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Microbial Biotechnology May 2024The human gut hosts numerous ecological niches for microbe-microbe and host-microbe interactions. Gut lactate homeostasis in humans is crucial and relies on various...
Mutualistic interactions of lactate-producing lactobacilli and lactate-utilizing Veillonella dispar: Lactate and glutamate cross-feeding for the enhanced growth and short-chain fatty acid production.
The human gut hosts numerous ecological niches for microbe-microbe and host-microbe interactions. Gut lactate homeostasis in humans is crucial and relies on various bacteria. Veillonella spp., gut lactate-utilizing bacteria, and lactate-producing bacteria were frequently co-isolated. A recent clinical trial has revealed that lactate-producing bacteria in humans cross-feed lactate to Veillonella spp.; however, their interspecies interaction mechanisms remain unclear. Veillonella dispar, an obligate anaerobe commonly found in the human gut and oral cavity, ferments lactate into acetate and propionate. In our study, we investigated the interaction between V. dispar ATCC 17748 and three representative phylogenetically distant strains of lactic acid bacteria, Lactobacillus acidophilus ATCC 4356, Lacticaseibacillus paracasei subsp. paracasei ATCC 27216, and Lactiplantibacillus plantarum ATCC 10241. Bacterial growth, viability, metabolism and gene level adaptations during bacterial interaction were examined. V. dispar exhibited the highest degree of mutualism with L. acidophilus. During co-culture of V. dispar with L. acidophilus, both bacteria exhibited enhanced growth and increased viability. V. dispar demonstrated an upregulation of amino acid biosynthesis pathways and the aspartate catabolic pathway. L. acidophilus also showed a considerable number of upregulated genes related to growth and lactate fermentation. Our results support that V. dispar is able to enhance the fermentative capability of L. acidophilus by presumably consuming the produced lactate, and that L. acidophilus cross-feed not only lactate, but also glutamate, to V. dispar during co-culture. The cross-fed glutamate enters the central carbon metabolism in V. dispar. These findings highlight an intricate metabolic relationship characterized by cross-feeding of lactate and glutamate in parallel with considerable gene regulation within both L. acidophilus (lactate-producing) and V. dispar (lactate-utilizing). The mechanisms of mutualistic interactions between a traditional probiotic bacterium and a potential next-generation probiotic bacterium were elucidated in the production of short-chain fatty acids.
Topics: Lactic Acid; Fatty Acids, Volatile; Glutamic Acid; Veillonella; Symbiosis; Microbial Interactions; Humans; Lactobacillus acidophilus; Lactobacillus; Microbial Viability; Fermentation
PubMed: 38801349
DOI: 10.1111/1751-7915.14484 -
International Dental Journal Mar 2024Psychological stress can be a common risk factor for the development of oral and systemic disease; therefore, analysis of a pathophysiologic mechanisms that may explain...
OBJECTIVE
Psychological stress can be a common risk factor for the development of oral and systemic disease; therefore, analysis of a pathophysiologic mechanisms that may explain this association may be significant in planning preventive strategies. The aim of this study was to investigate the association amongst academic stress, periodontal health, and salivary cortisol and nitrite and nitrate levels in a sample of university students.
METHODS
Participants (N = 14) were classified into 2 groups according to their exposure to academic stress due to periods of university exams (n = 6 and n = 8, respectively). All participants were subjected evlauted for their behavioural, psychological, and anthropometric parameters, as well as an oral health examination. A real-time polymerase chain reaction analysis in samples of saliva and plaque was used to detect Prevotella intermedia and Veillonella dispar as well as the total bacterial count. Nitrite/nitrate ratio (NR ratio) and cortisol in saliva were evaluated by enzyme-linked immunosorbent assay.
RESULTS
Full Mouth Bleeding Score, Full Mouth Plaque Score, and Gingival Index were significantly higher in the group exposed to academic stress. Nitrite was directly related to the presence of V dispar (coefficient, 0.13; P = .00; CI, 0.07 to 0.19) and inversely related to total bacterial count (coefficient, -0.07; P = .012; CI, -0.13 to 0.02). NR ratio was directly related to V dispar (coefficient, 4.35; P = .010; 95% CI, 1.35 to 7.36) and inversely related to total bacterial count (coefficient, -4.05; P = .018; 95% CI, -7.32 to 0.86).
CONCLUSIONS
These results confirm the importance of stress on periodontal health and salivary nitrite concentration and highlight a potential differential role of specific bacteria on nitrite concentration in saliva.
PubMed: 38538383
DOI: 10.1016/j.identj.2024.02.003 -
BMC Microbiology Mar 2024Oral microbiome dysbacteriosis has been reported to be associated with the pathogenesis of advanced esophageal cancer. However, few studies investigated the potential...
BACKGROUND
Oral microbiome dysbacteriosis has been reported to be associated with the pathogenesis of advanced esophageal cancer. However, few studies investigated the potential role of oral and gastric microbiota in early-stage intramucosal esophageal squamous carcinoma (EIESC).
METHOD
A total of 104 samples were collected from 31 patients with EIESC and 21 healthy controls. The compositions of oral and gastric microbiota were analyzed using 16 S rRNA V3-V4 amplicon sequencing. Linear discriminant analysis effect size (LEfSe) analysis was performed to assess taxonomic differences between groups. The correlation between oral microbiota and clinicopathological factors was evaluated using Spearman correlation analysis. Additionally, co-occurrence networks were established and random forest models were utilized to identify significant microbial biomarkers for distinguishing between the EIESC and control groups.
RESULTS
A total of 292 oral genera and 223 species were identified in both EIESC and healthy controls. Six oral genera were remarkably enriched in EIESC groups, including the genera Porphyromonas, Shigella, Subdoligranulum, Leptotrichia, Paludibacter, and Odoribacter. LEfSe analysis identified genera Porphyromonas and Leptotrichia with LDA scores > 3. In the random forest model, Porphyromonas endodontalis ranked the top microbial biomarker to differentiate EIESC from controls. The elimination rate of Porphyromonas endodontalis from the oral cavity to the stomach was also dramatically decreased in the EIESC group than controls. In the microbial co-occurrence network, Porphyromonas endodontalis was positively correlated with Prevotella tannerae and Prevotella intermedia and was negatively correlated with Veillonella dispar.
CONCLUSION
Our study potentially indicates that the dysbacteriosis of both the oral and gastric microbiome was associated with EIESC. Larger scale studies and experimental animal models are urgently needed to confirm the possible role of microbial dysbacteriosis in the pathogenesis of EIESC. (Chinese Clinical Trial Registry Center, ChiCTR2200063464, Registered 07 September 2022, https://www.chictr.org.cn/showproj.html?proj=178563).
Topics: Humans; Gastrointestinal Microbiome; Esophageal Squamous Cell Carcinoma; Esophageal Neoplasms; Dysbiosis; Mouth; Porphyromonas; RNA, Ribosomal, 16S
PubMed: 38491387
DOI: 10.1186/s12866-024-03233-4 -
Frontiers in Nutrition 2023Very Low Birth Weight (VLBW) infants, born weighing less than 1,500 grams, are at risk for both gut dysbiosis and later neuropsychological developmental deficits....
INTRODUCTION
Very Low Birth Weight (VLBW) infants, born weighing less than 1,500 grams, are at risk for both gut dysbiosis and later neuropsychological developmental deficits. Behavioral effects, while related to neurodevelopment, are often more subtle and difficult to measure. The extent of later neurobehavioral consequences associated with such microbial dysbiosis has yet to be determined. We explored associations between the infants' gut microbiome and early childhood behavior at 4 years of age and identified the bacterial taxa through a multivariate analysis by linear models.
METHODS
Parents completed the Child Behavior Checklist (CBCL) focused on different DSM diagnostic categories: affective, anxiety, pervasive developmental, attention deficit/hyperactivity, and oppositional defiant. All the CBCL scores were corrected for gender, delivery method, gestational age, infant birth weight, occurrence of sepsis, and days on antibiotics prior statistical analyses. Canonical correlation analysis (CCA) was performed to determine the relationship between early life gut microbiome and the adjusted CBCL scores. The association of bacterial Amplicon sequence Variants (ASVs) to the CBCL scores were tested with multivariate analysis by linear models (MaAsLin).
RESULTS
Nineteen children who were previously born with very low birth weight and studied while hospitalized in the Neonatal Intensive Care Unit (NICU) were included in this study. Statistically significant associations were observed between early life gut bacteria such as , and to later behavior at 4 years. No significant association could be observed with early-life gut microbiome alpha diversity and behavioral measures at 4 years.
DISCUSSION
These preliminary observational data provide insight into the relationships between VLBW gut microbiome dysbiosis and childhood behavior. This study contributes to the literature on gut microbiome analysis by examining various behavioral domains using a standardized tool linked to the Diagnostic and Statistical Manual of Mental Disorders (DSM).
PubMed: 38419643
DOI: 10.3389/fnut.2023.1294549 -
Scientific Reports Nov 2023Limited data exist on longitudinal changes in the sputum bacterial microbiome during treatment in nontuberculous mycobacterial pulmonary disease (NTM-PD) patients. We...
Limited data exist on longitudinal changes in the sputum bacterial microbiome during treatment in nontuberculous mycobacterial pulmonary disease (NTM-PD) patients. We prospectively collected serial sputum samples from 14 NTM-PD patients during treatment, at the start (n = 14) and at 1 (n = 10), 3 (n = 10), 6 (n = 12), and 12 (n = 7) months. The bacterial microbiome changes were analyzed using 16S rRNA sequences (V3-V4 regions). Subgroup analysis included culture conversion (n = 9) and treatment refractory (n = 5) groups. In all patients, sputum alpha-diversity (ACE, Chao1, and Jackknife) significantly decreased during antibiotic treatment at 1, 3, 6, and 12 months compared to treatment initiation levels. Within the culture conversion group, genus/species-level beta-diversity showed differences at 1, 3, 6, and 12 months compared to treatment initiation (all p < 0.05). However, in the refractory group, there were no differences in beta-diversity at the genus/species levels in the sputum at any time point. In the linear discriminant analysis (LDA) effect sizes (LEfSe) analysis, the culture conversion group exhibited decreasing taxa at various levels (phylum/genus/species), but no significant increase in taxa was observed. LEfSe analysis of the refractory patient group revealed multiple taxa decreased during treatment. However, proportions of Veillonella dispar (LDA = 4.78), Fusobacterium periodonticum (LDA = 4.35), and Pseudomonas aeruginosa (LDA = 2.92) increased as the treatment period progressed in the refractory group. Sputum microbiota diversity decreases during NTM-PD treatment. In the culture conversion group, most taxa decrease, while some increase in the refractory group. These findings suggest that a distinct respiratory microbial community may exist in refractory NTM-PD patients compared to responsive antibiotic-treated patients.
Topics: Humans; Sputum; RNA, Ribosomal, 16S; Mycobacterium Infections, Nontuberculous; Microbiota; Anti-Bacterial Agents; Bacteria; Lung Diseases
PubMed: 37957253
DOI: 10.1038/s41598-023-47230-5 -
Scientific Reports Nov 2023Crohn's disease (CD) is a chronic inflammatory bowel disease. An imbalanced microbiome (dysbiosis) can predispose to many diseases including CD. The role of oral...
Crohn's disease (CD) is a chronic inflammatory bowel disease. An imbalanced microbiome (dysbiosis) can predispose to many diseases including CD. The role of oral dysbiosis in CD is poorly understood. We aimed to explore microbiome signature and dysbiosis of the salivary microbiome in CD patients, and correlate microbiota changes to the level of inflammation. Saliva samples were collected from healthy controls (HC) and CD patients (n = 40 per group). Salivary microbiome was analyzed by sequencing the entire 16S rRNA gene. Inflammatory biomarkers (C-reactive protein and calprotectin) were measured and correlated with microbiome diversity. Five dominant species were significantly enriched in CD, namely Veillonella dispar, Megasphaera stantonii, Prevotella jejuni, Dolosigranulum pigrum and Lactobacillus backii. Oral health had a significant impact on the microbiome since various significant features were cariogenic as Streptococcus mutans or periopathogenic such as Fusobacterium periodonticum. Furthermore, disease activity, duration and frequency of relapses impacted the oral microbiota. Treatment with monoclonal antibodies led to the emergence of a unique species called Simonsiella muelleri. Combining immunomodulatory agents with monoclonal antibodies significantly increased multiple pathogenic species such as Salmonella enterica, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa. Loss of diversity in CD was shown by multiple diversity indices. There was a significant negative correlation between gut inflammatory biomarkers (particularly calprotectin) and α-diversity, suggesting more inflammation associated with diversity loss in CD. Salivary dysbiosis was evident in CD patients, with unique microbiota signatures and perturbed species that can serve as disease biomarkers or potential targets for microbiota modulation. The interplay of various factors collectively contributed to dysbiosis, although each factor probably had a unique effect on the microbiome. The emergence of pathogenic bacteria in the oral cavity of CD patients is alarming since they can disturb gut homeostasis and induce inflammation by swallowing, or hematogenous spread of microbiota, their metabolites, or generated inflammatory mediators.
Topics: Humans; Crohn Disease; Dysbiosis; RNA, Ribosomal, 16S; Gastrointestinal Microbiome; Microbiota; Inflammation; Biomarkers; Antibodies, Monoclonal; Leukocyte L1 Antigen Complex
PubMed: 37932491
DOI: 10.1038/s41598-023-46714-8 -
Antibiotics (Basel, Switzerland) Sep 2023Antifungal agents are widely used to specifically eliminate infections by fungal pathogens. However, the specificity of antifungal agents has been challenged by a few...
Antifungal agents are widely used to specifically eliminate infections by fungal pathogens. However, the specificity of antifungal agents has been challenged by a few studies demonstrating antibacterial inhibitory effects against and species. Here, we evaluated for the first time the potential effect of fluconazole, the most clinically used antifungal agent, on a human oral microbiota biofilm model. The results showed that biofilm viability on blood and mitis salivarius agar media was increased over time in the presence of fluconazole at clinically relevant concentrations, despite a reduction in biomass. Targeted PCR revealed a higher abundance of , and spp. in the fluconazole-treated samples compared to the control, while was reduced and spp were not significantly affected. Further, we tested the potential impact of fluconazole using single-species models. Our results, using and luciferase reporters, showed that planktonic growth was not significantly affected by fluconazole, whereas for , planktonic growth, but not biofilm viability, was inhibited at the highest concentration. Fluconazole's effects on biofilm biomass were concentration and time dependent. Exposure for 48 h to the highest concentration of fluconazole was associated with biofilms with the most increased biomass. Potential growth inhibitory effects were further tested using four non-streptococcal species. Among these, the planktonic growth of both and was inhibited by fluconazole. The data indicate bacterial responses to fluconazole that extend to a broader range of bacterial species than previously anticipated from the literature, with the potential to disturb biofilm communities.
PubMed: 37760729
DOI: 10.3390/antibiotics12091433 -
BioMed Research International 2022The use of low-temperature plasma (LTP) is a novel approach to treating peri-implantitis. LTP disrupts the biofilm while conditioning the surrounding host environment...
BACKGROUND
The use of low-temperature plasma (LTP) is a novel approach to treating peri-implantitis. LTP disrupts the biofilm while conditioning the surrounding host environment for bone growth around the infected implant. The main objective of this study was to evaluate the antimicrobial properties of LTP on newly formed (24 h), intermediate (3 days), and mature (7 days) peri-implant-related biofilms formed on titanium surfaces.
METHODS
(ATCC 12104), (W83), (ATCC 35037), and (ATCC 17748) were cultivated in brain heart infusion supplemented with 1% yeast extract, hemin (0.5 mg/mL), and menadione (5 mg/mL) and kept at 37°C in anaerobic conditions for 24 h. Species were mixed for a final concentration of ~10 colony forming units (CFU)/mL (OD = 0.01), and the bacterial suspension was put in contact with titanium specimens (7.5 mm in diameter by 2 mm in thickness) for biofilm formation. Biofilms were treated with LTP for 1, 3, and 5 min at 3 or 10 mm from plasma tip to sample. Controls were those having no treatment (negative control, NC) and argon flow under the same LTP conditions. Positive controls were those treated with 14 g/mL amoxicillin and 140 g/mL metronidazole individually or combined and 0.12% chlorhexidine ( = 6 per group). Biofilms were evaluated by CFU, confocal laser scanning microscopy (CLSM), and fluorescence in situ hybridization (FISH). Comparisons among bacteria; 24 h, 3-day, and 7-day biofilms; and treatments for each biofilm were made. Wilcoxon signed-rank and Wilcoxon rank sum tests were applied ( = 0.05).
RESULTS
Bacterial growth was observed in all NC groups, corroborated by FISH. LTP treatment significantly reduced all bacteria species compared to the NC in all biofilm periods and treatment conditions ( ≤ 0.016), and CLSM corroborated these results.
CONCLUSION
Within the limitation of this study, we conclude that LTP application effectively reduces peri-implantitis-related multispecies biofilms on titanium surfaces .
Topics: Humans; Peri-Implantitis; Temperature; Titanium; In Situ Hybridization, Fluorescence; Biofilms; Bacteria
PubMed: 37228507
DOI: 10.1155/2022/1549774 -
BioMed Research International 2023Peri-implant diseases are emerging issues in contemporary implant dentistry. As biofilms play a critical role in peri-implant diseases, the characteristic of resisting...
BACKGROUND
Peri-implant diseases are emerging issues in contemporary implant dentistry. As biofilms play a critical role in peri-implant diseases, the characteristic of resisting bacterial adhesion would be ideal for dental implants. The aims of the study were to compare titanium (Ti) and zirconia (Zr) implants regarding the amount of biofilm formation at different time frames and assess the distribution of biofilm on different aspects of dental implants.
METHODS
Biofilm was developed on Ti and Zr dental implants with a peri-implant-related multispecies model with , , , and , for 3 and 14 days. Quantitative assessment was performed with the measurement of total bacterial viability (colony forming units, CFU/mg). Scanning electron microscopy (SEM) was used to evaluate biofilm formation on different aspects of the implants.
RESULTS
Three-day-old biofilm on Ti implants was significantly higher than that on Zr implants ( < 0.001). The Ti and Zr groups were not significantly different for 14-day-old biofilm. SEM images demonstrated that 3-day-old biofilm on Zr implants was sparse while biofilm growth was more pronounced for 3-day-old biofilm on Ti implants and 14-day-old biofilm groups. It appeared that less biofilm formed on the valley compared to the thread top for 3-day-old biofilm on Zr implants. Differences between the valley and the thread top became indistinguishable with the development of mature biofilm.
CONCLUSION
While early formed biofilms show greater accumulation on Ti implants compared to Zr implants, older biofilms between the two groups are comparable. The distribution of biofilms was not uniform on different areas of implant threads during early biofilm development.
Topics: Humans; Titanium; Dental Implants; Peri-Implantitis; Biofilms; Surface Properties
PubMed: 37096222
DOI: 10.1155/2023/8728499 -
Microbiology Spectrum Mar 2023spp. are obligate, anaerobic, Gram-negative bacteria found in the human oral cavity and gut. Recent studies have indicated that gut promote human homeostasis by...
spp. are obligate, anaerobic, Gram-negative bacteria found in the human oral cavity and gut. Recent studies have indicated that gut promote human homeostasis by producing beneficial metabolites, specifically short-chain fatty acids (SCFAs), by lactate fermentation. The gut lumen is a dynamic environment with fluctuating nutrient levels, so the microbes present shifting growth rates and significant variations of gene expression. The current knowledge of lactate metabolism by has focused on log phase growth. However, the gut microbes are mainly in the stationary phase. In this study, we investigated the transcriptomes and major metabolites of Veillonella dispar ATCC 17748 during growth from log to stationary phases with lactate as the main carbon source. Our results revealed that reprogrammed its lactate metabolism during the stationary phase. Lactate catabolic activity and propionate production were significantly decreased during the early stationary phase but were partially restored during the stationary phase. The propionate/acetate production ratio was lowered from 1.5 during the log phase to 0.9 during the stationary phase. Pyruvate secretion was also greatly decreased during the stationary phase. Furthermore, we have demonstrated that the gene expression of is reprogrammed during growth, as evidenced by the distinct transcriptomes present during the log, early stationary, and stationary phases. In particular, propionate metabolism (the propanediol pathway) was downregulated during the early stationary phase, which explains the decrease in propionate production during the stationary phase. The fluctuations in lactate fermentation during the stationary phase and the associated gene regulation expand our understanding of the metabolism of commensal anaerobes in changing environments. Short-chain fatty acids produced by gut commensal bacteria play an important role in human physiology. Gut and the metabolites acetate and propionate, produced by lactate fermentation, are associated with human health. Most gut bacteria in humans are in the stationary phase. Lactate metabolism by spp. during the stationary phase is poorly understood and was therefore the focus of the study. To this end, we used a commensal anaerobic bacterium and explored its short-chain fatty acid production and gene regulation in order to provide a better understanding of lactate metabolism dynamics during nutrient limitation.
PubMed: 36975840
DOI: 10.1128/spectrum.03558-22