Wheat bran diet reduces tumor incidence in a rat model of colon cancer independent of effects on distal luminal butyrate concentrations
Wheat bran diet reduces tumor incidence in a rat model of colon cancer independent of effects on distal luminal butyrate concentrations
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DOI：
10.1093/jn/127.11.2217
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发表时间：
1997-11-01
影响因子：
4.2
通讯作者：
Lupton, JR
中科院分区：
文献类型：
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作者：
Zoran, DL;Turner, ND;Lupton, JR
为了研究膳食纤维在结肠腔生理中的作用及其在预防结肠癌中的作用，采用2×2析因设计，对两个饮食组和两个处理组进行了研究。两种饮食的不同之处仅在于膳食纤维的类型、麦麸皮和燕麦麸皮，两种处理分别注射结肠特异性致癌物质偶氮甲烷或生理盐水，作为对照，致癌物注射组34只大鼠，每饮食组注射生理盐水11只。这项研究的目的是确定适量摄入(6g/100g饮食)麦皮或燕麦皮是否会改变这种结肠癌大鼠模型的结肠肿瘤的发展，如果肿瘤发病率的差异与管腔丁酸盐浓度、管腔pH或粪便体积相关，则在研究的前半部分(肿瘤发展的促进阶段)和研究结束时再次测量粪便中的短链脂肪酸浓度(SCFA)。摄入燕麦麸皮的大鼠具有更大的体重(P<；0.002)，在近端和远端结肠产生包括丁酸在内的所有短链脂肪酸的浓度都要大得多(P<；0.0001)，具有更多的酸性管腔pH值(P<；0.0001)，但也有明显更多的结肠肿瘤的发生(P<；0.0001)，或者，食用麦麸的大鼠产生更典型的SCFA摩尔比(65：10：20)，丁酸的浓度相对高于丙酸，并产生更大的体积(P<；0.0001)。尽管与饲喂燕麦麸粉的大鼠相比，这项研究的结果显示它们在远端结肠中的浓度不同，但它们的粪便体积也更大，这项研究的结果支持了其他证据，即酸性的管腔pH值本身并不具有保护作用，而且含有小麦麸皮的饮食可防止结肠癌的发生，此外，这些数据表明，仅在远端结肠中存在高浓度的鲁米酸丁酸，如食用燕麦麸粉的老鼠体内存在的那样，无法阻止肿瘤的发展。
To investigate the effects of dietary fibers in colonic luminal physiology and their role in the prevention of colon cancer, a study was conducted using two diet groups and two treatment groups in a 2 x 2 factorial design. The two diets differed only in the type of dietary fiber, wheat bran and oat bran, and the two treatments were injection with the colon-specific carcinogen azoxymethane, or saline, as a control, There were 34 rats in the carcinogen-injected groups and 11 saline-injected rats per diet group. The goal of the study was to determine if a moderate consumption (6 g/100 g diet) of wheat bran or oat bran would alter the development of colonic tumors in this rat model of colon cancer, and if the differences in tumor incidence were correlated to luminal butyrate concentrations, luminal pH or fecal bulk, Short-chain fatty acid concentrations (SCFA) were measured in feces during the first half of the study (the promotion phase of tumor development) and again at the end of the study. Rats consuming oat bran had greater body weights (P < 0.002), produced much larger concentrations of all SCFA, including butyrate, in both the proximal and distal colon (P < 0.0001), had more acidic luminal pH values (P < 0.0001), but also had significantly more development of colon tumors (P < 0.03), Alternatively, rats consuming wheat bran produced more typical molar ratios of the SCFA (65:10:20), had a relatively greater concentration of butyrate than propionate, and produced a larger volume (P < 0.05) and more bulky stool than the rats fed oat bran, The results of this study support other evidence that an acidic luminal pH is not protective in and of itself, and that diets containing wheat bran are protective against colon cancer development, In addition, these data show that large luminal butyrate concentrations in the distal colon alone, as were present in the rats consuming oat bran diets, are not protective of tumor development.