# Parabacteroides goldsteinii dose protected LRRK2 mutant mice from Parkinson's-like brain damage

- Published: 2026-11-11 16:17 UTC
- Section: Life & Health › Neurotechnology
- Tags: Parabacteroides goldsteinii, Parkinson's disease in mice, LRRK2 G2019S mutation, gut-brain axis, germ-free mice, alpha-synuclein, dopamine neurons, TLR4 inflammation, National Taiwan University, Journal of Advanced Research
- URL: https://realtech.media/news/rt-3aae822e27e580c9735958f2_parabacteroides_goldsteinii_dose/

**A single oral dose of the gut bacterium, given before symptoms, preserved dopamine neurons and movement in germ-free mice with the G2019S mutation. The work was done in mice only.**

![Parabacteroides goldsteinii dose protected LRRK2 mutant mice from Parkinson's-like brain damage](https://realtech.media/media/2026/11/be010e04375555fd.jpg)
*International Gemini Observatory/NOIRLab/NSF/AURA, Wikimedia Commons, CC BY 4.0*

Researchers at National Taiwan University and National Taiwan University Hospital, with colleagues at Chang Gung University and the National Laboratory Animal Center, tested whether a gut bacterium can protect mice from Parkinson's-like changes, ResearchSEA reports. [1] The study is published in Journal of Advanced Research. The mice carried G2019S, a mutation in the LRRK2 gene that is one of the most common inherited risk factors for Parkinson's disease and also raises the risk of inflammatory bowel disease. The animals were raised germ-free, so the team controlled which bacteria entered their intestines. [1]

The idea comes from the observation that many patients have gut problems, constipation above all, years or decades before tremor begins. This has led researchers to ask whether the disease sometimes starts in the intestine.

## Effects in the brain

At five months of age, before any movement problems, some mice received a single oral dose of Parabacteroides goldsteinii. This bacterium normally lives in the human intestine and is found at reduced levels in people with Parkinson's disease. In the mice it settled in and persisted for more than a year. [1]

Five months later, treated mice moved far better than untreated ones. Their brains contained fewer clumps of alpha-synuclein, the protein deposits that mark Parkinson's disease, and showed less activation of microglia, the brain's resident immune cells. They had also lost far fewer of the dopamine-producing neurons that control movement. [1] The treated animals kept a sealed, uninflamed gut. [1]

## Gut mechanism

According to the authors, the bacterium turned down the inflammatory switch TLR4 and strengthened the molecular seals between intestinal cells, making the gut less leaky. It also improved the energy supply of those cells and expanded a population of calming immune cells in the intestinal lining. [1] With less inflammation leaving the gut, the brain stayed quieter, and a growth-supporting signal reaching neurons was strengthened at the same time. [1]

Co-corresponding author Chin-Hsien Lin, professor of neurology at National Taiwan University Hospital, said the years before movement symptoms may be a window of opportunity rather than a waiting period. The work was done in mice, and trials in people would be needed before any such approach could be offered to patients. [1]

## Sources

1. [ResearchSEA](https://www.asiaresearchnews.com/node/23678)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-3aae822e27e580c9735958f2_parabacteroides_goldsteinii_dose/