APC Microbiome Ireland, University College Cork, Cork T12 YT20, Ireland.
Department of Anatomy and Neuroscience, University College Cork, Cork T12 YT20, Ireland.
Exp Biol Med (Maywood). 2021 Apr;246(7):796-811. doi: 10.1177/1535370221995785. Epub 2021 Feb 28.
Healthy dietary intake has been acknowledged for decades as one of the main contributors to health. More recently, the field of nutritional psychiatry has progressed our understanding regarding the importance of nutrition in supporting mental health and cognitive function. Thereby, individual nutrients, including omega-3 fatty acids and polyphenols, have been recognized to be key drivers in this relationship. With the progress in appreciating the influence of dietary fiber on health, increasingly research is focusing on deciphering its role in brain processes. However, while the importance of dietary fiber in gastrointestinal and metabolic health is well established, leading to the development of associated health claims, the evidence is not conclusive enough to support similar claims regarding cognitive function. Albeit the increasing knowledge of the impact of dietary fiber on mental health, only a few human studies have begun to shed light onto the underexplored connection between dietary fiber and cognition. Moreover, the microbiota-gut-brain axis has emerged as a key conduit for the effects of nutrition on the brain, especially fibers, that are acted on by specific bacteria to produce a variety of health-promoting metabolites. These metabolites (including short chain fatty acids) as well as the vagus nerve, the immune system, gut hormones, or the kynurenine pathway have been proposed as underlying mechanisms of the microbiota-brain crosstalk. In this minireview, we summarize the evidence available from human studies on the association between dietary fiber intake and cognitive function. We provide an overview of potential underlying mechanisms and discuss remaining questions that need to be answered in future studies. While this field is moving at a fast pace and holds promise for future important discoveries, especially data from human cohorts are required to further our understanding and drive the development of public health recommendations regarding dietary fiber in brain health.
几十年来，健康的饮食摄入一直被认为是健康的主要因素之一。最近，营养精神病学领域的研究进展使我们更加了解营养在支持心理健康和认知功能方面的重要性。因此，包括欧米伽 3 脂肪酸和多酚在内的个别营养素已被认为是这种关系的关键驱动因素。随着人们对膳食纤维对健康影响的认识不断提高，越来越多的研究开始关注其在大脑过程中的作用。然而，虽然膳食纤维对胃肠道和代谢健康的重要性已得到充分证实，导致相关健康声称的发展，但目前的证据还不足以支持关于认知功能的类似声称。尽管人们越来越了解膳食纤维对心理健康的影响，但只有少数人体研究开始揭示膳食纤维与认知之间尚未充分探索的联系。此外，肠道菌群-肠-脑轴已成为营养对大脑影响的关键途径，特别是膳食纤维，它会被特定细菌作用产生多种促进健康的代谢物。这些代谢物（包括短链脂肪酸）以及迷走神经、免疫系统、肠道激素或犬尿氨酸途径被认为是肠道菌群-大脑相互作用的潜在机制。在这篇综述中，我们总结了人类研究中关于膳食纤维摄入与认知功能之间关联的现有证据。我们概述了潜在的机制，并讨论了未来研究中需要回答的剩余问题。虽然这个领域发展迅速，未来有望有重要发现，但仍需要来自人类队列的数据来进一步了解并推动有关膳食纤维在大脑健康方面的公共卫生建议的制定。
