Department of Food Science and Nutrition, Faculty of Human Life and Environmental Sciences, Nagoya Women's University, 3-40 Shioji-cho, Mizuho-ku, Nagoya, Aichi 467-8610, Japan.
Department of Anatomy and Neuroscience, Graduate School of Medical Sciences, Nagoya City University, 1Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-8601, Japan.
J Nutr Biochem. 2020 Jan;75:108247. doi: 10.1016/j.jnutbio.2019.108247. Epub 2019 Oct 28.
Nutrition and dietary habits contribute to the onset and progression of sensorineural hearing loss (SNHL). Fructo-oligosaccharides (FOS) are non-digestible oligosaccharides and are known as prebiotics, which enhance short-chain fatty acid (SCFA) production and antioxidant activity. Although a substantial number of studies have shown that FOS play a role in the prevention of lifestyle-related diseases as prebiotics, little is known about the effects on the inner ear. The purpose of this study is to investigate the effect of FOS on gene expression and spiral ganglion neuron (SGN) protection in the inner ear of DBA/2 J mice, which is a model for early-onset progressive hearing loss. DBA/2 J mice were fed either control diet or FOS diet contained 10% (w/w) of FOS for 8 weeks. Analysis of mice fed the FOS diet revealed a change in intestinal flora including an inversion of the ratio of Bacteroidetes and Firmicutes, which was followed by a significant increase in SCFAs in the cecum and a decrease in an oxidative stress marker in the serum. In the inner ear, gene expression of neurotrophin, brain-derived neurotrophic factor (BDNF), its receptor, tyrosine kinase receptor b (Trkb), and the SCFA receptor, free fatty acid receptor 3 (FFAR3), were increased by FOS. In addition, the survival rate of SGNs in the inner ear was maintained in FOS-fed mice. Altogether, these results suggest that a compositional variation of the intestinal flora due to a prebiotic effect may be involved in the progression of SNHL.
营养和饮食习惯是导致感音神经性听力损失（SNHL）发生和进展的因素之一。低聚果糖（FOS）是一种不可消化的低聚糖，被称为益生元，可促进短链脂肪酸（SCFA）的产生和抗氧化活性。虽然大量研究表明 FOS 作为益生元在预防与生活方式相关的疾病方面发挥作用，但对于其在内耳中的作用知之甚少。本研究旨在探讨 FOS 对 DBA/2 J 小鼠内耳中基因表达和螺旋神经节神经元（SGN）保护的影响，DBA/2 J 小鼠是一种早发性进行性听力损失的模型。DBA/2 J 小鼠分别喂食对照饮食或含 10%（w/w）FOS 的 FOS 饮食 8 周。分析喂食 FOS 饮食的小鼠的肠道菌群变化，包括拟杆菌门和厚壁菌门比例的反转，随后盲肠中 SCFA 显著增加，血清中氧化应激标志物减少。在内耳中，神经营养因子、脑源性神经营养因子（BDNF）及其受体、酪氨酸激酶受体 b（Trkb）和 SCFA 受体游离脂肪酸受体 3（FFAR3）的基因表达均因 FOS 而增加。此外，FOS 喂养的小鼠内耳中的 SGN 存活率得到维持。总之，这些结果表明，由于益生元的作用，肠道菌群组成的变化可能与 SNHL 的进展有关。
