisite for the deliberate application and improved handling of lactobacilli in traditional and novel applications. In this review, the achievements in the genetics of lactobacilli are described including detection systems, genetic elements, host vector systems, gene cloning and expression and risk assessment of genetically engineered lactobacilli.

Bioreactors↗
PubMed2005

A double-blind treatment study of bacterial vaginosis with normal vaginal lactobacilli after an open treatment with vaginal clindamycin ovules.

The expected 4-week cure rate after conventional treatment of bacterial vaginosis are only 65-70%. In an attempt to improve the cure rate by adding probiotic lactobacilli we performed a double-blind placebo-controlled study of adjuvant lactobacilli treatment after an open treatment with vaginal clindamycin ovules. Women with bacterial vaginosis as defined by Amsel's criteria were treated with clindamycin ovules. Vaginal smears were collected and analysed according to Nugent's criteria. During the following menstruation period the women used, as an adjuvant treatment, either lactobacilli-prepared tampons or placebo tampons. The lactobacilli tampons were loaded with a mixture of freeze-dried L. fermentum, L. casei var. rhamnosus and L. gasseri. The cure rate was recorded after the second menstruation period. There was no improvement in the cure rate after treatment with lactobacilli-containing tampons compared to placebo tampons; the cure rates as defined by Amsel's criteria were 56% and 62%, respectively, and 55% and 63%, as defined by Nugent's criteria. This is the first study to report cure rates for women with 'intermediate' wet smear ratings according to Nugent's classification and this group had an overall cure rate of 44%. The cure rate of treatment of bacterial vaginosis was not improved by using lactobacilli-prepared tampons for one menstruation.

Administration, Intravaginal↗
PubMed2006

Lactobacilli in the female genital tract in relation to other genital microbes and vaginal pH.

BACKGROUND: The relationship between lactobacilli and other microbes and the association with vaginal pH in the female genital tract were examined. The study also included evaluation of the possibility of supplying probiotics to the genital tract by using panty liners impregnated with the probiotic strain Lactobacillus plantarum LB931. METHODS: This was a randomized, placebo-controlled, double-blind, multicenter study involving 191 healthy fertile women. Specified microbes were counted and vaginal pH was measured once a month for five consecutive months. RESULTS: Major individual variations in the genital microflora composition and the vaginal pH were found among the women. The number of lactobacilli was significantly related to vaginal pH (p<0.001) and approximately 70% of the women were permanent carriers of individual lactobacilli strains. Women with high numbers of lactobacilli were less prevalent with Group B streptococci than women with low numbers (p=0.036), and these women had a lower mean vaginal pH. The number of lactobacilli also correlated with the prevalence of yeast. LB931 could be found in 86% of the labial samples and 54% of the vaginal samples. CONCLUSIONS: High numbers of lactobacilli may contribute to a low vaginal pH and seem to have a negative influence on Group B streptococci. LB931 could be transferred from the panty liners to both the vagina and the labial fold.

Absorbent Pads↗
PubMed2003

Inhibition of vaginal lactobacilli by a bacteriocin-like inhibitor produced by Enterococcus faecium 62-6: potential significance for bacterial vaginosis.

OBJECTIVE: Bacterial vaginosis (BV) is characterized by a shift in vaginal tract ecology, which includes a decrease in the concentration and/or prevalence of facultative lactobacilli. Currently, mechanisms which could account for the disappearance of lactobacilli are not well understood. The objective of this study was to determine whether vaginal streptococci/enterococci can produce bacteriocin-like inhibitors antagonistic to vaginal lactobacilli. METHODS: Seventy strains of vaginal streptococci or enterococci were tested for antagonistic activities against vaginal lactobacilli using the deferred antagonism technique. RESULTS: One strain, Enterococcus faecium 62-6, which strongly inhibited growth of lactobacilli was selected for further characterization. The spectrum of inhibitory activity of strain 62-6 included Gram-positive organisms from the vaginal environment, although native lactobacilli from the same host were resistant to inhibitor action. Following growth in MRS broth the strain 62-6 inhibitor was shown to be heat- (100 degrees C, 30 minutes), cold- (4 degrees C, less than 114 days) and pH- (4-7) stable. The sensitivity of inhibitor-containing supernatants to pepsin and alpha-chymotrypsin suggested an essential proteinaceous component. The inhibitor was sensitive to lipase but resistant to lysozyme. Dialysis of inhibitor-containing culture supernatants suggested a molecular mass greater than 12,000 Da. All physicochemical properties were consistent with its classification as a bacteriocin-like inhibitor. Kinetic assays demonstrated a sharp onset of inhibitor production coinciding with a concentration of 62-6 of 10(7) cfu/ml, suggesting that production may be regulated by quorum sensing. CONCLUSIONS: These results may have clinical significance as a novel mechanism to account for the decline of vaginal Lactobacillus populations and contribute to both the establishment and recurrence of BV.

Bacterial Adhesion↗
PubMed2006

Lactobacilli expressing variable domain of llama heavy-chain antibody fragments (lactobodies) confer protection against rotavirus-induced diarrhea.

BACKGROUND: Rotavirus-induced diarrhea poses a worldwide medical problem in causing substantial morbidity and mortality among children in developing countries. We therefore developed a system for passive immunotherapy in which recombinant lactobacilli constitutively express neutralizing variable domain of llama heavy-chain (VHH) antibody fragments against rotavirus. METHODS: VHH were expressed in Lactobacillus paracasei, in both secreted and cell surface-anchored forms. Electron microscopy was used to investigate the binding efficacy of VHH-expressing lactobacilli. To investigate the in vivo function of VHH-expressing lactobacilli, a mouse pup model of rotavirus infection was used. RESULTS: Efficient binding of the VHH antibody fragments to rotavirus was shown by enzyme-linked immunosorbent assay and scanning electron microscopy. VHH fragments expressed by lactobacilli conferred a significant reduction in infection in cell cultures. When administered orally, lactobacilli-producing surface-expressed VHH markedly shortened disease duration, severity, and viral load in a mouse model of rotavirus-induced diarrhea when administered both fresh and in a freeze-dried form. CONCLUSIONS: Transformed lactobacilli may form the basis of a novel form of prophylactic treatment against rotavirus infections and other diarrheal diseases.

Animals↗
PubMed1998

Use of nonoxynol-9 and changes in vaginal lactobacilli.

Several in vitro studies have shown nonoxynol-9 (N-9) to be toxic to lactobacilli, especially to strains that produce H2O2. Data from a randomized, double-blind, placebo-controlled crossover trial that investigated the safety and toxicity of 2 weeks of daily vaginal application of an N-9 gel were analyzed, to examine the effect of N-9 use on vaginal lactobacilli and bacterial vaginosis. In vivo, N-9 promoted sustained colonization by H2O2-producing lactobacilli among women already colonized (relative risk [RR], 1.8; 95% confidence interval [CI], 1.2-2.7). In addition, use of N-9 for 2 weeks reduced the likelihood of bacterial vaginosis (RR, 0.5; 95% CI, 0.3-1.0). In contrast, N-9 use by women initially colonized only by non-H2O2-producing lactobacilli resulted in loss of vaginal lactobacilli (RR, 2.5; 95% CI, 1.2-5.3). These data suggest that daily use of N-9 does not adversely affect vaginal colonization by H2O2-producing lactobacilli but that such use may promote loss of non-H2O2-producing strains.

Adult↗
PubMed1998

Incidence of mutans streptococci and lactobacilli in oral cleft children wearing acrylic plates from shortly after birth.

Children with a palatal cleft can be treated with preoperative infant orthopedics including an acrylic plate that is applied shortly after birth to obturate the cleft. It is advised to wear these plates until the 18th month of age. Such a plate, being a hard non-shedding surface, may be expected to facilitate early colonization of mutans streptococci. The first aim of the present investigation was to assess the incidence of mutans streptococci and lactobacilli in children with cleft lip and/or palate during the first 2 years of life. The second aim was to study whether preoperative orthopedics, that is, the wearing of an acrylic plate, had facilitated the establishment of mutans streptococci and lactobacilli. The third aim was to determine other factors associated with colonization of these organisms in these children. Sixty-two Caucasian Dutch children with cleft lip and/or palate participated in this study. Twenty-four of these children were treated with preoperative infant orthopedics and had been wearing an acrylic plate from within a few days after birth. At regular control visits plaque and saliva samples and samples from the surface of the acrylic plate were taken, while a dental examination was performed to document the emergence of the primary teeth, caries status, gingival condition and oral hygiene procedures. Saliva samples were also taken from the accompanying parents. At the visit at the age of 18 months, the parents were interviewed using a structured questionnaire. At this age, the prevalence of mutans streptococci and lactobacilli was compared to that in a control group of non-cleft children. The oral cleft children wearing an acrylic plate from shortly after birth were colonized earlier with mutans streptococci and lactobacilli than the non-plate oral cleft children. In the children wearing acrylic plates, the prevalence of lactobacilli decreased with age, while the prevalence of mutans streptococci increased. At the age of 18 months the prevalence of mutans streptococci was comparable in both groups of oral cleft children and in the control children. There was no relation between the numbers of mutans streptococci in the saliva of the mothers and their children. The presence of mutans streptococci in the saliva of the oral cleft children was significantly associated with between-meal snacking and with the presence of lactobacilli.

Acrylic Resins↗
PubMed2005

Oral lactobacilli in chronic periodontitis and periodontal health: species composition and antimicrobial activity.

BACKGROUND/AIMS: Lactobacilli are known to play an important role in the maintenance of health by stimulating natural immunity and contributing to the balance of microflora. However, their role in chronic periodontitis is unclear. We aimed to identify oral lactobacilli in chronic periodontitis and periodontally healthy subjects, and to determine their antimicrobial activity against putative oral pathogens. METHODS: A total of 238 Lactobacillus isolates from the saliva and subgingival sites of 20 chronic periodontitis and 15 healthy subjects were collected. In all, 115 strains were identified using rapid amplified ribosomal DNA restriction analysis. Antimicrobial activity against Streptococcus mutans, Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia was assessed. RESULTS: Lactobacilli belonging to 10 species were identified. The most prevalent strains in healthy persons were Lactobacillus gasseri and Lactobacillus fermentum and in chronic periodontitis patients, Lactobacillus plantarum. Obligately homofermentatives, particularly L. gasseri, were less prevalent in chronic periodontitis patients compared with healthy subjects (8% vs. 64% for L. gasseri, P < 0.01). Sixty-nine percent of tested lactobacilli inhibited S. mutans, 88% A. actinomycetemcomitans, 82% P. gingivalis and 65% P. intermedia. The strongest antimicrobial activity was associated with Lactobacillus paracasei, L. plantarum, Lactobacillus rhamnosus, and Lactobacillus salivarius. The strains from periodontally healthy patients showed a lower antimicrobial activity against S. mutans than the strains from chronic periodontitis patients. CONCLUSION: The composition of oral lactoflora in chronic periodontitis and healthy subjects differs, with a higher prevalence of homofermentative lactobacilli, particularly L. gasseri, in the latter group. Both homo- and heterofermentative oral lactobacilli suppress the growth of periodontal pathogens, but the antimicrobial properties are strain, species and origin specific.

Adult↗
PubMed1987

Dietary habits, gingival status and occurrence of Streptococcus mutans and lactobacilli as predictors of caries in 3-year-olds in Sweden.

The aim was to study whether dietary habits, oral hygiene expressed as gingival status, and presence/absence of S. mutans and lactobacilli, singly or in combinations, could be used as caries predictors. Sensitivity, specificity and predictive values for positive (PV+) and negative tests (PV-) were calculated. 133 children, 3 yr of age, were examined for caries and presence/absence of S. mutans and lactobacilli. Three levels of gingival status and dietary habits, respectively, were registered. Two groups in respect of dietary habits and oral hygiene were formed by stepwise pooling of the caries data for the nine possible combinations of oral hygiene and dietary habits, setting the most discriminating border (screening level) where sensitivity (0.86) and specificity (0.69) simultaneously reached their highest value. PV + was 0.58 and PV- 0.91. Higher predictive values were obtained when presence/absence of lactobacilli and of S. mutans were combined. Combinations of defined levels of dietary habits, gingival status and presence/absence of lactobacilli showed sensitivity 0.87, specificity 0.95, PV + 0.87 and PV- 0.95, presence/absence of S. mutans sensitivity 0.94, specificity 0.76, PV + 0.74 and PV- 0.95. A two-step prediction, with gingival status as the first predictor and presence/absence of lactobacilli or S. mutans as the second, was the most efficient when lactobacilli were involved.

Child, Preschool↗
PubMed1991

Salivary levels of mutans streptococci and lactobacilli in dentate 80- and 85-year-old Swedish men and women.

The number of Streptococcus mutans, Streptococcus sobrinus, and lactobacilli in whole stimulated saliva was examined in 130 dentate 80- and 85-yr-old persons. 88.5% were positive for mutans streptococci and 29% carried greater than 10(6) cfu per ml saliva. S. mutans was most frequently isolated and was found in 114 persons (88%) alone or in combination with S. sobrinus. S. sobrinus was detected in 33 persons (25%), who also showed significantly higher salivary numbers of both mutans streptococci and lactobacilli than persons from whom S. sobrinus was not isolated. The S. sobrinus carriers also had significantly lower stimulated saliva secretion rates than the non-carriers. 95% of the subjects had detectable levels of lactobacilli in saliva with 35% having greater than 10(5) cfu per ml saliva. When the subjects were divided into classes according to the number of intermaxillary contacts, i.e. the Eichner classification, the distribution of subjects with high and low salivary counts of cariogenic bacteria varied. Thus fewer subjects belonging to Eichner class A showed higher salivary numbers of mutans streptococci (14% had greater than 10(6) cfu/ml) as well as lactobacilli (21% had greater than 10(5) cfu/ml) than, for example, subjects belonging to Eichner class B (26% had greater than 10(6) cfu/ml of mutans streptococci, 35% had greater than 10(5) cfu/ml of lactobacilli). Subjects who carried a removable denture(s) had significantly higher salivary numbers of both mutans streptococci and lactobacilli than subjects without removable dentures.

Aged↗
PubMed2004

Effects of polyunsaturated fatty acids in growth medium on lipid composition and on physicochemical surface properties of lactobacilli.

Most probiotic lactobacilli adhere to intestinal surfaces, a phenomenon influenced by free polyunsaturated fatty acids (PUFA). The present study investigated whether free linoleic acid, gamma-linolenic acid, arachidonic acid, alpha-linolenic acid, or docosahexaenoic acid in the growth medium alters the fatty acid composition of lactobacilli and their physical characteristics. The most abundant bacterial fatty acids identified were oleic, vaccenic, and dihydrosterculic acids. PUFA, especially conjugated linoleic acid (CLA) isomers and gamma-linolenic, eicosapentaenoic, docosahexaenoic, and alpha-linolenic acids, also were identified in lactobacilli. When lactobacilli were cultured in MRS broth supplemented with various free PUFA, the incorporation of a given PUFA into bacterial fatty acids was clearly observed. Moreover, PUFA supplementation also resulted in PUFA-dependent changes in the proportions of other fatty acids; major interconversions were seen in octadecanoic acids (18:1), their methylenated derivatives (19:cyc), and CLA. Intermittent changes in eicosapentaenoic acid proportions also were noted. These results were paralleled by minor changes in the hydrophilic or hydrophobic characteristics of lactobacilli, suggesting that PUFA interfere with microbial adhesion to intestinal surfaces through other mechanisms. In conclusion, we have demonstrated that free PUFA in the growth medium induce changes in bacterial fatty acids in relation to the regulation of the degree of fatty acid unsaturation, cyclization, and proportions of CLA and PUFA containing 20 to 22 carbons. The potential role of lactobacilli as regulators of PUFA absorption may represent another means by which probiotics could redirect the delicate balance of inflammatory mediators derived from PUFA within the inflamed intestine.

Bacterial Adhesion↗
PubMed1989

Control of Escherichia coli populations by a combination of indigenous clostridia and lactobacilli in gnotobiotic mice and continuous-flow cultures.

The function of indigenous lactobacilli in the control of other intestinal microbial species is not clear. Still more controversial is the effect of dietary bacterial supplements containing lactobacilli or other species. This situation is unlikely to change unless the mechanisms that control the colonization of ingested bacteria are better understood, and until more detailed information becomes available on the mechanisms by which certain populations of indigenous bacteria can affect the population sizes of other species. We used gnotobiotic mice and a continuous-flow culture system to study the interactions between Escherichia coli and (i) clostridia (in chloroform-treated cecal suspensions from conventional mice) and (ii) three strains of lactobacilli isolated from conventional mice. In gnotobiotic mice, the lactobacilli suppressed E. coli multiplication in the stomach and the small intestine, but had no demonstrable effect on E. coli multiplication in the large intestine. In contrast, clostridia were most effective in controlling E. coli multiplication in the large intestine. In the presence of both lactobacilli and clostridia, E. coli populations in the various regions of the gastrointestinal tract resembled those found in conventionalized control animals. The control of E. coli populations was not related to changes in pH or intestinal motility. In vitro stimulation of the above-described in vivo interactions required a two-stage continuous-flow culture in which the effluent from the first stage represented the influx to the second. The first stage was inoculated with lactobacilli, and the second stage was inoculated with either a pure culture of E. coli or E. coli and clostridia. In these instances, the E. coli populations in the second stage of the culture resembled in size those found in the large intestine of gnotobiotic mice harboring a similar flora. Although there are some current shortcomings of this in vitro model, we expect that a multistage continuous-flow culture can be developed to satisfactorily model the interactions among bacterial populations along the entire gastrointestinal tract.

Animals↗
PubMed1969

Microbial interference between indigenous yeast and lactobacilli in the rodent stomach.

Indigenous yeasts grow in layers in the mucus on the secreting epithelium of the stomachs of some strains of rats and mice raised under conventional conditions. Likewise, indigenous lactobacilli appear in layers on the nonsecreting epithelium of the stomachs of rats and mice. The two microbial layers can coexist in the same animals. When I gave such rodents penicillin solution in the place of drinking water, the lactobacilli disappeared, and the yeast from the secreting epithelium colonized the nonsecreting epithelium within 24 hr. The yeast remained in layers on the nonsecreting, as well as the secreting epithelium, as long as penicillin was administered. There is no inflammatory reaction or any sign that the yeast invaded below the keratin layer. When the penicillin treatment was discontinued, within 5 to 8 days the indigenous lactobacilli again colonized the nonsecreting epithelium. Concomitantly the yeast was displaced from the keratinized tissue and once more could be found only on the secreting epithelium. Only 2 days were required, however, for the bacteria to recolonize the keratin layer and displace the yeast when the mice were given indigenous lactobacilli in pure culture immediately after the penicillin treatment was discontinued. The lactobacilli must displace the yeast from the nonsecreting epithelium by interfering either with multiplication of the yeast on the tissue or with attachment of the yeast cells to the keratin layer. This interference must proceed continuously during normal life since the yeast never populates the nonsecreting epithelium as long as the lactobacilli are present.

Animals↗
PubMed1995

Lactobacilli, mutants streptococci and dental caries: a longitudinal study in 2-year-old children up to the age of 5 years.

A 3-year cohort study was carried out in 252 pre-school children for early identification of caries-active individuals. During this period information was collected about the acquisition of mutants streptococci and lactobacilli from the age of 2 till 5 years old. At baseline mutants streptococci were detected in 43% of the children while the detection frequency of lactobacilli was low (11.5%). On an individual level, numbers of colony-forming units of mutans streptococci and lactobacilli in plaque and saliva varied largely during the study period. The correlations between the numbers of lactobacilli and mutants streptococci in the saliva of the mother and the saliva and plaque of the child were low and never exceeded r = 0.22. Very low correlations (< r = 0.22) were also found between the numbers of mutans streptococci or lactobacilli and the diet in terms of the number of sugar intakes. Nevertheless, in children older than 2.5 years correlations between the clinical caries score and lactobacilli in saliva (range 0.31-0.62) and mutans streptococci in plaque or saliva (range 0.24-0.46) were highly significant (p < 0.01).

Child, Preschool↗
PubMed1996

Effect of lactobacilli and antibiotics on E. coli urinary infections in mice.

Urinary antibiotic treatments usually affect the normal urethral flora. This work was developed in order to evaluate whether Lactobacillus fermentum CRL 1058 could reduce urinary tract infections (UTI) produced by uropathogenic Escherichia coli in mice treated with antimicrobial agents. Animals were inoculated intra-urethrically with agarose beads containing lactobacilli, and were challenged with E. coli. Ampicillin (13 mg/kg/dose) was administered orally. The number of microorganisms present at different days was evaluated in the urogenital tract. Serum inflammatory and systemic immune response were also registered. The use of 5 doses of ampicillin after 3 doses of lactobacilli in agarose beads significantly affected the viability of lactic acid bacteria, while the amount of E. coli was not altered. Lactate dehidrogenase (LDH) activity and anti-E. coli antibody levels showed no statistically significant difference between the challenged and non-challenged mice. Lactobacilli reinoculation and 3 doses of ampicillin proved to be a moderately effective treatment since a smaller amount of E. coli was recovered from the organs of treated mice than from the controls. The reinforcement of lactobacilli, administered on the 9th day, produced a faster elimination of the pathogen. The ampicillin dose used allowed lactobacilli permanence in the urinary tract, and caused the elimination of the pathogen. Serum LDH values seemed to show an inflammatory immune response. No successful preventive results could be achieved. We can conclude that lactobacilli and adequately low doses of ampicillin have a positive effect on the treatment of E. coli in this UTI model.

Ampicillin↗
PubMed2006

Lactobacilli, bifidobacteria and E. coli nissle induce pro- and anti-inflammatory cytokines in peripheral blood mononuclear cells.

AIM: To investigate whether the stimulation of peripheral blood mononuclear cells (PBMNC) with the cell debris and cell extraction of different probiotic strains is similar or species specific. METHODS: Three strains of bifidobacteria, 4 strains of lactobacilli, and E. coli nissle were sonicated and centrifuged in order to divide them into cell extract and cell debris. PBMNC were separated by density gradient and incubated for 36 h with either the cell debris or the cell extract of single strains of probiotic bacteria in doses from 10(2) to 10(8) CFU/mL. Cell supernatants were taken and interleukin (IL)-10, IL-1beta, and tumor necrosis factor (TNF)-alpha were determined by ELISA. RESULTS: Depending on the species super-family, the strains had different stimulation patterns. Except for both L. casei strains, the cell extract of bifidobacteria and lactobacilli had less stimulating capacity than cell debris, whereas the cell extract of E. coli nissle had similar stimulating properties to that of the cell debris of the strain and significantly more stimulating capacity than that of bifidobacteria and lactobacilli. The cell debris of bifidobacteria stimulated more cytokine release than the cell debris of lactobacilli. The cell debris of lactobacilli did not have a stimulating capacity when lower concentrations were used. Neither cell extraction nor cell debris had an inhibitory effect on the production of the tested cytokines by stimulated PBMNC. CONCLUSION: The incubation of probiotic strains, which have been used in clinical trials for inflammatory diseases, with immunocompetent cells leads to different species specific reactions. High IL-10 response to cell debris of bifidobacteria and E. coli nissle can be found. This corresponds to positive effects of bifidobacteria and E. coli nissle in clinical trials for inflammatory bowel disease compared to negative outcomes obtained with lactobacilli.

Adult↗