The human gut microbiome is closely linked to mental health and sleep. We aimed to verify the efficacy and safety of probiotic NVP-1704, a mixture of Lactobacillus reuteri NK33 and Bifidobacterium adolescentis NK98, in improving stress, depression, anxiety, and sleep disturbances, along with the measurement of some blood biomarkers. A total of 156 healthy adults with subclinical symptoms of depression, anxiety, and insomnia were retrospectively registered and randomly assigned to receive either NVP-1704 (n = 78) or a placebo (n = 78) for eight weeks. Participants completed the Stress Response Inventory, Beck’s Depression and Anxiety Inventory, Pittsburg Sleep Quality Index, and Insomnia Severity Index at baseline, at four and eight weeks of treatment. Pre- and post-treatment blood tests for biomarkers were conducted. After intervention, gut microbiota composition was quantified by pyrosequencing the bacterial 16S rRNA gene. The NVP-1704 group had a more significant reduction in depressive symptoms at four and eight weeks of treatment, and anxiety symptoms at four weeks compared to the placebo group. Those receiving NVP-1704 also experienced an improvement in sleep quality. NVP-1704 treatment led to a decrease in serum interleukin-6 levels. Furthermore, NVP-1704 increased Bifidobacteriaceae and Lactobacillacea, whereas it decreased Enterobacteriaceae in the gut microbiota composition. Our findings suggest that probiotic NVP-1704 could be beneficial for mental health and sleep.

Although several recent studies reported that probiotics might be beneficial for allergic rhinitis (AR), the effect of probiotics on AR is not consistent and have not been reproduced between studies. We aimed to determine the efficacy and safety of probiotic NVP-1703, a mixture of Bifidobacterium longum and Lactobacillus plantarum, in subjects with perennial AR. Adult subjects with perennial AR received either NVP-1703 (n = 47) or placebo (n = 48) for four weeks. Total nasal symptom scores (TNSS), rhinitis control assessment test (RCAT), blood eosinophil count, allergen-specific IgE, and immunological parameters in serum and urine were compared at baseline and after four weeks. TNSS changes from baseline at weeks 1, 3, and 4 were significant between the NVP-1703 and placebo groups (p = 0.033, 0.031, and 0.029, respectively). RCAT score showed significant differences between the NVP-1703 and placebo groups (p = 0.049) at week 4. Dermatophagoides farinae-specific IgE levels and serum IL-10 levels were significantly different between the NVP-1703 and placebo groups (p = 0.033 and p = 0.047, respectively). IL-10/IL-4 and IL-10/IL-13 ratios were different between the NVP-1703 and placebo groups at week 4 (p = 0.046 and 0.018, respectively). NVP-1703 treatment reduced urinary prostaglandin F_2α and leukotriene E₄ levels (p > 0.05). Therefore, NVP-1703 can be treatment option for perennial AR.