The processes that define mammalian physiology evolved millions of years ago in response to ancient signaling molecules, most of which were acquired by ingestion and digestion. In this way, evolution inextricably linked diet to all major physiological systems including the nervous system. The importance of diet in neurological development is well documented, although the mechanisms by which diet-derived signaling molecules (DSMs) affect cognition are poorly understood. Studies on the positive impact of nutritive and non-nutritive bioactive molecules on brain function are encouraging but lack the statistical power needed to demonstrate strong positive associations. Establishing associations between DSMs and cognitive functions like mood, memory and learning are made even more difficult by the lack of robust phenotypic markers that can be used to accurately and reproducibly measure the effects of DSMs. Lastly, it is now apparent that processes like neurogenesis and neuroplasticity are embedded within layers of interlocked signaling pathways and gene regulatory networks. Within these interdependent pathways and networks, the various transducers of DSMs are used combinatorially to produce those emergent adaptive gene expression responses needed for stimulus-induced neurogenesis and neuroplasticity. Taken together, it appears that cognition is encoded genomically and modified by epigenetics and epitranscriptomics to produce complex transcriptional programs that are exquisitely sensitive to signaling molecules from the environment. Models for how DSMs mediate the interplay between the environment and various neuronal processes are discussed in the context of the food–brain axis.

定义哺乳动物生理学的过程是在数百万年前进化的，以响应古老的信号分子，其中大部分是通过摄入和消化获得的。通过这种方式，进化将饮食与包括神经系统在内的所有主要生理系统密不可分地联系在一起。饮食在神经发育中的重要性已得到充分证明，但饮食衍生信号分子 (DSM) 影响认知的机制尚不清楚。关于营养性和非营养性生物活性分子对大脑功能的积极影响的研究令人鼓舞，但缺乏证明强烈的正相关性所需的统计能力。由于缺乏可用于准确、可重复地测量 DSM 效果的稳健表型标记，在 DSM 与情绪、记忆和学习等认知功能之间建立关联变得更加困难。最后，现在很明显，神经发生和神经可塑性等过程嵌入在互锁的信号通路和基因调控网络的层中。在这些相互依赖的途径和网络中，DSM 的各种传感器组合使用，以产生刺激诱导的神经发生和神经可塑性所需的新兴适应性基因表达反应。总而言之，认知似乎是通过基因组编码并通过表观遗传学和表观转录组学修改来产生对环境信号分子极其敏感的复杂转录程序。在食物-大脑轴的背景下讨论了 DSM 如何介导环境和各种神经元过程之间相互作用的模型。