Data_Sheet_1_Reduced Growth, Altered Gut Microbiome and Metabolite Profile, and Increased Chronic Kidney Disease Risk in Young Pigs Consuming a Diet Containing Highly Resistant Protein.docx

High-heat processed foods contain proteins that are partially resistant to enzymatic digestion and pass through to the colon. The fermentation of resistant proteins by gut microbes produces products that may contribute to chronic disease risk. This pilot study examined the effects of a resistant protein diet on growth, fecal microbiome, protein fermentation metabolites, and the biomarkers of health status in pigs as a model of human digestion and metabolism. Weanling pigs were fed with standard or resistant protein diets for 4 weeks. The resistant protein, approximately half as digestible as the standard protein, was designed to enter the colon for microbial fermentation. Fecal and blood samples were collected to assess the microbiome and circulating metabolites and biomarkers. The resistant protein diet group consumed less feed and grew to ~50% of the body mass of the standard diet group. The diets had unique effects on the fecal microbiome, as demonstrated by clustering in the principal coordinate analysis. There were 121 taxa that were significantly different between groups (adjusted-p < 0.05). Compared with control, plasma tri-methylamine-N-oxide, homocysteine, neopterin, and tyrosine were increased and plasma acetic acid was lowered following the resistant protein diet (all p < 0.05). Compared with control, estimated glomerular filtration rate (p < 0.01) and liver function marker aspartate aminotransferase (p < 0.05) were also lower following the resistant protein diet. A resistant protein diet shifted the composition of the fecal microbiome. The microbial fermentation of resistant protein affected the levels of circulating metabolites and the biomarkers of health status toward a profile indicative of increased inflammation and the risk of chronic kidney disease.

高温加工食品中含有部分难以被酶解消化的蛋白质，此类蛋白质可抵达结肠（colon）。肠道微生物（gut microbes）对该抗性蛋白（resistant protein）的发酵过程会产生代谢产物，或会增加慢性病（chronic disease）的发病风险。本预试验（pilot study）以猪作为人类消化与代谢的模型动物，探究了抗性蛋白饮食（resistant protein diet）对仔猪生长性能、粪便微生物组（fecal microbiome）、蛋白质发酵代谢物以及健康状态生物标志物的影响。本试验选取断奶仔猪，分别饲喂标准蛋白饮食与抗性蛋白饮食，持续4周。本次试验所用的抗性蛋白其消化率约为标准蛋白的一半，旨在使其抵达结肠以进行微生物发酵（microbial fermentation）。研究人员采集粪便与血液样本，以检测微生物组、循环代谢物以及相关生物标志物。抗性蛋白饮食组的仔猪摄食量更低，其体质量仅达到标准蛋白饮食组仔猪的约50%。主坐标分析（principal coordinate analysis）的聚类结果显示，两种饮食对粪便微生物组的影响存在显著差异。两组间共有121个分类单元（taxa）的相对丰度存在显著差异（校正后P值<0.05）。与对照组相比，抗性蛋白饮食组仔猪的血浆三甲胺-N-氧化物（tri-methylamine-N-oxide）、同型半胱氨酸（homocysteine）、新蝶呤（neopterin）以及酪氨酸（tyrosine）水平均升高，而血浆乙酸（acetic acid）水平则降低（所有指标P<0.05）。与对照组相比，抗性蛋白饮食组仔猪的估算肾小球滤过率（estimated glomerular filtration rate）以及肝功能标志物天冬氨酸氨基转移酶（aspartate aminotransferase）水平均有所降低（前者P<0.01，后者P<0.05）。抗性蛋白饮食可改变粪便微生物组的组成结构。抗性蛋白的微生物发酵过程会改变循环代谢物与健康状态生物标志物的水平，形成一种提示炎症水平升高以及慢性肾脏病（chronic kidney disease）发病风险增加的特征性谱型。