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 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 (<0.05) and abundances of the genera (<0.01), (<0.05), and (<0.05). Furthermore, the abundance of increased (<0.05) compared to baseline levels. In the synbiotics group, abundance increased significantly (<0.05) and defecation difficulty decreased (<0.05), confirming a synergistic effect of combined intake. All groups showed a significant reduction in the abundance of Clostridiaceae (<0.001) and alleviation of bloating symptoms (<0.05). Moreover, the relative abundance of significantly increased in the probiotics group (<0.05). Therefore, the individual or combined intake of a nutritionally balanced diet and PMO 08 beneficially modifies the gut microbiota with the potential to alleviate gastrointestinal symptoms and improve defecation habits.