Husebye E, Skar V, Høverstad T, Melby K
Department of Medicine, Ullevål University Hospital, Oslo, Norway.
Gut. 1992 Oct;33(10):1331-7. doi: 10.1136/gut.33.10.1331.
Fifteen healthy old people mean age 84 years (range 80-91 years), were examined to assess the effect of advanced age on the microecology of the upper gastrointestinal tract. Twelve of 15 (80%) were hypochlorhydric with pH 6.6 (0.3) (mean (SEM) and a mean bacterial count of 10(8) colony forming units (CFU) per ml (range 10(5)-10(10)) in fasting gastric aspirate. Normochlorhydric subjects had low counts (< or = 10(1) CFU/ml). The microbial flora was dominated by viridans streptococci, coagulase negative staphylococci, and Haemophilus sp. Only one subject harboured significant concentrations of Gram negative bacilli with Escherichia coli (10(4-5) CFU/ml) and Klebsiella (10(4-5)). Strict anaerobes were not found. The total concentration of short chain fatty acids in gastric aspirate was 10.6 (2.9) mmol/l (mean (SEM). Absence of significant, intraluminal fermentation of xylose to CO2 was shown by the 14C-d Xylose breath test, and ambulatory manometry showed preserved fasting motility pattern of the small intestine. Serum immunoglobulins were normal. Advanced age is accompanied by fasting hypochlorhydria and colonisation with mainly Gram positive flora in the upper gut. Other factors than old age and fasting hypochlorhydria are required for colonisation with Gram negative bacilli.
15名健康老年人，平均年龄84岁（范围80 - 91岁），接受了检查以评估高龄对上消化道微生态的影响。15人中有12人（80%）胃酸过少，pH值为6.6（0.3）（均值（标准误）），空腹胃液 aspirate 中的细菌计数平均为每毫升10⁸ 菌落形成单位（CFU）（范围10⁵ - 10¹⁰）。胃酸正常的受试者细菌计数较低（≤10¹ CFU/ml）。微生物菌群以草绿色链球菌、凝固酶阴性葡萄球菌和嗜血杆菌属为主。只有一名受试者携带大量革兰氏阴性杆菌，其中大肠杆菌为10⁴⁻⁵ CFU/ml，克雷伯菌为10⁴⁻⁵ CFU/ml。未发现严格厌氧菌。胃液 aspirate 中短链脂肪酸的总浓度为10.6（2.9）mmol/l（均值（标准误））。¹⁴C - d木糖呼气试验显示木糖在管腔内未显著发酵为二氧化碳，动态测压显示小肠空腹运动模式正常。血清免疫球蛋白正常。高龄伴随着空腹胃酸过少以及上消化道主要由革兰氏阳性菌群定植。革兰氏阴性杆菌定植除了需要高龄和空腹胃酸过少外，还需要其他因素。
