The Commensal
            <i>Streptococcus salivarius</i>
            K12 Downregulates the Innate Immune Responses of Human Epithelial Cells and Promotes Host-Microbe Homeostasis

Cosseau, Céline; DeVine, Deirdre; Dullaghan, Edie; Gardy, Jennifer L.; Chikatamarla, Avinash; Gellatly, Shaan L.; Yu, Lorraine L.; Pistolic, Jelena; Falsafi, Reza; Tagg, John; Hancock, Robert E. W.

doi:10.1128/iai.00188-08

Cited by 262 publications

(249 citation statements)

References 52 publications

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“…The Shannon index scores for the URT of the mice in this study, however, are about half of those found in the mouse gut (19), which is probably caused by the general predominance of certain bacterial species in the URT, a phenomenon which is also observed in humans (3,12). In the URT of naive mice, young-adult mice showed a high abundance of normal commensals, such as Streptococcaceae, Porphyromonadaceae, and Lachnospiraceae, which are generally considered beneficial for the host (1,(20)(21)(22). Interestingly, elderly mice had consistently lower abundances of anaerobic bacteria like the Porphyromonadaceae, and specifically, of Barnesiella bacteria.…”

Section: Discussionmentioning

confidence: 62%

Respiratory Microbiota Dynamics following Streptococcus pneumoniae Acquisition in Young and Elderly Mice

et al. 2014

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The upper respiratory tract (URT) is a distinct microbial niche of low-density bacterial communities and, also, a portal of entry for many potential pathogens, including Streptococcus pneumoniae. Thus far, animal models have been used to study the dynamics of and interactions between limited numbers of different species in the URT. Here, we applied a deep sequencing approach to explore, for the first time, the impact of S. pneumoniae acquisition on URT microbiota in a mouse model, as well as potential age-dependent effects. Young-adult and elderly mice were inoculated intranasally with S. pneumoniae, and nasal lavage samples were collected for up to 28 days postcolonization. Bacterial DNA extracted from lavage samples was subjected to barcoded pyrosequencing of the V5-to-V7 hypervariable region of the small-subunit rRNA gene. We observed highly diverse microbial profiles, with the presence overall of 15 phyla and approximately 645 operational taxonomic units (OTUs). We noted differences in the composition of microbiota between young and elderly mice, with a significantly higher abundance of Bacteroidetes in the young mice. The introduction of S. pneumoniae into the URT led to a temporary dominance of pneumococci in the microbiota of all mice, accompanied by a significant decrease in microbial diversity. As mice gradually cleared the colonization, the diversity returned to baseline levels. Diversification was accompanied by an early expansion of Bacteroidetes, Staphylococcus spp., and Lachnospiraceae. Moreover, the Bacteroidetes expansion was significantly greater in young-adult than in elderly mice. In conclusion, we observed differences in URT microbiota composition between naive young-adult and elderly mice that were associated with differences in pneumococcal clearance over time.

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Section: Discussionmentioning

confidence: 62%

Respiratory Microbiota Dynamics following Streptococcus pneumoniae Acquisition in Young and Elderly Mice

et al. 2014

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“…Additionally, health-associated commensal species can have comparable mechanisms; for example, Streptococcus salivarius inhibits IL-8 secretion (Cosseau 2008). The microbiota can thus correlate with antiinflammatory mediators and also actively prevent inflammation by inhibiting proinflammatory cytokines.…”

Section: Resilience To Destructive Inflammationmentioning

confidence: 99%

Resilience of the Oral Microbiota in Health: Mechanisms That Prevent Dysbiosis

2017

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word count: 278Reference number: 61 Figures: 6 2 AbstractDental diseases are now viewed as a consequence of a deleterious shift in the balance of the normally stable resident oral microbiome. It is known that frequent carbohydrate consumption or reduced saliva flow can lead to caries, and excessive plaque accumulation increases the risk of periodontal diseases. However, when these disease drivers are present, while some individuals appear to be susceptible, others are more tolerant or resilient to suffering from undesirable changes in their oral microbiome. Health-maintaining mechanisms that limit the effect of disease drivers include the complex set of metabolic and functional inter-relationships that develop within dental biofilms and between biofilms and the host. In contrast, 'positive feedback loops' can develop within these microbial communities that disrupt resilience and provoke a large and abrupt change in function and structure of the ecosystem (a microbial 'regime shift'), that promotes dysbiosis and oral disease. For instance, acidification due to carbohydrate fermentation or inflammation in response to accumulated plaque select for a cariogenic or periopathogenic microbiota, respectively, in a chain of selfreinforcing events. Conversely, in tolerant individuals, health-maintaining mechanisms, including negative feedback to the drivers, can maintain resilience and promote resistance to and recovery from disease drivers. Recently studied health-maintaining mechanisms include ammonium production, limiting a drop in pH that can lead to caries, and denitrification, which could inhibit several stages of disease-associated positive feedback loops. OMICS studies comparing the microbiome of, and its interaction with, susceptible and tolerant hosts can detect markers of resilience. The neutralization or inhibition of these 'disease drivers', together with the identification and promotion of health-promoting species and functions, for example by pre-and probiotics, could enhance microbiome resilience and lead to new strategies to prevent disease.3

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“…7 There is evidence for active communication ('crosstalk') between some of the resident bacteria and mucosal cells that downregulates potentially damaging pro-inflammatory host responses to the normal oral microflora, while the host retains the ability to respond to genuine microbial insults. 7,8 The precise biological mechanisms involved in this 'cross-talk' are still being determined, but pathogenic and non-pathogenic bacteria may initiate different intracellular signalling pathways and innate immune responses in epithelial cells. 9 As at other body sites, the resident oral microflora displays 'colonisation resistance' and prevents the establishment in the mouth of the many exogenous microorganisms we come into contact with on a daily basis.…”

Section: What Benefits Do the Resident Oral Microflora Provide To Thementioning

confidence: 99%

Contemporary perspective on plaque control

2012

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The Commensal Streptococcus salivarius K12 Downregulates the Innate Immune Responses of Human Epithelial Cells and Promotes Host-Microbe Homeostasis

Cited by 262 publications

References 52 publications

Respiratory Microbiota Dynamics following Streptococcus pneumoniae Acquisition in Young and Elderly Mice

Respiratory Microbiota Dynamics following Streptococcus pneumoniae Acquisition in Young and Elderly Mice

Resilience of the Oral Microbiota in Health: Mechanisms That Prevent Dysbiosis

Contemporary perspective on plaque control

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