RESUMO
O número de indivíduos diagnosticados com o transtorno do espectro autista (TEA) registrou aumento evidente na última década. Os principais sintomas, apresentados pelo portador, são neurológicos e digestórios, estando às intervenções nutricionais dentre as terapêuticas mais promissoras para amenizar a sintomatologia clínica. Assim, objetivou-se revisar sistematicamente os estudos sobre distúrbios alimentares e do trato gastrointestinal apresentado pelo indivíduo portador do TEA, a fim de compreender como o comportamento alimentar influência na etiopatogênese e manifestações clínicas da doença, com foco no eixo intestinocérebro. Para isso realizou-se uma revisão sistemática, seguindo as diretrizes PRISMA. A partir de uma busca estruturada e abrangente em bases de dados eletrônicas, 23 estudos foram recuperados e incluídos na revisão. Os critérios de inclusão definiam ser artigos originais relacionando o TEA com alterações nutricionais e/ou com o eixo intestino-cérebro. Após análise da composição da microbiota intestinal, os estudos mostraram um quadro de desequilíbrio. Foram encontradas, também, alterações na barreira de muco e permeabilidade intestinal e alterações em proteínas envolvidas na digestão e absorção de alimentos. Dietas restritivas e a modulação da microbiota, com uso de probióticos e de antibióticos específicos, são apresentadas como estratégias terapêuticas adjuvantes promissoras. Conclui-se que o eixo intestino-cérebro está envolvido tanto na etiologia, quanto nas manifestações clínicas do TEA. Porém, não sendo certo se alterações intestinais são causa ou consequência das alterações neurológicas. Até o presente momento, a comunidade científica não tem conclusões suficientes para indicar o uso de dietas restritivas, e uso de probióticos e de antibióticos como terapêutica para o TEA.
The number of individuals diagnosed with autism spectrum disorder (ASD) had an evident increase in the last decade. The primary symptoms exhibited amongst these patients were mostly digestive and neurological disorders; with nutritional interventions being one of the most promising therapies to assuage this clinical symptomology. As such, following the PRISMA guidelines, we systematically reviewed the research studies apropos of the ASD patients manifesting said digestive disorders, to comprehend how dietary behavior can influence the etiopathogenesis and clinical manifestations of the disease, with primary focus on the gut-brain axis. From a comprehensive and structured search through electronic databases, 23 studies were retrieved and admitted in this review. The inclusion criteria defined that there be original articles consociating ASD with nutritional disorders and/or with the gut-brain axis. These studies analyzed the composition of the intestinal flora of diagnosed patients, subsequently discerning cases of varying imbalances. Alterations in the gene expression of the proteins involved in the digestion and absorption of food, the mucous barrier and the intestinal permeability were described. Accordingly, restrictive diets and the modulation of the microbiota by administering specific anti- & probiotics were initially identified as promissory therapies. In conclusion, the gut-brain axis was observed to be a determinant factor in both the etiology and clinical symptomology of ASD - though it is still debatable the correlation of intestinal alterations with neurological changes. At present, there is no concrete scientific proof accrediting to restrictive diets and the use of specific anti- & probiotics, as successful treatments for ASD.
Assuntos
Humanos , Pré-Escolar , Criança , Ciências da Nutrição Infantil , Cérebro , Transtorno do Espectro Autista , Intestinos , Neurotoxinas , PediatriaRESUMO
Metsulfuron-methyl is a common active ingredient recommended for use in pre- and post-emergence control of annual grasses and broadleaf weeds in crops, usually applied with mineral oil as adjuvant to enhance its efficiency. Despite the increasing use of this herbicide, there are no information on its ecotoxicity effects to soil fauna. Avoidance and lethality tests were performed with earthworms and collembolans using tropical artificial soil contaminated with formulated products Ally® (600 g L-1 metsulfuron-methyl) and Assist® (756 g L-1 mineral oil) as adjuvant. Lethality test with earthworms showed no difference when tested with or without adjuvant. When Ally® was tested alone, it caused avoidance behavior only at high concentrations (5000 and 10,000 times field predicted dose). However, Assist® addition changed the response of soil invertebrates increasing the avoidance even at field predicted doses. The toxicity of the adjuvant was confirmed in tests exposing collembolans and earthworms to Assist® alone resulting in avoidance behavior. The results clearly show that the addition of mineral oil enhanced the ecotoxicity of metsulfuron-methyl. This study provides an important contribution to the knowledge on the toxicity of metsulfuron-methyl and indicates that adjuvants should be considered in risk assessment of pesticides, considering that under field conditions, these products are applied together.
