Relação entre grupos de bactérias da microbiota intestinal e do estado nutricional com marcadores clínicos e imunológicos da doença pulmonar obstrutiva crônica

Abstract

ABSTRACT Gut microbiota is constituted by an abundant and diversified bacterial community, involved in structural, regulatory, metabolic and immunological activities. Imbalance of the microbiota alters the levels of immune mediators, changes the capacity to induce inflammation and can lead to systemic metabolic dysfunction. Changes in intestinal microbiota have been described in several diseases of the respiratory tract, however, in Chronic obstructive pulmonary disease (COPD) the studies are limited. COPD is caused by the exposure or inhalation of harmful particles or gases and is characterized by chronic inflammation with respiratory and extrarespiratory consequences, being considered one of the main causes of mortality in the world. In addition, changes in nutritional status can impact the pathophysiology of the disease and contribute with worsening prognosis. The present study aimed to investigate the relationship between relative abundance of specific groups of bacteria of the intestinal microbiota and nutritional status with the clinical, biochemical and immunological markers of COPD. This work was approved by the Research Ethics Committee of Hospital Universitario Prof. Edgard Santos - UFBA (Number: 4.045.818). Participated in this study 38 patients and 38 controls, matched for sex and age between 50 and 70 years. All patients realized pulmonary function test with spirometry, 6-minute walk test and dyspnea assessment using the modified Medical Research Council scale and the BODE Index was calculated as a predictor of mortality. The classification of nutritional status was made by BMI. In addition, measurements of anthropometric indicators were performed, such as arm circumference and tricipital skinfold, following the techniques proposed by the WHO and the arm muscle circumference and arm muscle area were calculated. Venous blood was collected to determine triglycerides, total cholesterol, HDL-C, LDL-C, fasting glycemia and to quantify cytokines TNF, IL-6, IL-8, IL10 and IL-12. The evaluation of the gut microbiota was carried out by extracting DNA from fecal samples and amplifying the RNAr 16S region using the qPCR technique. Results of this work were presented in form of three articles according to the internal regulations of the Programa de Pós-Graduação em Alimentação, Nutrição e Saúde. The data found indicate a relationship between anthropometric measurements, nutritional status and intestinal microbiota with COPD. The assessment of these aspects can contribute to the identification clinical conditions of patients. KEY WORDS: Chronic obstructive pulmonary disease; Intestinal microbiota; Inflammation; Nutritional status; Anthropometry