Limited evidenceGut health

Lactobacillus Helveticus

Marketed as a "psychobiotic", almost always as the R0052 strain paired with Bifidobacterium longum R0175. The mood findings come from one small early study and have not been convincingly replicated.

Evidence last reviewed: August 2026

What the science says

Mood and anxiety Limited evidence
The often-cited study combined rat experiments with a small human trial of L. helveticus R0052 plus B. longum R0175 and reported reduced psychological distress scores. It was small, tested a two-strain combination, and later trials of the same combination have given mixed results.
Gastrointestinal symptoms Limited evidence
A randomized controlled trial of the R0052/R0175 combination in female dancers found some improvement in gastrointestinal symptoms alongside metabolomic changes, in a small and highly specific population.
Common cold prevention Limited evidence
A randomized, double-blind, placebo-controlled trial reported that L. helveticus reduced the onset of common colds and activated dendritic cells; this is a single trial and needs replication.

Dosage & safety

Studied doseMood trials used about 3 billion CFU per day of the R0052 + R0175 combination for 30 days.

SafetyWell tolerated; mild digestive upset at the start. Not a treatment for depression or an anxiety disorder — do not replace prescribed therapy with it. Standard caution for live probiotics in immunocompromised patients.

Scientific references

Assessment of psychotropic-like properties of a probiotic formulation (Lactobacillus helveticus R0052 and Bifidobacterium longum R0175) in rats and human subjects
Messaoudi M, Lalonde R, Violle N, Javelot H, Desor D, Nejdi A, Bisson JF, Rougeot C, Pichelin M, Cazaubiel M, Cazaubiel JM — Br J Nutr, 2011
A Randomized Controlled Trial Evaluating the Effects of a Probiotic Containing Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 on Gastrointestinal Symptoms and Metabolomic Profiles in Female Dancers
Wiącek J, Skonieczna-Żydecka K, Łoniewski I, Styburski D, Kaczmarczyk M, Karolkiewicz J — Int J Mol Sci, 2025
Lactobacillus helveticus Induces Two Types of Dendritic Cell Activation and Effectively Suppresses Onset of the Common Cold: A Randomized, Double-Blind, Placebo-Controlled Trial
Wada H, Mawatari T, Saito Y, Azuma N, Iwama Y — Nutrients, 2024

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