Alexandre-Silva GM, Brito-Souza PA, Oliveira AC, Cerni FA, Zottich U, Pucca MB. The hygiene hypothesis at a glance: Early exposures, immune mechanism and novel therapies.
Acta Trop 2018;
188:16-26. [PMID:
30165069 DOI:
10.1016/j.actatropica.2018.08.032]
[Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 08/20/2018] [Accepted: 08/25/2018] [Indexed: 02/07/2023]
Abstract
The hygiene hypothesis was proposed almost three decades ago. Nevertheless, its mechanism still remains with relevant controversies. Some studies defend that early exposures during childhood to microbes and parasites are key determinants to prevent allergies and autoimmune diseases; however, other studies demonstrated that these early exposures can even potentiate the clinical scenario of the diseases. Based on several studies covering the influences of microbiome, parasites, related theories and others, this review focuses on recent advances in the hygiene hypothesis field. In addition, the main immunological mechanisms underlying the hygiene hypothesis are also discussed. We also strongly encourage that researchers do not consider the hygiene hypothesis as a theory based strictly on hygiene habits, but a theory combining diverse influences, as illustrated in this review as the hygiene hypothesis net.
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