BACKGROUND The gut microbiota plays a pivotal role in the development of inflammatory bowel disease and colorectal cancer. OBJECTIVE To determine whether the gut microbiota is required for the chemoprotective effects of black raspberries (BRBs) in Apc Min/+ mice. METHODS Apc Min/+ mice were given (a) a control diet for 8 weeks, or (b) the control diet for 4 weeks and then a 5% BRB diet for additional 4 weeks, or (c) the control diet and antibiotics for 4 weeks followed by the 5% BRB diet and antibiotics for the next 4 weeks. At the end of the study, all the mice were euthanized, and colonic and intestinal polyps were counted. mRNA expression levels of TLR4, NF-κB1, and COX2 were determined in colon and small intestine of these Apc Min/+ mice by quantitative real-time PCR. RESULTS 5% BRBs significantly suppressed intestinal and colonic polyp development in the Apc Min/+ mice, whereas antibiotics significantly abolished BRBs' chemoprotective effects. BRBs decreased mRNA levels of TLR4, NF-κB1, and COX2 in colon, whereas significantly enhanced mRNA levels of TLR4 and NF-κB1 were observed in small intestine of BRB-treated Apc Min/+ mice fed antibiotics. CONCLUSIONS The gut microbiota is required for BRBs' chemoprotection against polyp development in Apc Min/+ mice.

中文翻译：

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黑树莓对 ApcMin/+ 小鼠的益处需要肠道细菌

背景肠道微生物群在炎症性肠病和结直肠癌的发展中起着关键作用。目的 确定黑树莓 (BRB) 对 Apc Min/+ 小鼠的化学保护作用是否需要肠道微生物群。方法 给予 Apc Min/+ 小鼠 (a) 8 周对照饮食，或 (b) 4 周对照饮食，然后 5% BRB 饮食另外 4 周，或 (c) 对照饮食和抗生素4 周之后是 5% BRB 饮食和接下来 4 周的抗生素。在研究结束时，对所有小鼠实施安乐死，并对结肠和肠息肉进行计数。通过实时定量 PCR 测定这些 Apc Min/+ 小鼠结肠和小肠中 TLR4、NF-κB1 和 COX2 的 mRNA 表达水平。结果 5% BRBs 显着抑制 Apc Min/+ 小鼠肠道和结肠息肉的发育，而抗生素显着消除 BRBs 的化学保护作用。BRBs 降低结肠中 TLR4、NF-κB1 和 COX2 的 mRNA 水平，而在喂食抗生素的 BRB 处理的 Apc Min/+ 小鼠的小肠中观察到 TLR4 和 NF-κB1 的 mRNA 水平显着增加。结论 在 Apc Min/+ 小鼠中，BRBs 对息肉发展的化学保护需要肠道微生物群。