Lee Hong Kim 2021

At the first visit, demographic, medical, and anthropometric data were gathered, and electrocardiogram, blood cell count, biochemistry profile, and urinalysis were conducted for each participant.

During the first visit, population data (demographic), medical background information, and body measurements (anthropometric data) were collected from participants. In addition, heart function was assessed using electrocardiograms, information about various components of blood were obtained using blood cell counts and biochemistry profiles, and urine was assessed through urinalyses.

The probiotic NVP-1704 is a mixture of Lactobacillus router NK33 and Bifidobacterium adolescentis NK98 isolated from the healthy human gut microbiota [17], and several preclinical trials have showed that NVP-1704 can alleviate anxiety and depression in mice by modulating gut immune responses and gut microbiota composition [17,18].

This present study used the probiotic named NVP-1704 which contains two bacterial strains that were obtained from the group of microorganisms (microbiota) found in the gut of a healthy human. The bacteria in the probiotic mixture are Lactobacillus reuteri NK33 and Bifidobacterium adolescentis NK98. Previous preclinical studies using non-human animals involving NVP-1704 have shown that this probiotic helped mice regulate immune responses from the gut and the gut microbiota, which in turn relieved anxiety and depression.

Regarding anxiety symptoms, we observed a more prominent decrease in the BAI score in the experimental group at the third visit (–4.73 ± 7.32 vs. –1.37 ± 7.27, p = 0.014) (Figure 3C).

Beck’s Anxiety Inventory (BAI) scores, a tool used to help measure anxiety severity, were determined during the third visit with the scores of the experimental group compared to those of the control group. This study found that the BAI score of the experimental group decreased, shown by a statistically significant p-value (0.014), indicating a greater improvement in anxiety symptoms in the experimental group compared to the control group.

Our findings are similar to the results reported in a previous mouse study, which concluded that treatment with NVP-1704 led to the alleviation of depression/anxiety, changes in serum IL-6 levels, and an altered gut microbiome [17].

This study’s findings are similar to those of a previous study that was conducted on mice. Both studies showed that treatment with NVP-1704 alleviated depression and anxiety in their study populations and altered the composition of microorganisms in the gut. These two studies also showed that NVP-1704 caused changes in the levels of serum interleukin 6, a cytokine that was used in this present study as a blood biomarker to evaluate inflammatory responses and the hypothalamic-pituitary-adrenal axis activity.

This article mentions that only a few clinical studies have been conducted that focus on the effects of probiotics with Lactobacillus and Bifidobacterium on mental health. Future clinical studies should be continued with larger study populations to further solidify the impacts of probiotics with these bacteria on mental health and sleep, and should also include testing for a greater number of physiological markers or indicators associated to mental health and sleep, especially if one or a group of biomarkers have been strongly linked to a mental illness or sleep disorder, for example.

I found it most challenging to understand the Results section of this paper as it included many figures and statistical analyses that I am not familiar with and found difficult to interpret. This study also used inventories and indices (e.g., Stress Response Inventory, Insomnia Severity Index) that I am not familiar with, so I learned more about those evaluations to better understand the paper and how participants were being assessed throughout the study.