Gastroenterology Group Practice, Brain-Gut Research Group, Bern, Switzerland.
Department of Pharmacy, National University of Singapore, Singapore City, Singapore.
Neurogastroenterol Motil. 2021 Dec;33(12):e14150. doi: 10.1111/nmo.14150. Epub 2021 Apr 12.
Symptoms following fructose ingestion, or fructose intolerance, are common in patients with functional gastrointestinal disorders (FGID) and are generally attributed to intestinal malabsorption. The relationships between absorption, symptoms, and intestinal gas production following fructose ingestion were studied in patients with FGID.
Thirty FGID patients ingested a single dose of fructose 35 g or water in a randomized, double-blind, crossover study. Blood and breath gas samples were collected, and gastrointestinal symptoms rated. Plasma fructose metabolites and short-chain fatty acids were quantified by targeted liquid chromatography-tandem mass spectrometry. Patients were classified as fructose intolerant or tolerant based on symptoms following fructose ingestion.
The median (IQR) areas under the curve of fructose plasma concentrations within the first 2 h (AUC ) after fructose ingestion were similar for patients with and without fructose intolerance (578 (70) µM·h vs. 564 (240) µM·h, respectively, p = 0.39), as well as for the main fructose metabolites. There were no statistically significant correlations between the AUC of fructose or its metabolites concentrations and the AUCs of symptoms, breath hydrogen, and breath methane. However, the AUCs of symptoms correlated significantly and positively with the AUC of hydrogen and methane breath concentrations (r = 0.73, r = 0.62, respectively), and the AUCs of hydrogen and methane concentrations were greater in the fructose-intolerant than in the fructose-tolerant patients after fructose ingestion (p ≤ 0.02).
CONCLUSIONS & INFERENCES: Fructose intolerance in FGID is not related to post-ingestion plasma concentrations of fructose and its metabolites. Factors other than malabsorption, such as altered gut microbiota or sensory function, may be important mechanisms.
功能性胃肠病（FGID）患者在摄入果糖后会出现症状，即果糖不耐受，这种情况较为常见，一般归因于肠道吸收不良。本研究旨在探讨 FGID 患者摄入果糖后吸收、症状与肠道气体生成之间的关系。
30 例 FGID 患者参与了一项随机、双盲、交叉研究，他们单次摄入 35g 果糖或水。采集血样和呼出气样本，并对胃肠道症状进行评分。采用靶向液相色谱-串联质谱法定量检测血浆果糖代谢产物和短链脂肪酸。根据摄入果糖后是否出现症状，将患者分为果糖不耐受或耐受。
果糖不耐受和耐受患者摄入果糖后 2 小时内（AUC ）的果糖血浆浓度曲线下面积（AUC ）中位数（IQR ）相似（分别为 578（70）µM·h 和 564（240）µM·h，p=0.39），主要果糖代谢产物也无明显差异。果糖或其代谢产物浓度 AUC 与症状 AUC 、呼气氢 AUC 、呼气甲烷 AUC 之间均无统计学相关性。然而，症状 AUC 与氢和甲烷呼气浓度 AUC 呈显著正相关（r=0.73，r=0.62），且果糖不耐受患者摄入果糖后氢和甲烷呼气浓度 AUC 均高于果糖耐受患者（p≤0.02）。
FGID 中的果糖不耐受与摄入后果糖及其代谢产物的血浆浓度无关。除了吸收不良外，其他因素，如肠道微生物群或感觉功能改变，可能是重要的机制。
