Sheflin Amy M, Borresen Erica C, Kirkwood Jay S, Boot Claudia M, Whitney Alyssa K, Lu Shen, Brown Regina J, Broeckling Corey D, Ryan Elizabeth P, Weir Tiffany L
Department of Food Science and Human Nutrition, Colorado State University, Fort Collins, CO, USA.
Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, USA.
Mol Nutr Food Res. 2017 Jan;61(1). doi: 10.1002/mnfr.201500905. Epub 2016 Sep 12.
Heat-stabilized rice bran (SRB) and cooked navy bean powder (NBP) contain a variety of phytochemicals that are fermented by colonic microbiota and may influence intestinal health. Dietary interventions with these foods should be explored for modulating colorectal cancer risk.
A randomized-controlled pilot clinical trial investigated the effects of eating SRB (30 g/day) or cooked navy bean powder (35 g/day) on gut microbiota and metabolites (NCT01929122). Twenty-nine overweight/obese volunteers with a prior history of colorectal cancer consumed a study-provided meal and snack daily for 28 days. Volunteers receiving SRB or NBP showed increased gut bacterial diversity and altered gut microbial composition at 28 days compared to baseline. Supplementation with SRB or NBP increased total dietary fiber intake similarly, yet only rice bran intake led to a decreased Firmicutes:Bacteroidetes ratio and increased SCFA (propionate and acetate) in stool after 14 days but not at 28 days.
These findings support modulation of gut microbiota and fermentation byproducts by SRB and suggest that foods with similar ability to increase dietary fiber intake may not have equal effects on gut microbiota and microbial metabolism.
热稳定米糠（SRB）和熟海军豆粉（NBP）含有多种可被结肠微生物群发酵的植物化学物质，可能会影响肠道健康。应探索用这些食物进行饮食干预以调节结直肠癌风险。
一项随机对照试验性临床试验研究了食用SRB（30克/天）或熟海军豆粉（35克/天）对肠道微生物群和代谢物的影响（NCT01929122）。29名有结直肠癌病史的超重/肥胖志愿者每天食用研究提供的餐食和零食，持续28天。与基线相比，接受SRB或NBP的志愿者在28天时肠道细菌多样性增加，肠道微生物组成改变。补充SRB或NBP同样增加了总膳食纤维摄入量，但仅米糠摄入在14天后导致粪便中厚壁菌门：拟杆菌门比例降低以及短链脂肪酸（丙酸和乙酸）增加，而在28天时未出现此情况。
这些发现支持SRB对肠道微生物群和发酵副产物的调节作用，并表明具有类似增加膳食纤维摄入能力的食物对肠道微生物群和微生物代谢的影响可能并不相同。
