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Probiotic mixture improves mental wellbeing in healthy adults

Article-Probiotic mixture improves mental wellbeing in healthy adults

Probiotic mixture improves mental wellbeing in healthy adults.jpg
Supplementation with Lactobacillus reuteri, Bifidobacterium adolescentis probiotic strains may enhance mental health and sleep quality.

According to research published in Nutrients (DOI:, the probiotic mixture NVP-1704—containing Lactobacillus reuteri and Bifidobacterium adolescentis strains—could help young adults to optimise their mental health by mediating stress-related conditions including depression, anxiety, and insomnia.

In this eight-week, double-blind, randomised trial, 156 healthy adults—aged 19 to 65 years old—with subclinical symptoms of depression, anxiety and insomnia, were given either 500 mg capsules of NVP-1704 or placebo. Researchers noted each NVP-1704 capsule “contained 2.5 x 109 colony-forming units of microorganisms (2.0 x 109 CFU for Lactobacillus reuteri NK33 and 0.5 x 109 CFU for Bifidobacterium adolescentis NK98).”

Two weeks before the intervention (first visit), all participants’ demographic, medical, anthropometric, electrocardiogram, blood cell count, biochemistry profile and urinalysis information were collected and screened. The intervention started following exclusion criteria and participants were asked to ingest their allocated capsules with water twice daily for the duration of the trial.

During the first visit and weeks 3 and 8 after the start of the intervention, participants reported their levels of stress, depression, and anxiety by filling a stress response inventory (SRI). Further, Beck's Depression Inventory-II (BDI-II) and Beck's Anxiety Inventory (BAI) were used for evaluating participants' depression and anxiety, respectively. The Pittsburgh Sleep Quality Index (PSQI) and Insomnia Severity Index (ISI) were used to analyse sleep quality and symptoms of insomnia, respectively.  Researchers also analysed participants’ blood biomarkers pre-and post-intervention and considered their dietary patterns duration of the trial. Overall, the data of 122 participants were analysed post-trial.

The results showed decreased levels of depressive symptoms in both the NVP-1704 and placebo groups. Participants taking NVP-1704 supplementation had a steeper decline in the BDI-II score than the placebo group. Researchers observed “a more prominent decrease in the BAI score in the experimental group at the third visit [week 4].” Further, at weeks 4 and 8, the NVP-1704 participants reported more notable enhancement when analysing their depression and anxiety symptoms.

When looking at the sleep quality, researchers reported: “Those taking NVP-1704 also showed a greater magnitude of decreases in the ISI scores after eight weeks of treatment, but not after four weeks.”  

When looking at blood biomarkers, researchers noted varied levels of interleukin 6 (IL-6)—used to assess inflammatory responses— and blood level of brain-derived neurotrophic factor (BDNF) concentrations in both groups. The results also showed that NVP-1704 supplementation altered participants’ gut microbiome diversity. Researchers explained: “NVP-1704 administration increased the Actinobacteria population and it tended to reduce the Proteobacteria population, leading to a significant suppression in the ratio of Proteobacteria to Actinobacteria. At the family level, NVP-1704 treatment significantly increased the Bifidobacteriaceae population. Lactobacillaceae population increased with borderline significance in the experimental group. NVP-1704 treatment also tended to reduce Enterobacteriaceae (belonging to Proteobacteria), Muribaculaceae, Peptostreptococcaceae, and Veilonellaceae populations. Interestingly, NVP-1704 treatment significantly reduced the ratios of Enterobacteriaceae to Bifidobacteriaceae and Enterobacteriaceae to Lactobacillaceae. We found a significant increase in Bifidobacteria, including the Bifidobacterium_uc (unclassified) and Bifidobacterium pseudolongum strains and the Lactobacillus reuteri strain in the gut microbiota composition of the experimental group compared to that of the control group.” Researchers found no major variations in nutritional habits when looking at participants' dietary habits except for vitamin K and magnesium. Participants body weight remained constant throughout the trial.

Researchers concluded: “Probiotic NVP-1704 may be helpful for alleviating subclinical symptoms of depression and anxiety in healthy adults. NVP-1704 treatment also improved sleep quality, especially sleep induction. This clinical benefit of NVP-1704 appears to stem from the restoration of a healthy gut microbiota composition, which is associated with anti-inflammatory effects. In addition, NVP-1704 treatment was well tolerated and safe, with few minor adverse events. Large-scale, highly controlled, longitudinal human studies may be conducted in the future to confirm the beneficial effects of various probiotics on mental health and sleep.”