USDA-Agricultural Research Service, Western Human Nutrition Research Center, Davis, CA, United States.
USDA-Agricultural Research Service, Western Human Nutrition Research Center, Davis, CA, United States; Department of Nutrition, University of California, Davis, Davis, CA, United States.
J Nutr. 2024 Nov;154(11):3298-3311. doi: 10.1016/j.tjnut.2024.08.012. Epub 2024 Aug 20.
Gut microbes produce short-chain fatty acids (SCFAs), which are associated with broad health benefits. However, it is not fully known how diet and/or the gut microbiome could be modulated to improve SCFA production.
The objective of this study was to identify dietary, inflammatory, and/or microbiome predictors of SCFAs in a cohort of healthy adults.
SCFAs were measured in fecal and plasma samples from 359 healthy adults in the United States Department of Agriculture Nutritional Phenotyping Study. Habitual and recent diet was assessed using a Food Frequency Questionnaire and Automated Self-Administered 24-h Dietary Assesment Tool dietary recalls. Markers of systemic and gut inflammation were measured in fecal and plasma samples. The gut microbiome was assessed using shotgun metagenomics. Using statistics and machine learning, we determined how the abundance and composition of SCFAs varied with measures of diet, inflammation, and the gut microbiome.
We show that fecal pH may be a good proxy for fecal SCFA abundance. A higher Healthy Eating Index for a habitual diet was associated with a compositional increase in fecal butyrate relative to acetate and propionate. SCFAs were associated with markers of subclinical gastrointestinal (GI) inflammation. Fecal SCFA abundance was inversely related to plasma lipopolysaccharide-binding protein. When we analyzed hierarchically organized diet and microbiome data with taxonomy-aware algorithms, we observed that diet and microbiome features were far more predictive of fecal SCFA abundances compared to plasma SCFA abundances. The top diet and microbiome predictors of fecal butyrate included potatoes and the thiamine biosynthesis pathway, respectively.
These results suggest that resistant starch in the form of potatoes and microbially produced thiamine provide a substrate and essential cofactor, respectively, for butyrate synthesis. Thiamine may be a rate-limiting nutrient for butyrate production in adults. Overall, these findings illustrate the complex biology underpinning SCFA production in the gut. This trial was registered at clinicaltrials.gov as NCT02367287.
肠道微生物会产生短链脂肪酸（SCFAs），这些酸与广泛的健康益处有关。然而，人们还不完全清楚如何调节饮食和/或肠道微生物群来提高 SCFA 的产量。
本研究的目的是确定健康成年人队列中 SCFA 的饮食、炎症和/或微生物组预测因子。
在美国农业部营养表型研究中，对 359 名健康成年人的粪便和血浆样本中的 SCFAs 进行了测量。使用食物频率问卷和自动自我管理的 24 小时膳食评估工具进行习惯性和近期饮食评估。粪便和血浆样本中测量了全身和肠道炎症标志物。使用 shotgun 宏基因组学评估肠道微生物组。我们使用统计学和机器学习来确定 SCFA 的丰度和组成如何随饮食、炎症和肠道微生物组的测量值而变化。
我们表明粪便 pH 值可能是粪便 SCFA 丰度的良好替代指标。习惯性饮食的健康饮食指数较高与粪便丁酸相对乙酸和丙酸的组成增加有关。SCFA 与亚临床胃肠道（GI）炎症标志物有关。粪便 SCFA 丰度与血浆脂多糖结合蛋白呈负相关。当我们用具有分类学意识的算法分析分层组织的饮食和微生物组数据时，我们观察到饮食和微生物组特征与粪便 SCFA 丰度的相关性远高于血浆 SCFA 丰度。预测粪便丁酸丰度的主要饮食和微生物组因素包括土豆和硫胺素生物合成途径。
这些结果表明，以土豆形式存在的抗性淀粉和微生物产生的硫胺素分别为丁酸合成提供了底物和必需的辅因子。硫胺素可能是成年人丁酸产生的限速营养素。总的来说，这些发现说明了支持肠道中 SCFA 产生的复杂生物学。该试验在 clinicaltrials.gov 上注册为 NCT02367287。
