We sought to determine whether radiation to the colorectum had an impact on parameters of hippocampal neurogenesis and, if so, whether it could be modulated by a fiber-rich diet. Male C57BL/6J mice were fed a diet containing bioprocessed oat bran or a fiber-free diet, starting two weeks before colorectal irradiation with 4 fractions of 8 Gray or sham-irradiation. Diets were then continued for 1, 6 or 18 weeks, whereafter parameters of hippocampal neurogenesis were analyzed and correlated to serum cytokine levels. No statistically significant changes in neuronal markers or cell proliferation were found at one week post-irradiation. Six weeks post-irradiation there was a decreased cell proliferation in the subgranular zone that appeared slightly more pronounced in irradiated animals on a fiber-free diet and increased numbers of immature neurons per mm² dentate gyrus in the irradiated mice, with a statistically significant increase in mice on a fiber-rich diet. Microglial abundancy was similar between all groups. 18 weeks post-irradiation, a fiber-free diet had reduced the number of immature neurons, whereas irradiation resulted in an increase. Despite this, the population of mature neurons was stable. Analysis of serum cytokines revealed a negative correlation between MIP1-α and the number of immature neurons one week after irradiation, regardless of diet. Our findings show that pelvic radiotherapy has the potential to cause a long-lasting impact on hippocampal neurogenesis, and dietary interventions may modulate this impact. More in-depth studies on the relationship between irradiation-induced intestinal injury and brain health are warranted.

我们试图确定对结肠直肠的辐射是否对海马神经发生的参数有影响，如果是，是否可以通过富含纤维的饮食来调节。雄性 C57BL/6J 小鼠在结肠直肠照射前两周开始喂食含有生物加工燕麦麸的饮食或无纤维饮食，用 4 份 8 格雷或假照射。然后继续饮食 1、6 或 18 周，然后分析海马神经发生的参数并将其与血清细胞因子水平相关联。辐照后 1 周未发现神经元标志物或细胞增殖的统计学显着变化。²辐照小鼠的齿状回，在富含纤维的饮食中小鼠的统计显着增加。所有组之间的小胶质细胞丰度相似。照射后 18 周，无纤维饮食减少了未成熟神经元的数量，而照射导致增加。尽管如此，成熟神经元的数量是稳定的。血清细胞因子分析显示，无论饮食如何，MIP1-α 与辐照后一周未成熟神经元的数量呈负相关。我们的研究结果表明，盆腔放疗有可能对海马神经发生产生长期影响，而饮食干预可能会调节这种影响。有必要对辐射引起的肠道损伤与大脑健康之间的关系进行更深入的研究。