Short-term use of Lacticaseibacillus rhamnosus SD11 and the oral microbiome: Low caries RCT study.

OBJECTIVES: The objective of the study was to investigate the effect of short-term lozenges containing Lacticaseibacillus rhamnosus SD11 on cariogenic pathogens and on oral microbiota. MATERIALS AND METHODS: This double-blind, randomized, controlled trial included 121 subjects and was randomly divided into the control and probiotic group. All subjects were blindly administered to receive the control- or probiotic L. rhamnosus SD11 lozenges every day for 4 weeks and then followed up for another 4 weeks. RESULTS: After probiotic consumption, the probiotic group had significantly lower levels of Streptococcus mutans and significantly higher levels of total lactobacilli at 4 and 8 weeks compared with the baseline. The 16S rRNA sequencing revealed an increase in bacterial diversity and beneficial bacteria in the Firmicutes phylum, Bacilli class, and a reduction in the mutans streptococci group in the probiotic group. The opposite results were found in the control group. This study did not find any caries increment, nor did the subjects have any side effects after product consumption. CONCLUSION: With the limitation of a short-time study in low caries children, it showed that L. rhamnosus SD11 could increase beneficial bacteria in the Firmicutes phylum and Bacilli class that might support good oral health in children.

Impact of Potential Probiotic Lactobacillus Strains on Host Growth and Development in a Drosophila melanogaster Model.

Lactobacillus paracasei SD1, Lactobacillus rhamnosus SD11, and Lactobacillus gasseri SD12 were proposed as potential probiotics for oral health. However, the effects of them on host physiology are still unknown. This study aimed to select strains that can promote host growth and development in monocolonized Drosophila model compared with axenic and the commercial Lactobacillus rhamnosus GG-treated flies. The morphogenesis and growth of axenic Drosophila melanogaster were assessed from embryo to adult stage when provided with each probiotic strain-supplemented food. The colonization and persistence of probiotic in fly gut were also evaluated. The results indicated that axenic condition caused the lowest adult weight and emergence rate. All probiotic groups had higher weight than axenic group. Lact. rhamnosus SD11 group presented high adult emergence rate equivalent to Lact. rhamnosus GG group, which is significantly higher than the others. However, Lact. gasseri SD12 group had significantly lower adult weight and emergence rate when compared with Lact. rhamnosus GG group. The gut probiotics levels were rapidly increased within the first day after receiving probiotics. After probiotic cessation, their number in gut decreased and was maintained at low level, except for Lact. gasseri SD12, which completely vanished since day one. In conclusion, Lact. paracasei SD1, Lact. rhamnosus SD11, and Lact. rhamnosus GG can affect morphogenesis and weight of flies when fed since immature stage and have short period gut colonization. The findings of this study could possibly imply comparable health-promoting effects between Lact. paracasei SD1 and Lact. rhamnosus SD11 to commercial strain in Drosophila model.

Significant elevation of salivary human neutrophil peptides 1-3 levels by probiotic milk in preschool children with severe early childhood caries: a randomized controlled trial.

OBJECTIVES: To determine salivary human neutrophil peptides 1-3 (HNP1-3) levels in caries-free preschool children and in those with early childhood caries (ECC) or severe-ECC, in a daily probiotic group, receiving reconstituted milk with the probiotic Lactobacillus paracasei SD1 once daily; a triweekly probiotic group, receiving the probiotic milk 3 days a week; and a placebo group. MATERIALS AND METHODS: Oral examination and unstimulated whole saliva collection were conducted in 354 children at baseline, 6 months after intervention (T6), and after probiotic discontinuation (T12). Of the 354, adequate volume of saliva samples from 268 children were simultaneously analyzed for Streptococcus mutans and total lactobacilli levels using qPCR and for HNP1-3 levels using ELISA. RESULTS: In the severe-ECC status, significant increases in the median HNP1-3 levels at T12 were found in both daily and triweekly probiotic groups (p < 0.001). The median S. mutans levels in the daily group were significantly decreased at T6 and T12 (p < 0.01), whereas the median total lactobacilli levels were significantly increased at T6 (p < 0.001). Significantly inverse correlations between altered HNP1-3 and S. mutans levels and significant decreases in caries progression were found in both probiotic groups (p < 0.05). CONCLUSIONS: In the severe-ECC status, daily or triweekly consumption of L. paracasei SD1 significantly enhanced salivary HNP1-3 levels, but reduced S. mutans levels, possibly resulting in reduction of caries progression. CLINICAL RELEVANCE: Significant enhancement of salivary HNP1-3 levels by probiotic consumption is associated with reduction in S. mutans levels, consistent with diminished caries progression in children with severe-ECC.

Efficacy of Probiotic Milk for Caries Regression in Preschool Children: A Multicenter Randomized Controlled Trial.

This multicenter double-blind randomized controlled trial aimed to determine the efficacy of daily or triweekly consumption of reconstituted milk powder, containing Lactobacillus paracaseiSD1, in preschool children for caries prevention. A 6-month intervention was conducted in 487 children (aged 37.6 ± 9.2 months) with ≤4 decayed teeth from 8 childcare centers. Using stratified block randomization, participants were randomly allocated into 3 groups, comprising: (1) daily probiotic, receiving probiotic milk once daily, (2) triweekly probiotic, randomly receiving probiotic milk 3 days a week and the placebo milk for the remaining 4 days, and (3) placebo, receiving milk without probiotics. Each tooth surface was assessed for caries status using the modified Nyvad criteria at baseline (T0), 6 (T6) and 12 (T12) months after T0. Study outcomes were caries transition, including caries progression and regression during the T0-T6, T6-T12 and T0-T12 periods. Negative binomial regression with a generalized linear model was used to estimate the caries outcomes, which were reported as incidence rate ratios (IRRs) and 95% confidence intervals (CIs). At baseline, caries prevalence and mean decayed surfaces were 81.9% and 7.29 ± 7.60, respectively. Three groups were balanced at baseline with an overall dropout rate of 25.2%. After adjusting for age, sex, and the number of noncavitated and cavitated caries at baseline, a decreased caries risk during T0-T6 was shown in both the daily and triweekly probiotic groups (adjusted IRR 0.83, 95% CI 0.72-0.96 in both groups) and during T0-T12 (adjusted IRR 0.84, 95% CI 0.76-0.94, and adjusted IRR 0.86, 95% CI 0.76-0.96, respectively) compared to the placebo group. In contrast, significantly increased regressive surfaces were demonstrated during T0-T6 by adjusted IRR 1.76 (95% CI 1.25-2.48) and 2.01 (95% CI 1.42-2.85) and during T0-T12 by adjusted IRR 1.98 (95% CI 1.50-2.61) and 1.92 (95% CI 1.45-2.55) for the daily and triweekly groups, respectively. In conclusion, probiotic milk consumption either daily or triweekly can modestly prevent new caries, but considerably reverse carious lesions, suggesting that a daily or triweekly dose interval is sufficient to reverse carious lesions.

Associations Between Temperament and Dental Caries Status in Thai Children.

PURPOSE: To examine the relationships between (1) the levels of each temperament traits and the levels of milk-feeding frequency, oral hygiene care and dental caries, and (2) the difference in mean numbers of decayed surfaces among temperament types. MATERIALS AND METHODS: Four hundred and ninety-three (493) 12-month-old infants were assessed for temperaments and characteristics of child-rearing practices. The data were analysed with their dental caries status at 18 months of age. The chi-squared test, Student's t test, ANOVA and Kruskal-Wallis tests were used to assess the association between temperament traits and the following variables; dental caries, oral cleaning habits and feeding frequency. Logistic regression models were used to identify the effect of temperament traits and other factors on dental caries status. RESULTS: The trait of adaptability was found to associate with feeding frequency at night, while those of activity and approach/withdrawal were significantly associated with regularity of oral cleaning habits by the children's caregiver. Three of the nine temperament traits - biological rhythmicity, approach/withdrawal and mood - were significantly associated with dental caries in bivariate analysis. Biological rhythmicity and approach/withdrawal traits were significantly associated with a higher chance of having caries after adjusting for regularity of oral cleaning habits and frequency of night feeding. CONCLUSION: Biological rhythmicity, approach/withdrawal and mood traits were related to caries in these young children.

Adhesion, anti-adhesion and aggregation properties relating to surface charges of selected Lactobacillus strains: study in Caco-2 and H357 cells.

This study aimed to assess adhesion and anti-adhesion, aggregation, and surface properties of four selected oral Lactobacillus strains, L. fermentum SD7, L. paracasei SD1, L. rhamnosus SD4, and L. rhamnosus SD11, together with Lactobacillus rhamnosus GG. Human cells, enterocytes Caco-2 and oral keratinocyte H357 were used, and various enteric and oral pathogens were included. Results showed that all Lactobacillus tested gave high adhesion and internalization in both Caco-2 and H357 cells similar to L. rhamnosus GG, and it suggests that such properties are strain dependent and specific to host cells. Anti-adhesion was different; it depended on the internalization ability of individual Lactobacillus and pathogenic strains to Caco-2 and H357. Coaggregation ability depended on autoaggregation of both the Lactobacillus and pathogenic strains. A positive correlation between surface charges and aggregation, and internalization and anti-adhesion of all Lactobacillus was found. In conclusion, results suggests that the selected Lactobacillus might be potential probiotics for usage in both the oral cavity and intestinal tract due to their abilities of aggregation, adherence and anti-internalization to both Caco-2 and H357 cells.

Fermented milk containing a potential probiotic Lactobacillus rhamnosus SD11 with maltitol reduces Streptococcus mutans: A double-blind, randomized, controlled study.

BACKGROUND/PURPOSE: Sucrose has been considered as a cariogenic substrate due to large amounts of acid production after fermentation by certain oral bacteria, thus sugar alcohols are often used to replace sucrose. The aims of this study were to investigate the effect of maltitol on the growth and acid production of Streptococcus mutans and Lactobacillus rhamnosus-SD11 compared to various sugars, and to examine whether the fermented milk containing a potential probiotic L. rhamnosus-SD11 with maltitol could reduce S. mutans. MATERIALS AND METHODS: The acid production of tested sugars by cariogenic S. mutans was measured using pH meter. In a clinical trial, 123 children were recruited and randomly assigned to either the probiotic- or control-fermented milk, once daily for 4 weeks. The target bacteria levels in the saliva were examined using a real-time PCR at baseline, 4 and 8 weeks. The oral examination was recorded at the baseline and 8 weeks. RESULTS: The results showed that maltitol exhibited less acid production than simple sugars. In the clinical trial, a significant reduction of salivary total streptococci and S. mutans occurred, while the levels of salivary lactobacilli significantly increased in the probiotic group compared to the control group after receiving the probiotic fermented milk. CONCLUSION: The daily consumption of the fermented milk containing L. rhamnosus-SD11 with maltitol had beneficial effects on oral health by reducing salivary S. mutans. Thus, the substitution of simple sugars by maltitol in dairy products containing L. rhamnosus-SD11 may be an alternative way to prevent the risk of caries.

Reduction of Streptococcus mutans by probiotic milk: a multicenter randomized controlled trial.

OBJECTIVE: To investigate the effects of probiotics, Lactobacillus paracasei SD1, on the quantities of Streptococcus mutans in saliva and plaque samples of preschool children. DESIGN: This randomized trial recruited 487 preschool children from eight childcare centers. Participants were assigned to receive a 6-month course of placebo milk daily (group I), probiotic milk either daily (group II) or three days a week (triweekly, group III). The absolute quantities of S. mutans and total lactobacilli in the saliva and plaque samples at baseline (T0), after intervention (T6), and 6 months after discontinuation (T12) were assessed by qPCR. RESULTS: Of 487 children, 354 completed all follow-up periods. However, only 268 children (3.2 ± 0.8 years old; groups I = 86, II = 89, and III = 93) provided adequate saliva for qPCR. Whereas the quantities of S. mutans were significantly decreased in groups II and III compared to group I in the saliva and plaque samples at T6 and T12, those of total lactobacilli were significantly increased (p < 0.0167). There was no difference in the quantities of S. mutans or total lactobacilli between groups II and III at any period. Significant changes in the quantities of S. mutans and total lactobacilli lasted until T12 compared to T0 (p < 0.0167). CONCLUSIONS: Probiotic administration daily or triweekly reduces S. mutans quantities, whereas it increases total lactobacilli quantities that persists at least 6 months after discontinuation in the saliva and plaque samples of preschool children. CLINICAL RELEVANCE: Daily or triweekly consumption of L. paracasei SD1 supplemented in milk may help prevent dental caries in preschool children.

Increasing salivary IgA and reducing Streptococcus mutans by probiotic Lactobacillus paracasei SD1: A double-blind, randomized, controlled study.

BACKGROUND/PURPOSE: Our previous study revealed that probiotic Lactobacillus paracasei SD1 could reduce mutans streptococci as evaluated by cultivation-method as well as stimulate innate immunity. This study aimed to further investigate the effect of the probiotic on various oral bacteria by real-time PCR and salivary IgA levels. MATERIALS AND METHODS: Forty children were included by randomization from either probiotic or control group in the previous study. The probiotic or control received milk-powder with or without L. paracasei SD1, respectively once daily for 6 months. Saliva were collected at baseline 3-, 6-, and 12-months and were evaluated for total bacteria, total lactobacilli (TL), L. paracasei/L. casei (LP/LC), total streptococci (TS) and Streptococcus mutans using the real-time PCR. The salivary IgA (sIgA) was examined using the ELISA method. RESULTS: All target bacterial levels were not significantly different at baseline in both groups. After milk-powder consumption, TL and LP/LC levels were significantly increased in the probiotic group, whereas TS and S. mutans levels were significantly decreased compared to baseline. TS and S. mutans levels were significantly lower, while the sIgA was greater in the probiotic compared to the control group. In the probiotic group, a positive correlation was found between LP/LC and sIgA, while negative correlations were observed between TS or S. mutans levels and sIgA. CONCLUSION: L. paracasei SD1 could control S. mutans level and could stimulate sIgA. Results indicate that the L. paracasei SD1 strain may have a benefit for prevention of dental caries.

Reducing mutans streptococci and caries development by Lactobacillus paracasei SD1 in preschool children: a randomized placebo-controlled trial.

OBJECTIVE: To examine a reducing effect of Lactobacillus paracasei SD1 on MS and caries in preschool children. MATERIALS AND METHODS: A total of 124 children, aged 1.5-5 years old, participated and were randomly assigned to the probiotic or control group. The probiotic group received L. paracasei SD1-milk and the control group received standard-milk once daily for 3 months. MS/lactobacilli were enumerated and the caries score was examined. Association between probiotic consumption and bacterial level, or caries progression was assessed by a multivariate logistic regression. This study was registered at the Thai-Clinical-Trials-Registry (TCTR20140903001). RESULTS: Probiotic was found to be a factor associated with the MS level. Children in the probiotic group had a significantly lower risk of an increase in the MS level than in the control group after receiving the probiotic milk at 3- and 4-months with p < .001 and p = .040, respectively. Probiotic significantly reduced the risk for caries compared to the control group (p = .016). There were no adverse effects or non-compliance reported in either group. CONCLUSIONS: Consumption of milk powder containing L. paracasei SD1 resulted in a reduction of both salivary MS and delayed new caries development, and the strain is safe for use in young children. Results suggest that L. paracasei SD1 may be an alternative way for caries prevention in young children.

Assessment of Prevalence, Adhesion and Surface Charges of Bifidobacterium spp. Isolated from Thai Women with Bacterial Vaginosis and Healthy Women

Background: Bifidobacterium spp. have been reported in women with bacterial vaginosis (BV), nevertheless data of prevalence and adhesion property of the vaginal bifidobacteria in Thai women with BV are still limited. Objective: To determine prevalence of Bifidobacterium spp. and to evaluate adhesion ability and cell surface properties of bifidobacterial isolates from Thai women with BV compared to healthy subjects. Material and Method: A total of 139 bifidobacterial isolates from 20 of 60 women with BV and 7 of 60 healthy women. The isolated strains were identified by molecular biology techniques and examined for adhesion property and surface charges. Results: The prevalence of vaginal bifidobacteria in women with BV (33.3%) was significantly (p<0.05) higher than healthy women (11.7%) with total counts of 8.9±3.4 Log CFU/ml and 5.7±2.9 Log CFU/ml, respectively. The frequent species of B. bifidum, B. longum, B. breve and B. dentium were found in women with BV, while healthy women harbored B. bifidum, B. longum and B. breve. All vaginal bifidobacteria from BV and healthy subjects were able to adhere cultured cells in vitro. The adhesion ability of B. bifidum and B. dentium from BV subjects showed high degree of adhesion property and was in correlation with cell surface characteristics. Conclusion: The prevalence of vaginal bifidobacteria occurred significantly higher in women with BV than healthy group. The strains of B. bifidum and B. dentium showed high adhesion property which implied as an important role of colonization in vaginas of women with BV.

Purification, Characterization, and Optimum Conditions of Fermencin SD11, a Bacteriocin Produced by Human Orally Lactobacillus fermentum SD11.

Fermencin SD11, a bacteriocin produced by human orally Lactobacillus fermentum SD11, was purified, characterized, and optimized in conditions for bacterial growth and bacteriocin production. Fermencin SD11 was purified using three steps of ammonium sulfate precipitation, gel filtration chromatography, and reverse-phase high-performance liquid chromatography. The molecular weight was found to be 33,000 Da using SDS-PAGE and confirmed as 33,593.4 Da by liquid chromatography-mass spectrometry. Fermencin SD11 exhibited activity against a wide range of oral pathogens including cariogenic and periodontogenic pathogens and Candida. The active activity was stable between 60 - 80 °C in a pH range of 3.0 to 7.0. It was sensitive to proteolytic enzymes (proteinase K and trypsin), but it was not affected by α-amylase, catalase, lysozyme, and saliva. The optimum conditions for growth and bacteriocin production of L. fermentum SD11 were cultured at acidic with pH of 5.0-6.0 at 37 or 40 °C under aerobic or anaerobic conditions for 12 h. It is promising that L. fermentum SD11 and its bacteriocin may be an alternative approach for promoting oral health or prevention of oral diseases, e.g., dental caries and periodontitis, which would require further clinical trials.

Virulence of Aggregatibacter actinomycetemcomitans serotypes and DGGE subtypes isolated from chronic adult periodontitis in Thailand.

A high proportion of non-serotypeable isolates of Aggregatibacter actinomycetemcomitans among Thai periodontitis cases has been previously reported. The aim of this study was to investigate the expression of leukotoxin and toxicity, cytolethal distending toxin (Cdts), and internalization and the killing effect on fibroblasts by A. actinomycetemcomitans subtypes from Thai chronic periodontitis cases. A total of 96 A. actinomycetemcomitans strains from 37 periodontitis cases, previously serotyped with PCR and subtyped with DGGE, were examined for the presence of the ltx gene and cdt genes (cdtBC), and tested for leukotoxin expression, leukotoxicity, internalization, and apoptosis of fibroblast cells. The ltx gene was present in all isolates, while 84.4% showed the cdtBC gene. Two strains with a JP2-like ltx gene with a deletion of 530 bp in the promoter region, serotyped as c, showed virulence of similar magnitude to the JP2 strain. Furthermore, a higher virulence was found in the two non-serotypeable DGGE subtypes, NS1 and NS2, compared with the serotypeable strains (serotype a-f, serotype b and d were absent). Generally, the virulence of strains obtained from deep periodontal pockets was higher than those isolated from shallow non-bleeding pockets. A. actinomycetemcomitans subtypes isolated from adult Thais with chronic periodontitis showed a highly variable virulence, leukotoxin expression, leukotoxicity, internalization and apoptosis of fibroblast, and are regulated both genetically and environmentally.

Aggregatibacter actinomycetemcomitans serotypes and DGGE subtypes in Thai adults with chronic periodontitis.

OBJECTIVE: To investigate the distribution of Aggregatibacter actinomycetemcomitans serotypes and DGGE subtypes among isolates from Thai chronic periodontitis patients. DESIGN: Forty-four adult Thai periodontitis patients were assessed by a full mouth recording for CAL, PPD, and BOP. Seventy-nine strains of A. actinomycetemcomitans were isolated from deep pockets on selective TSBV agar and 17 strains were isolated from shallow pockets. The strains were serotyped using PCR and subtyped using DGGE. RESULTS: The prevalence of A. actinomycetemcomitans was 84.1%. Non-serotypeable A. actinomycetemcomitans strains occurred equally frequent as serotypeable (54.5%); serotype a 18.2%, serotype c 15.9%, serotype e 9.1%, and serotype f 11.4%. Serotype b and d were not detected. A JP2 like strain but serotyped as c was isolated from two patients, and another two strains showed an 886bp insertion on the ltx promoter of their A. actinomycetemcomitans isolates. DGGE typing disclosed 16 different subtypes among the non-serotypeable strains. Two of them (NS1 and NS2) were more common (12.7 and 10.1%) among the strains than the other 14 subtypes (˂5.1%). Most patients showed only one subtype (32.4%) but 29.7% had 2 and 3 different subtypes while 8.1% revealed 4 subtypes in one and the same deep pocket. CONCLUSION: This study showed a greater subtype diversity of A. actinomycetemcomitans predominated by non-serotypeable strains than previously reported in an adult Thai population. It was also revealed for the first time that isolates with a 530bp deletion or 886bp insertion of the ltx promoter were serotyped as serotype c.

Enhancement of salivary human neutrophil peptide 1-3 levels by probiotic supplementation.

BACKGROUND: Probiotic supplementation can reduce mutans streptococci (MS) numbers. One of its proposed mechanisms is immunomodulation. Salivary human neutrophil peptide 1-3 (HNP1-3) levels have previously been demonstrated to be higher in caries-free than in caries-susceptible children, suggesting their preventive role against caries. We aimed to compare salivary HNP1-3 levels between an intervention group with probiotics and a control group. METHODS: A randomized double-blinded clinical trial was conducted. Sixty schoolchildren were equally allocated to either an intervention or control group. The use of a probiotic strain, Lactobacillus paracasei SD1, has shown to reduce MS numbers in volunteers. In unstimulated whole saliva, HNP1-3 levels were assayed by ELISA, and MS and lactobacilli counts were assayed by colony counting at baseline (T0) and at 3 (T3), 6 (T6), and 12 months (T12). The International Caries Detection and Assessment system was used to assess caries status. RESULTS: In the intervention group, salivary HNP1-3 levels were significantly greater than those in the control group at T3 and T6 (p < 0.001), whereas MS counts were significantly decreased (p < 0.01). In the intervention group, positive and negative correlations were found between HNP1-3 levels and lactobacilli counts and between MS and lactobacilli counts, respectively. However, there was no significant correlation between enhanced HNP1-3 levels and decreased MS numbers. The caries increment for the pit and fissure surface, but not for the smooth surfaces, was significantly decreased in the intervention group compared with the control group (p = 0.01). CONCLUSIONS: Probiotics can temporarily enhance salivary HNP1-3 levels; however, their action to reduce new pit and fissure caries probably involves microbial interactions. TRIAL REGISTRATION: TCTR20130904001 (registration date: September 04, 2013).

Effect of Long-Term Consumption of Lactobacillus paracasei SD1 on Reducing Mutans streptococci and Caries Risk: A Randomized Placebo-Controlled Trial.

BACKGROUND: A previous study revealed Lactobacillus paracasei SD1, a probiotic strain, could reduce mutans streptococci (MS). The aim of this study was to evaluate the long-term effects of L. paracasei SD1 on the colonization of MS, and whether caries lesions developed. METHODS: After informed consent, 122 children were recruited and randomly assigned to the probiotic or control groups. The probiotic group received milk-powder containing L. paracasei SD1 and the control group received standard milk-powder once daily for six months. Salivary MS and lactobacilli were enumerated using differential culture at baseline and at three-month intervals for 12 months. The persistence of L. paracasei SD1 was investigated using AP-PCR for DNA-fingerprinting. Oral health was examined at baseline and at the end of the study according to WHO criteria. RESULTS: The long-term consumption could prolong colonization of L. paracasei SD1. Significantly reduced MS counts and increased lactobacilli levels were found among children in the probiotic group. There were less caries lesions in the probiotic group at the end of the study. A significant reduction of the development of new caries lesions (4.5 times) was observed in the high caries risk group but not in the low caries risk group. CONCLUSIONS: Results demonstrate that the long-term daily ingestion of the human-derived probiotic L. paracasei SD1 significantly reduces the number of MS and caries risk in the high caries group.

Lactobacillus paracasei SD1, a novel probiotic, reduces mutans streptococci in human volunteers: a randomized placebo-controlled trial.

OBJECTIVES: The present study investigates the effect of an oral Lactobacillus paracasei SD1 isolate on a number of salivary mutans streptococci, lactobacilli, and yeasts and to examine whether the strain could persist in the oral cavity after a short period of consumption. The potential side effect of the probiotic was also evaluated. MATERIAL AND METHODS: After informed consent, 40 healthy young adults were recruited and randomly assigned to either the test (A) or placebo (B) groups. Group A received milk powder contained L. paracasei SD1, and group B received standard milk powder once daily for 4 weeks. Salivary mutans streptococci, lactobacilli, and yeasts were enumerated using quantitative differential culture at the baseline and then once a week for 4 weeks after the administration period. The persistence of L. paracasei SD1 was also investigated using AP-PCR for the DNA fingerprinting. RESULTS: A statistically significant reduction in mutans streptococci counts occurred within group A compared to the baseline B (P < 0.05) along with a non-statistically significant reduction in yeast counts. A significant increase in lactobacilli numbers occurred in group A (P < 0.05), and the probiotic strain could be detected up to 4 weeks following cessation of dosing. CONCLUSIONS: Our results demonstrate that short-term daily ingestion of the human-derived probiotic L. paracasei SD1 reduces the number of oral mutans streptococci. CLINICAL RELEVANCE: L. paracasei SD1 may help to decrease the risk of dental caries, and this organism may be a useful probiotic organism for dairy products.

Prevalence of lactobacilli in normal women and women with bacterial vaginosis.

OBJECTIVE: To study the prevalence and the number of lactobacilli in normal subjects and in women with bacterial vaginosis (BV). MATERIAL AND METHOD: The studied subjects consisted of 60 normal and 60 BV women. The diagnosis of BV was based on at least three of five indicators of Chandeying criteria. The vaginal specimens were collected and cultured on MRS plates for determination of lactobacilli counts. RESULTS: The number of lactobacilli was highly significant (p < 0.001) in the women with diagnosis of BK and the mean count of lactobacilli in BV was markedly decreased (5.3 +/- 1.8 log colony-forming unit--CFU/ml), compared with normal women (8.8 +/- 2.9 log CFU/ml). Among the treated BV group, follow-up vaginal specimen was encountered in 47 of 60 cases (78.3%). The proportion of lactobacilli isolation was slightly increased from 12 (25.5%) to 15 (31.9%) in 47 cases. Concordance with quantitative settlement of lactobacilli in BV was increased from 1.4 +/- 2.6 log CFU/ml, to 1.8 +/- 2.9 log CFU/ml in treated BV. Treated BV the lactobacilli had not restored significance (p = 0.5831), as well as the total bacteria. CONCLUSION: Lactobacilli dominantly occur in healthy women, and markedly decline in BV. However, the vaginal ecosystem is dynamically changed in the lactobacilli of either normal or BV women.

Vertical transmission of mutans streptococci and lactobacillus in Thai families.

PURPOSE: The purpose of this study was to investigate the vertical transmission of mutans streptococci (MS) and lactobacilli in a group of Thai families. METHODS: One hundred eighty-one mother-child pairs were included in this study. Unstimulated saliva was collected using the spatula method and counted for evaluating the number of MS and lactobacilli on a selective medium. Genotyping of MS and Lactobacillus species were performed in 37 and 22 child-mother pairs, respectively. Typically, 3 to 4 isolates of MS and/or Lactobacillus strains from each mother and child were collected for genotyping by an arbitrarily primed polymerase chain reaction (OPA-02 primer for MS and enterobacterial repetivive intergenic consensus primers for Lactobacillus species). RESULTS: Generally, MS and lactobacilli levels in children were associated with their mothers' levels. Genotyping of most isolates of MS and Lactobacillus strains in both mothers and children found diversity, and each individual showed a distinct genotypic pattern. The presence of matching genotypes of MS and Lactobacillus strains of mother-child was approximately 76% and 50%, respectively. The genotypes acquired from the maternal route show effective persistence in the children's oral cavities. CONCLUSIONS: In Thai families, mothers can be the source for transmission of mutans streptococci and Lactobacillus strains to their children.

Acid production and growth by oral Lactobacillus species in vitro.

AIM: To analyze the acid-producing and growth abilities of different oral Lactobacillus species. METHODS: Thirty-nine oral clinical strains and type strains of Lactobacillus, representing nine species, including Lactobacillus casei/paracasei, Lactobacillus fermentum, Lactobacillus gasseri, Lactobacillus mucosae, Lactobacillus oris, Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacillus salivarius, and Lactobacillus vaginalis were studied. Anaerobically-grown bacterial cells were inoculated overnight in de Man, Rogosa, and Sharpe broth containing 2% glucose (pH 7.0). Acid production and growth were measured at 0, 1.5, 3, 5, 7, and 24 h. RESULTS: Lactobacillus salivarius, Lactobacillus rhamnosus, Lactobacillus casei/paracasei, and Lactobacillus plantarum grew rapidly and reached an optical density higher than other species. They also produced more acid than the others. Lactobacillus vaginalis showed the lowest rate of growth and acid production. These findings demonstrated that the different species of Lactobacillus showed different abilities to generate acid, allowing the species to be categorized into three groups: strongly, moderately, and weakly acidogenic. CONCLUSION: There was variation in acid production and growth between the Lactobacillus species. The strongest acid producers were Lactobacillus salivarius, Lactobacillus rhamnosus, Lactobacillus plantarum, and Lactobacillus casei/paracasei, respectively. It seems possible that these species might play a more important role in caries development than the others.