Intake of Lactiplantibacillus plantarum HEAL9 Improves Cognition in Moderately Stressed Subjects: A Randomized Controlled Study.

Nutrients. 2023;15(15)
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It is thought that there is a bidirectional communication pathway between the gut microbiota and the brain, known as the gut-brain axis. Stress, anxiety and low mood and the hormones produced when experiencing these have been shown to be improved by the introduction of healthy gut microbiota through probiotic use. As such, the use of probiotics may be of benefit to mental health problems. This randomised control trial of 129 individuals with moderate stress aimed to determine the effect of one probiotic strain Lactoplantibacillus plantarum HEAL9 (LPHEAL9) on the gut-brain axis. The results showed that following supplementation for 12 weeks, cognitive function was significantly improved compared to placebo and there was an improvement in the feelings of confusion, anger, and depression. There was a trend for improved sleep for individuals given LPHEAL9, however this was not significantly better than individuals given placebo. There were no benefits to perceived stress following LPHEAL9 supplementation. It was concluded that LPHEAL9 improved cognitive function compared to placebo and this may be due to improved mood and sleep. This study could be used by healthcare professionals to specifically recommend LPHEAL9 to individuals with stress, anxiety, and low mood.


BACKGROUND The usage of probiotics has expanded beyond the areas of gut and immune health improvement. Several studies have shown the positive impact associated between probiotics and stress, cognition, and mood; a relationship referred to as the gut-brain axis. METHOD The aim of this exploratory study was to evaluate the effect of the probiotic strain Lactiplantibacillus plantarum HEAL9 (LPHEAL9) on the gut-brain axis in subjects with moderate stress. One hundred and twenty-nine subjects aged 21-52 years completed the study, randomized to consume either LPHEAL9 (n = 65) or placebo (n = 64) for 12 weeks. RESULTS Perceived stress and awakening cortisol were significantly reduced over time in both groups. A significant improvement in four cognition tests after consumption of LPHEAL9 compared to placebo was observed (rapid information processing test, numeric working memory test, paired associated learning, and word recall, p < 0.05). There was a tendency for a significantly better improvement in the LPHEAL9 group for three mood subscales (Confusion-Bewilderment, Anger-Hostility, and Depression-Dejection) and for fewer subjects with poor sleep in the LPHEAL9 group compared to placebo (p < 0.10). CONCLUSIONS Intake of LPHEAL9 significantly improved cognitive functions compared to the placebo, potentially by ameliorating aspects of mood and sleep.

Lifestyle medicine

Fundamental Clinical Imbalances : Neurological ; Digestive, absorptive and microbiological
Patient Centred Factors : Mediators/Gut microbiota dysbiosis
Environmental Inputs : Microorganisms
Personal Lifestyle Factors : Sleep and relaxation ; Stress and resilience
Functional Laboratory Testing : Blood

Methodological quality

Jadad score : 3
Allocation concealment : No


Nutrition Evidence keywords : Gut microbiota ; Cortisol