Simge Burgaz1, Oytun Erbaş1

1ERBAS Institute of Experimental Medicine, Illinois, USA & Gebze, Türkiye

Keywords: 5-HT, germ-free animals, gut microbiota, second brain, serotonin


The second brain, also known as gut microbiota, outnumbers our own cells in our bodies and contains 150 times as many genes as our genome. The impact of gut microbiota on the brain can be estimated by using germ-free animals, fecal transplantation, probiotic supplementation, and antibiotic treatment. An important signaling molecule serotonin (5-hydroxytryptamine; 5-HT) modulates key gut functions such as gut motility, immunity, and gut microbiota composition and function. Despite being dispersed throughout the body, 90-95% of 5-HT is present in the gut. Thus, there is a linkage between gut microbiota and host levels of 5-HT. A wide range of immune-related neurological disorders, neurodegeneration, and emotional dysregulation are affected by alterations in the gut microbiota. This review aims to summarize gut microbiota, its composition, and its effect on 5-HT production.

Cite this article as: Burgaz S, Erbaş O. Microbial Influence on Serotonin: A Fascinating Gut-Brain Interaction. JEB Med Sci 2023;4(2):134-139.

Conflict of Interest

The authors declared no conflicts of interest with respect to the authorship and/or publication of this article.

Financial Disclosure

The authors received no financial support for the research and/or authorship of this article.