Verdict No. 447 · Search date 2026-07-17 · Methodology v0.6
Lactiplantibacillus plantarum PS128,
does it really help with Relief of stress, anxiety, and depressive feelings?
30-Second Summary
C
Evidence Grade C · 40 · Safety unknown
Safety is separate from efficacy. Trials generally reported good tolerability, but people with severe immunocompromise or central venous catheters should discuss probiotic use with a clinician.
What the
research showsA 40-person trial in adults with self-reported insomnia found between-group differences for depressive symptoms and fatigue, while several measures including anxiety improved in both groups. The high-stress worker study was an uncontrolled 36-person study, and an adjunctive randomized trial in major depressive disorder found no between-group difference on the clinical depression scale.
research showsA 40-person trial in adults with self-reported insomnia found between-group differences for depressive symptoms and fatigue, while several measures including anxiety improved in both groups. The high-stress worker study was an uncontrolled 36-person study, and an adjunctive randomized trial in major depressive disorder found no between-group difference on the clinical depression scale.
What the
ads claimThe label psychobiotic describes a mechanistic hypothesis and research category, not an efficacy grade. Findings from other L. plantarum strains, multi-strain products, heat-treated organisms, or neurodevelopmental and neurodegenerative patient studies cannot be repurposed as evidence for stress relief in healthy adults.
ads claimThe label psychobiotic describes a mechanistic hypothesis and research category, not an efficacy grade. Findings from other L. plantarum strains, multi-strain products, heat-treated organisms, or neurodevelopmental and neurodegenerative patient studies cannot be repurposed as evidence for stress relief in healthy adults.
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Gap Measurement · Verdict 447 · C 40
What the research actually shows
The core evidence consists of a 30-day double-blind trial in 40 adults with self-reported insomnia, an eight-week single-arm study in 36 highly stressed information-technology workers, an eight-week placebo-controlled adjunctive trial in 32 patients with major depressive disorder on stable antidepressants, and a 200-person comparison adding PS128 to drug treatment for anxiety disorders.
Why this is classified as C (40)
A partly positive small placebo-controlled trial and adjunctive patient evidence support C, while uncontrolled healthy-adult evidence, subjective outcomes, conflicts, and a null major-depression trial keep the score low.
Counterpoint. Symptom-scale improvement may matter, but designs that cannot remove natural fluctuation, expectancy, and concurrent drug treatment cannot attribute it securely to the organism.
Rejudgment record. New verdict — The assessment separated healthy adults from patients, monotherapy from drug adjuncts, and PS128 from other strains, then evaluated randomization, controls, subjective outcomes, and conflicts.
Sub-claim grades by effect
This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.
| Effect (sub-claim) | Grade | Basis |
|---|---|---|
| Stress and anxiety relief in healthy or highly stressed adults | D | Direct evidence is mainly an uncontrolled 36-person study, and anxiety did not show a clear between-group benefit in the small insomnia trial. |
| Relief of depressive symptoms in adults reporting insomnia | C | A 40-person, 30-day trial found a between-group depression-scale signal, but it was an exploratory small study with multiple outcomes. |
| Adjunctive use with antidepressants in major depressive disorder | D | In a 32-person placebo-controlled adjunctive trial, both groups improved and the between-group difference in depressive symptoms was not significant. |
| Adjunctive use with medication for anxiety disorders | C | A 200-person study reported benefit, but allocation and blinding were insufficiently described and concurrent medication prevents isolation of a stand-alone effect. |
Cross-check — Codex and Claude
This verdict was drafted by Codex through literature review and source-existence checks, cross-checked through blind grading and adversarial audit, and settled by reapplying the methodology boundary rules. Cases with split grades were resolved through rejudgment.
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| Study 1 | Double-blind, placebo-controlled randomized pilot trial lasting 30 days | 19 | Supported by an academic program; Bened Biomedical supplied capsules and one author held company stock | BDI-II, BAI, sleep quality, fatigue, and autonomic measures | Between-group signals favored PS128 for depressive symptoms and fatigue, while several outcomes including anxiety improved in both groups or did not differ clearly. | Moderate |
| Study 2 | Open-label, single-arm pilot study lasting eight weeks | 36 | Multiple authors were Bened Biomedical employees or shareholders | Subjective scales for stress, anxiety, depression, and insomnia | Several scales improved from baseline, but the lack of a control group prevents exclusion of regression to the mean and expectancy effects. | Low |
| Study 3 | Double-blind, placebo-controlled randomized trial adding eight weeks of treatment to stable antidepressants | 32 | Public research funding; authors reported no conflicts of interest | HAM-D, depression and somatic-symptom scales, inflammatory markers, and microbiome measures | Both groups improved, the between-group difference in depressive symptoms was not significant, and major biomarker findings were not clear. | Moderate |
| Study 4 | Two-group comparison of standard medication versus medication plus PS128 for two months; blinding and allocation methods were unclear | 200 | PS128 was supplied by Bened Biomedical; funding information was insufficient | HAMA, SAS, quality of life, and adverse events | The adjunctive group improved more, but concurrent drugs and incomplete methodological reporting prevent isolation of the PS128 effect. | Low to moderate |
Receipt — 5 References
All 5 cited sources were verified for existence at the original page (as of 2026-07-17).
Ho YT, Tsai YC, Kuo TBJ, Yang CCH. Effects of Lactobacillus plantarum PS128 on Depressive Symptoms and Sleep Quality in Self-Reported Insomniacs: A Randomized, Double-Blind, Placebo-Controlled Pilot Trial. Nutrients. 2021;13(8):2820. PMID: 34444980. DOI: 10.3390/nu13082820.
checkedWu SI, et al. Psychobiotic Supplementation of PS128 Improves Stress, Anxiety, and Insomnia in Highly Stressed Information Technology Specialists: A Pilot Study. Frontiers in Nutrition. 2021;8:614105. PMID: 33842519. DOI: 10.3389/fnut.2021.614105.
checkedLin SKK, Kuo PH, Hsu CY, Chiu YH, Chen CH. The effects of Lactobacillus plantarum PS128 in patients with major depressive disorder: an eight-week double-blind, placebo-controlled study. Asian Journal of Psychiatry. 2024;101:104210. PMID: 39232392. DOI: 10.1016/j.ajp.2024.104210.
checkedMeng X, Gao Y, Qi H, Ding Y, Sun Y. Clinical Application Value of Lactobacillus Plantarum PS128 in Patients with Anxiety Disorders. Clinical Psychopharmacology and Neuroscience. 2022;20(3):560-566. PMID: 35879040. DOI: 10.9758/cpn.2022.20.3.560.
checkedBened Life. Neuralli MP official product information, South Korean storefront. Accessed 2026-07-17.
checkedDraft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-07-17 · Corrections: none
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-07-17 · Corrections: none
Cite this verdict
[Chamgap] PS128 and mood: small mixed signals that do not generalize to healthy adults or monotherapy — Evidence Grade C·40. 5 cited sources checked. Source: https://chamgap.com/en/verdicts/mood/lactiplantibacillus-plantarum-ps128-mood/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
What this document does and does not do
Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.