不同碳水化合物对孤独症患儿肠道菌群 体外发酵产生短链脂肪酸的影响

目的探究孤独症谱系障碍(autism spectrum disorder,ASD)患儿与健康儿童的肠道菌群利用不同碳水化合物产生短链脂肪酸(short-chain fatty acids,SCFAs)的差异。方法前瞻性病例对照研究。选择2016年12月至2017年10月解放军总医院儿科门诊的15例ASD患儿为研究对象,并匹配15名健康儿童为对照组;收集研究对象粪便,稀释成10%悬浊液,然后分别接种到以乳果糖(LAU)、乳糖(LAT)、棉籽糖(RAF)、低聚半乳糖(GOS)、低聚异麦芽糖(IMO)和低聚甘露糖(MOS)为单碳源的肠道微生态小型模拟发酵系统中批量发酵24 h,检测SCFAs浓度、底物降解率和产气气压。结果 ASD组患儿粪便SCFAs浓度与对照组差异无统计学意义,在YCFA(无碳源对照培养基,蛋白发酵为主)培养基发酵后总SCFAs、乙酸和丙酸均低于对照组,差异有统计学意义(Z=-2.509、-2.509、-3.007,P=0.011、0.011、0.002);在添加LAT、RAF、GOS、IMO和MOS的培养基发酵后总SCFAs浓度显著高于对照组,差异有统计学意义(Z=2.385、2.344、2.675、2.344、2.302,P=0.016、0.019、0.007、0.019、0.021),而含LAU的培养基发酵后,两组研究对象总SCFAs浓度比较差异无统计学意义。结论 ASD患儿肠道菌群利用蛋白发酵产SCFAs能力显著低于健康对照,利用碳水化合物产SCFAs能力显著高于健康对照。6种发酵底物中,乳果糖是最适合ASD患儿的碳水化合物,有改善ASD患儿肠道菌群产SCFAs的潜力。

In vitro fermentation of carbohydrates: Impact on short-chain fatty acids production in children with autism spectrum disorders

Abstract: Objective To investigate the effects of carbohydrates on short chain fatty acids (SCFAs) in subjects with versus without autism spectrum disorder (ASD). Methods This was a prospective case-control study. Fifteen children with ASD and fifteen neurotypical children in the pediatric outpatient department of our hospital from December 2016 to October 2017 participated voluntarily. Fecal samples were collected and diluted into 10% suspension, then inoculated into the batch fermentation systems which contained respectively lactulose (LAU), lactin (LAT), raffinose (RAF), galactooligosaccharides (GOS), isomaltooligosacharrides (IMO) and mannooligosaccharides (MOS) as the sole carbon source. SCFAs concentration, gas production and degradation rate of carbohydrate were detected after 24 hours of fermentation. Results No significant difference in the level of SCFAs in feces was found between two groups. The levels of total SCFAs, acetic acid and propionic acid in group ASD after YCFA fermentation were lower than in control group (Z=-2.509, -2.509, -3.007, P=0.011, 0.011, 0.002), but a higher level of total SCFAs was obtained after fermentation in media containing LAT, RAF, GOS, IMO and MOS respectively compared to healthy controls (Z=2.385, 2.344, 2.675, 2.344, 2.302, P=0.016, 0.019, 0.007, 0.019, 0.021). Conclusion In contrast with healthy controls, SCFAs produced by fecal microbiota through protein fermentation are lower, whereas those through carbohydrate fermentation are higher in ASD children. Lactulose is the most suitable carbohydrate for ASD children, which has a potential to improve SCFAs production by fecal microbiota of ASD children.