The implication of probiotics in the prevention of dental caries

The current oral health crisis, whose causes are varied and complex, necessitates timely oral evaluation and early detection and treatment of oral health problems. Dramatic changes in eating habits and lifestyles are associated with the recent decline in oral health. Probiotics are “good” bacteria that support digestion and a healthy immune system and offer various health benefits to the host. Traditionally, probiotics have been used to improve gut health; the most common uses have historically been as a treatment or prevention of gastrointestinal infections and disease. During the last decade, studies have additionally suggested the intake of probiotics for oral health purposes. Probiotic use provides an effective strategy to combat oral disease, including the development of dental caries and periodontal infection. The aim of this review is to describe the beneficial roles of probiotic bacteria in the oral cavity and the potential mechanisms by which these bacteria exert their effects on oral health.

     

Adherence capacities of oral lactobacilli for potential probiotic purposes

The most abundantly used probiotic strains come from the genus Lactobacillus and only a few studies have investigated their role in oral health. Even if a positive correlation has been established between the saliva Lactobacillus count and dental caries, this genus is generally recognized as safe (GRAS). Moreover, lactobacilli could in some cases play a beneficial role by inhibiting the growth of some oral pathogenic bacteria. This activity could justify their use as probiotic. To establish the potential health benefit of probiotic candidates, appropriate in?vitro tests are required, particularly on their adhesive capacity. The aim of this work was to investigate the adhesive properties and surface characteristics of 70 oral lactobacilli that could be used as probiotics for oral health. For this, three methods were used: biofilm formation on a glass surface and on saliva-coated hydroxyapatite discs and the microbial adhesion to solvent method. The results of the biofilm formed on glass surface showed 13 strains with an adhesion score equal to or higher than 3. 57/70 (81%) of the tested lactobacilli did not form any biofilm on glass surfaces. All of the 13 strains formed biofilms on HA discs. Among these 13 strains, 10/13 (77%) showed low surface hydrophobicity (0-35%) and 3/13 (23%) showed medium hydrophobicity (36-70%). Some of the selected strains showed potentially useful adhesive capacity. This work paves the way for the selection of probiotics that could be used for oral health purposes with the aim to reduce carious risk.     

A comparative study of the effect of probiotics on cariogenic biofilm model for preventing dental caries

Dental caries is induced by oral biofilm containing Streptococcus mutans. Probiotic bacteria were mainly studied for effect on the gastrointestinal tract and have been known to promote human health. However, the information of probiotics for oral health has been lack yet. In this study, we investigated influence of various probiotics on oral bacteria or cariogenic biofilm and evaluated candidate probiotics for dental caries among them. The antimicrobial activity of the spent culture medium of probiotics for oral streptococci was performed. Probiotics were added during the biofilm formation with salivary bacteria including S. mutans. The oral biofilms were stained with a fluorescent dye and observed using the confocal laser scanning microscope. To count bacteria in the biofilm, the bacteria were plated on MSB and BHI agar plates after disrupting the biofilm and cultivated. Glucosyltransferases (gtfs) expression of S. mutans and integration of lactobacilli into the biofilm were evaluated by real-time RT-PCR. Among probiotics, Lactobacillus species strongly inhibited growth of oral streptococci. Moreover, Lactobacillus species strongly inhibited formation of cariogenic biofilm model. The expression of gtfs was significantly reduced by Lactobacillus rhamnosus. The integration of L. rhamnosus into the biofilm model did not exhibit. However, L. acidophilus and L casei integrated into the biofilm model. These results suggest that L. rhamnosus may inhibit oral biofilm formation by decreasing glucan production of S. mutans and antibacterial activity and did not integrate into oral biofilm, which can be a candidate for caries prevention strategy.     

益生菌与口腔微生态调控的研究进展

口腔疾病的发生和发展与口腔微生物群落的失衡密切相关。益生菌是一类对人体健康有益的活的微生物,主要通过分泌抗菌物质、与致病菌竞争性定殖、调节毒力相关基因表达、调节宿主免疫反应、调节氧化应激反应、参与硝酸盐—亚硝酸盐—一氧化氮代谢循环通路、调整生物膜pH值等过程发挥其益生效能。研究发现,益生菌疗法能够降低龋齿的风险、改善牙周状况、提高口腔黏膜病的治疗效果,有望成为防治口腔疾病的潜在途径。本文就近年来益生菌与口腔微生态调控相关的研究情况做一综述。     

Role of Probiotics in Oral Health Maintenance Among Patients Undergoing Fixed Orthodontic Therapy: a Systematic Review of Randomized Controlled Clinical Trials

The aim was to assess the role of probiotics in oral health maintenance among patients undergoing fixed orthodontic therapy (OT). An unrestricted search of indexed databases was performed until April 2020 using the following Mesh-terms: (1) probiotic and (2) orthodontic. Randomized controlled clinical trials (RCTs) evaluating the influence of probiotic therapy (PT) towards oral health maintenance/improvement in patients undergoing fixed OT were included. Data screening, selection, and extraction were performed; and the risk of bias was assessed using the Cochrane Collaboration’s tool. All evaluations were performed by 2 independent researchers; and disagreements were resolved via discussion. Nine RCTs were included. Eight studies reported that PT improves oral health in patients undergoing fixed OT. Seven studies showed that PT reduces the counts of oral pathogenic bacteria in the oral biofilm and/or saliva. One study reported that PT reduces halitosis in patients undergoing fixed OT. One study found that PT reduces the scores of plaque index (PI) and gingival index (GI); and one study reported that PT has no significant influence on PI and GI in patients undergoing fixed OT. One study reported that PT does not prevent the formation of white spot lesions during fixed OT. Three and 6 studies had a moderate and low risk of bias, respectively. A power analysis was performed in 4 studies. In conclusion, probiotics exhibit antimicrobial activity against oral pathogenic bacteria; however, due to the limitations of the studies assessed, further well-designed RCTs are needed.

     

Probiotic Formulations: Application and Status as Pharmaceuticals—A Review

The use of probiotics is a new way to control and treat infections in this modern era. Application of beneficial bacteria to protect against detrimental bacteria in the gastrointestinal tract and thus reap a positive health benefit is the basis of probiotic therapy. Probiotics have a long global history of traditional use. They are normally consumed through fermented foods and are currently sold mostly as ingredients in foods or nutritional supplements. They are also supplied as pharma products. Recent research has highlighted the probiotic potential in the treatment or prevention of disease conditions, maintenance of health, improving immunity and in the reduction in the risk of future diseases. But their position in the pharmaceutical industry is still not very clear. Clinical practitioners use probiotic pharma products mostly as supplements. Their status as drugs is still unclear. This review is aimed to analyze probiotics as pharmaceuticals, their current status as dietary supplements and drugs, existing probiotic preparations and future research needs.     

Recovery of Viable Bacteria from Probiotic Products that Target Oral Health

Probiotic therapy has predominantly been directed toward promoting and maintaining intestinal health. In recent years, however, probiotic regimens that target oral health have appeared on the market. These regimens are often delivered in the form of lozenges. Despite the oral health claims made by the manufacturers of these products, there is little independent evidence in the literature to support such claims. In theory, probiotic organisms can be beneficial by several different means including direct inhibition of pathogens and boosting of the host immune response, with the underlying assumption that these mechanisms require a critical number of viable organisms. In this study, five brands of probiotics marketed for oral health were tested for the recovery of viable bacteria. For only one brand could viable bacteria be recovered within one log of the manufacturer’s stated starting amount of bacteria. Nearly, a billion viable bacteria could be recovered from a lozenge of this brand. The other brands claimed similar starting amounts of bacteria at the time of manufacture but at least a three-log drop-off was observed in the amount of viable bacteria recovered from those products. Refrigeration of the probiotics significantly improved the recovery for one brand, but recoveries for all but one brand remained below the recommended daily dosage for probiotic regimens. It is concluded that probiotic brands differ significantly in the quantities of bacteria that remain viable with most failing to meet recommended dosage targets.     

益生菌辅助治疗牙周病的研究进展

牙周病是累及牙周支持组织的慢性感染性疾病。牙菌斑生物膜中的微生物及其代谢产物是其必不可少的始动因素,可导致口腔微生态失衡和宿主免疫反应,最终引起牙周病的发生发展。目前,牙周病的基础治疗主要是机械清除牙菌斑生物膜和牙石,但治疗效果具有局限性。益生菌通过产生抑菌物质、刺激局部免疫反应、与致病菌争夺黏膜受体和营养物质,从而改善口腔微生态平衡,促进牙周病的治疗。本文就近年来益生菌在牙周病治疗上的实验和临床研究、作用机制、安全性等进行综述,为将来益生菌辅助治疗牙周病的应用提供参考。     

Insight into probiotic properties of lactic acid bacterial endosymbionts of Apis mellifera L. derived from the Polish apiary

Taking into account that fructophilic lactic acid bacteria (FLAB) can play an important role in the health of honey bees and can be used as probiotics, phenotypic properties of probiotic interest of Lactobacillus kunkeei (12 strains) and Fructobacillus fructossus bacteria (2 strains), isolated from Apis mellifera gastrointestinal tract, have been studied. We have evaluated survival of tested FLAB in honey bee gut, their susceptibility to antibiotics (ampicillin, erythromycin, tylosin), cell surface hydrophobicity, auto-aggregation ability, co-aggregation with model pathogenic bacteria, biofilm formation capacity, and effect of studied FLAB, added to sucrose syrup bee diet, on longevity of honey bees. The tested FLAB exhibited good gastrointestinal tract tolerance and high antibiotic susceptibility, which are important criteria in the screening of probiotic candidates. It was also found that all FLAB studied have high cell surface hydrophobicity and fulfil next selection criterion for their use as probiotics. Symbionts of A. mellifera showed also auto- and co-aggregation capacities regarded as valuable features for biofilm formation and inhibition of pathogens adhesion to the bee gut cells. Biofilm-development ability is a desired characteristic of probiotic lactic acid bacteria. As indicated by quantitative crystal violet-stained microplate assay and confocal laser scanning microscopy imaging, all studied A. mellifera gut isolates exhibit a biofilm positive phenotype. Moreover, it was also documented, on honey bees kept in cages, that supplementation of A. mellifera sucrose diet with FLAB decreases mortality and improves significantly longevity of honey bees. Presented research showed that A. mellifera FLAB symbionts are good candidates for application as probiotics.     

乳杆菌对生物膜的作用及其机制研究进展

慢性炎症和感染性疾病与致病菌生物膜(biofilm,BF)的形成密切相关,目前治疗BF相关疾病还局限于应用抗生素,但抗生素滥用会导致多重耐药,治疗不彻底会引起慢性感染,预防和治疗BF相关疾病的新方法亟待提出。随着益生菌生物制剂应用价值的不断体现与验证,益生菌生物制剂不断发展为消除某些致病菌BF感染的新方案。其中发展的最好的莫过于乳杆菌活菌制剂,大量的科研文献及临床实践已证明其具有强大的益生潜力,特别是在抑制致病菌生物膜方面,这为临床治疗BF相关感染开拓了新视野。本文主要综述当前国内外乳杆菌对生物膜作用及其机制的研究进展,旨在通过综述相关研究进展为临床治疗生物膜相关感染提供全新思路。     

Probiotic and other functional microbes: from markets to mechanisms

Insight into the diversity and function of the human intestinal microbiota has been stimulated by clinical studies with bacteria that exhibit specific functions and which are marketed as probiotics to positively affect our health. Initial efforts concentrated on establishing sound scientific support for the efficacy of these probiotic bacteria, which mainly include Lactobacillus and Bifidobacterium species. Following these evidence-based functional approaches, considerable research is now focused on the mechanisms of action of probiotic bacteria. The mechanisms identified to date mainly relate to the stimulation of host defence systems, immune modulation and the competitive exclusion of pathogens. Recent efficacy, molecular and genomics-based studies have also been reported for some probiotic strains that have found their position in the market place.     

The oral biome in the aetiology and management of dental disease: Current concepts and ethical considerations

Our understanding of the complexity of the oral biome and of the role of the various constituent bacteria in the aetiology of dental disease is growing. Probiotics and their relationship with prebiotics, as well as other microbiome‐based interventions, could be useful in preventing and treating dental disease and in promoting oral health. However, given the promise and early stage of this treatment approach, there are also a number of ethical, social and regulatory issues associated with innovative probiotic therapy. In this article, a brief update is given on contemporary theories of the aetiology and management of the two commonest dental diseases, and on the roles of pre‐ and probiotics and oral biome transplant in the management of these diseases. The focus is primarily on four core issues: informed consent, risk–benefit assessment, how to determine suitable healthy donors, and commercialization and regulation. We discuss the safety and benefits of oral probiotics, not only concerning the products and quality control during their manufacture, but also regarding the depth of public knowledge about this topic. We point out that the requirement of listing ingredients honestly might be insufficient, and that the prevalent rhetoric of ‘natural’ and ‘organic’ as well as some health claims in the translational, innovative probiotic industry and markets are themselves misleading and should be carefully scrutinized. Finally, we suggest an ethical imperative to find a balance between scientific research and industry, and public health in the regulation of probiotics.     

益生菌的治疗现状与前景以及 对呼吸道有益菌探索的研究进展

益生菌是调节机体微生态失衡的有效途径。肝功能异常影响肠道微生物,慢性肝衰竭、2型糖尿病、动脉粥样硬化相关心血管疾病等与肠道微生态失衡密切相关。同时肠道菌群亦受环境、遗传等复合条件影响,改变菌群组成可能导致疾病的发生发展。提倡益生菌对疾病的预防、治疗、预后,改善机体微环境,提高生命质量。近年来,益生菌、益生元、合生元三方面的研究飞速发展,对肠道益生菌研发已经取得一定成果。呼吸道作为与外界相通的腔道其优势菌群已经有相关报道,但对呼吸道益生菌的探索尚不明确,呼吸道内的优势菌是否可以制成益生菌制剂尚有待研究。     

Genes and Molecules of Lactobacilli Supporting Probiotic Action

Summary: Lactobacilli have been crucial for the production of fermented products for centuries. They are also members of the mutualistic microbiota present in the human gastrointestinal and urogenital tract. Recently, increasing attention has been given to their probiotic, health-promoting capacities. Many human intervention studies demonstrating health effects have been published. However, as not all studies resulted in positive outcomes, scientific interest arose regarding the precise mechanisms of action of probiotics. Many reported mechanistic studies have addressed mainly the host responses, with less attention being focused on the specificities of the bacterial partners, notwithstanding the completion of Lactobacillus genome sequencing projects, and increasing possibilities of genomics-based and dedicated mutant analyses. In this emerging and highly interdisciplinary field, microbiologists are facing the challenge of molecular characterization of probiotic traits. This review addresses the advances in the understanding of the probiotic-host interaction with a focus on the molecular microbiology of lactobacilli. Insight into the molecules and genes involved should contribute to a more judicious application of probiotic lactobacilli and to improved screening of novel potential probiotics.     

Evidence-based review of probiotics for antibiotic-associated diarrhea and Clostridium difficile infections

Probiotics are living microbes taken to confer a health benefit on the host. Although probiotics have a long history of use in Europe and Asia and have been on the U.S. market for over 14 years, there is still confusion about how to effectively use them. The use of probiotics for the prevention of antibiotic-associated diarrhea (AAD) and the treatment of Clostridium difficile infections (CDI) has been tested in randomized controlled clinical trials.This paper will review the evidence supporting probiotic therapy for these two diseases and also review the advantages and disadvantages of probiotics. The advantages of probiotic therapy include multiple mechanisms of action against pathogens, the ability to interact with the host's natural defense systems, survival to the target organ and a good risk to benefit ratio. Disadvantages of probiotics include lack of standardization for clinical trial designs, variations in regulatory standards, poor quality control for some products and infrequent serious adverse reactions. Overall, probiotics offer a promising strategy for the prevention and treatment for AAD and CDI     

牙菌斑生物膜的形成与控制

牙菌斑生物膜是附着于牙釉质表面,由复杂的微生物群落构成的一种聚集体。牙菌斑生物膜的形成与生长对口腔健康有着直接或间接的影响,许多研究证实口腔疾病如龋齿和牙周病都与细菌的积累及牙菌斑的形成有关。在牙菌斑生物膜形态建成过程中,牙齿表面最初的定殖菌对生物膜的微生物组成和结构至关重要,这些初级定殖菌决定了后续与之结合形成共生体的微生物种类和数量。不同的微生物组成可能在与生物膜形成相关的口腔病理状况中发挥不同的作用。因此,本文就牙菌斑生物膜的生长及控制进行综述,介绍其微生物的早期定殖和成熟过程、以及通过物理和化学方法对牙菌斑生物膜的控制,以期为了解牙菌斑生物膜的形成机制及相关口腔疾病的预防和治疗提供有价值的参考。     

生物被膜：益生菌肠道定植的新策略

益生菌可改善机体微生态平衡,在促进营养吸收、控制肠道感染和调节免疫功能等方面具有特殊的功效,但存在胃肠道环境难定植、口服生物利用度低等问题。生物被膜是多个细菌黏附于非生物或生物表面,分泌胞外聚合物(extracellular polymeric substances),并将自身包裹其中形成的一种有组织的细菌集团,包含胞外多糖(exopolysaccharides,EPS)、蛋白质、胞外DNA(extracellular deoxyribonucleic acid, eDNA)和脂质等多种组成成分,是一个具有三维立体空间结构的聚集体。被膜状态的益生菌较浮游菌在抗逆性、对抗病原菌和调节免疫功能等方面具有明显优势,这些特点为新型益生菌的开发提供了新的研究思路。本文阐述了被膜状态益生菌的优势,重点介绍了促进益生菌生物被膜形成的活性物及其形成机制,简述了益生菌生物被膜的安全性问题。当前,益生菌生物被膜的研究尚处于起步阶段,希望本文能为该领域未来的研究提供参考。     

Impact of genomics on the field of probiotic research: historical perspectives to modern paradigms

For thousands of years, humans have safely consumed microorganisms through fermented foods. Many of these bacteria are considered probiotics, which act through diverse mechanisms to confer a health benefit to the host. However, it was not until the availability of whole-genome sequencing and the era of genomics that mechanisms of probiotic efficacy could be discovered. In this review, we explore the history of the probiotic concept and the current standard of integrated genomic techniques to discern the complex, beneficial relationships between probiotic microbes and their hosts.     

Application of Microencapsulated Synbiotics in Fruit-Based Beverages

In the last years, demand for functional products containing both prebiotics and probiotics (known as synbiotic) has increased, which stimulated their incorporation into other food matrices than milk-based ones. Synbiotics improve gut functionality as well as respond to the increasing demand of consumers who have become aware of the health benefits of a proper diet. The most important criterion for preserving consumer acceptance in such products is maintaining the minimum viability and activity of probiotics from the beginning of production to the end of shelf-life. For their viability, fixation and multiplying within the host, several solutions have been proposed including the fortification with prebiotics and microencapsulation of prebiotics along with probiotics. The challenge of microencapsulation is to protect the probiotic cells in foods that are not usually considered their vehicle, such as fruit matrices. It is generally known that different prebiotics may exert different degrees of protection on the entrapped bacteria cells. For food products, such as fruit beverages, few works exist that investigate the functionality of synbiotic microcapsules in protecting the survivability of probiotic cells during processing and storage. This article provides an overview of this novel trend based on a review of relevant literature. The article summarizes the synbiotic concept, challenges for synbiotic formulation in fruit beverages, and future perspectives.