Banca de DEFESA: GEISY MUNIZ DE LEMOS

Oral microbiota profile in obese, overweight and eutrophic adolescents.

Spit. Bacteria. Life Quality.

The purpose of this study is to associate obesity with oral microbiota profiles in eutrophic, overweight, and obese adolescents. In 2015, the rate of increase in childhood obesity in many countries was greater than the rate of increase in adult obesity, potentially leading to future declines in life expectancy and raising concern about associated health risks. Gut and oral microbiota disturbances have been observed in obese adults and adolescents, pointing to possible obesity-related mechanisms, including increased oxidative stress, low-grade systemic inflammation, and insulin resistance, among other conditions. Recently, a potential relationship between childhood weight gain and oral microbiota has been reported, due to the perceived distinct composition in the oral microbiota of children with higher weight gain. In this work, two stages of experiments were performed, in order to standardize the technique and perform the analyses after identifying the best technique. Unstimulated saliva, mouthwash, oral cytological brushing and oral biofilm were collected, generating 124 samples, 1 for each type of collection per adolescent, to standardize the detection of 16SrRNA gene, Firmicutes and Bacteroidetes. Initially, we tested the primers previously for evaluation of the load of Firmicutes, Bacteroidetes and 16S rRNA, observing a higher percentage of samples that detected bacterial DNA in the oral biofilm. Then, the oral microbiota composition of 31 adolescents was evaluated, 14 (45.16%) females and 17 (54.84%) males. Among them, two groups were classified by nutritional status as assessed by BMI: eutrophic, making up group E, and overweight and obese, making up group OS, obtaining 9 adolescents (29.03%) for OS and 22 adolescents (70.97%) for group E.  The standardization of the technique showed significance for further experiments, because the bacteria that make up the oral biofilm are quite abundant and colonize different places in the oral cavity, including the teeth. The analysis of bacterial load showed significant influence when associated with weight, where the OS group had the highest number of copies of Firmicutes and Bacteroidetes in males, while the lowest values of bacteroidetes were found in girls from group E, reaffirming the idea of interaction between metabolism, obesity and these phylos, which indicates the relevance of evaluation and surveillance in oral health to control cases of overweight and obesity in children and adolescents.