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Microbiome ; 8(1): 62, 2020 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-32375874


BACKGROUND: The archaeological incidence of ancient human faecal material provides a rare opportunity to explore the taxonomic composition and metabolic capacity of the ancestral human intestinal microbiome (IM). Here, we report the results of the shotgun metagenomic analyses of an ancient South African palaeo-faecal specimen. METHODS: Following the recovery of a single desiccated palaeo-faecal specimen from Bushman Rock Shelter in Limpopo Province, South Africa, we applied a multi-proxy analytical protocol to the sample. The extraction of ancient DNA from the specimen and its subsequent shotgun metagenomic sequencing facilitated the taxonomic and metabolic characterisation of this ancient human IM. RESULTS: Our results indicate that the distal IM of the Neolithic 'Middle Iron Age' (c. AD 1460) Bantu-speaking individual exhibits features indicative of a largely mixed forager-agro-pastoralist diet. Subsequent comparison with the IMs of the Tyrolean Iceman (Ötzi) and contemporary Hadza hunter-gatherers, Malawian agro-pastoralists and Italians reveals that this IM precedes recent adaptation to 'Western' diets, including the consumption of coffee, tea, chocolate, citrus and soy, and the use of antibiotics, analgesics and also exposure to various toxic environmental pollutants. CONCLUSIONS: Our analyses reveal some of the causes and means by which current human IMs are likely to have responded to recent dietary changes, prescription medications and environmental pollutants, providing rare insight into human IM evolution following the advent of the Neolithic c. 12,000 years ago. Video Abtract.

Arqueologia , Fezes/microbiologia , Microbioma Gastrointestinal , África Subsaariana , História do Século XV , Humanos , Metagenômica
Arch Oral Biol ; 73: 79-87, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27697693


OBJECTIVE: Bacterial metabolism of arginine in the oral cavity has a pH-raising and thus, potential anti-caries effect. However, the influence of arginine on the oral microbial ecosystem remains largely unresolved. DESIGN: In this pilot study, nine healthy individuals used toothpaste containing 8% arginine for eight weeks. Saliva was collected to determine arginolytic potential and sucrose metabolic activity at the Baseline, Week 4, Week 8 and after a two weeks Wash-out period. To follow the effects on microbial ecology, 16S rDNA sequencing on saliva and plaque samples at Baseline and Week 8 and metagenome sequencing on selected saliva samples of the same time-points was performed. RESULTS: During the study period, the arginolytic potential of saliva increased, while the sucrose metabolism in saliva decreased. These effects were reversed during the Wash-out period. Although a few operational taxonomic units (OTUs) in plaque changed in abundance during the study period, there was no real shift in the plaque microbiome. In the saliva microbiome there was a significant compositional shift, specifically the genus Veillonella had increased significantly in abundance at Week 8. CONCLUSION: Indeed, the presence of arginine in toothpaste affects the arginolytic capacity of saliva and reduces its sucrose metabolic activity. Additionally, it leads to a shift in the salivary microbiome composition towards a healthy ecology from a caries point of view. Therefore, arginine can be regarded as a genuine oral prebiotic.

Arginina/farmacologia , Microbiota/efeitos dos fármacos , Boca/efeitos dos fármacos , Boca/microbiologia , Cremes Dentais/farmacologia , Adulto , Feminino , Voluntários Saudáveis , Humanos , Concentração de Íons de Hidrogênio , Masculino , Projetos Piloto , RNA Ribossômico 16S/genética , Saliva/microbiologia , Análise de Sequência
Microb Ecol ; 72(2): 479-92, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27155967


Nitrate is emerging as a possible health benefactor. Especially the microbial conversion of nitrate to nitrite in the oral cavity and the subsequent conversion to nitric oxide in the stomach are of interest in this regard. Yet, how nitrate influences the composition and biochemistry of the oral ecosystem is not fully understood. To investigate the effect of nitrate on oral ecology, we performed a 4-week experiment using the multiplaque artificial mouth (MAM) biofilm model. This model was inoculated with stimulated saliva of two healthy donors. Half of the microcosms (n = 4) received a constant supply of nitrate, while the other half functioned as control (n = 4). Additionally, all microcosms received a nitrate and sucrose pulse, each week, on separate days to measure nitrate reduction and acid formation. The bacterial composition of the microcosms was determined by 16S rDNA sequencing. The origin of the saliva (i.e., donor) showed to be the strongest determinant for the development of the microcosms. The supplementation of nitrate was related to a relatively high abundance of Neisseria in the microcosms of both donors, while Veillonella was highly abundant in the nitrate-supplemented microcosms of only one of the donors. The lactate concentration after sucrose addition was similarly high in all microcosms, irrespective of treatment or donor, while the concentration of butyrate was lower after nitrate addition in the nitrate-receiving microcosms. In conclusion, nitrate influences the composition and biochemistry of oral microcosms, although the result is strongly dependent on the inoculum.

Bactérias/classificação , Ácidos Graxos Voláteis/biossíntese , Nitratos/análise , Saliva/microbiologia , Adulto , Bactérias/isolamento & purificação , Bactérias/metabolismo , Biomassa , Butiratos/análise , Feminino , Genes Bacterianos , Genômica , Humanos , Masculino , Neisseria/genética , Neisseria/isolamento & purificação , Neisseria/metabolismo , Nitritos/análise , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Sacarose/análise , Veillonella/genética , Veillonella/isolamento & purificação , Veillonella/metabolismo , Adulto Jovem
PLoS One ; 10(9): e0137318, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26332408


While the aesthetic effect of orthodontic treatment is clear, the knowledge on how it influences the oral microbiota and the consequential effects on oral health are limited. In this randomized controlled clinical trial we investigated the changes introduced in the oral ecosystem, during and after orthodontic treatment with fixed appliances in combination with or without a fluoride mouthwash, of 10-16.8 year old individuals (N = 91). We followed several clinical parameters in time, in combination with microbiome changes using next-generation sequencing of the bacterial 16S rRNA gene. During the course of our study, the oral microbial community displayed remarkable resilience towards the disturbances it was presented with. The effects of the fluoride mouthwash on the microbial composition were trivial. More pronounced microbial changes were related to gingival health status, orthodontic treatment and time. Periodontal pathogens (e.g. Selenomonas and Porphyromonas) were highest in abundance during the orthodontic treatment, while the health associated Streptococcus, Rothia and Haemophilus gained abundance towards the end and after the orthodontic treatment. Only minor compositional changes remained in the oral microbiome after the end of treatment. We conclude that, provided proper oral hygiene is maintained, changes in the oral microbiome composition resulting from orthodontic treatment are minimal and do not negatively affect oral health.

Fluoretos/administração & dosagem , Microbiota , Boca/microbiologia , Antissépticos Bucais , Aparelhos Ortodônticos , Adolescente , Criança , Gengiva/microbiologia , Humanos , Placebos
Microb Ecol ; 69(2): 422-33, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25433583


Dysbiosis induced by low pH in the oral ecosystem can lead to caries, a prevalent bacterial disease in humans. The amino acid arginine is one of the pH-elevating agents in the oral cavity. To obtain insights into the effect of arginine on oral microbial ecology, a multi-plaque "artificial mouth" (MAM) biofilm model was inoculated with saliva from a healthy volunteer and microcosms were grown for 4 weeks with 1.6 % (w/v) arginine supplement (Arginine) or without (Control), samples were taken at several time-points. A cariogenic environment was mimicked by sucrose pulsing. The bacterial composition was determined by 16S rRNA gene amplicon sequencing, the presence and amount of Candida and arginine deiminase system genes arcA and sagP by qPCR. Additionally, ammonium and short-chain fatty acid concentrations were determined. The Arginine microcosms were dominated by Streptococcus, Veillonella, and Neisseria and remained stable in time, while the composition of the Control microcosms diverged significantly in time, partially due to the presence of Megasphaera. The percentage of Candida increased 100-fold in the Control microcosms compared to the Arginine microcosms. The pH-raising effect of arginine was confirmed by the pH and ammonium results. The abundances of sagP and arcA were highest in the Arginine microcosms, while the concentration of butyrate was higher in the Control microcosms. We demonstrate that supplementation with arginine serves a health-promoting function; it enhances microcosm resilience toward acidification and suppresses outgrowth of the opportunistic pathogen Candida. Arginine facilitates stability of oral microbial communities and prevents them from becoming cariogenic.

Arginina/farmacologia , Bactérias/efeitos dos fármacos , Candida/crescimento & desenvolvimento , Boca/microbiologia , Bactérias/crescimento & desenvolvimento , Bactérias/isolamento & purificação , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Candida/efeitos dos fármacos , DNA Bacteriano/genética , Cárie Dentária/tratamento farmacológico , Cárie Dentária/microbiologia , Genes Bacterianos , Humanos , Concentração de Íons de Hidrogênio , Hidrolases/genética , Hidrolases/metabolismo , Neisseria/efeitos dos fármacos , Neisseria/crescimento & desenvolvimento , RNA Ribossômico 16S/genética , Saliva/microbiologia , Análise de Sequência de DNA , Streptococcus/efeitos dos fármacos , Streptococcus/crescimento & desenvolvimento , Veillonella/efeitos dos fármacos , Veillonella/crescimento & desenvolvimento