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Probióticos. Introducción y definiciones

26.02.2018
Probiotyki – aktualny stan wiedzy i zalecenia dla praktyki klinicznej
Hanna Szajewska

Szajewska H., “Probiotyki – aktualny stan wiedzy i zalecenia dla praktyki klinicznej”, Med. Prakt., 2017, 7-8: 19-37.

Nota del editor: El artículo se basa en una ponencia presentada durante la 16.a Conferencia Nacional Formativa de la Sociedad Polaca de Medicina Internista “Avances en la medicina interna” (Interna 2017).

Siglas y abreviaturas: ACG — American Gastroenterological Society (Sociedad Estadounidense de Gastroenterología), ESPGHAN — European Society for Paediatric Gastroenterology, Hepatology, and Nutrition (Sociedad Europea de Gastroenterología, Hepatología y Nutrición Pediátrica), IC — intervalo de confianza, RCT (randomized controlled trial) — prueba controlada aleatorizada, RR — riesgo relativo

Introducción

El mercado ofrece decenas de probióticos, si bien la decisión sobre su uso y la elección de un preparado adecuado a veces constituyen un problema. No todos los probióticos han sido examinados en pruebas fidedignas, lo cual conlleva dudas sobre su eficacia. Aquí y en la segunda parte del presente artículo presentamos la información básica sobre la microbiota y los datos acerca de la eficacia clínica y seguridad del uso de los probióticos. Con este fin se ha revisado la base de datos médicos MEDLINE y Cochrane Library (hasta el junio de 2017). El análisis aborda pruebas controladas aleatorizadas (RCT) o sus metaanálisis, publicados durante los últimos 5 años (2012-2017). Dentro de lo posible presentamos también las opiniones de las sociedades científicas.

Definiciones

Microbiota y microbioma

En Europa el término “microbiota” designa todos los microorganismos (bacterias, eucariotas y virus) presentes en el organismo humano (sobre todo en el tracto digestivo), además de sus genes.1 El término “microbioma” hace referencia solamente a los genes pertenecientes a la microbiota. En otras partes del mundo (p. ej. en EE. UU) microbioma es un sinónimo de microbiota. En la literatura científica los términos “microbiota“/”microbioma” han sustituido completamente el término “microflora”, que se refiere al mundo de la flora. Se estima que en la composición de la microbiota se distinguen aprox. 1000 especies de bacterias, pero tan solo 150-170 son dominantes en cada persona. El número de genes de los microorganismos asciende a 3 millones, es decir, supera 150 veces el número de genes del ser humano.2

Disbiosis

El término “disbiosis” se refiere al desequilibrio en la composición y función de los microorganismos. La etiopatogenia de varias enfermedades, entre otras, de la diarrea asociada al uso de los antibióticos, síndrome del intestino irritable, enteritis inespecífica, alergias, diabetes mellitus y obesidad, se relaciona con los trastornos en la microbiota.3-6 La disbiosis parece jugar un papel importante también en los trastornos del espectro de autismo, así como en la depresión, esquizofrenia y enfermedades neurodegenerativas. En todos los casos hablamos solamente de las asociaciones y no de las relaciones causa-efecto documentadas. No se dispone de un “patrón” claro de los trastornos de la microbiota característicos para cada una de las enfermedades. La característica más consistente es la disminución en la diversidad de la microbiota. Es raro o incluso imposible que el desequilibrio de la microbiota sea el único factor etiológico de una enfermedad.

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