The Role of Gut-Brain Signalling in Functional Responses to Chronic Social Stress
Bibliographic record
Abstract
Chronic stress has a cumulative physiological impact, causing dysregulation of multiple systems due to allostatic overload. There is growing evidence that one such system, the microbiota, is engaged in persistent bidirectional interplay with the brain—a phenomenon that influences neural function and behaviour. However, the functional role of the microbiota in stress-associated changes and the underlying pathways of communication are unknown. Using a murine model of depression, we demonstrate that chronic stress has top-down effects on the structure of the microbiota community, reducing its richness and diversity, altering its profile, and causing differential abundance of various bacterial genera. These structural changes have functional consequences, including in metabolic pathways responsible for the synthesis of short chain fatty acids, tryptophan, and tyrosine. Using a physiologically active bacteria, Lactobacillus rhamnosus (JB-1), we probed for bottom-up signalling in chronic stress. JB-1 attenuated deficits in anxiety-like and social behaviours, and induced systemic immunoregulatory effects, independent of affecting stress-induced changes in the microbiota. In examining possible mechanisms of gut-brain brain signalling, we observed that in unstressed mice, a single dose of JB-1 causes rapid expression of c-Fos—a marker of neuronal activation—in distributed areas of the brain within 165 minutes, absent behavioural changes. No such effects were observed with heat-killed JB-1, despite that both live and heat-killed preparations facilitated vagal activity. Sub-diaphragmatic vagotomy prevented neuronal activation in most but not all brain regions, suggesting that vagal signalling is critical but indicating the presence of additional independent pathways. Finally, only chronic JB-1 treatment increased ΔFosB expression in the brain, which is indicative of long-term neuronal adaptations, in association with behavioural changes. These studies demonstrate a role for bidirectional gut-brain signalling in chronic stress, and highlight the signalling pathways and brain regions through which gut bacteria exert their influence on host behaviour.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".