Probiotics help balance intestinal flora to promote better digestion and healthy regularity (1, 2, 3).
The gut-brain connection
Your gut, through its Gut Microbe System, influences your brain's function. The Gut Microbe System includes beneficial bacteria, viruses, and yeast.
A growing body of evidence has shown two-way signaling between the gut and the brain which include multiple neuro and endocrine signal mechanisms (4). Probiotics help make the feel-good neurotransmitter serotonin (5, 6).
(1) Lee ES, Song EJ, Nam YD, Lee SY. Probiotics in human health and disease: from nutribiotics to pharmabiotics. J Microbiol. 2018;56(11):773-782. doi:10.1007/s12275-018-8293-y.
(2) Brown AC, Valiere A. Probiotics and medical nutrition therapy. Nutr Clin Care. 2004;7(2):56-68.
(3) Bowe WP, Logan AC. Acne vulgaris, probiotics and the gut-brain-skin axis - back to the future?. Gut Pathog. 2011;3(1):1. Published 2011 Jan 31. doi:10.1186/1757-4749-3-1.
(4) The effects of probiotics on depressive symptoms in humans: a systematic review, Ann Gen Psychiatry. 2017; 16: 14. Published online 2017 Feb 20.
(5) Effects of regulating gut microbiota on the serotonin metabolism in the chronic unpredictable mild stress rat model, Neurogastroenterology & Motility, Volume31, Issue10, October 2019, e13677.
(6) Singhal, M., Turturice, B.A., Manzella, C.R.et al.Serotonin Transporter Deficiency is Associated with Dysbiosis and Changes in Metabolic Function of the Mouse Intestinal Microbiome.Sci Rep9,2138 (2019).