Department of General Medicine and Emergency Care, Toho University School of Medicine, Tokyo 143-8541, Japan.
World J Gastroenterol. 2023 Jun 7;29(21):3269-3279. doi: 10.3748/wjg.v29.i21.3269.
Alcoholism is regarded as a risk factor for vitamin B (VB) deficiency. Because VB serves as a coenzyme of methylmalonyl-CoA mutase, a key enzyme in propionate metabolism, the C-propionate breath test (PBT) has been studied as a non-invasive diagnostic modality for VB deficiency. However, the conventional PBT requires 2 h, which is inconvenient in clinical practice. We hypothesized that a faster PBT can be used to evaluate propionate metabolism and is more easily adaptable for clinical practice.
To evaluate a faster PBT for assessing the effects of long-term ethanol consumption on propionate metabolism in ethanol-fed rats (ERs).
ERs were obtained by replacing standard drinking water (for control rats, CRs) with 16% ethanol solution in descendants of F344/DuCrj rats. Faster PBT was performed by administering C-propionate aqueous solution to male and female ERs and CRs by inserting a metal tubule from the mouth to the stomach; exhaled gas was collected in a bag to measure its CO/CO isotope ratio infrared isotope spectrometry. Serum VB and alanine transaminase (ALT) levels were measured chemiluminescence immunoassay and the lactate dehydrogenase-ultraviolet method, respectively. We evaluated statistical differences in mean body weight, change in CO (ΔCO‰), peak ΔCO‰, and serum VB and ALT, between males and females and between ERs and CRs using the -test and Mann-Whitney U test for normally and non-normally distributed variables, respectively.
Males weighed significantly more than females ( < 0.001); CRs weighed significantly more than ERs ( < 0.008). ΔCO reached a peak (C) at 20 min and 30 min in females and males, respectively, decreasing after 20-30 min without rebound in all groups. Males had significantly higher C and ΔCO at 15-45 min than females ( < 0.05; for all pairs). Propionate metabolism was enhanced in male ERs relative to male CRs, whereas metabolism did not differ markedly between ERs and CRs for females. Males had higher serum VB levels than females, without prominent differences between the ER and CR groups. Male CRs had notably higher ALT levels than male ERs. Thus, chronic ethanol consumption may trigger fatty acid production intestinal bacteria and changes in gut microbiome composition.
Faster PBT shows that 16% ethanol consumption promotes propionate metabolism without inducing liver injury. This PBT may be used clinically to evaluate gut flora status.
酗酒被认为是维生素 B（VB）缺乏的一个风险因素。因为 VB 是丙酰辅酶 A 变位酶的辅酶，而丙酰辅酶 A 变位酶是丙酸代谢的关键酶，所以 C-丙酸呼气试验（PBT）已被研究作为 VB 缺乏的一种非侵入性诊断方法。然而，传统的 PBT 需要 2 小时，在临床实践中不太方便。我们假设，更快的 PBT 可用于评估丙酸代谢，并更易于适应临床实践。
评估更快的 PBT 用于评估长期乙醇摄入对乙醇喂养大鼠（ERs）丙酸代谢的影响。
通过用 16%乙醇溶液替代 F344/DuCrj 大鼠后代的标准饮用水（对照大鼠，CRs），获得 ERs。通过从口腔插入金属管到胃中，给雄性和雌性 ERs 和 CRs 施用 C-丙酸水溶液，进行更快的 PBT；收集呼出的气体并通过红外同位素光谱法测量其 CO/CO 同位素比。通过化学发光免疫测定法和乳酸脱氢酶-紫外法分别测量血清 VB 和丙氨酸转氨酶（ALT）水平。我们使用 t 检验和 Mann-Whitney U 检验分别评估了男性和女性之间以及 ERs 和 CRs 之间平均体重、CO 变化（ΔCO‰）、峰值 ΔCO‰以及血清 VB 和 ALT 的统计学差异，对于正态和非正态分布变量分别使用。
男性体重明显大于女性（<0.001）；CRs 体重明显大于 ERs（<0.008）。女性的 ΔCO 在 20 分钟和 30 分钟时达到峰值（C），而男性则分别在 30 分钟和 20 分钟时达到峰值，在所有组中，20-30 分钟后没有反弹而逐渐下降。与女性相比，男性在 15-45 分钟时 C 和 ΔCO 显著更高（<0.05；所有配对）。与雄性 CRs 相比，雄性 ERs 中的丙酸代谢增强，而雌性 ERs 和 CRs 之间的代谢差异不明显。男性的血清 VB 水平高于女性，但 ER 和 CR 组之间没有明显差异。雄性 CRs 的 ALT 水平明显高于雄性 ERs。因此，慢性乙醇摄入可能会引发脂肪酸产生、肠道细菌和肠道微生物群落组成的变化。
更快的 PBT 表明，16%的乙醇摄入促进了丙酸代谢，而不会引起肝损伤。这种 PBT 可能在临床上用于评估肠道菌群状态。
