Church Jamie S, Bannish Jane A M, Adrian Leighelle A, Rojas Martinez Kimberly, Henshaw Asari, Schwartzer Jared J
Program in Neuroscience and Behavior, Department of Psychology and Education, Mount Holyoke College, South Hadley, MA, United States.
Front Neurosci. 2023 Apr 11;17:1134080. doi: 10.3389/fnins.2023.1134080. eCollection 2023.
Dietary components, such as prebiotic fiber, are known to impact brain chemistry the gut-brain axis. In particular, short chain fatty acids (SCFAs) generated from excessive soluble fiber consumption are thought to impact neuroimmune signaling and brain function through increased production of neurotropic factors. Given reports that high dietary fiber intake is associated with increased mental health and improved quality of life scores, we set out to identify whether changes in SCFA levels as a result of a high soluble fiber diet mediate hippocampal neuroinflammation and brain derived neurotrophic factor (BDNF) in mice.
Adult male and female C57BL/6 mice were fed a 1-month high pectin fiber or cellulose-based control diet. Following 1 month of excessive pectin consumption, serum SCFAs were measured using gas chromatography-mass spectrometry (GC-MS) and hippocampal cytokines and BDNF were assessed multiplex magnetic bead immunoassay.
Pectin-based fiber diet increased circulating acetic acid in both sexes, with no effect on propionic or butyric acid. In the hippocampus, a high fiber diet decreased TNFa, IL-1ß, IL-6, and IFNγ and increased BDNF levels. Furthermore, increased SCFA levels were inversely correlated with neuroinflammation in the hippocampus, with acetic acid revealed as a strong mediator of increased BDNF production.
Collectively, these findings highlight the beneficial effects of fiber-induced molecular changes in a brain region known to influence mood- and cognition-related behaviors. Dietary composition should be considered when developing mental health management plans for men and women with an emphasis on increasing soluble fiber intake.
已知益生元纤维等饮食成分会影响脑化学——肠-脑轴。特别是，过量摄入可溶性纤维产生的短链脂肪酸（SCFAs）被认为通过增加神经营养因子的产生来影响神经免疫信号传导和脑功能。鉴于有报道称高膳食纤维摄入量与心理健康改善和生活质量评分提高相关，我们着手确定高可溶性纤维饮食导致的SCFA水平变化是否介导小鼠海马神经炎症和脑源性神经营养因子（BDNF）。
给成年雄性和雌性C57BL/6小鼠喂食1个月的高果胶纤维或基于纤维素的对照饮食。在过量食用果胶1个月后，使用气相色谱-质谱联用仪（GC-MS）测量血清SCFAs，并通过多重磁珠免疫测定法评估海马细胞因子和BDNF。
基于果胶的纤维饮食增加了两性的循环乙酸，对丙酸或丁酸没有影响。在海马体中，高纤维饮食降低了TNFα、IL-1β、IL-6和IFNγ水平，并增加了BDNF水平。此外，SCFA水平的升高与海马体中的神经炎症呈负相关，乙酸被证明是BDNF产生增加的强介导因子。
总的来说，这些发现突出了纤维诱导的分子变化在一个已知会影响情绪和认知相关行为的脑区中的有益作用。在为男性和女性制定心理健康管理计划时，应考虑饮食组成，重点是增加可溶性纤维的摄入量。
