# GABA-Producing Capabilities of Lactococcus lactis PL186 in Murine and Human

## TL;DR

A new probiotic strain of Lactococcus lactis produces GABA in the gut and raises GABA levels in mice and humans.

## Contribution

This is the first report showing Lactococcus lactis can produce GABA that circulates in the human body.

## Key findings

- Lactococcus lactis PL186 increases GABA levels in mouse serum and brain tissue.
- The strain colonizes the human gut and raises GABA concentration in urine.
- Oral administration supports persistent endogenous GABA biosynthesis and systemic benefits.

## Abstract

The novel strain Lactococcus lactis PL186 exhibits high GABA productivity in vitro and has demonstrated proven safety as a probiotic. In mice, this strain adheres to the intestinal mucosa, resulting in increased GABA levels in both serum and brain tissue. Additionally, L. lactis PL186 effectively colonizes the human gut and elevates GABA concentration in urine, highlighting its potential for systemic GABA enhancement. Oral administration of GABA-producing probiotics such as L. lactis PL186 therefore supports persistent endogenous GABA biosynthesis, helps maintain relatively stable systemic concentrations, and enables prolonged functional benefits. To our knowledge, this is the first report demonstrating that L. lactis can produce GABA that circulates within the human body.