Manipulation of Saliva-Derived Microcosm Biofilms To Resemble Dysbiotic Subgingival Microbiota.

Periodontitis is a highly prevalent oral inflammatory disease triggered by dysbiotic subgingival microbiota. For the development of microbiome modulators that can reverse the dysbiotic state and reestablish a health-associated microbiota, a high-throughput in vitro multispecies biofilm model is needed. Our aim is to establish a model that resembles a dysbiotic subgingival microbial biofilm by incorporating the major periodontal pathogen Porphyromonas gingivalis into microcosm biofilms cultured from pooled saliva of healthy volunteers. The biofilms were grown for 3, 7, and 10 days and analyzed for their microbial composition by 16S rRNA gene amplicon sequencing as well as measurement of dipeptidyl peptidase IV (DPP4) activity and butyric acid production. The addition of P. gingivalis increased its abundance in saliva-derived microcosm biofilms from 2.7% on day 3 to >50% on day 10, which significantly reduced the Shannon diversity but did not affect the total number of operational taxonomic units (OTUs). The P. gingivalis-enriched biofilms displayed altered microbial composition as revealed by principal-component analysis and reduced interactions among microbial species. Moreover, these biofilms exhibited enhanced DPP4 activity and butyric acid production. In conclusion, by adding P. gingivalis to saliva-derived microcosm biofilms, we established an in vitro pathogen-enriched dysbiotic microbiota which resembles periodontitis-associated subgingival microbiota in terms of increased P. gingivalis abundance and higher DPP4 activity and butyric acid production. This model may allow for investigating factors that accelerate or hinder a microbial shift from symbiosis to dysbiosis and for developing microbiome modulation strategies.IMPORTANCE In line with the new paradigm of the etiology of periodontitis, an inflammatory disorder initiated by dysbiotic subgingival microbiota, novel therapeutic strategies have been proposed targeting reversing dysbiosis and restoring host-compatible microbiota rather than eliminating the biofilms unselectively. Thus, appropriate laboratory models are required to evaluate the efficacy of potential microbiome modulators. In the present study, we used the easily obtainable saliva as an inoculum, spiked the microcosm biofilms with the periodontal pathogen Porphyromonas gingivalis, and obtained a P. gingivalis-enriched microbiota, which resembles the in vivo pathogen-enriched subgingival microbiota in severe periodontitis. This biofilm model circumvents the difficulties encountered when using subgingival plaque as the inoculum and achieves microbiota in a dysbiotic state in a controlled and reproducible manner, which is required for high-throughput and large-scale evaluation of strategies that can potentially modulate microbial ecology.

Synergetic antimicrobial effect of chlorin e6 and hydrogen peroxide on multi-species biofilms.

Antimicrobial photodynamic therapy (aPDT) has been considered as a potential alternative to antibiotics for the treatment of biofilm infections. There is evidence that an additional H2O2 enhances the antimicrobial efficacy of aPDT. However, the minimum H2O2 concentration to achieve this synergistic effect is unclear. A saliva-derived multi-species biofilm was treated with the photosensitizer chlorin e6 (Ce6, 50 µM), H2O2 (0.3, 3.3, 33.3 mM), or their combination for 5 min, followed by no irradiation or irradiation at 15 J (cm2)-1 (λ = 450 nm or 660 nm), with or without oxygen. Biofilm viability and metabolic activity were evaluated. The combination of 33.3 mM H2O2 and Ce6-aPDT strongly enhanced antimicrobial efficacy compared with either component alone, irrespective of oxygen availability and irradiation wavelength. In particular, the combination resulted in a 6.6-log colony forming unit (CFU) reduction anaerobically under blue irradiation. This combination is a promising treatment for biofilm infections, especially those thriving in an anaerobic microenvironment.

Effects of bacterial physiological states and bacterial species on host-microbe interactions.

This study investigated how the physiological states of Aggregatibacter actinomycetemcomitans (Aa) and Streptococcus mitis affect their intracellular invasion capabilities and the resulting host cell responses. The physiological states included two forms of planktonic states, floating or sedimented (by centrifugation) and the biofilm state (with centrifugation). Confluent epithelial Ca9-22 cells were challenged with floating or sedimented planktonic cultures, or with 24-h biofilms for 3 h. The results show that intracellular invasion efficiencies were clearly affected by the bacterial physiological states. For both bacterial species, the sedimented-cells displayed 2-10 times higher invasion efficiency than the floating-cells (p < 0.05). The invasion efficiency of Aa biofilms was three fold lower than sedimented cells, whereas those of S. mitis biofilms were similar to sedimented cells. Unlike invasion, the metabolic activities of Ca9-22 were unaffected by different bacterial physiological states. However, Aa biofilms induced higher IL-1ß expression than planktonic cultures. In conclusion, different bacterial physiological states can affect the outcomes of (in vitro) host-microbe interaction in different ways.

A Single Nucleotide Change in the Promoter mutp Enhances Fluoride Resistance of Streptococcus mutans.

Previously, we identified a single nucleotide mutation in the promoter (mutp) of the fluoride antiporter-coding genes in a naturally fluoride-resistant Streptococcus mutans strain. Here, we studied the role of this mutation in a defined genetic background. The results confirmed that this mutation alone confers fluoride resistance on S. mutans, as shown by growth and lactic acid production assays. This resistance was explained by constitutively higher mutp promoter activity and upregulation of the fluoride antiporter-coding genes.

Epithelial cell detachment by Porphyromonas gingivalis biofilm and planktonic cultures.

Porphyromonas gingivalis is present as a biofilm at the sites of periodontal infections. The detachment of gingival epithelial cells induced by P. gingivalis biofilms was examined using planktonic cultures as a comparison. Exponentially grown planktonic cultures or 40-h biofilms were co-incubated with epithelial cells in a 24-well plate for 4 h. Epithelial cell detachment was assessed using imaging. The activity of arginine-gingipain (Rgp) and gene expression profiles of P. gingivalis cultures were examined using a gingipain assay and quantitative PCR, respectively. P. gingivalis biofilms induced significantly higher cell detachment and displayed higher Rgp activity compared to the planktonic cultures. The genes involved in gingipain post-translational modification, but not rgp genes, were significantly up-regulated in P. gingivalis biofilms. The results underline the importance of including biofilms in the study of bacterial and host cell interactions.

Diversity of Streptococcus mutans strains in bacterial interspecies interactions.

Biofilms are matrix-enclosed microbial population adhere to each other and to surfaces. Compared to planktonic bacterial cells, biofilm cells show much higher levels of antimicrobial resistance. We aimed to investigate Streptococcus mutans strain diversity in biofilm formation and chlorhexidine (CHX) resistance of single S. mutans and dual S. mutans-Enterococcus faecalis biofilms. Four clinical S. mutans strains (C180-2, C67-1, HG723 and UA159) formed 24-h biofilms with or without an E. faecalis strain. These biofilms were treated for 10 min with 0.025% CHX. Biofilm formation, CHX resistance and S.mutans-E. faecalis interactions were evaluated by biomass staining, resazurin metabolism, viable count and competition agar assays. The main finding is that the presence of E. faecalis generally reduced all dual-species biofilm formation, but the proportions of S. mutans in the dual-species biofilms as well as CHX resistance displayed a clear S. mutans strain dependence. In particular, decreased resistance against CHX was observed in dual S. mutans C67-1 biofilms, while increased resistance was found in dual S. mutans UA159 biofilms. In conclusion, the interaction of S. mutans with E. faecalis in biofilms varies between strains, which underlines the importance of studying strain diversity in inter-species virulence modulation and biofilm antimicrobial resistance.

[Analysis of genetic diversity of cultivated Eucommia ulmoides from Guizhou Province by phenotypic traits and SCoT markers].

OBJECTIVE: To explore the phenotypic characteristics and the genetic diversity of cultivated Eucommia ulmoides from Guizhou Province. METHODS: The genetic diversity of cultivated Eucommia ulmoides in Guizhou Province was analyzed by phenotypic traits and start condon targeted polymorphism(SCoT)markers. RESULTS: The phenotypic diversity index of the number of buds on neonatal branch was the highest, which was 2.0638, and the number of blades on neonatal branch was the lowest,which was 1.7084. By data obtained, 40 cultivated samples of Eucommia ulmoides in Guizhou Province could be divided into 4 groups. A total of 76 bands were produced by 10 primers, among which 50 bands were polymorphic bands, and the percentage of polymorphic bands was 65.79%. The average value of Nei's genetic diversity index (H) was 0.1937, Shannon's information index (I) was 0.2832, Genetic differentiation coefficient (Gst) was 0.1733, and the gene flow (Nm) among populations was 2.3848. Cluster analysis based on genetic identity indicated that 4 populations could be divided into 2 groups. CONCLUSION: Genetic diversity of cultivated populations of Eucommia ulmoides in Guizhou Province had little differences. The genetic differentiation within populations was bigger than that among the populations. The high level of gene flow among populations was beneficial to extension of Eucommia ulmoides. The phenotypic cluster was similar to the SCoT cluster, the two classification results were significantly correlated with geographic position,which can providing a good foundation for the identification of Eucommia ulmoides germplasms.

Fungal mycobiome-mediated immune response: a non-negligible promoter in pancreatic oncogenesis and chemoresistance.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers in humans due to late diagnosis and poor response to treatments. The tumor microenvironment (TME) of PDAC is characterized by a distinctive, suppressive immune profile, which inhibits the protective functions of anti-tumor immunity and thereby contributes to PDAC progression. Recently, the study of Alam et al. discovered for the first time that the intratumoral fungal mycobiome could contribute to the recruitment and activation of type 2 immune cells in the TME of PDAC via enhancing the secretion of a chemoattractant, interleukin (IL-) 33. In this article, we reviewed the important findings of this study. Together with our findings, we synthetically discussed the role of the fungal mycobiome in orchestrating the immune response and thereby modulating tumor progression.

Reflectance Confocal Microscopy and Dermoscopy For the Diagnosis and Treatment of Cutaneous Larva Migrans.

We describe a 39-year-old woman with a 1-month-old linear erythema diagnosed with cutaneous larva migrans by reflectance confocal microscopy (RCM). This case reveals that the great significance of diagnosing and treating cutaneous larva migrans (CLM) by RCM and dermoscopy, which might provide novel insights into dermatological clinical practice.

Differential Modulation of Saliva-Derived Microcosm Biofilms by Antimicrobial Peptide LL-31 and D-LL-31.

Microbiome modulation, aiming to restore a health-compatible microbiota, is a novel strategy to treat periodontitis. This study evaluated the modulation effects of antimicrobial peptide LL-31 and its D-enantiomer (D-LL-31) on saliva-derived microcosm biofilms, spiked with or without Porphyromonas gingivalis. To this end, one-day-old biofilms were incubated for 24 h with biofilm medium alone, or medium containing 40 µM LL-31 or D-LL-31, after which biofilms were grown for 5 days. Biofilms were assessed at 1 day and 5 days after intervention for the total viable cell counts, dipeptidyl peptidase IV (DPP4) activity, P. gingivalis amount (by qPCR) and microbial composition (by sequencing). The results showed that D-LL-31, not LL-31, significantly reduced the total viable cell counts, the P. gingivalis amount, and the DPP4 activity of the biofilms spiked with P. gingivalis, but only at 1 day after intervention. In the biofilms spiked with P. gingivalis, D-LL-31 tended to reduce the α-diversity and the compositional shift of the biofilms in time as compared to the control and LL-31 groups. In conclusion, D-LL-31 showed a better performance than LL-31 in biofilm modulation. The biofilm modulation function of the peptides could be impaired when the biofilms were in a severely dysbiotic state.

Adjuvant Chemotherapy May Not Be Necessary for Women with Stage IC1 Epithelial Ovarian Cancer.

OBJECTIVE: To determine whether adjuvant chemotherapy improves the prognoses in women with stage IC1 epithelial ovarian cancer (EOC). METHODS: All eligible women diagnosed with stage IC1 EOC from 2003 to 2019 in Tongji Hospital were included. Patient characteristics, tumor features, surgical types, and chemotherapeutic treatments were collected. Kaplan-Meier analysis and Cox regression analysis were performed to evaluate progression-free survival (PFS) and overall survival (OS). RESULTS: Of the 140 patients (median age: 47 years old), 13 patients did not receive chemotherapy, and 127 received adjuvant chemotherapy. Kaplan-Meier analysis indicated that adjuvant chemotherapy offered no obvious improvements in PFS or OS. Subgroup analysis was conducted to adjust for the significant difference in incomplete staging surgery between the two groups, and chemotherapy still showed no benefit for survival. Cox regression analysis indicated that incomplete staging surgery was a risk factor for a worse PFS and that adjuvant chemotherapy remained unrelated to the prognosis. The patients were further divided based on the National Comprehensive Cancer Network recommendations: patients for whom observation is optional and chemotherapy would not improve the prognosis; and patients for whom chemotherapy is recommended. The results showed that postoperative chemotherapy had little correlation with survival. CONCLUSION: Our study suggests that postoperative chemotherapy may be unnecessary for patients with stage IC1 EOC. According to our results, incomplete staging surgery is a significant risk factor for PFS.

The macrophage scavenger receptor CD163 functions as an innate immune sensor for bacteria.

The plasma membrane glycoprotein receptor CD163 is a member of the scavenger receptor cystein-rich (SRCR) superfamily class B that is highly expressed on resident tissue macrophages in vivo. Previously, the molecule has been shown to act as a receptor for hemoglobin-haptoglobin complexes and to mediate cell-cell interactions between macrophages and developing erythroblasts in erythroblastic islands. Here, we provide evidence for a potential role for CD163 in host defense. In particular, we demonstrate that CD163 can function as a macrophage receptor for bacteria. CD163 was shown to bind both Gram-positive and -negative bacteria, and a previously identified cell-binding motif in the second scavenger domain of CD163 was sufficient to mediate this binding. Expression of CD163 in monocytic cells promoted bacteria-induced proinflammatory cytokine production. Finally, newly generated antagonistic antibodies against CD163 were able to potently inhibit cytokine production elicited by bacteria in freshly isolated human monocytes. These findings identify CD163 as a macrophage receptor for bacteria and suggest that, during bacterial infection, CD163 on resident tissue macrophages acts as an innate immune sensor and inducer of local inflammation.

[Regulatory effect of Bushenfang on the serum testosterone level of naturally aging rats and its mechanism].

OBJECTIVE: To study the regulatory effect of Bushenfang on the serum testosterone (T) level of naturally aging rats and its mechanism, in order to provide a theoretical and experimental basis for the clinical treatment of late onset hypogonadism (LOH) in males. METHODS: Thirty-two 18-month-old male SD rats were randomly divided into four groups of equal number, naturally aging model and low-, medium- and high-dose Bushenfang groups, and another eight 4-month-old rats were taken as normal controls. The rats of the aging model and normal control groups were treated with normal saline, while those of the low-, medium- and high-dose Bushenfang groups received intragastrically Bushenfang at 3.25, 7.50 and 15.00 g/kg, respectively, all for 3 weeks. Then the rats were sacrificed, the histomorphologic changes of the testis observed by HE staining, the serum T level measured by radioimmunoassay, and the expressions of the StAR protein, P450scc and 3beta-HSD I determined by RT-PCR. RESULTS: The number of Leydig cells was obviously increased after Bushenfang treatment. The levels of serum T were significantly higher in the low-, medium- and high-dose Bushenfang groups ([6.74 +/- 1.56] nmol/L, [8.50 +/- 1.99] nmol/L and [12.41 +/- 2.91] nmol/L) than in the model group ([3.48 +/- 0.75] nmol/L) (P < 0.05). The three Bushenfang groups also showed a remarkable elevation in the mRNA expressions of StAR (0.74 +/- 0.29, 0.83 +/- 0.32 and 1.35 +/- 0.50), P450scc (0.72 +/- 0.36, 1.023 +/- 0.30 and 1.41 +/- 0.37) and 3beta-HSD I (0.58 +/- 0.14, 0.72 +/- 0.07 and 0.85 +/- 0.18), as compared with the models (StAR: 0.44 +/- 0.09; P450scc: 0.33 +/- 0.05; 3beta-HSD I: 0.34 +/- 0.02), with significant differences in the StAR expression between the high-dose Bushenfang and the model groups, as well as in P450scc and 3beta-HSD I expressions between the medium- and high-dose Bushenfang and the model groups (P < 0.05). CONCLUSION: Bushenfang could improve the pathological status of testicular injury and increase the expression of testosterone synthetase, which might be the mechanism behind its regulatory effect on the serum T level of aging rats.

Reprocessing 16S rRNA Gene Amplicon Sequencing Studies: (Meta)Data Issues, Robustness, and Reproducibility.

High-throughput sequencing technology provides an efficient method for evaluating microbial ecology. Different bioinformatics pipelines can be used to convert 16S ribosomal RNA gene amplicon sequencing data into an operational taxonomic unit (OTU) table that is used to analyze microbial communities. It is important to assess the robustness of these pipelines, each with specific algorithms and/or parameters, and their influence on the outcome of statistical tests. Articles with publicly available datasets on the oral microbiome were searched for, and five datasets were retrieved. These were from studies on changes in microbiota related to smoking, oral cancer, caries, diabetes, or periodontitis. Next, the data was processed with four pipelines based on VSEARCH, USEARCH, mothur, and UNOISE3. OTU tables were rarefied, and differences in α-diversity and ß-diversity were tested for different groups in a dataset. Finally, these results were checked for consistency among these example pipelines. Of articles that deposited data, only 57% made all sequencing and metadata available. When processing the datasets, issues were encountered, caused by read characteristics and differences between tools and their defaults in combination with a lack of detail in the methodology of the articles. In general, the four mainstream pipelines provided similar results, but importantly, P-values sometimes differed between pipelines beyond the significance threshold. Our results indicated that for published articles, the description of bioinformatics methods and data deposition should be improved, and regarding reproducibility, that analysis of multiple subsamples is required when using rarefying as library-size normalization method.

Saliva-derived microcosm biofilms grown on different oral surfaces in vitro.

The microbial composition of a specific oral niche could be influenced by initial bacterial adherence, nutrient and physiological property of the local surface. To investigate the influence of nutrient and surface properties on microbial composition, saliva-derived biofilms were grown in agar on three substrata: Reconstructed Human Gingiva (RHG), a hydroxyapatite (HAP) surface, and a titanium (TI) surface. Agar was mixed with either Brain Heart Infusion (BHI) or Thompson (TP) medium. After 1, 3, or 5 days, biofilm viability (by colony forming units) and microbiome profiles (by 16 S rDNA amplicon sequencing) were determined. On RHG, biofilm viability and composition were similar between BHI and TP. However, on the abiotic substrata, biofilm properties greatly depended on the type of medium and substratum. In BHI, the viability of HAP-biofilm first decreased and then increased, whereas that of TI-biofilm decreased in time until a 6-log reduction. In TP, either no or a 2-log reduction in viability was observed for HAP- or TI-biofilms respectively. Furthermore, different bacterial genera (or higher level) were differentially abundant in the biofilms on 3 substrata: Haemophilus and Porphyromonas for RHG; Bacilli for HAP and Prevotella for TI. In conclusion, RHG, the biotic substratum, is able to support a highly viable and diverse microbiome. In contrast, the viability and diversity of the biofilms on the abiotic substrata were influenced by the substrata type, pH of the environment and the richness of the growth media. These results suggest that the host (oral mucosa) plays a vital role in the oral ecology.

Comparison of Red-Complex Bacteria Between Saliva and Subgingival Plaque of Periodontitis Patients: A Systematic Review and Meta-Analysis.

The development of periodontitis is associated with an imbalanced subgingival microbial community enriched with species such as the traditionally classified red-complex bacteria (Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola). Saliva has been suggested as an alternative to subgingival plaque for the microbial analysis due to its easy and non-invasive collection. This systematic review aims to determine whether the levels of red-complex bacteria assessed using saliva reflect those in subgingival plaque from periodontitis patients. The MEDLINE, EMBASE, and Cochrane Library databases were searched up to April 30, 2021. Studies were considered eligible if microbial data of at least one of the red-complex species were reported in both saliva and subgingival plaque from periodontitis patients, based on DNA-based methods. Of the 17 included studies, 4 studies used 16S rRNA gene sequencing techniques, and the rest used PCR-based approaches. The detection frequency of each red-complex species in periodontitis patients was reported to be > 60% in most studies, irrespective of samples types. Meta-analyses revealed that both detection frequencies and relative abundances of red-complex bacteria in saliva were significantly lower than those in subgingival plaque. Moreover, the relative abundances of all 3 bacterial species in saliva showed significantly positive correlation with those in subgingival plaque. In conclusion, current evidence suggests that one-time saliva sampling cannot replace subgingival plaque for microbial analysis of the red-complex bacteria in periodontitis patients. Given the positive microbial associations between saliva and subgingival plaque, a thorough review of longitudinal clinical studies is needed to further assess the role of saliva.

Streptococcus mutans competence-stimulating peptide inhibits Candida albicans hypha formation.

The oral cavity is colonized by microorganisms growing in biofilms in which interspecies interactions take place. Streptococcus mutans grows in biofilms on enamel surfaces and is considered one of the main etiological agents of human dental caries. Candida albicans is also commonly found in the human oral cavity, where it interacts with S. mutans. C. albicans is a polymorphic fungus, and the yeast-to-hypha transition is involved in virulence and biofilm formation. The aim of this study was to investigate interkingdom communication between C. albicans and S. mutans based on the production of secreted molecules. S. mutans UA159 inhibited C. albicans germ tube (GT) formation in cocultures even when physically separated from C. albicans. Only S. mutans spent medium collected in the early exponential phase (4-h-old cultures) inhibited the GT formation of C. albicans. During this phase, S. mutans UA159 produces a quorum-sensing molecule, competence-stimulating peptide (CSP). The role of CSP in inhibiting GT formation was confirmed by using synthetic CSP and a comC deletion strain of S. mutans UA159, which lacks the ability to produce CSP. Other S. mutans strains and other Streptococcus spp. also inhibited GT formation but to different extents, possibly reflecting differences in CSP amino acid sequences among Streptococcus spp. or differences in CSP accumulation in the media. In conclusion, CSP, an S. mutans quorum-sensing molecule secreted during the early stages of growth, inhibits the C. albicans morphological switch.

Photodynamic inactivation mediated by methylene blue or chlorin e6 against Streptococcus mutans biofilm.

BACKGROUND: An appropriate photosensitizer (PS) for photodynamic inactivation should have a pronounced antimicrobial efficacy but low dark toxicity. The aim of this study is to investigate the concentration-dependent antimicrobial efficacies of methylene blue (MB) and chlorin e6 (Ce6), against Streptococcus mutans biofilms and to compare the efficacies of these two PSs. METHODS: The 48-h S. mutans UA159 biofilms, grown on glass coverslips, were subjected to MB or Ce6 at 25, 50, 100 and 200 µM with or without irradiation by 660 nM LED light (L). Control groups (-PS-L and -PS + L) were also included. Viability of the biofilm was analyzed by CFU/biofilm and biofilm lactic acid production was quantified by an enzymatic assay. RESULTS: With irradiation, MB under 25 µM resulted in 2-log reduction in biofilm viability and 30-fold reduction in biofilm lactic acid production. However, this biofilm killing efficacy did not change with increasing MB concentration. The biofilm killing efficacy of Ce6 increased with increasing Ce6 concentrations and resulted in 5-log reduction in biofilm viability. The lactic acid inhibitory effect of Ce6 was significantly lower than MB at 25 µM (p<0.01) but higher than MB at 200 µM (p=0.05), although the difference at 200 µM did not reach statistical significance. No dark toxicity could be observed for MB whereas low dark toxicity could be seen for Ce6 when the concentration is above 50 µM. CONCLUSION: Ce6 under 200 µM showed to be a more powerful PS for photodynamic inactivation than MB. Both Ce6- and MB-based photodynamic inactivation are useful methods for biofilm control in caries prevention.

Efficiency of chemical versus mechanical disruption methods of DNA extraction for the identification of oral Gram-positive and Gram-negative bacteria.

OBJECTIVE: Clinical diagnostics often requires the detection of multiple bacterial species in limited clinical samples with a single DNA extraction method. This study aimed to compare the bacterial DNA extraction efficiency of two lysis methods automated with the MagNA-Pure LC instrument. The samples included five oral bacterial species (three Gram-positive and two Gram-negative) with or without human saliva background. METHODS: Genomic DNA (gDNA) was extracted from bacterial cultures by bead-beating lysis (BMP) or chemical lysis (MP), followed by automated purification and measurement by quantitative PCR. RESULTS: For pure bacterial cultures, the MP method yielded higher quantities of extracted DNA and a lower detection limit than the BMP method, except where the samples contained high numbers of Gram-positive bacteria. For bacterial cultures with a saliva background, no difference in gDNA extraction efficacy was observed between the two methods. CONCLUSIONS: The efficiency of a bacterial DNA extraction method is not only affected by the bacterial cell wall structure but also by the sample milieu. The MP method provided superior gDNA extraction efficiency when the samples contained a single bacterial species, whereas either of the BMP and MP methods could be applied with similar efficiencies to samples containing multiple species of bacteria.

The Role of the Microbiome in Cancer and Therapy Efficacy: Focus on Lung Cancer.

The microbiome is extremely important for human health; more recently its role in the context of cancer became clear. Microbial effects range from enhancing cancer immunity and cancer therapy efficacy, to promoting cancer progression and inhibiting treatment efficacy. These broad implications led researchers to investigate these specific interactions, as well as how modification of the microbiome can improve cancer survival and treatment efficacy. While these interactions are better established for cancers such as gastric cancer, they are far less understood in others. As non-small cell lung cancer (NSCLC) makes up the majority of lung cancer cases, and is among the top causes of cancer deaths worldwide, understanding the mechanisms by which the microbiome may impact progression and treatment is crucial to improve patient survival and treatment response. A literature review was conducted to reveal the crosslink between human microbiome and lung cancer. This includes immune priming, induction of pro- or anti-tumor response, and the local effects of intra-tumoral microbiota. Overall, this is a complex multifactorial relationship, and there are broad implications as to how this knowledge can improve cancer treatment. Solutions include manipulation of the microbiome using probiotics, bacterial vaccines and antibiotics. Bacteria biomarkers may also be used as a diagnostic tool.