ABSTRACT
The SARS-CoV-2 virus primarily infects salivary glands suggesting a change in the saliva metabolite profile; this shift may be used as a monitoring instrument during SARS-CoV-2 infection. The present study aims to determine the salivary metabolomic profile of patients with and post-SARS-CoV-19 infection. Patients were without (PCR-), with SARS-CoV-2 (PCR+), or post-SARS-CoV-2 infection. Unstimulated whole saliva was collected, and the 1H spectra were acquired in a 500 MHz Bruker nuclear magnetic resonance spectrometer at 25 °C. They were subjected to multivariate analysis using principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA), as well as univariate analysis through t-tests (SPSS 20.0, IL, USA), with a significance level of p < 0.05. A distinction was found when comparing PCR- subjects to those with SARS-CoV-2 infection. When comparing the three groups, the PLS-DA cross-validation presented satisfactory accuracy (ACC = 0.69, R2 = 0.39, Q2 = 0.08). Seventeen metabolites were found in different proportions among the groups. The results suggested the downregulation of major amino acid levels, such as alanine, glutamine, histidine, leucine, lysine, phenylalanine, and proline in the PCR+ group compared to the PCR- ones. In addition, acetate, valerate, and capronic acid were higher in PCR- patients than in PCR+. Sucrose and butyrate were higher in post-SARS-CoV-2 infection compared to PCR-. In general, a reduction in amino acids was observed in subjects with and post-SARS-CoV-2 disease. The salivary metabolomic strategy NMR-based was able to differentiate between non-infected individuals and those with acute and post-SARS-CoV-19 infection.
ABSTRACT
The oral environment is an essential part of the human microbiome. The consumption of probiotic products may improve the oral microbiota and reduce the risk of diseases. This paper presents a bibliometric and critical review of randomized clinical trials (RCTs) that used probiotics to analyze oral parameters in humans. RCTs carried out with no age, gender, and ethnicity restrictions and published in the pre-COVID-19 period were included. Furthermore, the utilization of probiotic dairy products to improve oral health is discussed. The bibliometric review demonstrated that 'Microbiology,' 'Dental caries,' and 'Streptococcus mutants' were the most highlighted keywords. Furthermore, Sweden and India have the highest number of publications. The most prevalent outcomes were 'salivary parameters,' 'periodontal disease,' and 'dental caries.' The most used vehicles for probiotic administration were pharmaceutical formulas and dairy products. The administration of probiotic dairy products could modify the oral microbiota (reductions in S. mutans counts), influence the caries development and periodontal disease in children, adolescents, adults, and the elderly, and improve gingival health. The main probiotic dairy products investigated were milk, fermented milk, yogurt, kefir, curd, and cheese. Lacticaseibacillus paracasei SD1 was the most used probiotic culture. The studies demonstrated that the probiotic effect lasted 2-4 weeks after discontinuing consumption. However, the results depended on the subject type, study design, probiotic strain and concentration, and dairy product type. In conclusion, probiotic dairy products are promising alternatives to improve oral health.