Effect of a Nutritionally Balanced Diet Comprising Whole Grains and Vegetables Alone or in Combination with Probiotic Supplementation on the Gut Microbiota

Dysbiosis is a microbial imbalance, which often causes diseases and can be triggered by diet. Here, we deter-mined the effect of a nutritionally balanced diet rich in vegetables and whole grains alone and/or in combination with probiotics on the gut microbiota of healthy adults. We conducted a parallel-group randomized trial enrolling 63 healthy participants who were administered either a balanced diet (B-diet group), a probiotic capsule containing Lactobacillus plantarum PMO 08 (probiotics group), or a balanced diet plus probiotic capsule (synbiotics group) once daily for 2 weeks. The gut microbiota of each participant was analyzed via 16S ribosomal RNA MiSeq-based sequencing. Gastrointestinal symptoms and defecation habits were evaluated using questionnaires. The B-diet group showed significantly reduced Firmicutes-to-Bacteroidetes ratio (P