Lactobacillus Research Articles

Growth Kinetics of Kefir Biomass: Influence of the Incubation Temperature in Milk

Kefir is a fermented milk that can be produced from kefir grains or industrial starter cultures. It differs from other fermented milks by the performance of various types of microorganisms on the milk components. The kefir grains are gelatinous and irregular, formed by a set of microorganisms, such as yeasts and lactic acid bacteria, which are incorporated in a matrix of polysaccharides called kefiran. Lactobacilli make up most of the microbial population, but the total composition of the grains is not fully elucidated. There are few studies that evaluated the kinetics of kefir biomass growth at different temperatures, but the exact behavior was not explained in a consistent form, such as using mathematical models. In this context, this work aimed to improve the procedure of kefir production by studying the kinetics of the growth of kefir biomass in milk at different temperatures (298, 303 and 308 K) and characterize it by Scanning Electron Microscopy (SEM). Furthermore, the application of mathematical models to determine the growth function of the kefir biomass in relation to the time and temperature of the fermentation process was evaluated. An amount of 2% kefir grains was added to the milk and the fermentation process was carried out at 298, 303 and 308 K for 5 days. The biomass growth (increase in mass) was evaluated daily and four different mathematical models (Richards, Logistic, Gompertz and Quadratic) were applied to the data. The samples were visualized in a double-beam scanning electron microscope. The Gompertz model showed the highest values ??of the coefficient of correlation (R², 0.97-0.99) and the smallest standard deviations for the increase in the kefir grain biomass, being considered the most appropriate mathematical model. The temperature of 298 K was the most suitable for the incubation of the grains in milk, resulting in a higher increase in the biomass and a larger quantity of lactobacilli, coccus-like bacteria and yeast observed in the SEM. It can be concluded that 298 K may be used as the temperature for fermentation of kefir grains in milk, resulting in higher kefir biomass, which could be useful in the production of kefir fermented milks, because of the reduction in the processing time.

Effect of Lactobacillus delbrueckii fermented supernatant on Candida albicans biofilm formation

Objective To investigate the effect of Lactobacillus delbrueckii fermented supernatant on Candida albicans biofilm and explore its possible mechanism and effective components. Methods Lactobacillus delbrueckii was isolated from vaginal Lactobacillus capsules (Ding Junsheng) and identified by mass spectrometer and sequencing. Lactobacillus delbrueckii fermented supernatant was prepared. The effect of Lactobacillus delbrueckii fermented supernatant on Candida albicans biofilm was tested by microplate crystal violet staining method and catheterization tube modeling method. Biofilm morphological changes were analyzed by crystal violet staining and Live/Dead fluorescent dyes. Exopolysaccharides of Candida albicans biofilm was measured by the sulphruic acid-phenol method. The effect of Lactobacillus delbrueckii fermented supernatant on the adherence of Candida albicans biofilm was tested by the method of colony counting on plate. The fermented supernatant was treated with NaOH, catalase, typsin and proteinase K respectively. Then the treated fermented supernatant′s effect on Candida albicans biofilm formation was detected. One-way ANOVA or Wilcoxon Rank Sum Test was used as statistical analysis for quantitative data. Results Lactobacillus delbrueckii was successfully isolated and identified from Ding Junsheng. Lactobacillus delbrueckii fermented supernatant could significantly and dose-dependantly inhibited the formation of Candida albicans biofilm(F=10.804, P=0.000). The morphological changes showed that the fermented supernatant could decrease the formation of biofilm. When treated with Lactobacillus delbrueckii fermented supernatant, Candida albicans biofilm expolysaccharides was significantly inhibited (F=17.140,P=0.000) and adherence ability was reduced. Compared to untreated fermented supernatant (A490=0.486±0.112), the biofilm inhibition effect of fermented supernatant treated with NaOH (A490=0.675±0.095), catalase (A490=0.577±0.118), typsin (A490=0.600±0.044) and proteinase K (A490=0.495±0.084) only decreased slightly, but when compared to the control group (A490=1.079±0.158), the treated fermented supernatant still showed significant biofilm inhibition effect (χ2=26.052, P=0.000), which suggested that the effective components of fermented supernatant were organic acid and bacteriocin-like substance. Conclusions Lactobacillus delbrueckii fermented supernatant can effectively inhibit Candida albicans biofilm formation. The action mechanisms are related with expolysaccharides decreasement and adherence reduction. The function components of fermented supernatant are possibly organic acids and bacteriocin-like substance. Key words: Candida albicans; Biofilms; Bacterial adhesion; Lactobacillus delbrueckii; Fermentation

Lactobacillus for Acute Gastroenteritis: Unfortunately, It Doesn't Work

In a randomized, controlled, double-blind trial, researchers in Poland evaluated the efficacy of the probiotic Lactobacillus reuteri for treatment of

Change in Vaginal Flora as Indicated by Pap Smear (Schröder’s Classification) in Women Using Levonorgestrel-Releasing Intrauterine System “Mirena”—Prospective Cohort Study

Background: The use of intrauterine device alters the normal balance between vaginal flora. It might change cervicovaginal environment, which was suggested to increase the risk for vulvovaginitis. It was found that up to 85% of levonorgestrel-releasing intrauterine system users become amenorrheic 4 months after insertion, or bleed only sporadically. It was hypothesized that this would have a beneficial effect on vaginal flora maintaining normal balance. Objectives: The aim of this study was to detect the effect of hormonal intrauterine system (“Mirena”: 20 microgram/24 hours intrauterine delivery system Levonorgestrel) on vaginal flora by using pap smear before and 6 months after insertion. Study design: A prospective cohort study was carried out in a university maternity hospital. 210 subjects were included with pap smear taken at time of insertion of IUS “Mirena” and another one taken 6 months later to detect percentage of incidence of infection in IUS users. Vaginal flora was studied, and lactobacilli were graded according to Schr?der’s classification. A comparison was made to allow detection of changes in vaginal flora caused by presence of hormonal IUS “Mirena”. Results: Over half of cases (57.2%) showed worse vaginal flora after hormonal IUS “Mirena” insertion than before. There was a highly statistically significant difference between Schr?der’s Grades before and after insertion (P value < 0.001) as 44.8% of cases presented by Grade I, 44.4% of cases presented by grade IIa, 38% of cases presented by grade IIb before insertion developed Grade III after insertion. Conclusion: Insertion of hormonal IUS “Mirena” results in significant change in microbial flora towards pathological bacteria.

Progress in lactic acid-mediated maintenance of healthy vaginal microecology

Lactic acid is the main substance produced by Lactobacillus and plays an important role in maintaining a healthy vaginal microecology. Recent studies indicates that both L- and D-chiral isomers of lactic acid can be protonated and destroy the cell membranes of pathogens, thereby inhibiting bacterial vaginosis- and aerobic vaginitis-related pathogens. Lactic acid also can inhibit the pathogens of sexually transmitted diseases such as Chlamydia trachomatis and human immunodeficiency virus. Moreover, lactic acid acts as an immunomodulator to inhibit the inflammatory responses caused by pathogenic microorganisms and as an epigenetic regulator regulating gene expression in vaginal epithelial cells. In this paper, we reviewed the progress in lactic acid-mediated maintenance of a healthy vaginal microbiology in recent years for providing reference for further research. Key words: Lactobacillus; Lactic acid; Pathogen; Immunomodulator; Vaginal microecology

Enzymatic Monolith Continuous Microreactors for the Synthesis of Xylooligosaccharides by Controlled Hydrolysis of Xylans

Immobilized enzymes are increasingly used in enzymatic microreactors, to encourage applications in different fields: food industry, medical diagnostics, organic synthesis, drug discovery, biosensors. As a matter of facts, microfluidic systems offer many advantages over conventional packed-bed bioreactors, such as higher efficiency, feasibility of multi-enzyme systems, higher mechanical stability, reduced amounts of reagents required [Pirozzi et al., 2016].In this study s-1,4-xylan obtained from hemicelluloses was used to obtain xylo-oligosaccharides (XOS), the only nutraceutical that can be produced from lignocellulosic biomass. XOS are considered non-digestible food ingredients, and their prebiotic effect of XOS on Bifidobacterium and Lactobacillus species has been recently demonstrated [Aachary et al., 2011; Broekaert et al., 2011; Nacos et al., 2006; Samanta et al, 2015; Vazquez]et al., 2000]. In addition XOS are stable at wide range of pH (2.5–8.0) and temperature (100 °C), they can stimulate the selective growth of the gut microflora, reduce the blood glucose and cholesterol, reduce the pro-carcinogenic enzymes in gastrointestinal tract, and enhance the mineral absorption from large intestine [Aachary et al., 2011; Broekaert et al., 2011; Nacos et al., 2006; Samanta et al, 2015; Vazquez]et al., 2000].In this view, sol-gel methods were used for the physical entrapment of xylanase from T. lanuginosus. Due to the mild conditions usually adopted for the gel synthesis, enzymes could be added to the initial mixture of precursors and so entrapped within monolithic porous layers in capillary tubes [Pirozzi et al., 2016].A suitable combination of sol-gel precursors was found for the simultaneous improvement of the monolith adhesion to the tubing internal surfaces and of the catalytic properties of the entrapped enzymes. Specific attention was devoted to the determination of operating conditions suitable to enhance enzyme stability as well as selectivity in terms of XOS produced.

Analysis of the efficacy of lactobacillus vaginalis capsule in the treatment of senile vaginitis

Objective To explore the effect of lactobacillus vaginal capsule in the treatment of senile vaginitis. Methods From January 2017 to February 2018, 100 elderly patients with vaginitis in the Second People's Hospital of Haining were selected in the study. They were randomly divided into observation group and control group according to the digital table, with 50 cases in each group. The observation group was treated by lactobacillus vagina capsule, and the control group was treated by compound metronidazole suppository. The clinical effects of the two groups were compared. Results The total effective rate of the observation group (96.00%) was significantly higher than that of the control group(76.00%), the difference was statistically significant(χ2=12.547, P 0.05], and there were statistically significant differences in vaginal pH of the two groups before and after treatment(t=8.204, 5.112, all P<0.05), the vaginal pH of the observation group after treatment was significantly lower than that of the control group, the difference was statistically significant[(4.49±0.11) vs. (5.76±0.37), t=5.024, P<0.05]. In the observation group, only 1 case had recurrence at 2 months after treatment, and no recurrence was observed at 3 months and 6 months after treatment, the recurrence rate was 2.00%. In the control group, there were 2 cases, 4 cases, 6 cases had recurrence at 2 months, 3 months and 6 months after treatment, and the recurrence rate was 24.00%. The recurrence rate of the observation group was significantly lower than that of the control group (χ2=25.634, P<0.05). Conclusion Lactobacillus vaginal capsule in the treatment of senile vaginitis has curative effect is distinct, the recurrence rate is low, also the use process is very simple, has high clinical application value. Key words: Vaginitis; Lactobacillaceae; Capsules; Metronidazole; Suppository; Recurrence; Comparative effectiveness research; Aged

Influence of black tea on Streptococcus mutans and Lactobacillus levels in saliva in a Saudi cohort.

ObjectivesDental caries are associated with high counts of Streptococcus mutans (SM) and Lactobacillus (LB) and low saliva buffering capacity (BC). This study aimed to evaluate the antimicrobial activity of black tea on salivary cariogenic microflora, SM and LB species in an adult population. Antimicrobial activity was measured from the number of colony forming units (CFUs) of SM and LB, and BC of saliva.MethodsIn this prospective experimental study, unstimulated saliva samples were acquired from the participants before, immediately after, and 1 h after drinking tea by collecting saliva in sterilised containers. Samples were taken to the laboratory for incubation and subsequent counting. SM and LB counts and BC of saliva were calculated using the caries risk test (CRT).ResultsA total of 21 participants, 13 males and 8 females, with a mean age of 32.6 ± 8.02, were recruited in this study. Black tea had no significant effect on reducing the cariogenic bacterial counts (p > 0.05).ConclusionBased on this study, it can be deduced that black tea exhibits an insignificant antimicrobial effect against Streptococcus mutans and Lactobacillus bacteria.

Characteristics of microbiota of colonic lavage fluid from patients with diarrhea-predominant irritable bowel syndrome

Objective To investigate the characteristics of the microbiota of colonic lavage fluid from patients with diarrhoea-predominant irritable bowel syndrome (D-IBS). Methods From August 2014 to March 2015, at the Department of Gastroenterology Shanxi Provincial People′s Hospital, 39 patients with D-IBS were enrolled and during the same period 39 patients with self-reported symptoms such as occasional abdominal discomfort or abdominal pain but were excluded from the diagnosis of irritable bowel syndrome (IBS) were selected as control group. The colonic mucosal tissues and colonic lavage fluid of two groups of patients were collected. DNA was extracted from tissues and colonic fluid. Ten dominant bacteria, including Bacteriodes prevotella, Bacteroidetes, Clostridium, Bifidobacterium, Dialister pneumosintes, Enteropathogenic Escherichia coli, Faecalibacterium prausnitzii, Firmicutes, Lactobacillus and Salmonella, were analyzed by real-time fluorescence quantitative polymerase chain reacticn (RT-PCR). T test and Spearman correlation analysis were performed for statistical analysis. Results The numbers of Bacteriodes prevotella in colonic lavage fluid and the descending colon mucosal tissues of patients in D-IBS group were 3.096±1.462 and 4.278±0.290, respectively, which were lower than those of control group (4.842±1.032 and 5.341±0.433, respectively), and the differences were statistically significant (t=6.093 and 12.657, both P<0.01). Correspondingly, the numbers of Bacteroidetes were 3.259±0.607 and 3.698±0.554, respectively, which were lower than those of control group (4.085±0.504 and 4.339±0.263, respectively), and the differences were statistically significant (t=6.538 and 6.528, both P<0.01). The numbers of Clostridium were 5.254±0.522 and 4.471±0.690, which were lower than those of control group (5.949±0.505 and 4.950±0.604, respectively), and the differences were statistically significant ( t=5.976, P<0.01; t=3.262, P=0.002). The number of Faecalibacterium prausnitzii from colonic lavage fluid of patients in D-IBS group was 2.238±1.845, which was lower than that of control group (3.222±1.450), and the difference was statistically significant (t=2.619, P=0.011). The Firmicutes (r=0.678, P=0.012), Lactobacillus (r=0.358, P=0.034), Bifidobacterium (r=0.418, P=0.042) and Faecalibacterium prausnitzii (r=0.568, P=0.022) from colonic mucosal tissues were all positively correlated with those from colonic lavage fluid. However, Salmonella (r=-0.638, P=0.012) and Enteropathogenic Escherichia coli (r=-0.343, P=0.025) were negatively correlated with those from mucosal tissues. Conclusions An imbalance of the microbiota in colonic lavage fluid is found in D-IBS patients. The numbers of Bacteriodes prevotella, Bacteroidetes, Clostridium and Faecalibacterium prausnitzii significantly decrease. Key words: Irritable bowel syndrome; Colonic lavage fluid; Microbiota

414 - Impact of Lactobacillus probiotics on biofilm formed by Pseudomonas aeruginosa

414 - Impact of Lactobacillus probiotics on biofilm formed by Pseudomonas aeruginosa

Probiotics Did Not Enhance Iron Absorption in Iron-Deficient Children

Whether lactobacillus enhances therapy for iron deficiency in children is unknown. Investigators conducted a randomized, controlled trial comparing

Effect of temperature stress treatment of Lactobacillus plantarum K25 on the quality of fermented ice cream and survival of the strain.

Effect of temperature stress treatment of Lactobacillus plantarum K25 on the quality of fermented ice cream and survival of the strain.

Salivary characteristics and dental caries experience in remote Indigenous children in Australia: a cross-sectional study

BackgroundWhile associations between salivary characteristics and dental caries have been well studied, we are not aware of this being assessed in a remote Indigenous child population, where lifestyles may be different from urban children. Our aim was to assess associations between caries experience and putative biomarkers in saliva, accounting for oral hygiene and dietary habits.MethodsChildren attending schools in an Indigenous community in remote north Queensland, Australia were invited to an oral examination by qualified and calibrated examiners. Salivary flow rate, pH, buffering capacity and loads of mutans streptococci (MS), lactobacilli (LB) and yeasts were determined. Also, data on tooth brushing frequency and soft drinks consumption were obtained via a questionnaire. Caries experience was recorded by the International Caries Detection and Assessment System (ICDAS-II), and quantified as decayed, missing and filled surfaces. Relationships between the salivary variables and the cumulative caries experience (dmfs+DMFS) in the deciduous and permanent dentitions were examined by multivariate analyses to control the effect of confounders.ResultsThe mean cumulative decayed (DS + ds), missing (MS + ms) and filled (FS + fs) surfaces were 3.64 (SD: 4.97), 1.08 (4.38) and 0.79 (1.84) respectively. Higher salivary MS and LB counts, low tooth brushing frequency and daily soft drink consumption were significantly related to greater caries experience. Caries experience was about twice in those with ≥10^5 CFU/ml saliva counts of MS (mean = 6.33, SD: 8.40 vs 3.11, 5.77) and LB (7.03, 7.49 vs 4.41, 8.00). In the fully-adjusted multivariate model, caries experience in those with higher counts of MS and LB were 51 and 52% more than those with lower counts.ConclusionsAs with studies in other populations, childhood salivary counts of MS and LB were significantly associated with greater caries experience in this remote Indigenous community. To address the serious burden of oral disease, we are researching ways to promote a healthy oral environment by encouraging good dietary habits, and emphasising the importance of daily tooth brushing with a fluoridated toothpaste. Our ongoing longitudinal studies will indicate the success of measures employed to reduce the counts of bacteria closely associated with cariogenesis and their impact on caries increment.Trial registrationAustralian New Zealand Clinical Trials Registry (ANZCTR), No: ACTRN12615000693527; date of registration: 3rd July 2015.

Antibacterial efficacy of green tea mouth rinse in children with early childhood caries

Purpose Of this study was to compare the antimicrobial efficacy of green tea (0.5%) mouth rinse to that of chlorhexidine (CHX) (0.125%) against Streptococcus mutans and Lactobacilli spp. Participants and methods Forty-two children had early childhood cairns were recruited in this study, and randomly divided, using lottery method, into three groups; group A: children using green tea mouthwash; group B: children using CHX (0.12%) mouthwash; group C: children using colored flavored nonsweetened tape water. They were instructed to rinse the mouth for 1 min using 5 ml of the respective mouth rinse 30 min after the tooth brushing for 2 weeks. A volume of 2 ml saliva samples were collected prior to the commencement of mouth rinsing, and after 2 weeks rinsing, data were collected and statistically analyzed. Results Revealed both CHX and green tea mouth rinses showed a statistically significant fall in the colony counts of S. mutans and Lactobacilli spp. (P < 0.001 and <0.001), while in the third group not statistically significant (P = 0.003 and 0.183) for S. mutans and Lactobacilli spp., respectively). When the antimicrobial efficacy of CHX and green tea was evaluated against both S. mutans and Lactobacillus spp., no statistically significant difference was found (P = 0.462 and 0.824, respectively).

The In-vitro Antiviral Activity of Lactobacillus casei MCJ Protein-based Metabolites on Bovine Viral Diarrhea Virus

Bovine viral diarrhea virus (BVDV) is a ubiquitous immunosuppressive etiological agent that is economically important for a wide host range in the livestock industry. Lactobacillus spp. has widely been using in the field of management and treatment of gastro-enteric disease for both human and animal. The ability of Lactobacillus casei MCJ (L. casei) protein-based metabolized (LPM) to suppress BVDV infection in Madin-Darby Bovine Kidney (MDBK) cell line was demonstrated in this study. The protein-based metabolites were extracted from the cultured L. casei to obtain the safest and beneficial form of the probiotic bacteria. The results of cytotoxicity test reveal that LPM has no cytotoxic effect and the cell viability remains more than 80% even after the cells are treated with 3000 μg/mL of LPM. In comparing positive control, 3000 μg/mL concentration of LPM reduced plaque formation by 73.45% whereas 1000, 100 and 10 μg/mL reduced 65.95%, 39.67% and 4.02% consecutively. The results of plaque formation unit (pfu) assay showed that LPM can reduce the viral infection rate. To know the mechanism of LPM for anti-BVDV activity, MDBK cells were exposed to LPM before, after and co-incubation of virus infection. The co-treatment of LPM with BVDV revealed the best results for the decreased viral protein expression by Western blot, RNA copy number by Quantitative real-time PCR and fewer BVDV infected cells by Immunofluorescences assay. The results suggest that the LPM has a potential anti-BVDV activity which could be a prospective application for the prevention and control of BVDV infection in animal.

Abincol® (Lactobacillus plantarum LP01, Lactobacillus lactis subspecies cremoris LLC02, Lactobacillus delbrueckii LDD01), an oral nutraceutical, pragmatic use in patients with chronic intestinal disorders.

Chronic intestinal disorders (CID), including inflammatory bowel disease (IBD), such as ulcerative colitis and Crohn’s disease, irritable bowel syndrome (IBS), and diverticular disease (DD), are diseases that relapse episodes. There is evidence that patients with CID have intestinal dysbiosis, so probiotics may counterbalance the impaired microbiota. Therefore, the current survey evaluated the efficacy and safety of Abincol®,an oral nutraceuticalcontaining a probiotic mixture with Lactobacillus plantarum LP01 (1 billion of living cells), Lactobacillus lactis subspecies cremoris LLC02 (800 millions of living cells), and Lactobacillus delbrueckii LDD01 (200 millions of living cells), in 3,460 outpatients (1,660 males and 1,800 females, mean age 55 years) with chronic intestinal disorders. Patients took 1 stick/daily for 8 weeks. Abincol® significantly diminished the presence and the severity of intestinal symptoms and improved stool form. In conclusion, the current survey suggests that Abincol® may be considered an effective and safe therapeutic option in the management of patients with chronic intestinal disorders. (www.actabiomedica.it)

Lactobacillus plantarum LP01, Lactobacillus lactis subspecies cremoris LLC02, and Lactobacillus delbrueckii LDD01) in patients undergoing bowel preparation.

Bowel preparation (BP) for colonoscopy induces significantly changes in gut microbiota and elicit intestinal symptoms. Impaired microbiota causes an intestinal dysbiosis. Consequently, probiotics may counterbalance the disturbed microbiota after BP. The current survey evaluated the efficacy and safety of Abincol®,an oral nutraceuticalcontaining a probiotic mixture with Lactobacillus plantarum LP01 (1 billion of living cells), Lactobacillus lactis subspecies cremoris LLC02 (800 millions of living cells), and Lactobacillus delbrueckii LDD01 (200 millions of living cells), in 2,979 outpatients (1,579 males and 1,400 females, mean age 56 years) undergoing BP. Patients took 1 stick/daily for 4 weeks after colonoscopy. Abincol® significantly diminished the presence and the severity of intestinal symptoms and improved stool form. In conclusion, the current survey suggests that Abincol® may be considered an effective and safe therapeutic option in the management of patients undergoing BP. (www.actabiomedica.it)

Post-surgical intestinal dysbiosis: use of an innovative mixture (Lactobacillus plantarum LP01, Lactobacillus lactis subspecies cremoris LLC02, Lactobacillus delbrueckii LDD01).

Abdominal surgery represents a high risk for hospital-acquired infections and complication that may compromise the surgery outcome. Patients with recent abdominal surgery have an intestinal dysbiosis. There is evidence that probiotics may counterbalance the impaired microbiota. Therefore, the current survey evaluated the efficacy and safety of Abincol®,an oral nutraceuticalcontaining a probiotic mixture with Lactobacillus plantarum LP01 (1 billion of living cells), Lactobacillus lactis subspecies cremoris LLC02 (800 millions of living cells), and Lactobacillus delbrueckii LDD01 (200 millions of living cells), in 612 outpatients (344 males and 268 females, mean age 58 years) undergoing digestive surgery. Patients took 1 stick/daily for 8 weeks. Abincol® significantly diminished the presence and the severity of intestinal symptoms and improved stool form. In conclusion, the current survey suggests that Abincol® may be considered an effective and safe therapeutic option in the management of patients undergoing digestivesurgery. (www.actabiomedica.it)

Effect of a Daily Dose of Snacks Containing Maltitol or Stevia rebaudiana as Sweeteners in High Caries Risk Schoolchildren. A Double-blind RCT Study.

To evaluate the effect of sugar-free snacks on caries-related factors in 6- to 9-year-old schoolchildren. Two hundred seventy-one children at risk for caries as measured through the Cariogram were randomly assigned to three groups consuming twice-daily snacks containing Stevia, maltitol or sugar for 42 days. Parents filled out a standardised questionnaire regarding personal, medical and oral behavioural information. Bleeding on probing, plaque pH and salivary mutans streptococchi (MS) and lactobacilli (LB) were assessed at baseline (t0), 42 days of snack use (t1) and 120 days after the end of use (t2). The Cariogram calculation was repeated at t1. Treatment effects were estimated using linear mixed-effects regression models. At t2, a decrease in cariogenic bacteria (MS X2 = 8.01, p < 0.01 and LB X2 = 4.60, p = 0.03) and an increase of the minimum pH (F = 4.48, p < 0.01), maximum pH (F = 2.88 p < 0.01) and pH drop (F = 2.95 p < 0.01) was recorded in the Stevia group compared to baseline. In the maltitol group, an improvement effect was noted: LB concentration decreased (p = 0.04) and maximum pH (F = 3.16 p < 0.01) increased. Subjects classified by the Cariogram as have a low probability of developing caries increased in the Stevia and maltitol groups (X2(4) = 25.44, p < 0.01, C*sV = 0.38 and X2(4) = 12.85, p = 0.01, C*sV = 0.27, respectively). Regression analysis underlines the effect of Stevia snacks on the cariogenic microflora, mainly on MS and plaque pH variations. The short-term administration of Stevia or maltitol snacks improves some important factors related to caries. This preventive strategy might be an additional means of combatting this common childhood disease.

Dental Caries and Risk Factors in Swedish Adolescents about to Start Orthodontic Treatment with Fixed Appliances

The aim of this study is to investigate the caries situation in a group of Swedish adolescents, who were scheduled for orthodontic treatment with fixed appliances. An age- and gender-matched control group was selected from the same city (Malmö, Sweden). Caries and fillings on smooth surfaces and fillings on occlusal surfaces were diagnosed clinically and caries and fillings on approximal surfaces by bitewings. Numbers of mutans streptococci (MS) and lactobacilli (LB) were analyzed in saliva. There were no significant differences regarding manifest caries lesions and fillings on smooth surfaces. Numbers of occlusal-filled surfaces (FS) and approximal decayed and filled surfaces were around 10%, but did not differ between the groups. However, 53% had approximal enamel caries lesions in the test group and 46% in the control group. The prevalence of approximal decayed surfaces (DS) and FS was low in both groups, 0.57 ± 1.41 in the test group and 0.65 ± 1.38 in the control group (p > 0.05), i.e., somewhat more DS in the control group (p < 0.05). Most individuals had low/medium counts of cariogenic bacteria in their saliva and less than 10% high counts in both groups. Most Swedish adolescents who have been scheduled for treatment with fixed appliances appear to have a low-to-medium caries risk nowadays. However, around 10% of all approximal tooth surfaces of premolars/molars had enamel caries and one-third of the individuals had medium/high counts of cariogenic bacteria in their saliva, which may be risk factors for future caries during orthodontic treatment. Bitewing radiographs are important before starting orthodontic treatment and approximal caries and many cariogenic bacteria may be risk factors for orthodontic treatment.