Variability of Thiobarbituric Acid Reacting Substances in Saliva

Introduction: Salivary TBARS are a potential marker of oxidative stress in the oral cavity. Previous studies have found increased levels of salivary TBARS in various diseases. The aim of this study was to assess the variability of salivary TBARS in both genders

The Short-Term Effects of Soybean Intake on Oxidative and Carbonyl Stress in Men and Women

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Salivary microbiome composition changes after bariatric surgery

Recent studies show that the salivary microbiome in subjects with obesity differ from those without obesity, but the mechanism of interaction between the salivary microbiome composition and body weight is unclear. Herein we investigate this relation by analyzing saliva samples from 35 adult patients with obesity undergoing bariatric surgery. Our aim was to describe salivary microbiome changes during body weight loss on an individual-specific level, and to elucidate the effect of bariatric surgery on the salivary microbiome which has not been studied before. Analysis of samples collected before and 1 day after surgery, as well as 3 and 12 months after surgery, showed that the salivary microbiome changed in all study participants, but these changes were heterogeneous. In the majority of participants proportions of Gemella species, Granulicatella elegans, Porphyromonas pasteri, Prevotella nanceiensis and Streptococcus oralis decreased, while Veillonella species, Megasphaera micronuciformis and Prevotella saliva increased. Nevertheless, we found participants deviating from this general trend which suggests that a variety of individual-specific factors influence the salivary microbiome composition more effectively than the body weight dynamics alone. The observed microbiome alternations could be related to dietary changes. Therefore, further studies should focus on association with altered taste preferences and potential oral health consequences.This work was supported by grants to AM from the Spanish Ministry of Science and Innovation (project PID2019-105969GB-I00), Generalitat Valenciana (project Prometeo/2018/A/133) and co-financed by the European Regional Development Fund (ERDF). PC, RG, RL and BV were supported by ERDF as part of the project ITMS 26240120027 and by grants 2018/33-LFUK-7 from the Ministry of Health, VEGA 1/0307/19 from the Ministry of Education of the Slovak Republic and the grant from the Slovak Research and Development Agency APVV-17-0505.Peer reviewe

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

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

On the Physiology and Pathophysiology of Antimicrobial Peptides

Antimicrobial peptides (AMP) are a heterogeneous group of molecules involved in the nonspecific immune responses of a variety of organisms ranging from prokaryotes to mammals, including humans. AMP have various physical and biological properties, yet the most common feature is their antimicrobial effect. The majority of AMP disrupt the integrity of microbial cells by 1 of 3 known mechanisms—the barrel-stave pore model, the thoroidal pore model, or the carpet model. Results of growing numbers of descriptive and experimental studies show that altered expression of AMP in various tissues is important in the pathogenesis of several gastrointestinal, respiratory, and other diseases. We discuss novel approaches and strategies to further improve the promising future of therapeutic applications of AMP. The spread of antibiotic resistance increases the importance of developing a clinical role for AMP