Probiotics as oral health biotherapeutics

Utilization of Probiotics Among Dental Students: A KAP Study

Aim

The aim of the study is to know about the awareness of probiotics among undergraduate dental students.

Materials and Methods

We conducted cross-sectional research where we had distributed a questionnaire consisting of ten open-ended questions, among 150 dental students through emails. The questions were based on the utilization of probiotics in dentistry. The data obtained was statistically analyzed with the help of Chi-square test.

Results

In our study, we noted that most of the participants were aware of the term probiotics and had general ideas but were not fully aware of its pathogenesis. Around 83.2% of the participants were aware of probiotics and general concepts. We also noted that only 42.5% of the students agreed that probiotics can be used in the management of halitosis as well as periodontitis.

Conclusion

We concluded that most of the dental students had a lack of awareness as well as were not familiar with the usage of probiotics in dentistry.

Evolving Advances in the Cosmetic use of Probiotics and Postbiotics: Health, Regulatory and Marketing Aspects

Ongoing development in cosmetics is increasingly making use of probiotics, which are defined as "live microorganisms with health-enhancing properties mediated through ingestion or topical application to the host". The observation that several bacterial strains augment normal processes of healthy tissue maintenance, particularly for the skin, has opened up new avenues for the use of bacterial strains in cosmetics. A principal feature of such "cosmeceuticals" is an application of increasing insight into the biochemical nature of the skin's normal microbial flora, also called its microbiome. The opportunity of manipulating the skin microbiome to address various skin disorders has revealed novel routes for treatment. The skin microbiome manipulation approaches to address various skin disorders include skin microbiome transplantation, skin bacteriotherapy, and prebiotic stimulation. Research in this field has revealed that medical outcome-targeted manipulation of skin microbiome bacterial strain makeup may significantly increase skin health and appearance. Commercial availability of probiotic skincare products is rapidly expanding worldwide due to satisfactory laboratory results and public perception of probiotics as being intrinsically more wholesome than other bioactive substances, such as synthetics. Major outcomes of probiotic use include a significant reduction in skin wrinkling, acne and other conditions adversely affecting skin appearance and healthy function. Moreover, probiotics may additionally promote normal skin hydration, resulting in a vibrant and lustrous appearance. Nevertheless, significant technical challenges remain for the full optimization of probiotics in cosmetic products. This article summarizes the evolving nature of this field and explores current probiotic research initiatives, along with regulatory aspects and significant challenges in the manufacturing of cosmetics in the context of market expansion for these products.

The effect of synbiotic-fluoride therapy on multi-species biofilm

OBJECTIVES

The study objective was to examine the effect of synbiotic-fluoride (SF) therapy within a multi-species cariogenic biofilm model system comprising of S. mutans, S. sanguinis, and S. gordonii.

METHODS

The SF therapy was prepared using 2% L-arginine (Arg), 0.2% NaF and probiotic L. rhamnosus GG (LRG). The 8 treatment groups were: Group 1: No treatment, Group 2: 2% Arg, Group 3: 0.2% NaF, Group 4: LRG, Group 5: 2% Arg+0.2% NaF, Group 6: 2% Arg+LRG, Group 7: 0.2% NaF+LRG, and Group 8: SF therapy (2% Arg+0.2% NaF +LRG). Multi-species biofilm model over 96 h comprising Streptococcus mutans, Streptococcus sanguinis, and Streptococcus gordonii was utilized. The biofilms received cariogenic challenge and SF therapy 2 × /day. The extracellular matrix components were analyzed for carbohydrates, proteins, and extra-cellular DNA (eDNA). The live/dead cells were imaged and quantified using confocal microscopy. The viable/dead bacterial concentrations were estimated using propidium monoazide-quantitative polymerase chain reaction (PMA-qPCR). The gene expressions for gtfB, sagP, arcA, argG, and argH were measured using real-time reverse transcriptase qPCR.

RESULTS

Carbohydrates and protein content with SF therapy were higher than non-LRG containing groups, while eDNA content was lower than other groups (p<0.05). Live bacterial proportions determined using confocal imaging with SF therapy were the lowest (p<0.05). The 2% Arg+LRG and SF therapy showed higher viable L. rhamnosus GG than 0.2% NaF+LRG (p<0.05). The dead S. mutans with SF therapy were higher than the other groups (p<0.05) with no difference from 2% Arg+0.2% NaF and 2% Arg+LRG (p>0.05). The SF therapy significantly downregulates gtfB and upregulates sagP, arcA, argG, argH gene expression (p<0.05).

CONCLUSION

Synbiotic-fluoride therapy effectuates multi-fold changes in the multi-species biofilm matrix and cellular components leading to superior ecological homeostasis than its individual contents, prebiotics (arginine), probiotic (L. rhamnosus GG), and fluorides (NaF).

CLINICAL SIGNIFICANCE

The ecological-based synbiotic-fluoride caries-preventive therapy aids in maintaining biofilm homeostasis to preempt/restore dysbiosis thereby sustaining dynamic-diverse health-associated microbial stability significant as a preventive regimen for high caries-risk patients.

A comprehensive review of the application of probiotics and postbiotics in oral health

Oral diseases are among the most common diseases around the world that people usually suffer from during their lifetime. Tooth decay is a multifactorial disease, and the composition of oral microbiota is a critical factor in its development. Also, Streptococcus mutans is considered the most important caries-causing species. It is expected that probiotics, as they adjust the intestinal microbiota and reduce the number of pathogenic bacteria in the human intestine, can exert their health-giving effects, especially the anti-pathogenic effect, in the oral cavity, which is part of the human gastrointestinal tract. Therefore, numerous in vitro and in vivo studies have been conducted on the role of probiotics in the prevention of tooth decay. In this review, while investigating the effect of different strains of probiotics Lactobacillus and Bifidobacteria on oral diseases, including dental caries, candida yeast infections, periodontal diseases, and halitosis, we have also discussed postbiotics as novel non-living biological compounds derived from probiotics.

In vitro assessment of the effect of probiotic lactobacillus reuteri on peri-implantitis microflora

BACKGROUND

Probiotics affect both the development and stability of microbiota by altering the colonization of pathogens and thus helps in stimulating the immune system of the individual. The aim of the present study is to assess the effect of probiotics on peri-implantitis microflora, by determining the minimum inhibitory concentration (MIC) of Lactobacillus reuteri, that can be effectively administered as an antimicrobial agent on specific peri-implantitis pathogens. Hence, this study will be helpful in finding the MIC of L. Reuteri that can be effectively administered as an antimicrobial agent on specific peri-implantitis pathogens.

METHODS

This experimental research was conducted on patients visiting the periodontology department in M. A. Rangoonwala college of dental sciences and research centre. Sub-gingival plaque samples were collected from peri-implantitis patients to identify various peri-implantitis microorganisms. The identified microorganisms were compared to each other and Chi-Square test was used to calculate statistical significance. The isolated microorganisms were subjected to the effect of probiotic Lactobacillus reuteri in-vitro. Minimum inhibitory concentration (MIC) was assessed using serial dilution method.

RESULTS

The research results showed the presence of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Streptococcus salivaris and Staphylococcus aureus in the subgingival samples from peri-implantitis patients. Statistically, significantly higher proportion of samples had Porphyromonas gingivalis. When subjected to the effect of L. reuteri, all the microorganisms were affected by L.reuteri except Aggregatibacter actinomycetemcomitans.

CONCLUSION

This study provides the various MIC value for each isolated pathogen against L.reuteri. The authors recommend to avoid using standard guidelines for probiotic dose in the treatment of peri-implant infections as the antimicrobial profile is different for each periodontal pathogen.

Oral colonization by Levilactobacillus brevis KABPTM-052 and Lactiplantibacillus plantarum KABPTM-051: A Randomized, Double-Blinded, Placebo-Controlled Trial (Pilot Study)

Background

To determine the oral colonization capacity of the strains Levilactobacillus brevis KABPTM-052 (CECT 7480) and Lactiplantibacillus plantarum KABPTM-051 (CECT 7481) in healthy subjects.

Material and Methods

This randomized, double-blinded, placebo-controlled study included 40 volunteers (22 females, 18 males; age range 18-55 years) with healthy gingiva or mild gingivitis, allocated to receiving probiotic chewing gum (n=20) or placebo (n=20) b.i.d for 6 weeks. At baseline and after 6 weeks of treatment, a periodontics specialist collected saliva samples to assess probiotic colonization by qPCR, and analysed dental plaque, gingival index and dental probing pocket depth in Community Periodontal Index (CPI) teeth subset. Protocol was registered as NCT03540498.

Results

Treatment compliance was high (99%). Both L. brevis and L. plantarum were detected in the oral microbiota at baseline. After 6 weeks, volunteers receiving probiotic showed a significant increase of both L. brevis (p = 0.017) and L. plantarum (p = 0.004) versus placebo. This effect remained significant after adjusting for gender and gingival index at baseline. In the probiotic group, reduction in plaque index significantly correlated to higher levels of L. brevis (rho = 0.57, p = 0.022) but not of L. plantarum at study endpoint, and the number of subjects with dental plaque was reduced during intervention (7 of 17, p = 0.016). No such effects were observed in the placebo group. No adverse drug reactions were reported.

Conclusions

Levilactobacillus brevis KABPTM-052 and Lactiplantibacillus plantarum KABPTM-051 colonize the buccal microbiota of healthy volunteers, and higher colonization by L. brevis positively correlated to reduction in dental plaque. 

Key words:Probiotic, Levilactobacillus brevis, Lactiplantibacillus plantarum, oral colonization, oral microbiota, dental plaque.

Effects of Probiotic Culture Supernatant on Cariogenic Biofilm Formation and RANKL-Induced Osteoclastogenesis in RAW 264.7 Macrophages

Postbiotics are a promising functional ingredient that can overcome the limitations of viability and storage stability that challenge the production of probiotics. To evaluate the effects of postbiotics on oral health, eight spent culture supernatants (SCSs) of probiotics were prepared, and the effects of SCSs on Streptococcus mutans-induced cariogenic biofilm formation and the receptor activator of the nuclear factor κB ligand (RANKL)-induced osteoclastogenesis were evaluated in RAW 264.7 macrophages. SCS of Lactobacillus salivarius MG4265 reduced S. mutans-induced biofilm formation by 73% and significantly inhibited tartrate-resistant acid phosphatase (TRAP) activity, which is a biomarker of mature osteoclasts in RAW 264.7 macrophages. The suppression of RANKL-induced activation of mitogen activated the protein kinases (c-Jun N-terminal kinase, extracellular signal-regulated kinase, and p38) and nuclear factor κB pathways, as well as the upregulation of heme oxygenase-1 expression. The suppression of RANK-L-induced activation of mitogen also inhibited the expression of transcriptional factors (c-fos and nuclear factor of activated T cells cytoplasmic 1) and, subsequently, osteoclastogenesis-related gene expression (tartrate-resistant acid phosphatase-positive (TRAP), cathepsin K, and matrix metalloproteinase-9).Therefore, SCS of L. salivarius MG4265 has great potential as a multifunctional oral health ingredient that inhibits biofilm formation and suppresses the alveolar bone loss that is associated with periodontitis.

Weissella cibaria CMU exerts an anti‑inflammatory effect by inhibiting Aggregatibacter actinomycetemcomitans‑induced NF‑κB activation in macrophages

Periodontitis is a chronic inflammatory disease caused by various periodontal pathogens. Weissella cibaria CMU (oraCMU) is a probiotic that promotes oral health. However, its anti‑inflammatory effects against periodontal pathogens have not yet been investigated. The present study evaluated the anti‑inflammatory effects of live oraCMU against stimulation with the formalin‑inactivated periodontal pathogen Aggregatibacter actinomycetemcomitans in RAW 264.7 macrophages. Cell viability was analyzed by the MTS assay in a dose‑dependent manner (at multiplicities of infection of 0.1, 1, 10, 100 and 1,000). Nitric oxide (NO) was monitored using the Griess test. The mRNA expression of proinflammatory cytokines such as interleukin (IL)1β and IL6 was assessed by reverse transcription‑quantitative PCR. Western blotting was used to examine the effects of oraCMU on the phosphorylation of NF‑κB inhibitor α (IκBα) and IκBα kinase (IKK), the nuclear translocation of the NF‑κB subunit p65 and the expression of inducible NO synthase (iNOS). Live oraCMU had no cytotoxic effects on RAW 264.7 macrophages. In A. actinomycetemcomitans‑stimulated RAW 264.7 macrophages, oraCMU reduced NO production by suppressing iNOS expression and downregulating the mRNA expression of proinflammatory cytokines in a dose‑dependent manner. IKK phosphorylation and IκBα degradation were dose‑dependently inhibited by oraCMU and the nuclear translocation of p65 via the canonical NF‑κB pathway was simultaneously reduced. The results indicated that oraCMU possessed anti‑inflammatory activity associated with the inhibition of NF‑κB signal activation in response to periodontal pathogens. This suggests that oraCMU is a beneficial anti‑inflammatory probiotic that can aid in the maintenance of oral health.

Probiotics-A complete oral healthcare package

Probiotics are living bacterial cells that have significant therapeutic potential for treating human infectious diseases. There is a huge market for probiotics in the pharmaceutical sector. They have been frequently used to treat the gastrointestinal diseases and improve gut immunity. In this review, the strains currently in use for manufacturing oral probiotic formulations are discussed. The review further recommends the use of probiotics for the control of various oral health disorders, like dental caries, periodontitis, gingivitis, halitosis, burning mouth syndrome, and oral cancer. Finally, this review also explores the use of various commercial probiotic products in maintaining oral health, their market values, and government acts and regulations that are relevant to the production and marketing of probiotics. Probiotics have tremendous therapeutic potential and more in-depth research must be done on these beneficial bacteria to make them one of the leading drugs in treating oral disorders.

Effect of a novel synbiotic on Streptococcus mutans

We examined the effect of L-arginine - (i) on the growth of L. rhamnosus GG (LrG) and (ii) combined LrG synbiotic on the growth of cariogenic S. mutans. Viability of LrG was assessed using MTT/XTT assays, confocal imaging with ADS activity measurement. The effect of L-arginine (0.5%/1%/2%) (2×/24 h) with LrG on S. mutans was evaluated by measuring the colony forming units, biofilm biomass, real-time qPCR and confocal imaging. The pH of the spent media was measured immediately and 24 h post-treatment with assessment of lactic acid. The LrG viability was highest with 2% L-arginine (p < 0.001). Confocal imaging showed that 2% L-arginine increased biofilm thickness of LrG. The 2% L-arginine and LrG synbiotic significantly inhibited the growth of S. mutans (p < 0.001) reducing the viable counts (p = 0.002) and biofilm biomass (p < 0.001). The pH of spent media was the highest when treated with 2% L-arginine and LrG synbiotic (p < 0.001) with no difference between post-treatment and 24 h post-treatment (p > 0.05). Conversely, the 2% L-arginine and LrG synbiotic showed the lowest lactic acid production (p < 0.001). This study demonstrated that L-arginine enhanced the growth of LrG. The 2% L-arginine and LrG synbiotic synergistically inhibits the growth of S. mutans with significant potential to develop as an anti-caries regimen.

Oral probiotics reduce halitosis in patients wearing orthodontic braces: a randomized, triple-blind, placebo-controlled trial

Orthodontic braces can impede oral hygiene and promote halitosis. The aim of the study was to investigate the effect of the oral probiotic Streptococcus salivarius M18 on oral hygiene indices and halitosis in patients wearing orthodontic braces. The study was a prospective, randomized, triple-blind, placebo-controlled trial. Patients undergoing fixed orthodontic treatment were randomly allocated to a probiotic group (n = 32) and a placebo group (n = 32). Patients consumed 2 lozenges d^-1 for one month. Assessments were taken at baseline, at the end of the intervention, and at a 3 month follow-up. The outcome measures were plaque index (PI), gingival index (GI) and halitosis-causing volatile sulfur compound (VSC) levels. The dental biofilms before and after the intervention were analyzed utilizing next-generation sequencing of bacterial 16S rRNA genes. PI and GI scores were not significantly influenced by the probiotic intervention (intervention × time: p > 0.05). The level of VSCs decreased significantly in both the probiotic group (VSC reduction = -8.5%, 95%CI = -7.4% to -9.1%, p = 0.015) and the placebo group (-6.5%, 95%CI = -6.0% to -7.4%, p = 0.039) after 1 month intervention. However, at the 3 month follow-up, the VSC levels in the placebo group returned to baseline levels whereas those in the probiotic group decreased further (-10.8%, 95%CI = -10.5% to -12.9%, p = 0.005). Time, but not treatment, was associated with the decrease in microbial community alpha diversity and a modest effect on beta diversity. Oral probiotic S. salivarius M18 reduced the level of halitosis in patients with orthodontic braces, but had minimal effects on PI, GI and dental biofilm microflora.

Efficacy of probiotics: clinical and microbial parameters of halitosis

BACKGROUND & AIM

Halitosis is defined as an offensive breath odour of whatever source and therefore may affect a person's social interactions. Intra-oral halitosis is a result of bacterial activity. Therefore, probiotics may offer an appropriate and biological solution as a part of the therapy of intra-oral halitosis. The aim of this systematic review was to study the effect of the administration of probiotics alone or as an adjunct to other treatments on the level of halitosis as measured by volatile sulphur compound (VSC) levels, organoleptic scores (ORG) or hydrogen sulphide, methyl mercaptan and dimethyl sulphide levels. In addition, the effect of probiotic usage on oral microbial composition was summarised.

METHODS

The MEDLINE-PubMed and Embase databases were searched up to September 2017 with language restricted to English. Eligible papers were selected according to pre-set criteria; the data was extracted and analysed descriptively.

RESULTS

The search resulted in 1104 original research articles and a final six were selected as being eligible including 129 subjects. These studies used different detection methods and combinations thereof to measure halitosis. Five studies were randomised placebo-controlled clinical trials of which two studies reported a significant reduction in ORG between probiotic and placebo groups, and two studies on the basis of total VSC levels. The two studies reporting a significant improvement in ORG did not find an improvement in total VSC levels. Three studies included a microbiological assessment. In these three studies, the probiotic strain was detected at the end of the treatment period, but no detailed data was reported on the abundance of the strain before and after the treatment period.

CONCLUSIONS

Probiotics may be beneficial in treating intra-oral halitosis. However, due to limited data and the heterogeneity of the studies, the efficacy of probiotics remains unclear. Studies with more subjects and standardised protocols need to be designed.

Use of design of experiments to optimize the production of microbial probiotic biofilms

Here, we describe the production of a probiotic biofilm through three intermediate steps: (1) measurement of the adhesion capacity of 15 probiotic strains to evaluate their tendency to form biofilm on different surfaces (stainless steel, glass, and polycarbonate); (2) evaluation of the effects of pH, temperature, cellular growth phase, agitation, and presence of surfactants on probiotic biofilm formation (BF) through the Design of Experiments (DoE) approach; (3) study of the effects of pH, temperature and surfactants concentration on probiotic BF using the Central Composite Design. Finally, we show that biofilms pre-formed by selected probiotics can delay the growth of pathogens, such as Listeria monocytogenes chosen as model organism. Among the tested strains, Bifidobacterium infantis DSM20088 and Lactobacillus reuteri DSM20016 were found to be as the probiotics able to ensure the greatest adhesion (over 6 Log CFU cm2) to the surfaces tested in a very short time (<24 h). Cellular growth phase and agitation of the medium were factors not affecting BF, pH exerted a very bland effect and a greater tendency to adhesion was observed when the temperature was about 30 °C. The results obtained in the last experimental phase suggest that our probiotic biofilms can be used as an efficient mean to delay the growth of L. monocytogenes: the λ phase length, in fact, was longer in samples containing probiotic biofilms (0.30-1.02 h) against 0.08 h observed in the control samples. A reduction of the maximum cell load was also observed (6.99-7.06 Log CFU mL-1 against about 8 Log CFU mL-1 observed in the control samples).

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.

The Anti-Periodontitis Effects of Ethanol Extract Prepared Using Lactobacillus paracasei subsp. paracasei NTU 101

Poor oral health and related diseases, including caries, periodontal disease, and oral cancer, are highly prevalent across the world, particularly in the elderly. This study aimed to investigate the anti-periodontitis activity of fermented skim milk produced using the promising probiotic Lactobacillus paracasei subsp. paracasei NTU 101 (NTU101FM). An initial analysis found that an ethanol extract of NTU101FM displayed anti-oxidative activities. Further investigation of pathogen growth inhibition zones, minimum inhibitory concentrations (MICs), and minimum bactericidal concentrations (MBCs) revealed that the NTU101FM ethanol extract also had anti-periodontal pathogen activities. In addition, the NTU101FM ethanol extract significantly decreased the release of pro-inflammatory cytokines induced by lipopolysaccharide (LPS) in RAW 264.7 macrophage cells. Finally, the NTU101FM ethanol extract was found to inhibit receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation by reducing tartrate-resistant acid phosphatase (TRAP) activity and the number of TRAP-positive multinucleated osteoclasts. In summary, our study demonstrated that ethanol extract prepared from NTU101FM has potential use as an anti-periodontitis agent.

Effect of a Lactobacillus Salivarius Probiotic on a Double-Species Streptococcus Mutans and Candida Albicans Caries Biofilm

The aim of the study was to evaluate the anti-cariogenic effects of Lactobacillus salivarius by reducing pathogenic species and biofilm mass in a double-species biofilm model. Coexistence of S. mutans with C. albicans can cause dental caries progression or recurrence of the disease in the future. Fifty-nine children with diagnosed early childhood caries (ECC) were recruited onto the study. The condition of the children's dentition was defined according to the World Health Organization guidelines. The participants were divided into children with initial enamel demineralization and children showing dentin damage. The study was performed on the S. mutans and C. albicans clinical strains, isolated from dental plaque of patients with ECC. The effect of a probiotic containing Lactobacillus salivarius on the ability of S. mutans and C. albicans to produce a double-species biofilm was investigated in an in vitro model. The biomass of the formed/non-degraded biofilm was analyzed on the basis of its crystal violet staining. The number of colonies of S. mutans and C. albicans (CFU/mL, colony forming units/mL) forming the biofilm was determined. Microorganism morphology in the biofilm was evaluated using a scanning electron microscope (SEM). In vitro analysis demonstrated that the presence of S. mutans increased the number of C. albicans colonies (CFU/mL); the double-species biofilm mass and hyphal forms produced in it by the yeast. L. salivarius inhibited the cariogenic biofilm formation of C. albicans and S. mutans. Under the influence of the probiotic; the biofilm mass and the number of S. mutans; C. albicans and S. mutans with C. albicans colonies in the biofilm was decreased. Moreover; it can be noted that after the addition of the probiotic; fungi did not form hyphae or germ tubes of pathogenic potential. These results suggest that L. salivarius can secrete intermediates capable of inhibiting the formation of cariogenic S. mutans and C. albicans biofilm; and may inhibit fungal morphological transformation and thereby reduce the pathogenicity of C. albicans; weakening its pathogenic potential. Further research is required to prove or disprove the long-term effects of the preparation and to achieve preventive methods.

Use of Probiotics and Oral Health

PURPOSE OF REVIEW

The purpose of this study is to critically assess recent studies concerning the use of probiotics to control periodontal diseases, dental caries and halitosis (oral malodour).

RECENT FINDINGS

Clinical studies have shown that probiotics when allied to conventional periodontal treatment can ameliorate microbial dysbiosis and produce significant improvement in clinical indicators of disease. However, this effect is often not maintained by the host after the end of probiotic use. Current probiotics also show limited effects in treating caries and halitosis. Novel approaches based up on replacement therapy and using highly abundant health-associated oral species, including nitrate-reducing bacteria, have been proposed to improve persistence of probiotic strains and maintain oral health benefits.

SUMMARY

Probiotics have potential in the management of multifactorial diseases such as the periodontal diseases and caries, by more effectively addressing the host-microbial interface to restore homeostasis that may not be achieved with conventional treatments.

Probiotics: A Promising Role in Dental Health

Probiotics have a role in maintaining oral health through interaction with oral microbiome, thus contributing to healthy microbial equilibrium. The nature and composition of any individual microbiome impacts the general health, being a major contributor to oral health. The emergence of drug resistance and the side effects of available antimicrobials have restricted their use in an array of prophylactic options. Indeed, some new strategies to prevent oral diseases are based on manipulating oral microbiota, which is provided by probiotics. Currently, no sufficient substantial evidence exists to support the use of probiotics to prevent, treat or manage oral cavity diseases. At present, probiotic use did not cause adverse effects or increased risks of caries or periodontal diseases. This implicates no strong evidence against treatment using probiotics. In this review, we try to explore the use of probiotics in prevention, treatment and management of some oral cavity diseases and the possibilities of developing designer probiotics for the next generation of oral and throat complimentary healthcare.

Health-Associated Niche Inhabitants as Oral Probiotics: The Case of Streptococcus dentisani

Oral diseases, including dental caries and periodontitis, are among the most prevalent diseases worldwide and develop as a consequence of a microbial dysbiosis. Several bacterial strains are being tested as potential oral health-promoting organisms, but usually they are species isolated from niches other than the site where they must exert its probiotic action, typically from fecal samples. We hypothesize that oral inhabitants associated to health conditions will be more effective than traditional, gut-associated probiotic species in key aspects such as colonization of the oral site where disease takes place or the possession of oral health promoting functions, as well as more practical issues like safety and toxicity, and establishing proper doses for administration. As an example of these active colonizers, we describe the case of Streptococcus dentisani, a new streptococcal species isolated from dental plaque of caries-free individuals. We have detected it in 98% of dental plaque samples from healthy individuals and, as expected, it does not produce any toxic secondary metabolite and does not survive a simulated stomach digestion, preventing potential secondary effects. Besides, this species has a double probiotic action, as it inhibits the growth of major oral pathogens through the production of bacteriocins, and also buffers acidic pH (the primary cause of dental caries) through an arginolytic pathway. We propose the use of S. dentisani as a promising probiotic against tooth decay.

Mature Biofilm Degradation by Potential Probiotics: Aggregatibacter actinomycetemcomitans versus Lactobacillus spp

The biofilm degradation of Aggregatibacter actinomycetemcomitans is essential as a complete periodontal disease therapy, and here we show the effects of potential probiotic bacteria such as Lactobacillus spp. for the biofilm of several serotypes of A. actinomycetemcomitans strains. Eight of the 13 species showed the competent biofilm degradation of ≥ 90% reduction in biofilm values in A. actinomycetemcomitans Y4 (serotype b) as well as four of the seven species for the biofilm of A. actinomycetemcomitans OMZ 534 (serotype e). In contrast, the probiotic bacteria did not have a big impact for the degradation of A. actinomycetemcomitans SUNY 75 (serotype a) biofilm. The dispersed A. actinomycetemcomitans Y4 cells through the biofilm detachment were still viable and plausible factors for the biofilm degradation were not due to the lactic acid and low pH conditions. The three enzymes, protease, lipase, and amylase may be responsible for the biofilm degradation; in particular, lipase was the most effective enzyme for the biofilm degradation of A. actinomycetemcomitans Y4 along with the protease activity which should be also important for the other serotypes. Remarkable lipase enzyme activities were detected from some of the potential probiotics and a supporting result using a lipase inhibitor presented corroborating evidence that lipase activity is one of the contributing factors for biofilm degradation outside of the protease which is also another possible factor for the biofilm of the other serotype of A. actinomycetemcomitans strains. On the other hand, the biofilm of A. actinomycetemcomitans SUNY 75 (serotype a) was not powerfully degraded by the lipase enzyme because the lipase inhibitor was slightly functional for only two of potential probiotics.

Beyond Antibiotics: New Therapeutic Approaches for Bacterial Infections

The utility of conventional antibiotics for the treatment of bacterial infections has become increasingly strained due to increased rates of resistance coupled with reduced rates of development of new agents. As a result, multidrug-resistant, extensively drug-resistant, and pandrug-resistant bacterial strains are now frequently encountered. This has led to fears of a "postantibiotic era" in which many bacterial infections will be untreatable. Alternative nonantibiotic treatment strategies need to be explored to ensure that a robust pipeline of effective therapies is available to clinicians. In this review, we highlight some of the recent developments in this area, such as the targeting of bacterial virulence factors, utilization of bacteriophages to kill bacteria, and manipulation of the microbiome to combat infections.

Comparison of Antimicrobial Activity of Chlorhexidine, Coconut Oil, Probiotics, and Ketoconazole on Candida albicans Isolated in Children with Early Childhood Caries: An In Vitro Study

Background. Early childhood caries (ECC) is associated with early colonisation and high levels of cariogenic microorganisms. With C. albicans being one of those, there is a need to determine the effectiveness of various chemotherapeutic agents against it. The study is aimed at isolating Candida species in children with ECC and at studying the antifungal effect of coconut oil, probiotics, Lactobacillus, and 0.2% chlorhexidine on C. albicans in comparison with ketoconazole. Materials and Methods. Samples were collected using sterile cotton swabs, swabbed on the tooth surfaces from children with ECC of 3 to 6 yrs and streaked on Sabouraud dextrose agar (HI Media) plates and incubated in a 5% CO2 enriched atmosphere at 37°C for 24 hours. Candida was isolated and its susceptibility to probiotics, chlorhexidine, ketoconazole, and coconut oil was determined using Disc Diffusion method. Results. The mean zone of inhibition for chlorhexidine was 21.8 mm, whereas for coconut oil it was 16.8 mm, for probiotics it was 13.5 mm, and for ketoconazole it was 22.3 mm. The difference between the groups was not statistically significant (Chi-square value 7.42, P value 0.06). Conclusion. Chlorhexidine and coconut oil have shown significant antifungal activity which is comparable with ketoconazole.

Lactobacillus fermentum NCIMB 5221 and NCIMB 2797 as cholesterol-lowering probiotic biotherapeutics: in vitro analysis

Cardiovascular and coronary artery disease risk are correlated with cholesterol levels and are significant health concerns. Current cholesterol-lowering approaches includes lifestyle and diet modifications, as well as statins which presents numerous shortcomings. The probiotic bacteria, Lactobacillus fermentum NCIMB 5221 and NCIMB 2797, have demonstrated cholesterol-lowering potential in animal studies. However, there is a lack in understanding the mechanism(s) behind these observed effects. The goal of this work is to investigate, in vitro, the cholesterol-lowering mechanisms of these two strains. To determine the cholesterol-lowering mechanisms, probiotic cholesterol assimilation, colon epithelial adhesion and inhibition of cholesterol uptake by colon epithelial (Caco-2) cells were investigated. L. fermentum NCIMB 2797 (P=0.012) and NCIMB 5221 (P=0.003) assimilated cholesterol and their cell surface hydrophobicity was 70.30±8.85% and 55.60±2.59%, respectively. Both L. fermentum strains showed no significant impact (P>0.05) on Caco-2 cell viability. Of most interest, Caco-2 pre-exposure to L. fermentum NCIMB 5221 significantly decreased (P=0.015) cholesterol uptake, with 85.98±2.07% uptake compared to the untreated cells. Similarly, L. fermentum NCIMB 2797 probiotic cells significantly decreased (P=0.019) cholesterol uptake by Caco-2 cells, with 86.45±1.71% uptake observed compared to the control cells. The results demonstrate that L. fermentum NCIMB 5221 and L. fermentum NCIMB 2797 have the potential via various modes of action to lower cholesterol. Additional studies are required to understand the mechanism(s) of action behind probiotic cholesterol assimilation and behind the cholesterol uptake inhibition by colon epithelial cells.

Investigation of probiotic bacteria as dental caries and periodontal disease biotherapeutics

Oral diseases, specifically dental caries and periodontal disease, are characterised by increases in pathogenic microorganisms, increased demineralisation and increased inflammation and levels of inflammatory markers. Despite the therapeutic strategies, oral diseases have elevated prevalence rates. Recent work has demonstrated that probiotic bio-therapeutics can decrease oral pathogen counts, including caries-causing Streptococcus mutans and oral inflammation. The aim of this work was to investigate putative probiotic bacteria, selected for S. mutans inhibition and for their oral health-promoting characteristics. The probiotic bacteria were screened for S. mutans inhibition, probiotic bacteriocin activity, salivary pH modulation, probiotic nutrient (sucrose) competition, probiotic co-aggregation with S. mutans, bacterial attachment to oral epithelial keratinocytes, bacterial nitric oxide production and bacterial antioxidant activity. The results indicate that Lactobacillus reuteri strains NCIMB 701359, NCIMB 701089, NCIMB 702655 and NCIMB 702656 inhibited S. mutans to non-detectable levels (<10 cfu/ml). L. reuteri strains also demonstrated the highest antioxidant capacity of the tested strains (7.73-13.99 µM Trolox equivalents), suggesting their use as both caries and periodontal disease therapeutics. Although Lactobacillus fermentum NCIMB 5221 inhibited S. mutans at lower levels, it significantly buffered the pH (4.18) of saliva containing S. mutans, co-aggregated with S. mutans (10.09%), demonstrated high levels of sucrose consumption (138.11 mM) and successfully attached to gingival epithelial cells (11%). This study identified four L. reuteri strains and one L. fermentum strain to be further investigated as oral disease biotherapeutics.

Fickian-Based Empirical Approach for Diffusivity Determination in Hollow Alginate-Based Microfibers Using 2D Fluorescence Microscopy and Comparison with Theoretical Predictions

Hollow alginate microfibers (od = 1.3 mm, id = 0.9 mm, th = 400 µm, L = 3.5 cm) comprised of 2% (w/v) medium molecular weight alginate cross-linked with 0.9 M CaCl₂ were fabricated to model outward diffusion capture by 2D fluorescent microscopy. A two-fold comparison of diffusivity determination based on real-time diffusion of Fluorescein isothiocyanate molecular weight (FITC MW) markers was conducted using a proposed Fickian-based approach in conjunction with a previously established numerical model developed based on spectrophotometric data. Computed empirical/numerical (D_empiricial/D_numerical) diffusivities characterized by small standard deviations for the 4-, 70- and 500-kDa markers expressed in m²/s are (1.06 × 10⁻⁹ ± 1.96 × 10⁻¹⁰)/(2.03 × 10⁻¹¹), (5.89 × 10⁻¹¹ ± 2.83 × 10⁻¹²)/(4.6 × 10⁻¹²) and (4.89 × 10⁻¹² ± 3.94 × 10⁻¹³)/(1.27 × 10⁻¹²), respectively, with the discrimination between the computation techniques narrowing down as a function of MW. The use of the numerical approach is recommended for fluorescence-based measurements as the standard computational method for effective diffusivity determination until capture rates (minimum 12 fps for the 4-kDa marker) and the use of linear instead of polynomial interpolating functions to model temporal intensity gradients have been proven to minimize the extent of systematic errors associated with the proposed empirical method.

Probiotics to counteract biofilm-associated infections: promising and conflicting data

Altered bowel flora is currently thought to play a role in a variety of disease conditions, and the use of Bifidobacterium spp. and Lactobacillus spp. as probiotics has been demonstrated to be health-promoting, even if the success of their administration depends on the applied bacterial strain(s) and the targeted disease. In the last few decades, specific probiotics have been shown to be effective in the treatment or the prevention of acute viral gastroenteritis, pediatric post-antibiotic-associated diarrhea, some pediatric allergic disorders, necrotizing enterocolitis in preterm infants, inflammatory bowel diseases and postsurgical pouchitis. The potential application of probiotics is continuously widening, with new evidence accumulating to support their effect on the prevention and treatment of other disease conditions, including several oral diseases, such as dental caries, periodontal diseases and oral malodor, as well as genitourinary and wound infections. Considering the increasingly widespread ability of pathogens to generate persistent biofilm-related infections, an even more attractive proposal is to administer probiotics to prevent or counteract biofilm development. The response of biofilm-based oral, intestinal, vaginal and wound infections to probiotics treatment will be reviewed here in light of the most recent results obtained in this field.

Comparison of fecundity and offspring immunity in zebrafish fed Lactobacillus rhamnosus CICC 6141 and Lactobacillus casei BL23

To increase the knowledge of probiotic effects on zebrafish (Danio rerio), we compare the effects of two probiotic strains, Lactobacillus rhamnosus CICC 6141 (a highly adhesive strain) and Lactobacillus casei BL23 (a weakly adhesive strain), on zebrafish reproduction and their offsprings' innate level of immunity to water-borne pathogens. During probiotics treatments from 7 to 28 days, both the Lactobacillus strains, and especially L. casei BL23, significantly increased fecundity in zebrafish: higher rates of egg ovulation, fertilization, and hatching were observed. Increased densities of both small and large vitellogenic follicles, seen in specimens fed either Lactobacillus strain, demonstrated accelerated oocyte maturation. Feeding either strain of Lactobacillus upregulated gene expression of leptin, kiss2, gnrh3, fsh, lh, lhcgr, and paqr8, which were regarded to enhance fecundity and encourage oocyte maturation. Concomitantly, the gene expression of bmp15 and tgfb1 was inhibited, which code for local factors that prevent oocyte maturation. The beneficial effects of the Lactobacillus strains on fecundity diminished after feeding of the probiotics was discontinued, even for the highly adhesive gut Lactobacillus strain. Administering L. rhamnosus CICC 6141 for 28 days was found to affect the innate immunity of offspring derived from their parents, as evinced by a lower level of alkaline phosphatase activity in early larval stages. This study highlights the effects of probiotics both upon the reproductive process and upon the offsprings' immunity during early developmental stages.

Probiotics from research to market: the possibilities, risks and challenges

Probiotic foods can affect large parts of the population, while therapeutic applications have a less wide scope. While commercialization routes and regulatory requirements differ for both applications, both will need good scientific support. Today, probiotics are mainly used for gastrointestinal applications, their use can easily be extended to skin, oral and vaginal health. While most probiotics currently belong to food-grade species, the future may offer new functional microorganisms in food and pharma. This review discusses the crosstalk between probiotic producers, regulatory people, medical care and healthcare workers, and the scientific community.

The use of probiotic strains in caries prevention: a systematic review

This paper aims to provide a systematic review of the caries-prevention effect of probiotics in human. The hypothesis was that the administration of probiotic strains might play a role in caries lesion prevention and in the control of caries-related risk factors. The main relevant databases (Medline, Embase) were searched. Quality of the Randomized Clinical Trials (RCTs) was classified using the “Consolidated Standards of Reporting Trials” (CONSORT) checklist and the Impact Factor (IF) value of each journal was recorded. Sixty-six papers were identified, and 23 fulfilled the inclusion criteria. Only three studies had caries lesion development as outcome, all the others reported caries risk factors as interim evaluation. Using the CONSORT Score, the papers were coded as 4 excellent, 9 good and 10 poor. The mean IF value recorded was 1.438. Probiotics may play a role as antagonistic agent on mutans streptococci (MS), acidogenic/aciduric bacteria that contributes to the caries process. In two-thirds of the selected papers, probiotics have demonstrated the capacity to reduce MS counts in saliva and/or plaque in short-term. The effect of probiotics on the development of caries lesion seems encouraging, but to date, RCTs on this topic are insufficient to provide scientific clinical evidence.

Novel probiotic dissolvable carboxymethyl cellulose films as oral health biotherapeutics: in vitro preparation and characterization

OBJECTIVES

Oral health is influenced by the mouth's resident microorganisms. Dental caries and periodontitis are oral disorders caused by imbalances in the oral microbiota. Probiotics have potential for the prevention and treatment of oral disorders. Current formulations, including supplements and foods, have limitations for oral delivery including short storage time, low residence time in the mouth, effects on food consistency, and low patient compliance. Oral thin films (OTFs) may be efficient in delivering probiotics to the mouth. This research aims to develop a novel carboxymethyl cellulose (CMC)-probiotic-OTF to deliver probiotics for the treatment/prevention of oral disorders.

METHODS

CMC-OTFs were developed with varying CMC concentration (1.25 - 10 mg/mL), weight (5 - 40 g), thickness (16 - 262 μm), hygroscopicity (30.8 - 78.9 mg/cm(2) film), and dissolving time (135 - 600 s). The 10 g 5 mg/mL CMC-OTF was selected and used to incorporate Lactobacillus fermentum NCIMB 5221 (6.75 × 10(8) cells/film), a probiotic with anti-inflammatory potential for periodontitis treatment and capable of inhibiting microorganisms responsible for dental caries and oral candidiasis.

RESULTS

The CMC-OTF maintained probiotic viability and antioxidant activity following 150 days of storage with a production of 549.52 ± 26.08 μM Trolox equivalents.

CONCLUSION

This research shows the successful development and characterization of a novel probiotic-CMC-OTF with potential as an oral health biotherapeutic.

Oral probiotic microcapsule formulation ameliorates non-alcoholic fatty liver disease in Bio F1B Golden Syrian hamsters

The beneficial effect of a microencapsulated feruloyl esterase producing Lactobacillus fermentum ATCC 11976 formulation for use in non-alcoholic fatty liver disease (NAFLD) was investigated. For which Bio F1B Golden Syrian hamsters were fed a methionine deficient/choline devoid diet to induce non-alcoholic fatty liver disease. Results, for the first time, show significant clinical benefits in experimental animals. Examination of lipids show that concentrations of hepatic free cholesterol, esterified cholesterol, triglycerides and phospholipids were significantly lowered in treated animals. In addition, serum total cholesterol, triglycerides, uric acid and insulin resistance were found to decrease in treated animals. Liver histology evaluations showed reduced fat deposits. Western blot analysis shows significant differences in expression levels of key liver enzymes in treated animals. In conclusion, these findings suggest the excellent potential of using an oral probiotic formulation to ameliorate NAFLD.

Bioactives from probiotics for dermal health: functions and benefits

Probiotics have been extensively reviewed for decades, emphasizing on improving general gut health. Recently, more studies showed that probiotics may exert other health-promoting effects beyond gut well-being, attributed to the rise of the gut-brain axis correlations. Some of these new benefits include skin health such as improving atopic eczema, atopic dermatitis, healing of burn and scars, skin-rejuvenating properties and improving skin innate immunity. Increasing evidence has also showed that bacterial compounds such as cell wall fragments, their metabolites and dead bacteria can elicit certain immune responses on the skin and improve skin barrier functions. This review aimed to underline the mechanisms or the exact compounds underlying the benefits of bacterial extract on the skin based on evidences from in vivo and in vitro studies. This review could be of help in screening of probiotic strains with potential dermal enhancing properties for topical applications.

Cholesterol lowering with bile salt hydrolase-active probiotic bacteria, mechanism of action, clinical evidence, and future direction for heart health applications

INTRODUCTION

Cardiovascular diseases (CVD) are the leading cause of global mortality and morbidity. Current CVD treatment methods include dietary intervention, statins, fibrates, niacin, cholesterol absorption inhibitors, and bile acid sequestrants. These formulations have limitations and, thus, additional treatment modalities are needed. Probiotic bacteria, especially bile salt hydrolase (BSH)-active probiotic bacteria, have demonstrated cholesterol-lowering efficacy in randomized controlled trials.

AREAS COVERED

This review describes the current treatments for CVD and the need for additional therapeutics. Gut microbiota etiology of CVD, cholesterol metabolism, and the role of probiotic formulations as therapeutics for the treatment and prevention of CVD are described. Specifically, we review studies using BSH-active bacteria as cholesterol-lowering agents with emphasis on their cholesterol-lowering mechanisms of action. Potential limitations and future directions are also highlighted.

EXPERT OPINION

Numerous clinical studies have concluded that BSH-active probiotic bacteria, or products containing them, are efficient in lowering total and low-density lipoprotein cholesterol. However, the mechanisms of action of BSH-active probiotic bacteria need to be further supported. There is also the need for a meta-analysis to provide better information regarding the therapeutic use of BSH-active probiotic bacteria. The future of BSH-active probiotic bacteria most likely lies as a combination therapy with already existing treatment options.