Benefits
Mood scores with the R0052 and B. longum R0175 strain pair
In 110 adults with major depression, one daily sachet of R0052 with B. longum R0175 for 8 weeks lowered depression questionnaire scores more than placebo, though only 81 finished. Two other placebo-controlled trials of the same pair, in 79 adults with low mood and 135 healthy adults, found no difference. This is research, not a treatment for depression.
Psychological distress and urinary cortisol in healthy volunteers
In a 30-day placebo-controlled trial in healthy volunteers, the R0052 and R0175 pair improved overall distress scores and lowered 24-hour urinary cortisol, while the anxiety subscale fell just short of significance. A later 4-week trial of the same pair in 135 healthy adults found no effect in the group as a whole. Neither trial tested L. helveticus alone.
Positive mood ratings with heat-killed strain MCC1848
In 58 healthy young adults, 4 weeks of heat-killed MCC1848 improved two positive mood ratings, friendliness and feeling relaxed, versus placebo. Negative mood items, anxiety, sleep and fatigue scores did not change. The cells were not alive, so the result does not carry over to live strains, and several authors work for the maker.
Upper respiratory symptoms with two specific strains
In 200 healthy adults, 6 billion heat-killed cells a day of strain GCL1815 for 8 weeks cut the total days with cold-like symptoms versus placebo; four of the five authors work for the maker. In 39 elite athletes, 14 weeks of strain Lafti L10 shortened respiratory infection episodes by about 3 days but did not change how often or how severely they occurred.
Bowel habits in trials of specific strains and fermented milk
In 160 healthy adults on an antibiotic, R0052 with L. rhamnosus R0011 did not change stool consistency or frequency, the main outcomes. In 886 children with gastroenteritis the same pair did not help. In 120 adults prone to constipation, a drink of heat-treated milk fermented with strain CP790 improved stool consistency and straining over 4 weeks.
Blood pressure with peptide-rich fermented milk
Milk fermented with some L. helveticus strains contains the peptides VPP and IPP. In 94 adults with untreated high blood pressure, 300 mL a day of LBK-16H fermented milk for 10 weeks gave 24-hour systolic pressure about 4 mmHg lower than control. Another 94-person trial found no significant difference, nor did a crossover trial in its combined analysis. See the lactotripeptides page.
Mechanism of action
Strain-specific contact with immune cells
In the GCL1815 cold trial, activation markers on two kinds of dendritic cells, immune cells that help respond to viruses, rose more than with placebo. This was shown for one strain only, and a blood marker is not the same as fewer colds.
Peptides made while fermenting milk
When certain strains ferment milk, they cut the milk protein casein into short peptides, including VPP and IPP, which block the ACE enzyme in the test tube. Whether this explains blood pressure changes in people is not established; the lactotripeptides page covers that research.
Gut-brain signaling (proposed)
In the depression trial of R0052 with R0175, the kynurenine to tryptophan ratio fell versus placebo only after statistical adjustment, and a later analysis of the same trial found higher blood BDNF, a nerve growth factor. These are secondary markers from a single trial.
Shifts in gut bacteria and their products
Heat-treated CP790 fermented milk lowered Desulfobacterota bacteria in stool, which tracked with better stool consistency. In a small trial in dancers, R0052 with R0175 shifted stool metabolites without improving gut symptoms.
Clinical trials
Randomized, double-blind, three-arm trial comparing L. helveticus R0052 with B. longum R0175 (10 billion CFU in one daily sachet, products supplied by Lallemand), a galactooligosaccharide prebiotic and placebo (Kazemi et al. 2019, Clin Nutr)
110 adults in Iran with major depressive disorder; 81 completed (28 probiotic, 27 prebiotic, 26 placebo).
The Beck Depression Inventory score fell from 17.4 to 9.1 with the probiotic, 18.2 to 15.6 with placebo and 19.7 to 14.1 with the prebiotic (p = 0.042). The kynurenine to tryptophan ratio did not differ between groups unless adjusted for isoleucine. About a quarter of those randomized did not finish. Dose and strain details come from a later analysis of the same trial (Heidarzadeh-Rad et al. 2020).
Randomized, placebo-controlled trial of L. helveticus R0052 with B. longum R0175 (3 billion CFU), with products supplied by Lallemand (Morales-Torres et al. 2023, Nutrients)
135 healthy adults.
No significant effect of the probiotic on wellbeing, quality of life, emotional regulation, anxiety, mindfulness or body awareness across the whole group. In an exploratory model, people with high healthy-lifestyle scores who took the probiotic did better on anxiety, emotional regulation and mindfulness; this subgroup finding needs confirmation.
Randomized, double-blind, placebo-controlled trial of heat-killed L. helveticus MCC1848 powder, with POMS 2 mood scores as the primary outcome (Mutoh et al. 2023, Benef Microbes)
58 healthy young adults in Japan.
Two positive mood ratings, friendliness and feeling relaxed, improved versus placebo. Negative mood items (such as anger, nervousness and confusion), STAI anxiety, insomnia and fatigue scores did not differ. No adverse effects. The cells were not alive, and several authors work for Morinaga Milk Industry, which makes the ingredient.
Randomized, double-blind, placebo-controlled trial of capsules containing 6 billion heat-sterilized L. helveticus GCL1815 cells, taken once daily (Wada et al. 2024, Nutrients)
200 healthy adults in Japan.
Among the 192 people in the efficacy analysis, cumulative days with cold-like symptoms such as feverishness, fatigue, runny nose, nasal congestion and phlegm were 938 with GCL1815 versus 1116 with placebo, a significant difference. An activation marker (HLA-DR) on plasmacytoid dendritic cells rose more than with placebo at 4 and 8 weeks. The cells were heat-killed, four of the five authors are employees of Ezaki Glico, the strain's maker, and no independent repeat is cited here.
10-week randomized, double-blind, placebo-controlled trial of L. helveticus R0052 with L. rhamnosus R0011 (8 billion CFU a day) taken with a 1-week course of amoxicillin-clavulanate and for 1 week after (Evans et al. 2016, Br J Nutr)
160 healthy adults (80 probiotic, 80 placebo).
Stool consistency and frequency, the primary outcomes, did not differ from placebo, nor did diarrhea-like episodes, symptom scores or safety measures. A post hoc analysis found diarrhea-like episodes lasted 2.7 versus 3.7 days (P = 0.037). Two authors are from Lallemand Health Solutions.
Multicenter, randomized, double-blind, placebo-controlled trial of L. rhamnosus R0011 with L. helveticus R0052, 4 billion CFU twice daily for 5 days, funded by the Canadian Institutes of Health Research and others (Freedman et al. 2018, N Engl J Med)
886 children aged 3 to 48 months seen for gastroenteritis at six pediatric emergency departments in Canada.
Moderate-to-severe gastroenteritis within 14 days occurred in 26.1% on the probiotic and 24.7% on placebo (P = 0.72). Median diarrhea duration (52.5 versus 55.5 hours), vomiting duration and unscheduled doctor visits did not differ. Adverse events were similar (34.8% versus 38.7%).
Randomized, double-blind, placebo-controlled trial of a 100 mL daily drink made with heat-treated milk fermented by L. helveticus CP790, against nonfermented milk flavored with lactic acid (Tanihiro et al. 2024, Nutrients)
120 healthy Japanese adults aged 20 to 59 with a tendency toward constipation (60 per group).
Stool consistency and straining improved versus placebo, and Desulfobacterota bacteria in stool fell; these changes were correlated. Total mood disturbance and depression-dejection scores were also better than placebo. The drink contained no live bacteria, and six of the seven authors work for an Asahi Group company.
Randomized, double-blind, placebo-controlled parallel trial of milk fermented with L. helveticus LBK-16H containing the tripeptides IPP and VPP, 150 mL twice daily, measured by 24-hour ambulatory monitoring (Jauhiainen et al. 2005, Am J Hypertens)
94 adults with hypertension not on drug treatment, after a 4-week run-in.
24-hour systolic pressure was 4.1 mmHg and diastolic 1.8 mmHg lower than with the control product (P = .001 and P = .048), with no difference in adverse events. A Danish trial of L. helveticus fermented milk in 94 adults with high-normal pressure found no 24-hour difference (Usinger et al. 2010), so results vary between products and trials.