Modulation of Gut Microbiome Composition: Effects of Fruits and Vegetables

Background/Objective: It has been well defined over the last decade that the diet influences the health of an individual, especially plant based diet has been proposed to improve/maintain people’s health. But, it remains unclear until recently is the role of gut microbiome to this effect. So, in this study, we aimed to evaluate the beneficial effects of formulated fruits and vegetables supplementation (FVS) on the gut microbiome composition from healthy population. Materials and Methods: This study is a randomized, double-blind, placebo-controlled study. This pilot study involves 30 healthy subjects aged 18-65 years, were randomly assigned to the treatment or placebo group, 15 subjects in each group and the duration of FVS supplementation/treatment was 6 weeks. Phenotypes, such as anthropometry, nutritional intake (by 24 h food recall method), biochemical parameters were recorded before and after treatment. The stool samples were collected before and after treatment. The gut microbial composition was evaluated by 16s rRNA sequencing on Illumina Miseq platform targeting V1-V3 hypervariable region. The short chain fatty acids (SCFA) were estimated using Agilent Gas Chromotography-MS. The anti- oxidant capacity was measured by Oxygen radical absorbance capacity (ORAC) method. Results: The anti-oxidant level from plasma measured by ORAC was comparatively higher (+21%, P=0.036) in the FVS groups than the placebo group. The FVS group have shown a significant increase in the plasma folic acid level (+59.7%, P= 0.0001), and vitamin B2 (VitB2; +25.6%, P=0.04) compared to placebo group. No significant differences were observed for vitamins A, E, K and serum potassium level. The 16s rRNA sequencing analysis have shown that FVS treatment greatly affects the bacterial lipid metabolism, gluconeogenesis and pentose pathways. In addition, gut microbiome composition positively correlated with butanoic, isobutanoic, ethanoic acids, and dietary intake of Lipids, Sugar, VitC and VitB in the FVS treatment group. Conclusion: The formulated fruits and vegetables supplementation effectively modified gut microbial composition in healthy subjects.