Serotonin-modulating probiotics

Serotonin-modulating probiotics

Serotonin-modulating probiotics

By Prof. Gene Bruno, MS, MHS, RH(AHG) Huntington College of Health Sciences

Research into probiotics has exploded in the last decade. Certainly probiotics have been shown to have a positive impact on digestion1-3 and immune function4-6, but beyond that, research has shown that probiotics can also influence other aspects of our biochemistry and health. One such area is serotonin modulation.

Psychobiotics
According to Wall et al7, the term “psychobiotics” was coined to describe a new class of probiotics with relevance to psychiatry. These probiotics may work through their ability to produce various biologically active compounds, such as peptides and mediators, which are usually associated with mammalian neurotransmission. Several molecules with neuroactive functions, including serotonin, have been reported to be derived from and isolated from bacteria in the human intestine. Secreted neurotransmitters from bacteria in the intestinal lumen can cause epithelial cells to release molecules that in turn modulate neural signaling within the enteric nervous system and consequently signal host brain function and behavior. Consequently, probiotic bacteria that contain/produce neurochemicals can be considered as delivery vehicles for neuroactive compounds, and as such, probiotic bacteria may potentially have the potential as a therapeutic strategy in the prevention and/or treatment of certain neurological and neurophysiological conditions.

Examples of serotonin-modulating probiotics
B. in animal experiments the oral intake ofBifidobacteria infantisincreased plasma levels of tryptophan, the precursor of serotonin, suggesting that commensal bacteria have the ability to influence tryptophan metabolism and could potentially act as antidepressants.8 Another example is a study in which Caco-2 cells and intestinal tissue from mice were examined after treatment withLactobacillus rhamnosusGG. The results showed that serotonin transporter (SERT) mRNA and serotonin transporter protein (SERT-P) levels were higher than those in the control group 24 h after treatment. This research has clearly shown thatLactobacillus rhamnosusGG can upregulate SERT mRNA and SERT-P levels in intestinal epithelial cells and intestinal tissues of mice.

Potential for appetite control
In addition to their relevance to psychiatry, serotonin-modulating probiotics may also be valuable in appetite control. Gastrointestinal hormone release and regulation of appetite and body weight are thought to be imbalanced in obesity. The researchers examined9 the expression of the serotonergic system in stomach tissue and serum from obese and non-obese subjects. The results were that serum serotonin was reduced in obese subjects compared to non-obese subjects (p < 0.05). Given serotonin's established role in appetite control, improving its expression through probiotic supplementation may prove effective in promoting healthy serotonin levels.

References
1 Gupta V, Garg R. Probiotics.Indian J Med Microbiol. 2009 Jul-Sep;27(3):202-9. 2 Goldin BR, Gorbach SL. Clinical indications for probiotics: an overview.Clin Infect Dis. February 1, 2008;46 Appendix 2:S96-100. 3 Hojsak I., Abdović S., Szajewska H., Milošević M., Krznarić Ž, Kolaček S.LactobacilliGG in the prevention of nosocomial infections of the gastrointestinal tract and respiratory tract.Pediatrics2010;125: e1171–e1177. 4 Elmadfa I, Klein P, Meyer AL. Session 7: Benefits of prebiotics and probiotics against pathologies: Immunostimulating effects of lactic acid bacteriain vivoandin vitro. Proc Nutr Soc.2010;69:416–420. 5 Cosenza L., Nocerino R., Di Scala C., di Costanzo M., Amoroso A., Leone L., Paparo L., Pezzella C., Aitoro R., Berni Canani R. Bugs for atopy: theLactobacillus rhamnosusGG strategy for preventing and treating food allergies in children.Benef microbes.2015;6(2):225-32. 6 Ashraf R, Shah NP. Stimulating the immune system through probiotic microorganisms.Crit Rev Food Sci Nutr.2014;54(7):938-56. 7 Wall R, Cryan JF, Ross RP, Fitzgerald GF, Dinan TG, Stanton C. Bacterial neuroactive compounds produced by psychobiotics.Adv Exp Med Biol. 2014;817:221-39. 8 Patterson E, Cryan JF, Fitzgerald GF, Ross RP, Dinan TG, Stanton C. Gut microbiota, the pharmacobiotics they produce and harbor health.Proc Nutr Soc.Nov 2014;73(4):477-89. 9 Y. Ritze, A. Schollenberger, M. Hamze Sinno, N. Bühler, M. Böhle, G. Bárdos, H. Sauer, I. Mack, P. Enck, S. Zipfel, T. Meile, A. Königsrainer, M. Kramer, SC Bischoff , and LeptinR expression as well as peripheral serotonin are dysregulated in people with obesity.Neurogastroenterol Motil.2016 Jun;28(6):806-15.

Professor Gene Bruno, MS, MHS, the provost for Huntington College of Health Sciences, is a nutritionist, herbalist, writer and educator. For more than 37 years, he has educated and trained natural products retailers and healthcare professionals, researched and formulated natural products for dozens of dietary supplement companies, and written articles on nutrition, herbal medicine, nutraceuticals, and integrative health topics for trade and consumer magazines and peer-reviewed publications. He can be reached at gbruno@hchs.edu.

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