In addition, the report notes that theta brain waves were lower at rest and during performance of a task in the afternoon, indicating reduced sleepiness.
The Japanese researchers emphasise: “Our results suggest that LcS intervention improves mood when measured as daytime performance indices compared with the placebo. Furthermore, the daytime perceived mood indices were associated with physiological parameters such as EEG and autonomic nerve activity data.”
Gut-brain axis
It is known that psychological stress can affect an array of both mental and physical health areas via the nervous and endocrine systems. Adversities such as depression, headaches, appetite changes, and insomnia are known to result from stress, which can ultimately affect quality of life as well as working performance.
Sleep disorders resulting from heightened stress are known to have significant effects on a range of performance parameters, including increased cognitive task errors and risk of incidents.
With increasing evidence highlighting the importance of the gut-brain axis and the effect of the microbiome on an array of cognitive factors and stress, there has been significant interest in the use of probiotics to exert positive benefits via this gut-brain axis.
Specifically, LcS has previously demonstrated benefits to digestion, immunity, infection prevention as well as improved sleep quality in previous studies. Thus, the present study sought to investigate the efficacy of LcS for improving daytime performance in those suffering from poor sleep.
Study
A double-blind, randomised, placebo-controlled trial including 12 healthy office workers was conducted by the researchers, which involved the administration of fermented milk containing viable LcS with 1x1011 CFU over a four-week intervention period. The placebo group were given a non-fermented milk over the same period.
Assessments determining the participants’ subjective mood and psychological state via electroencephalogram (EEG) and heart rate variability in both the morning and afternoon.
It was observed that attention score measurements were significantly higher during the LcS intake period than the placebo group. Furthermore, the power of theta brain waves on EEG measurements at rest or during an auditory task in the afternoon were reported to be lower than the placebo group scores.
It was also noted that LcS intakes were associated with alternations in heart rate and sympathetic nerve activity index.
Explained
The researchers conclude: “These results indicate that LcS has possible efficacy for improving daytime performance, supported by observations of the related physiological state indicators.”
Explaining the effect. the report emphasises that attention and performance levels are known to be reduced in the afternoon, yet attention scores in the LcS group in the afternoon were similar to those of the placebo group in the morning. Thus, the researchers speculate that the probiotic may be able to restore attention to optimal levels within the normal range.
The researchers urge further RCTs to utilise larger sample sizes to further improve the reliability of the results.
Source: Nutrients
https://doi.org/10.3390/nu15245119
“Effects of Lacticaseibacillus paracasei Strain Shirota on Daytime Performance in Healthy Office Workers: A Double-Blind, Randomized, Crossover, Placebo-Controlled Trial”
by Hiroko Kikuchi-Hayakawa, Hiroshi Ishikawa, Kazunori Suda, Yusuke Gondo, Genki Hirasawa, Hayato Nakamura, Mai Takada, Mitsuhisa Kawai and Kazunori Matsuda