The oxygen (O₂) concentration of gastrointestinal tract (GIT) contents decreases distally, but little is known about how O₂ concentrations are influenced by ingestion of a meal. The O₂ concentration in luminal contents at different GIT locations (stomach [cardia and pylorus], proximal, mid- and distal small intestine and caecum) and how these concentrations changed post-prandially were determined. Fifty entire male pigs (22 kg bodyweight at the start of study) were fed semi-synthetic diets containing casein, α-lactalbumin, whey protein isolate or zein as the sole source of protein for 8 days. A further group of pigs received the casein diet for six days and a semi-synthetic protein-free diet for a further 2 days. On day 8, pigs (n = 2 per diet and time point) were euthanized post-prandially (0, 1, 2, 4 and 6 h), and the stomach, small intestine and caecum were isolated and O₂ determined in the GIT contents. Observations at each time point were averaged across the diets (n = 10). The mean O₂ concentration was markedly higher (p ≤ 0.05) in the stomach compared with the rest of the GIT. The O₂ concentration was similar in the small intestinal regions (p > 0.05; 1.0%–1.1%) and the caecum (0.9%), apart for the proximal small intestine which had a 24% higher (p ≤ 0.05) O₂ concentration than the caecum. The mean O₂ concentration in the GIT varied post-prandially (p ≤ 0.05). The O₂ concentration in the cardia decreased 1.8%/h over the first two hours post-feeding and thereafter increased 0.3%/h (p ≤ 0.05). In the caecum, the O₂ concentration was constant during the first 4 h and thereafter increased slightly (p ≤ 0.05). The flow of food through the GIT influenced both the concentration and amount of O₂ in GIT luminal contents.

中文翻译：

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生长猪餐后肠腔内容物的氧浓度变化

胃肠道 (GIT) 内容物的氧气 (O _{2 ) 浓度在远端降低，但关于 O 2}浓度如何受到膳食摄入的影响知之甚少。测定了不同 GIT 位置（胃 [贲门和幽门]、近端、中部和远端小肠和盲肠）的管腔内容物中的 O _{2浓度以及这些浓度在餐后如何变化。}50 头整头公猪（研究开始时体重 22 公斤）饲喂含有酪蛋白、α-乳清蛋白、乳清蛋白分离物或玉米醇溶蛋白作为唯一蛋白质来源的半合成日粮 8 天。另一组猪接受 6 天的酪蛋白饮食和 2 天的半合成无蛋白质饮食。第 8 天，猪 ( n = 2 每个饮食和时间点）在餐后（0、1、2、4 和 6 小时）实施安乐死，分离胃、小肠和盲肠并测定 GIT 内容物中的O _{2 。}每个时间点的观察结果在饮食中进行平均（n  = 10）。与 GIT 的其余部分相比，胃中的平均 O ₂浓度明显更高 ( p  ≤ 0.05)。O ₂浓度在小肠区域 ( p  > 0.05; 1.0%–1.1%) 和盲肠 (0.9%) 相似，但近端小肠的O ₂浓度高出 24% ( p  ≤ 0.05)比盲肠。平均 O ₂餐后 GIT 中的浓度变化 ( p  ≤ 0.05)。贲门中的O ₂浓度在喂食后的前两个小时内下降了1.8%/h，之后增加了0.3%/h（p  ≤ 0.05）。在盲肠中，O ₂浓度在前 4 小时内保持不变，随后略有增加（p  ≤ 0.05）。通过 GIT 的食物流影响GIT 腔内容物中 O _{2的浓度和数量。}