High-Fiber, Whole-Food Dietary Intervention Alters the Human Gut Microbiome but Not Fecal Short-Chain Fatty Acids.
High-Fiber, Whole-Food Dietary Intervention Alters the Human Gut Microbiome but Not Fecal Short-Chain Fatty Acids.
复制标题
高纤维、全食饮食干预改变了人类肠道微生物群，但不改变粪便短链脂肪酸。
DOI：
10.1128/msystems.00115-21
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发表时间：
2021-03-16
期刊：
影响因子：
6.4
通讯作者：
Whiteson K
中科院分区：
文献类型：
--
作者：
Oliver A;Chase AB;Weihe C;Orchanian SB;Riedel SF;Hendrickson CL;Lay M;Sewall JM;Martiny JBH;Whiteson K
饮食变化可以通过优先选择能够利用各种膳食营养素的微生物来直接影响肠道微生物群。在上个世纪，膳食纤维的摄入量急剧下降，而加工食品的消费量却在增加。纤维，或微生物可利用的碳水化合物（MACs），持续存在于消化道中，可以被编码纤维降解酶的特定细菌代谢。MACs的消化会导致短链脂肪酸（SCFAs）和其他对人体健康至关重要的代谢副产物的积累。在这里，我们实施了为期两周的膳食纤维干预，目标是在基于课程的本科生研究经历（CURE）的背景下每天摄入40至50克纤维（n = 20）。通过将霰弹枪宏基因组测序和靶向气相色谱-质谱（GC-MS）相结合，我们发现饮食干预显著改变了个体肠道微生物组的组成，占受试者体内纵向变异的8.3%。值得注意的是，由于饮食变化，微生物分类群的相对丰度增加，包括已知的MAC降解菌（即双歧杆菌和乳杆菌）。我们进一步评估了双歧杆菌内的遗传多样性，通过扩增groEL基因进行检测。伴随着微生物组成的变化，我们发现参与肌醇降解的基因丰度增加。尽管肠道微生物组成发生了这些变化，但我们没有发现SCFA丰度的持续变化。总的来说，我们的研究结果表明，在2周的短期时间内，增加纤维摄入量可以诱导肠道微生物组的组成变化，包括mac降解细菌的增加。上个世纪，世界许多地区膳食纤维摄入量的大幅下降可能与II型糖尿病、结肠癌和其他健康问题的日益流行有关。典型的美国饮食每天含有约15克纤维，远低于每日推荐摄入量。膳食纤维摄入量的变化不仅通过营养物质的吸收直接影响人体健康，而且还通过微生物群落及其相关代谢的变化间接影响人体健康。在这里，我们对健康的年轻人进行了为期两周的饮食干预，以调查纤维摄入对肠道微生物群的影响。参与者在两周内平均每天增加25克纤维摄入量。高纤维饮食干预改变了研究参与者的肠道微生物群，包括已知的纤维降解微生物的增加，如双歧杆菌和乳杆菌。
Dietary shifts can have a direct impact on the gut microbiome by preferentially selecting for microbes capable of utilizing the various dietary nutrients. The intake of dietary fiber has decreased precipitously in the last century, while consumption of processed foods has increased. Fiber, or microbiota-accessible carbohydrates (MACs), persist in the digestive tract and can be metabolized by specific bacteria encoding fiber-degrading enzymes. The digestion of MACs results in the accumulation of short-chain fatty acids (SCFAs) and other metabolic by-products that are critical to human health. Here, we implemented a 2-week dietary fiber intervention aiming for 40 to 50 g of fiber per day within the context of a course-based undergraduate research experience (CURE) (n = 20). By coupling shotgun metagenomic sequencing and targeted gas chromatography-mass spectrometry (GC-MS), we found that the dietary intervention significantly altered the composition of individual gut microbiomes, accounting for 8.3% of the longitudinal variability within subjects. Notably, microbial taxa that increased in relative abundance as a result of the diet change included known MAC degraders (i.e., Bifidobacterium and Lactobacillus). We further assessed the genetic diversity within Bifidobacterium, assayed by amplification of the groEL gene. Concomitant with microbial composition changes, we show an increase in the abundance of genes involved in inositol degradation. Despite these changes in gut microbiome composition, we did not detect a consistent shift in SCFA abundance. Collectively, our results demonstrate that on a short-term timescale of 2 weeks, increased fiber intake can induce compositional changes of the gut microbiome, including an increase in MAC-degrading bacteria. IMPORTANCE A profound decrease in the consumption of dietary fiber in many parts of the world in the last century may be associated with the increasing prevalence of type II diabetes, colon cancer, and other health problems. A typical U.S. diet includes about ∼15 g of fiber per day, far less fiber than the daily recommended allowance. Changes in dietary fiber intake affect human health not only through the uptake of nutrients directly but also indirectly through changes in the microbial community and their associated metabolism. Here, we conducted a 2-week diet intervention in healthy young adults to investigate the impact of fiber consumption on the gut microbiome. Participants increased their average fiber consumption by 25 g/day on average for 2 weeks. The high-fiber diet intervention altered the gut microbiome of the study participants, including increases in known fiber-degrading microbes, such as Bifidobacterium and Lactobacillus.