Comparação entre a microbiota fecal de crianças e adolescentes com diabetes mellitus do tipo 1 com seus irmãos e indivíduos saudáveis

• Ano de defesa: 2018
• Autor(a) principal: Araujo Filho, Humberto Bezerra De [UNIFESP]
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Paulo (UNIFESP)
• Palavras-chave em Português: Type 1 diabetes mellitus; Child; Adolescent; Gastrointestinal microbiome metagenomics; Real time polimerase chain reaction; Diabete mellitus tipo 1; Criança; Adolescente; Microbioma gatrintestinal; Metagenômica; Reação em cadeias de polimerase em tempo real
• Link de acesso: https://sucupira.capes.gov.br/sucupira/public/consultas/coleta/trabalhoConclusao/viewTrabalhoConclusao.jsf?popup=true&id_trabalho=6642334; https://repositorio.unifesp.br/handle/11600/52453

The human intestinal microbiota has a great diversity of microorganisms, playing an important role in metabolism. Despite the positive aspects, the intestinal microbiota is associated with the development of various diseases such as inflammatory bowel disease, celiac disease, allergic diseases, and diabetes. Type 1 diabetes mellitus (T1D) is a chronic autoimmune disease characterized by increased blood glucose levels due to a deficiency in insulin production as a result of pancreatic βcell destruction. The pathophysiology of DM1 is still not fully understood, however, only genetic factors are not sufficient to determine the risk of developing the disease. The role of the intestinal microbiota as one of the triggers of T1D has been evaluated in animal and human studies, and strong evidence is available for a microbiota that promotes disease development. This study aims to compare fecal microbiota among children and adolescents with T1D, their siblings and healthy children with no family relationship to the diabetics. Fecal samples were collected from 13 children and adolescents with T1D, 9 siblings from these patients and 21 healthy children with no Family relationship to the patients. The DNA extracted from the feces was submitted to PCR amplification of the 16S rRNA gene and submitted to next generation sequencing. In addition, realtime PCR was performed for quantification of bacteria representative of the fecal microbiota. The DNA sequences were analyzed in the free plataform QIIME, and the data obtained were analyzed for alpha and beta diversity. The alpha diversity indexes did not present statistical differences between the groups, however it was possible to observe statistically significant differences regarding the relative abundance of the Phylum Firmicutes and the genus Prevotella, among the patients with T1D and healthy group without kinship. Realtime PCR showed that patients with T1D had higher concentrations of the Phylum Bacteroidetes and Firmicutes, Escherichia coli and Methanobrevibacter smithii species, compared to the healthy nonrelated group. It is concluded that there are differences between the fecal microbiota composition of patients with T1D and healthy individuals with no degree of kinship, there are no significant differences in the microbiota between individuals with a high degree of kinship, and environmental factors play an important role in the composition of the intestinal microbiota.