2024 Undergraduate Research Showcase

The Manipulation of the Gut Microbiome Using GAD-Lactococcus lactis Bacteria and Gnotobiotic Zebrafish (Danio rerio) to Alleviate Symptoms of Anxiety and PTSD

Document Type

Student Presentation

Presentation Date


Faculty Sponsor

Dr. Javier Ochoa-Reparaz


Affecting more than 301 million people in the year 2019, anxiety disorders are the world’s most common mental health disorder (1). Although Post-Traumatic Stress Disorder (PTSD) is not classified as an anxiety disorder, it does share many neurobiological features (2). In addition, anxiety related co-morbidities are found to exist from 18% to 36% of people affected by PTSD (3). Therefore, affordable, effective treatment of anxiety related conditions could help alleviate symptoms for a large majority of the human population. Today, the main treatments for anxiety related disorders are Cognitive Behavioral Therapy (CBT) and oral medications (4). However, research indicates that there is a large treatment gap globally for people with these disorders, particularly when it comes to low- or middle-income countries (5). This study aims to provide an alternative treatment of anxiety related conditions by manipulation of the gut microbiome in gnotobiotic zebrafish (Danio rerio) by introducing the bacterial strain GAD-Lactococcus lactis. Using GABA producing microbes as a natural source of the inhibitory neurotransmitter, it is expected that symptoms of anxiety should be alleviated or decreased in treated fish when compared to the controls. Extending these findings to humans could provide a cheaper, alternative treatment for anxiety using probiotics.

  1. https://www.who.int/news-room/fact-sheets/detail/anxiety-disorders
  2. https://pubmed.ncbi.nlm.nih.gov/34881734/
  3. https://link.springer.com/article/10.1007/s11126-020-09797-4
  4. https://www.mayoclinic.org/diseases-conditions/anxiety/diagnosis-treatment/drc-20350967#:~:text=Cognitive%20behavioral%20therapy%20(CBT)%20is,of%20psychotherapy%20for%20anxiety%20disorders
  5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6008788/
  6. (6) https://www.ncbi.nlm.nih.gov/books/NBK470361/#:~:text=The%20autonomic%20nervous%20system%2C%20especially,amygdala%20response%20to%20anxiety%20cues

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