The therapeutic effects of Lacticaseibacillus rhamnosus on stress-induced anxiety: a systematic review of evidence from animal studies.

2025
Gut microbiome (Cambridge, England) 6
- Iman Imtiyaz Ahmed Juvale
- Alina Arulsamy

PubMed: 41497537
DOI: 10.1017/gmb.2025.10015

Study Design

Type: Review
Sample size: n = 8
Population: animal studies evaluating the role of L. rhamnosus in stress-induced anxiety; species included mice (n=7), rats (n=5), and hens (n=3)
Methods: Following PRISMA guidelines, PubMed, Embase, and Scopus were searched (2011-2024) for animal studies evaluating the role of L. rhamnosus in stress-induced anxiety. Primary outcomes were behavioural anxiety measures; secondary outcomes included neuroendocrine, immune, epithelial, and microbiota changes. Fifteen studies met the inclusion criteria.

Lacticaseibacillus rhamnosus may modulate stress-induced anxiety, yet animal evidence has not been systematically evaluated. Following PRISMA guidelines, PubMed, Embase, and Scopus were searched (2011-2024) for animal studies evaluating the role of L. rhamnosus in stress-induced anxiety. Primary outcomes were behavioural anxiety measures; secondary outcomes included neuroendocrine, immune, epithelial, and microbiota changes. Fifteen studies met the inclusion criteria. Species included mice (n=7), rats (n=5), and hens (n=3). Stress models comprised chronic unpredictable mild stress (n=8), social defeat (n=2), maternal separation (n=1), restraint stress (n=1), and severe feather-pecking (n=3). Common strains were JB-1 (n=8), HN001 (n=2), LGG (n=2), LR-32 (n=1), 4B15 (n=1), and LR3201 (n=1). Of the 15 studies, 12 reported significant anxiolytic effects, most frequently in the elevated plus maze (7/10) and open-field test (6/9). JB-1 showed the most consistent behavioural improvement (7/8 studies). Mechanistic findings were reported in subsets of studies: HPA axis modulation in 4/15, monoamine changes in 4/15, GABAergic effects in 4/15, immune/anti-inflammatory changes in 4/15, tight junction restoration in 2/15, and gut microbiota or SCFA-related changes in 7/15. L. rhamnosus, particularly strain JB-1, shows consistent anxiolytic effects and multiple putative mechanistic pathways, though more rigorous and standardised preclinical designs are needed.

Research Insights

Supplement	Dose	Health Outcome	Effect Type	Effect Size	Source
Lactobacillus rhamnosus HN001	—	Altered Monoamine Signaling	Beneficial	Small	View source Mechanistic findings were reported in subsets of studies: ... monoamine changes in 4/15
Lactobacillus rhamnosus HN001	—	Improved Gut Barrier Function	Beneficial	Small	View source Mechanistic findings were reported in subsets of studies: tight junction restoration in 2/15
Lactobacillus rhamnosus HN001	—	Increased GABAergic Signaling	Beneficial	Small	View source Mechanistic findings were reported in subsets of studies: ... GABAergic effects in 4/15
Lactobacillus rhamnosus HN001	—	Modulated HPA Axis	Beneficial	Small	View source Mechanistic findings were reported in subsets of studies: HPA axis modulation in 4/15
Lactobacillus rhamnosus HN001	—	Reduced Anxiety	Beneficial	Moderate	View source Common strains were JB-1 (n=8), HN001 (n=2), LGG (n=2), LR-32 (n=1), 4B15 (n=1), and LR3201 (n=1). Of the 15 studies, 12 reported significant anxiolytic effects
Lactobacillus rhamnosus HN001	—	Reduced Inflammation	Beneficial	Small	View source Mechanistic findings were reported in subsets of studies: immune/anti-inflammatory changes in 4/15
Lactobacillus rhamnosus Lr-32	—	Reduced Anxiety	Beneficial	Moderate	View source Common strains were JB-1 (n=8), HN001 (n=2), LGG (n=2), LR-32 (n=1), 4B15 (n=1), and LR3201 (n=1). Of the 15 studies, 12 reported significant anxiolytic effects