Lactobacillus reuteri E9 regulates sleep disorders by modulating inhibitory neurotransmitters and sleep-related receptor expression via the microbiota-gut-brain axis.

Q: What is Lactobacillus reuteri E9?

It is a non-toxic, drug-resistant probiotic strain isolated and characterized for its potential psychobiotic effects on sleep.

Q: How does Lactobacillus reuteri E9 affect sleep?

It upregulates inhibitory neurotransmitters like GABA and taurine, and increases expression of GABA and melatonin receptors, leading to sedative effects in a zebrafish model.

Q: What was the study model used?

The study used a pentylenetetrazol (PTZ)-induced zebrafish model of sleep disorder to evaluate the effects of E9.

Q: Is Lactobacillus reuteri E9 safe for humans?

The abstract states it is non-toxic and drug-resistant, but human safety and efficacy have not been tested in this study.

In a PTZ-induced zebrafish model of sleep disorder, Lactobacillus reuteri E9 significantly upregulated inhibitory neurotransmitters including GABA, taurine, glycine, and serine (p < 0.05). It also reduced seizures and hyperactivity, and upregulated GABA receptor genes and melatonin receptor (Mtnr1aa) genes in neural tissue.

Last updated: Jul 7, 2026•0 RCTs•📖 Read as article →

Evidence Score

Evidence Score24/100

Human RCT☆☆☆☆☆

Meta-analysis☆☆☆☆☆

Mechanism★★★★★

Safety★★★★☆

Confidencelow

Study Evidence

Study 1. Lactobacillus reuteri E9 Regulates Sleep Disorders Through Its Metabolite GABA.

observational

Jiang Y, Guo L, He H, Chen H, Chen T, Liu Y, Zhao W · Frontiers in bioscience (Landmark edition) (2025)

Participants: N/A

Duration: N/A

Intervention: Lactobacillus reuteri E9 (probiotic strain)

Outcome: Neurotransmitter levels (GABA, taurine, glycine, serine), seizure activity, hyperactivity, GABA receptor gene expression, melatonin receptor (Mtnr1aa) gene expression

Effect Size: N/A

Population: Pentylenetetrazol (PTZ)-induced zebrafish model of sleep disorder

Result:

PubMed: 40613302 DOI: 10.31083/FBL39587

Mechanism Graph

Lactobacillus reuteri E9 is administered to PTZ-induced zebrafish

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E9 upregulates inhibitory neurotransmitters (GABA, taurine, glycine, serine)

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E9 upregulates GABA receptor and melatonin receptor (Mtnr1aa) gene expression in neural tissue

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Result: Reduced seizures and hyperactivity, indicating sedative and sleep-regulating effects

Limitations

⚠Animal model (zebrafish) may not fully translate to human sleep disorders
⚠Abstract does not report effect sizes or confidence intervals for key outcomes

Frequently Asked Questions

What is Lactobacillus reuteri E9?▼

It is a non-toxic, drug-resistant probiotic strain isolated and characterized for its potential psychobiotic effects on sleep.

How does Lactobacillus reuteri E9 affect sleep?▼

It upregulates inhibitory neurotransmitters like GABA and taurine, and increases expression of GABA and melatonin receptors, leading to sedative effects in a zebrafish model.

What was the study model used?▼

The study used a pentylenetetrazol (PTZ)-induced zebrafish model of sleep disorder to evaluate the effects of E9.

Is Lactobacillus reuteri E9 safe for humans?▼

The abstract states it is non-toxic and drug-resistant, but human safety and efficacy have not been tested in this study.

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References

1.Jiang Y, Guo L, He H, Chen H, Chen T, Liu Y, Zhao W. "Lactobacillus reuteri E9 Regulates Sleep Disorders Through Its Metabolite GABA.." Frontiers in bioscience (Landmark edition), 2025. PMID: 40613302 DOI: 10.31083/FBL39587

Disclaimer: This content is for educational purposes only and is not medical advice. Evidence scores reflect the quality and quantity of available research, not clinical recommendations. Always consult a healthcare professional before starting any supplement or intervention.