Regulatory T Cells
Regulatory T cells, or Tregs, are special immune cells in the gut that help keep the immune system calm and prevent unnecessary inflammation.
They make sure the body reacts appropriately to food and friendly gut bacteria, rather than treating them like threats. By keeping gut inflammation under control, Tregs also help support healthy communication between the gut and the brain, which is important for mental wellbeing.
When these cells don’t work properly, it can contribute to long‑term inflammation that may play a role in conditions like anxiety, depression, and neurodegenerative diseases.
Expert information on regulatory T cells
< Previous PageRegulatory T cells (Tregs) play a central role in maintaining immune homeostasis within the gut, where they help balance effective host defense with tolerance to commensal microbes and dietary antigens. In the gut, Tregs are enriched in the lamina propria and are shaped by continuous exposure to microbial metabolites, particularly short‑chain fatty acids such as butyrate, which promote their differentiation and suppressive function.
Tregs limit excessive inflammatory responses by producing immunoregulatory cytokines, including IL‑10 and TGF‑β, thereby preventing excessive inflammation and preserving epithelial barrier integrity. Gut‑resident Tregs also contribute to oral tolerance, preventing inappropriate immune activation against harmless antigens, and help modulate the composition of local immune cell populations, including effector T cells and innate lymphoid cells. Disruption of Treg function or abundance is strongly associated with inflammatory bowel diseases, highlighting their essential role in sustaining immune equilibrium within the intestinal environment (1,2).
Increasing evidence suggests that gut‑resident Tregs influence mental health by modulating systemic inflammation and signaling along the gut–immune–brain axis, thereby contributing to the regulation of neuroinflammatory processes and stress‑related behavioural outcomes. Impaired Treg function can exacerbate microglial activation and accelerate neuroinflammatory pathways associated with diseases such as Alzheimer’s Disease and Parkinson’s Disease (3, 4).
Text by Jessica Teeling, University of Southampton
References:
1 PMID: 40517372, DOI: 10.1080/19490976.2025.2516702
2 PMID: 38570678, DOI: 10.1038/s41586-024-07251-0
3 PMID: 35844606, DOI: 10.3389/fimmu.2022.916066
4 PMID: 40885186, DOI: 10.1016/j.celrep.2025.116109
