Written by Joyce Smith, BS. Twelve weeks of supplementation with Lactobacillus plantarum P8 significantly improved inflammatory markers but had no impact on depression scores; however, there was some improvement in psychological tests of stress in the probiotic group.
Over 300 million people globally are affected by depression and approximately 800,000 deaths by suicide occur annually 1. Data from animal and human studies have suggested that probiotics may exert anti-anxiety benefits. For example, Linghong Zhou and Jane Foster from McMaster University in Canada have shown that prebiotics and probiotics may alter the gut microbiota and influence the gut-brain axis to possibly open up new ways of influencing neuropsychological conditions 2. The gut-brain axis (GBA) consists of a bidirectional homeostatic communication system between the central and the enteric nervous systems, linking emotional and cognitive centers of the brain with peripheral intestinal functions. Included are intricate neural pathways and signaling molecules (cytokines, neuropeptides and hormones) that are regulated at the neural, hormonal and immunological levels 3. Many studies have focused on the potential implications of this link between the emotional and cognitive centers of the brain and peripheral intestinal functions, including the impact of probiotics on gut, brain and emotional health 4. In a 2016 study, researchers Zhou et al 5 investigated the ability of Lactobacillus plantarum P8, known for its gut health benefits, to reduce stress, anxiety, and depression, and to evaluate its impact on memory and cognitive abilities.
The 12-week randomized, double-blind, placebo-controlled study involved 103 moderately stressed adult participants (P8 group= 52; placebo =51) who supplemented with Lactobacillus plantarum P8 (10 log CFU daily). The study objective was to measure two different aspects of stress: blood stress markers [cortisol and pro-inflammatory cytokines interferon (IFN-y), tumor necrosis factor (TNF-α), interlukin-1ß] as well as psychological stress markers such as anxiety, depression, memory and cognition.
Study results showed no change in blood cortisol between placebo and probiotic. Markers of inflammation, IFN-gamma and TNF-alpha were significantly reduced compared to the placebo. No impact on depression scores was evident; however, there was improvement in psychological tests of stress in the probiotic group (P=0.048). Accompanying these improvements were a range of non-significant cognitive and memory measures.
The data demonstrates that Lactobacillus. plantarum P8 may be helpful in managing psychological aspects of stress.
Source: Lew, Lee-Ching, Yan-Yan Hor, Nur Asmaa’A. Yusoff, Sy-Bing Choi, Muhamad SB Yusoff, Nurhanis S. Roslan, Anisa Ahmad et al. “Probiotic Lactobacillus plantarum P8 alleviated stress and anxiety while enhancing memory and cognition in stressed adults: A randomised, double-blind, placebo-controlled study.” Clinical Nutrition (2018).
© 2018 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.
Posted April 1, 2019.
Joyce Smith, BS, is a degreed laboratory technologist. She received her bachelor of arts with a major in Chemistry and a minor in Biology from the University of Saskatchewan and her internship through the University of Saskatchewan College of Medicine and the Royal University Hospital in Saskatoon, Saskatchewan. She currently resides in Bloomingdale, IL.
References:
- Organization WH. Depression. 2018; http://www.who.int/ news-room/fact-sheets/detail/depression, 2018.
- Zhou L, Foster JA. Psychobiotics and the gut-brain axis: in the pursuit of happiness. Neuropsychiatr Dis Treat. 2015;11:715-723
- Prins A. The brain-gut interaction: the conversation and the implications. South African Journal of Clinical Nutrition. 2011;24(sup3):8-14.
- Carabotti M, Scirocco A, Maselli MA, Severi C. The gut-brain axis: interactions between enteric microbiota, central and enteric nervous systems. Annals of gastroenterology: quarterly publication of the Hellenic Society of Gastroenterology. 2015;28(2):203.
- Lew, Lee-Ching, Yan-Yan Hor, Nur Asmaa’A. Yusoff, Sy-Bing Choi, Muhamad SB Yusoff, Nurhanis S. Roslan, Anisa Ahmad et al. “Probiotic Lactobacillus plantarum P8 alleviated stress and anxiety while enhancing memory and cognition in stressed adults: A randomised, double-blind, placebo-controlled study.” Clinical Nutrition (2018).
