Lactobacillus rhamnosus JB-1

What it acts on

1. In an 8-week randomized placebo-controlled cross-over design with 29 healthy male volunteers there was no overall effect of probiotic treatment on measures of mood, anxiety, stress or sleep quality and no significant effect over placebo on subjective stress measures or the hypothalamic-pituitary-adrenal response to a socially evaluated cold pressor test, visuospatial memory performance, attention switching, rapid visual information processing, emotion recognition and associated electroencephalographic measures did not show improvement over placebo, and no significant anti-inflammatory effects were seen as assessed by basal and stimulated cytokine levels.

   Lactobacillus rhamnosus JB-1 → Self-reported stress, cognition and HPA response in healthy volunteers source_derived_draftungraded
   Experimental context and source evidence

   evidence_span

   {"source_cache": "artifacts/gaba-research/27865949.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "e575c804cff60d6e87ab46520788fa3619705071562c2c39ff2b6ea57d5552b2", "start_char": 0, "end_char": 2278, "text_sha256": "e575c804cff60d6e87ab46520788fa3619705071562c2c39ff2b6ea57d5552b2"}

   experimental_model

   Randomised placebo-controlled cross-over trial over eight weeks in healthy male volunteers

   exposure

   The same Lactobacillus rhamnosus JB-1 strain against placebo, with a socially evaluated cold pressor test

   limitations

   Twenty-nine healthy men, which is the population most likely to show nothing. The authors state the limitation and call for study in people with stress-related disorders.

   nutrient_topic

   GABA research collection; topical membership is not evidence of a direct clinical effect, and the sign of a GABA response depends on the chloride gradient of the cell it was measured in. · Gamma-aminobutyric acid

   organism

   Human

   plain_language

   The same bacterium given to healthy men changed nothing that was measured.

   primary_references

   [gb-p27865949] Lost in translation? The potential psychobiotic Lactobacillus rhamnosus (JB-1) fails to modulate stress or cognitive performance in healthy male subjects. (2017). https://pubmed.ncbi.nlm.nih.gov/27865949/ DOI: 10.1016/j.bbi.2016.11.018

   tissue_or_cell_type

   Behaviour, cortisol, cytokines and electroencephalography

   GABA: a ligand with no sign of its own, the cofactor that limits its synthesis, the barrier that keeps it out of the brain, and the immune settings where the same molecule protects and harms (2026-09-22) · lines 482–493

   AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Randomised placebo-controlled cross-over trial over eight weeks in healthy male volunteers · source_derived_draft · unverified_draft

   ### gb-it-did-not-translate In an 8-week randomized placebo-controlled cross-over design with 29 healthy male volunteers there was no overall effect of probiotic treatment on measures of mood, anxiety, stress or sleep quality and no significant effect over placebo on subjective stress measures or the hypothalamic-pituitary-adrenal response to a socially evaluated cold pressor test, visuospatial memory performance, attention switching, rapid visual information processing, emotion recognition and associated electroencephalographic measures did not show improvement over placebo, and no significant anti-inflammatory effects were seen as assessed by basal and stimulated cytokine levels. Condition category: normal nutrient_topic: GABA research collection; topical membership is not evidence of a direct clinical effect, and the sign of a GABA response depends on the chloride gradient of the cell it was measured in. plain_language: The same bacterium given to healthy men changed nothing that was measured. organism: Human tissue_or_cell_type: Behaviour, cortisol, cytokines and electroencephalography experimental_model: Randomised placebo-controlled cross-over trial over eight weeks in healthy male volunteers limitations: Twenty-nine healthy men, which is the population most likely to show nothing. The authors state the limitation and call for study in people with stress-related disorders. exposure: The same Lactobacillus rhamnosus JB-1 strain against placebo, with a socially evaluated cold pressor test evidence_span: {"source_cache": "artifacts/gaba-research/27865949.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "e575c804cff60d6e87ab46520788fa3619705071562c2c39ff2b6ea57d5552b2", "start_char": 0, "end_char": 2278, "text_sha256": "e575c804cff60d6e87ab46520788fa3619705071562c2c39ff2b6ea57d5552b2"} [gb-p27865949] Lost in translation? The potential psychobiotic Lactobacillus rhamnosus (JB-1) fails to modulate stress or cognitive performance in healthy male subjects. (2017). https://pubmed.ncbi.nlm.nih.gov/27865949/ DOI: 10.1016/j.bbi.2016.11.018

   Complete structured claim and evidence

2. Chronic treatment with L. rhamnosus JB-1 induced region-dependent alterations in GABA-B1b messenger RNA in the brain with increases in cortical regions and concomitant reductions in expression in the hippocampus, amygdala and locus coeruleus compared with control-fed mice, the strain reduced stress-induced corticosterone and anxiety- and depression-related behavior, and the neurochemical and behavioral effects were not found in vagotomized mice, identifying the vagus as a major modulatory constitutive communication pathway between the bacteria exposed to the gut and the brain.

   Lactobacillus rhamnosus JB-1 → Brain GABA-B receptor subunit 1b messenger RNA expression source_derived_draftungraded
   Experimental context and source evidence

   evidence_span

   {"source_cache": "artifacts/gaba-research/21876150.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "0008d58bc1bdc0cafce716c1ec3bf74e4bb7a74df49ccec93dafe087aee1183f", "start_char": 0, "end_char": 1706, "text_sha256": "0008d58bc1bdc0cafce716c1ec3bf74e4bb7a74df49ccec93dafe087aee1183f"}

   experimental_model

   Chronic feeding of a single bacterial strain with regional brain receptor expression, behaviour and vagotomy

   exposure

   Chronic Lactobacillus rhamnosus JB-1 in normal healthy mice, with and without vagotomy

   limitations

   The vagotomy arm is what localises the route. It is a single strain in one mouse background, and the receptor changes are messenger RNA rather than protein.

   nutrient_topic

   GABA research collection; topical membership is not evidence of a direct clinical effect, and the sign of a GABA response depends on the chloride gradient of the cell it was measured in. · Gamma-aminobutyric acid

   organism

   Mouse

   plain_language

   Feeding one bacterium changed behaviour and brain receptors, and cutting the nerve from gut to brain abolished it.

   primary_references

   [gb-p21876150] Ingestion of Lactobacillus strain regulates emotional behavior and central GABA receptor expression in a mouse via the vagus nerve. (2011). https://pubmed.ncbi.nlm.nih.gov/21876150/ DOI: 10.1073/pnas.1102999108

   tissue_or_cell_type

   Brain, gut and vagus nerve

   GABA: a ligand with no sign of its own, the cofactor that limits its synthesis, the barrier that keeps it out of the brain, and the immune settings where the same molecule protects and harms (2026-09-22) · lines 469–480

   AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Chronic feeding of a single bacterial strain with regional brain receptor expression, behaviour and vagotomy · source_derived_draft · unverified_draft

   ### gb-the-effect-travels-by-nerve Chronic treatment with L. rhamnosus JB-1 induced region-dependent alterations in GABA-B1b messenger RNA in the brain with increases in cortical regions and concomitant reductions in expression in the hippocampus, amygdala and locus coeruleus compared with control-fed mice, the strain reduced stress-induced corticosterone and anxiety- and depression-related behavior, and the neurochemical and behavioral effects were not found in vagotomized mice, identifying the vagus as a major modulatory constitutive communication pathway between the bacteria exposed to the gut and the brain. Condition category: normal nutrient_topic: GABA research collection; topical membership is not evidence of a direct clinical effect, and the sign of a GABA response depends on the chloride gradient of the cell it was measured in. plain_language: Feeding one bacterium changed behaviour and brain receptors, and cutting the nerve from gut to brain abolished it. organism: Mouse tissue_or_cell_type: Brain, gut and vagus nerve experimental_model: Chronic feeding of a single bacterial strain with regional brain receptor expression, behaviour and vagotomy limitations: The vagotomy arm is what localises the route. It is a single strain in one mouse background, and the receptor changes are messenger RNA rather than protein. exposure: Chronic Lactobacillus rhamnosus JB-1 in normal healthy mice, with and without vagotomy evidence_span: {"source_cache": "artifacts/gaba-research/21876150.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "0008d58bc1bdc0cafce716c1ec3bf74e4bb7a74df49ccec93dafe087aee1183f", "start_char": 0, "end_char": 1706, "text_sha256": "0008d58bc1bdc0cafce716c1ec3bf74e4bb7a74df49ccec93dafe087aee1183f"} [gb-p21876150] Ingestion of Lactobacillus strain regulates emotional behavior and central GABA receptor expression in a mouse via the vagus nerve. (2011). https://pubmed.ncbi.nlm.nih.gov/21876150/ DOI: 10.1073/pnas.1102999108

   Complete structured claim and evidence