Oxidative stress in the oral cavity is driven by individual-specific bacterial communities

• Published in: NPJ biofilms and microbiomes 2018-11, Vol.4 (1), p.29-10, Article 29
• Main Authors: Džunková, Mária, Martinez-Martinez, Daniel, Gardlík, Roman, Behuliak, Michal, Janšáková, Katarína, Jiménez, Nuria, Vázquez-Castellanos, Jorge F., Martí, Jose Manuel, D’Auria, Giuseppe, Bandara, H. M. H. N., Latorre, Amparo, Celec, Peter, Moya, Andrés
• Format: Article
• Language: English
• Subjects: 631/326/107; 692/700/3032/3039; Bacteria; Biomedical and Life Sciences; Dental caries; DNA sequencing; Dysbacteriosis; Inflammation; Life Sciences; Medical Microbiology; Microbial Ecology; Microbial Genetics and Genomics; Microbiology; Microbiomes; Oral cavity; Oxidation; Oxidative stress; Saliva
• ISSN: 2055-5008; 2055-5008
• DOI: 10.1038/s41522-018-0072-3

The term “bacterial dysbiosis” is being used quite extensively in metagenomic studies, however, the identification of harmful bacteria often fails due to large overlap between the bacterial species found in healthy volunteers and patients. We hypothesized that the pathogenic oral bacteria are individual-specific and they correlate with oxidative stress markers in saliva which reflect the inflammatory processes in the oral cavity. Temporally direct and lagged correlations between the markers and bacterial taxa were computed individually for 26 volunteers who provided saliva samples during one month (21.2 ± 2.7 samples/volunteer, 551 samples in total). The volunteers’ microbiomes differed significantly by their composition and also by their degree of microbiome temporal variability and oxidative stress markers fluctuation. The results showed that each of the marker-taxa pairs can have negative correlations in some volunteers while positive in others. Streptococcus mutans , which used to be associated with caries before the metagenomics era, had the most prominent correlations with the oxidative stress markers, however, these correlations were not confirmed in all volunteers. The importance of longitudinal samples collections in correlation studies was underlined by simulation of single sample collections in 1000 different combinations which produced contradictory results. In conclusion, the distinct intra-individual correlation patterns suggest that different bacterial consortia might be involved in the oxidative stress induction in each human subject. In the future, decreasing cost of DNA sequencing will allow to analyze multiple samples from each patient, which might help to explore potential diagnostic applications and understand pathogenesis of microbiome-associated oral diseases. Oral bacteria: The significance of difference Repeatedly sampling oral bacterial species in 26 volunteers over one month revealed considerable personal differences in the bacteria associated with oral disease, and some significant variation in individuals at different times. The findings come from an international team of researchers led by Mária Džunková at the Foundation for the Promotion of Health and Biomedical Research of Valencia Region, Spain. They emphasize the importance of repeated sampling to understand the significance of changing and varying oral bacterial populations in both health and disease. The study used chemical markers of ‘oxidative stress’ due to inflammat