Dalile Boushra, La Torre Danique, Kalc Polona, Zoppas Francesca, Roye Chiara, Loret Chrystel, Lamothe Lisa, Bergonzelli Gabriela, Courtin Christophe M, Vervliet Bram, Oudenhove Lukas Van, Verbeke Kristin
Translational Research Center in Gastrointestinal Disorders (TARGID), Department of Chronic Diseases and Metabolism, Faculty of Medicine, KU Leuven, Leuven, Belgium.
Leuven Brain Institute, KU Leuven, Leuven, Belgium.
Front Nutr. 2022 May 26;9:896154. doi: 10.3389/fnut.2022.896154. eCollection 2022.
Incorporation of wheat bran (WB) into food products increases intake of dietary fiber, which has been associated with improved mood and cognition and a lower risk for psychiatric disorders such as depression, with short-chain fatty acids (SCFAs) as candidate mediators of these effects. Modifying WB using extrusion cooking increases SCFA production relative to unmodified WB.
The aim of this study was to evaluate the effects of extruded WB on psychobiological functioning and the mediating role of SCFAs.
In a randomized, triple-blind, placebo-controlled trial, 69 healthy male participants consumed 55 g of breakfast cereal containing either extruded WB or placebo daily for 28 days. At pre- and post-intervention visits, the cortisol response to experimentally induced stress was measured as a primary outcome. In addition, serum SCFAs and brain-derived neurotrophic factors were quantified as potential mediators. Secondary psychobiological outcomes included subjective stress responses, responses to experimentally induced fear, cortisol awakening response, heart rate variability, and retrospective subjective mood ratings. Intestinal permeability, fecal SCFAs, and stool consistency were measured as secondary biological outcomes.
Extruded WB increased serum acetate and butyrate ( < 0.05). None of the primary or secondary outcomes were affected by the intervention. Participants who consumed a placebo exhibited an increase in the percentage of fecal dry weight but did not report increased constipation. Despite these statistically significant effects, these changes were small in magnitude.
Extruded WB consumption increased serum short-chain fatty acids but did not modulate psychobiological functions in healthy men. Effective modulation of psychobiological functions may require greater increases in SCFAs than those achieved following extruded WB consumption. Rather than attempting to induce health benefits with a single fiber-rich food, combinations of different fibers, particularly highly fermentable ones, might be needed to further increase SCFA production and uptake in the systemic circulation to observe an effect on psychobiological processes.
将麦麸（WB）添加到食品中可增加膳食纤维的摄入量，这与情绪和认知改善以及诸如抑郁症等精神疾病风险降低有关，短链脂肪酸（SCFAs）被认为是这些作用的潜在介导因子。与未改性的WB相比，采用挤压蒸煮改性的WB可增加SCFA的产生量。
本研究旨在评估挤压蒸煮的WB对心理生物学功能的影响以及SCFAs的介导作用。
在一项随机、三盲、安慰剂对照试验中，69名健康男性参与者每天食用55克含有挤压蒸煮的WB或安慰剂的早餐谷物，持续28天。在干预前后访视时，测量皮质醇对实验性诱导应激的反应作为主要结局。此外，对血清SCFAs和脑源性神经营养因子进行定量，作为潜在的介导因子。次要心理生物学结局包括主观应激反应、对实验性诱导恐惧的反应、皮质醇觉醒反应、心率变异性和回顾性主观情绪评分。测量肠道通透性、粪便SCFAs和粪便稠度作为次要生物学结局。
挤压蒸煮的WB可增加血清乙酸盐和丁酸盐（<0.05）。主要和次要结局均未受干预影响。食用安慰剂的参与者粪便干重百分比增加，但未报告便秘增加。尽管这些影响具有统计学意义，但变化幅度较小。
食用挤压蒸煮的WB可增加血清短链脂肪酸，但未调节健康男性的心理生物学功能。要有效调节心理生物学功能，可能需要比食用挤压蒸煮的WB后更大幅度地增加SCFAs。与其试图通过单一富含纤维的食物来诱导健康益处，可能需要不同纤维的组合，尤其是高度可发酵的纤维，以进一步增加SCFA的产生量及其在体循环中的吸收，从而观察到对心理生物学过程的影响。
