Microbiomes provide key contributions to health and potentially important therapeutic targets. Conceived nearly 30 years ago, the prebiotic concept posits that targeted modulation of host microbial communities through the provision of selectively utilized growth substrates provides an effective approach to improving health. Although the basic tenets of this concept remain the same, it is timely to address certain challenges pertaining to prebiotics, including establishing that prebiotic-induced microbiota modulation causes the health outcome, determining which members within a complex microbial community directly utilize specific substrates in vivo and when those microbial effects sufficiently satisfy selectivity requirements, and clarification of the scientific principles on which the term ‘prebiotic’ is predicated to inspire proper use. In this Expert Recommendation, we provide a framework for the classification of compounds as prebiotics. We discuss ecological principles by which substrates modulate microbiomes and methodologies useful for characterizing such changes. We then propose statistical approaches that can be used to establish causal links between selective effects on the microbiome and health effects on the host, which can help address existing challenges. We use this information to provide the minimum criteria needed to classify compounds as prebiotics. Furthermore, communications to consumers and regulatory approaches to prebiotics worldwide are discussed.

微生物组为健康提供了关键贡献，并可能成为重要的治疗靶点。益生元概念构思于近 30 年前，它假设通过提供选择性利用的生长基质来靶向调节宿主微生物群落提供了一种改善健康的有效方法。尽管这一概念的基本原则保持不变，但现在是时候解决与益生元有关的某些挑战了，包括确定益生元诱导的微生物群调节会导致健康结果，确定复杂微生物群落中的哪些成员在体内直接利用特定底物，以及这些微生物效应何时充分满足选择性要求，以及阐明“益生元”一词所依据的科学原则以激发正确使用。在本专家建议中，我们提供了一个将化合物分类为益生元的框架。我们讨论了底物调节微生物组的生态学原理以及可用于表征此类变化的方法。然后，我们提出了可用于建立对微生物组的选择性影响和对宿主的健康影响之间的因果关系的统计方法，这有助于解决现有挑战。我们使用这些信息来提供将化合物归类为益生元所需的最低标准。此外，还讨论了与消费者的沟通和全球益生元的监管方法。