Data_Sheet_1_Modulation of gut microbiota: The effects of a fruits and vegetables supplement.PDF

The consumption of an optimal amount of fruits and vegetables is known to improve physical fitness and physiological body functions. Healthy eating habits, including intake of fruits and vegetables, can modify gut microbiota. This study aimed to demonstrate the effectiveness of a formulated fruit and vegetable supplement (FVS) in modulating the antioxidant capacity and the gut microbiota composition. We enrolled 30 healthy volunteer subjects, matched for age, gender, BMI, and smoking habits, and randomized them into the FVS and the placebo (PLA) groups. Among the serum vitamins, the folic acid level was significantly higher (p = 0.001) in the FVS group than in the PLA group, whereas the vitamin B2 level was significantly higher in the PLA group than in the FVS group (p = 0.028). The antioxidant capacity, measured by using the oxygen radical absorbance capacity (ORAC) method, was also slightly higher in the FVS group than in the PLA group but did not reach statistical significance. The dietary intake, assessed by 24-h recalls, did not show any significant changes after the supplementation in both the groups. The gut microbiome composition, measured by 16S rDNA sequencing, showed no difference in both alpha and beta diversities, whereas the LEfse analysis revealed a microbial shift after the treatment, with a decreased abundance of the genus Ruminococcus from the Lachnospiraceae family (p = 0.009), and the unclassified genus from the family Erysipelotrichaceae (UC36, p = 0.003) in the FVS group compared with the PLA group (confirmed by SIAMCAT analysis, AUC = 74.1%). With a minor effect, the genus Faecalibacterium and unclassified genus and family from the order Lactobacillales (UC31) were also increased in the FVS group compared with the PLA group (p = 0.0474, p = 0.0352, respectively). SCFA measurement by gas chromatography–mass spectrometry showed an increased level of 2-methylbutyrate in the FVS group compared with the PLA group (p = 0.0385). Finally, the Spearman correlation analysis showed that in the FVS group, the genus Faecalibacterium positively correlated with 2-methyl butyrate (p = 0.040). In the PLA group, none of the significant bacteria correlated with either SCFA or serum biomarkers. The network analysis confirmed the positive correlation between genus Faecalibacterium and 2-methyl butyrate. We can conclude that the FVS in healthy individuals modified the gut microbiota composition and metabolites, and it can potentially contribute to reduce the pro-inflammatory response along with the antioxidant capacity.

已知适量摄入果蔬可改善机体健康状况与生理功能。健康饮食习惯（包括果蔬摄入）可调节肠道菌群（gut microbiota）。本研究旨在验证一款定制化果蔬补充剂（formulated fruit and vegetable supplement, FVS）在调节抗氧化能力与肠道菌群组成方面的有效性。本研究招募了30名健康志愿者，按年龄、性别、体重指数（body mass index, BMI）及吸烟习惯进行匹配，并随机分为果蔬补充剂组与安慰剂（placebo, PLA）组。血清维生素检测结果显示，果蔬补充剂组的叶酸水平显著高于安慰剂组（p=0.001），而安慰剂组的维生素B2水平则显著高于果蔬补充剂组（p=0.028）。采用氧自由基吸收能力（oxygen radical absorbance capacity, ORAC）法测定的抗氧化能力，在果蔬补充剂组中略高于安慰剂组，但未达到统计学显著性。通过24小时膳食回顾法评估的膳食摄入情况，在两组干预后均未出现显著变化。肠道菌群组成方面，经16S rDNA测序检测，两组的α多样性与β多样性均无显著差异，但线性判别分析效应大小（linear discriminant analysis effect size, LEfSe）分析显示干预后菌群结构发生偏移：与安慰剂组相比，果蔬补充剂组中毛螺菌科（Lachnospiraceae）瘤胃球菌属（Ruminococcus）丰度显著降低（p=0.009），丹毒丝菌科（Erysipelotrichaceae）未分类菌属（UC36）丰度亦显著降低（p=0.003），该结果经SIAMCAT分析验证，曲线下面积（area under curve, AUC）为74.1%。此外，与安慰剂组相比，果蔬补充剂组的粪杆菌属（Faecalibacterium）、乳杆菌目（Lactobacillales）未分类菌属与科（UC31）丰度亦有小幅升高（分别对应p=0.0474、p=0.0352）。采用气相色谱-质谱联用法（gas chromatography–mass spectrometry）检测的短链脂肪酸（short-chain fatty acid, SCFA）结果显示，果蔬补充剂组的2-甲基丁酸水平显著高于安慰剂组（p=0.0385）。最后，斯皮尔曼相关性分析（Spearman correlation analysis）显示，在果蔬补充剂组中，粪杆菌属与2-甲基丁酸呈显著正相关（p=0.040）；而在安慰剂组中，未发现任何菌群与短链脂肪酸或血清生物标志物存在显著相关性。网络分析进一步验证了粪杆菌属与2-甲基丁酸之间的正相关关系。综上，本研究表明，对于健康人群，定制化果蔬补充剂可调节肠道菌群组成与代谢产物，或可在提升抗氧化能力的同时，辅助降低机体促炎反应。