J Acad Nutr Diet. 2018 Apr;118(4):606-616.e3. doi: 10.1016/j.jand.2017.09.013. Epub 2017 Dec 21.
Relatively high serum carotenoid levels are associated with reduced risks of chronic diseases, but inter-individual variability in serum carotenoid concentrations is modestly explained by diet. The bacterial community in the colon could contribute to the bioaccessibility of carotenoids by completing digestion of plant cells walls and by modulating intestinal permeability.
To evaluate whether colonic bacterial composition is associated with serum and colon carotenoid concentrations.
The study was a randomized dietary intervention trial in healthy individuals who were at increased risk of colon cancer. Colon mucosal biopsy samples were obtained before and after 6 months of intervention without prior preparation of the bowels.
PARTICIPANTS/SETTING: Participants were recruited from Ann Arbor, MI, and nearby areas from July 2007 to November 2010. Biopsy data were available from 88 participants at baseline and 82 participants after 6 months.
Study participants were randomized to counseling for either a Mediterranean diet or a Healthy Eating diet for 6 months.
At baseline, bacterial communities in biopsy samples from study participants in the highest vs the lowest tertile of total serum carotenoid levels differed by several parameters. Linear discriminant analysis effect size identified 11 operational taxonomic units that were significantly associated with higher serum carotenoid levels. In linear regression analyses, three of these accounted for an additional 12% of the variance in serum total carotenoid concentrations after including body mass index, smoking, and dietary intakes in the model. These factors together explained 36% of the inter-individual variance in serum total carotenoid concentrations. The bacterial community in the colonic mucosa, however, was resistant to change after dietary intervention with either a Mediterranean diet or Healthy Eating diet, each of which doubled fruit and vegetable intakes.
The colonic mucosal bacterial community was associated with serum carotenoid concentrations at baseline but was not appreciably changed by dietary intervention.
血清类胡萝卜素水平较高与慢性病风险降低有关，但个体间血清类胡萝卜素浓度的差异仅能通过饮食得到适度解释。结肠中的细菌群落可以通过完成植物细胞壁的消化和调节肠道通透性来促进类胡萝卜素的生物利用度。
评估结肠细菌组成与血清和结肠类胡萝卜素浓度之间的关系。
这是一项在有结直肠癌风险增加的健康个体中进行的随机饮食干预试验。在干预前和干预 6 个月后，未经肠道准备的情况下，从参与者的结肠黏膜活检样本中获得样本。
参与者/设置：参与者于 2007 年 7 月至 2010 年 11 月期间从密歇根州安阿伯及其周边地区招募。基线时有 88 名参与者和 6 个月后有 82 名参与者提供了活检数据。
研究参与者被随机分配到地中海饮食或健康饮食组进行 6 个月的饮食咨询。
在基线时，研究参与者的活检样本中，总血清类胡萝卜素水平最高和最低三分位组的细菌群落存在多个参数的差异。线性判别分析效应大小确定了 11 个与较高血清类胡萝卜素水平显著相关的操作分类单元。在线性回归分析中，在将体重指数、吸烟和饮食摄入量纳入模型后，其中 3 个解释了血清总类胡萝卜素浓度变异性的另外 12%。这些因素共同解释了血清总类胡萝卜素浓度个体间变异性的 36%。然而，在用地中海饮食或健康饮食进行饮食干预后，结肠黏膜中的细菌群落并没有发生变化，每种饮食都使水果和蔬菜的摄入量增加了一倍。
结肠黏膜细菌群落与基线时的血清类胡萝卜素浓度相关，但饮食干预对其影响不大。
