The prevalence of dental caries continues to increase, and novel strategies to reverse this trend appear necessary. The probiotic Streptococcus salivarius strain M18 offers the potential to confer ...oral health benefits as it produces bacteriocins targeting the important cariogenic species Streptococcus mutans, as well as the enzymes dextranase and urease, which could help reduce dental plaque accumulation and acidification, respectively. In a randomized double-blind, placebo-controlled study of 100 dental caries-active children, treatment with M18 was administered for 3 months and the participants were assessed for changes to their plaque score and gingival and soft-tissue health and to their salivary levels of S. salivarius, S. mutans, lactobacilli, β-haemolytic streptococci and Candida species. At treatment end, the plaque scores were significantly (P = 0.05) lower for children in the M18-treated group, especially in subjects having high initial plaque scores. The absence of any significant adverse events supported the safety of the probiotic treatment. Cell-culture analyses of sequential saliva samples showed no differences between the probiotic and placebo groups in counts of the specifically enumerated oral micro-organisms, with the exception of the subgroup of the M18-treated children who appeared to have been colonized most effectively with M18. This subgroup exhibited reduced S. mutans counts, indicating that the anti-caries activity of M18 probiotic treatments may be enhanced if the efficiency of colonization is increased. It was concluded that S. salivarius M18 can provide oral health benefits when taken regularly.
Cationic antimicrobial peptides are a novel type of antibiotic offering much potential in the treatment of microbial-related diseases. They offer many advantages for commercial development, including ...a broad spectrum of action and modest size. However, despite the identification or synthetic production of thousands of such peptides, the mode of action remains elusive, except for a few examples. While the dogma for the mechanism of action of antimicrobial peptides against bacteria is believed to be through pore formation or membrane barrier disruption, some peptides clearly act differently and other intracellular target sites have been identified. This article presents an updated review of how cationic antimicrobial peptides are able to affect bacterial killing, with a focus on internal targets.
The human oral cavity contains a diversity of microbial habitats that have been adopted and adapted to as homeland by an amazingly heterogeneous population of microorganisms collectively referred to ...as the oral microbiota. These microbes generally co-habit in harmonious homeostasis. However, under conditions of imposed stress, as with changes to the host's physiology or nutritional status, or as a response to foreign microbial or antimicrobial incursions, some components of the oral "microbiome" (viz. the
microbiota) may enter a dysbiotic state. This microbiome dysbiosis can manifest in a variety of guises including streptococcal sore throats, dental caries, oral thrush, halitosis and periodontal disease. Most of the strategies currently available for the management or treatment of microbial diseases of the oral cavity focus on the repetitive "broad sweep" and short-term culling of oral microbe populations, hopefully including the perceived principal pathogens. Both physical and chemical techniques are used. However, the application of more focused approaches to the harnessing or elimination of key oral cavity pathogens is now feasible through the use of probiotic strains that are naturally adapted for oral cavity colonization and also are equipped to produce anti-competitor molecules such as the bacteriocins and bacteriocin-like inhibitory substances (viz BLIS). Some of these probiotics are capable of suppressing the proliferation of a variety of recognized microbial pathogens of the human mouth, thereby assisting with the restoration of oral microbiome homeostasis. BLIS K12 and BLIS M18, the progenitors of the BLIS-producing oral probiotics, are members of the human oral cavity commensal species
More recently however, a number of other streptococcal and some non-streptococcal candidate oral probiotics have also been promoted. What is becoming increasingly apparent is that the future for oral probiotic applications will probably extend well beyond the attempted limitation of the direct pathological consequences of oral microbiome dysbiosis to also encompass a plethora of systemic diseases and disorders of the human host. The background to and the evolving prospects for the beneficial modulation of the oral microbiome
the application of BLIS-producing
probiotics comprises the principal focus of the present review.
Bacteriocin-producing probiotic Streptococcus salivarius M18 offers beneficial modulatory capabilities within the oral microbiome, apparently through potent inhibitory activity against potentially ...deleterious bacteria, such as Streptococcus pyogenes. The oral cavity persistence of S. salivarius M18 was investigated in 75 subjects receiving four different doses for 28 days. Sixty per cent of the subjects already had some inhibitor-producing S. salivarius in their saliva prior to probiotic intervention. Strain M18's persistence was dependent upon the dose, but not the period of administration. Culture analysis indicated that in some individuals the introduced strain had almost entirely replaced the indigenous S. salivarius, though the total numbers of the species did not increase. Selected subjects showing either high or low probiotic persistence had their salivary populations profiled using Illumina sequencing of the V6 region of the 16S rRNA gene. Analysis indicated that while certain bacterial phenotypes were markedly modulated, the overall composition of the oral microbiome was not modified by the probiotic treatment. Megaplasmids encoding bacteriocins and adhesion factors were transferred in vitro to generate a transconjugant S. salivarius exhibiting enhanced antimicrobial production and binding capabilities to HEp-2 cells. Since no widespread perturbation of the existing indigenous microbiota was associated with oral instillation and given its antimicrobial activity against potentially pathogenic streptococci, it appears that application of probiotic strain M18 offers potential low impact alternative to classical antibiotic prophylaxis. For candidate probiotic strains having relatively poor antimicrobial or adhesive properties, unique derivatives displaying improved probiotic performance may be engineered in vitro by megaplasmid transfer.
The skin is the largest organ in the human body, and it orchestrates many functions that are fundamentally important for our survival. Although the skin might appear to present a relatively ...inhospitable or even hostile environment, a multitude of commensals and also some potentially pathogenic microorganisms have successfully adapted to survive and/or thrive within the diverse ecological niches created by the skin’s topographical architecture. Dysbiosis within these microbial populations can result in the emergence and pathological progression of skin diseases. Unsurprisingly, this has led to a new focus of research both for the medical dermatology and cosmetic industries that is concerned with modulation of the skin microbiome to help address common microbially mediated or modulated conditions such as acne, body odour, and atopic dermatitis. This review presents an overview of our current understanding of the complex relationship of the skin with its microbiome and then introduces the concept of probiotic intervention for the management of microbial dysbiosis within the skin ecosystem.
Probiotics in cosmetics represent a new and burgeoning area of research, attracting attention from cosmetic manufacturers and customers looking for natural or additional alternatives in their ...skincare regimens. Probiotics not only promote beneficial microbiomes to improve skin health but can also modulate the visual, topographical, and mechanical attributes to improve skin quality. This study was conducted in healthy adults to determine the effect of direct skin application of a topical serum formulation containing the live probiotic Micrococcus luteus Q24 on several key cosmetic skin quality parameters and its beneficial impact on the modulation of the skin microbiome. Quantitative changes in various skin parameters were measured using a skin analyser device and skin swabs were analysed using whole-genome sequencing to monitor microbial diversity and levels of probiotic colonization. Compared to the baseline, significant reductions in the pores, spots, wrinkles, and impurities scores, and an increase of 101% in the hydration score were observed. Additionally, 45–80% of participants showed a decrease in pores, spots, wrinkles, and impurities and 90% of participants showed an increase in hydration after 25 days of probiotic serum application. The WGS analysis of the skin swab samples showed a significant increase in the relative abundance of M. luteus Q24. The results from this study indicate that topical application of a serum containing the probiotic M. luteus Q24 offers the benefit of improving skin health quality.
Streptococcus salivarius
BLIS K12 is a probiotic strain developed for application to the oral cavity. The strain was originally characterised for its in vitro antibacterial activity against the ...prominent oral pathogen
Streptococcus pyogenes.
More recent research has expanded its applications to include reducing halitosis, preventing otitis media and protecting against virus infections of the respiratory tract. A potential mechanism for this anti-viral activity could be the stimulation of salivary interferon gamma (IFN-γ) production in the oral cavity. The aim of this study was to investigate whether the ingestion of and oral cavity colonisation by
S. salivarius
BLIS K12 is associated with enhancement of IFN-γ levels in saliva. Application of ELISA demonstrated that consumption of
S. salivarius
BLIS K12 effected an increase in salivary IFN-γ, and this response was more consistent with use of viable cells than following ingestion of heat-killed
S. salivarius
BLIS K12. Interestingly, those subjects who more successfully colonised with
S. salivarius
BLIS K12 did not experience a relatively larger increase in their IFN-γ levels, indicating that the observed IFN-γ response occurs independently of colonisation efficacy. In summary, the consumption of
S. salivarius
BLIS K12 increases salivary levels of IFN-γ, an effect that may contribute to protection of the host against certain virus infections.
Acanthosis nigricans (AN) is a strong correlate of obesity and is considered a marker of insulin resistance (IR). AN is associated with various other cardiometabolic risk factors (CMRFs). However, ...the direct causal relationship of IR with AN in obesity has been debated. Therefore, we aimed to examine the complex causal relationships among the troika of AN, obesity, and IR in Mexican Americans (MAs).
We used data from 670 non-diabetic MA children, aged 6-17 years (49% girls). AN (prevalence 33%) severity scores (range 0-5) were used as a quasi-quantitative trait (AN-q) for analysis. We used the program SOLAR for determining phenotypic, genetic, and environmental correlations between AN-q and CMRFs (e.g., BMI, HOMA-IR, lipids, blood pressure, hs-C-reactive protein (CRP), and Harvard physical fitness score (PFS)). The genetic and environmental correlations were subsequently used in mediation analysis (AMOS program). Model comparisons were made using goodness-of-fit indexes.
Heritability of AN-q was 0.75 (p<0.0001). It was positively/significantly (p<0.05) correlated with traits such as BMI, HOMA-IR, and CRP, and negatively with HDL-C and PFS. Of the models tested, indirect mediation analysis of BMI→HOMA-IR→AN-q yielded lower goodness-of-fit than a partial mediation model where BMI explained the relationship with both HOMA-IR and AN-q simultaneously. Using complex models, BMI was associated with AN-q and IR mediating most of the CMRFs; but no relationship between IR and AN-q.
Our study suggests that obesity explains the association of IR with AN, but no causal relationship between IR and AN in Mexican American children.
Streptococcus salivarius
K12 is an oral probiotic known to contribute to protection against oral pathogenic bacteria in humans. Studies of immune responses to
S. salivarius
K12 have focused on the ...oral cavity, and systemic immune responses have not yet been reported. The aim of this study was to identify acute systemic immune responses to the commercial product,
S. salivarius
BLIS K12, in a double-blinded, placebo-controlled human clinical trial. It was hypothesised that consumption of
S. salivarius
BLIS K12 would induce an anti-inflammatory response and a decrease in pro-inflammatory cytokines. Blood samples were obtained from participants prior to a single dose of
S. salivarius
BLIS K12 or a placebo and then secondary blood samples were obtained 24 h and 7 days post-consumption. Samples were analysed using multi-parametric flow cytometry, to quantify immune cell frequency changes, and by a LEGENDplex assay of human inflammatory cytokines. Consumption of
S. salivarius
BLIS K12 was associated with increased levels of IL-8 at 24 h. The frequency of Tregs increased in samples taken 7 days after probiotic consumption, and IL-10 concentrations were higher at 7 days than 24 h after consumption. There was no difference in the frequency and/or activation of CD4
+
T cells, CD8
+
T cells, B cells and NK cells. Interestingly, there was an increase in IL-12, 7 days after the consumption of
S. salivarius
BLIS K12. Collectively, this research demonstrates that ingestion of the probiotic
S. salivarius
K12 can induce changes in the systemic immune response. The implications of the generation and type of immune response warrant further study to determine potential health benefits.
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