Benefits
Bowel symptom scores over 8 weeks
In a placebo-controlled trial in 285 adults with irritable bowel syndrome, 10 billion CFU a day for 8 weeks did not lower symptom severity scores more than placebo: scores fell 22% on the strain and 31% on placebo. In a small subgroup with diarrhea, bowel movements were less frequent than on placebo at week 4 only. Lallemand funded the trial.
Mood, energy and wellbeing ratings in adults with bowel complaints
In the same 8-week trial, anxiety and depression scores did not change on the strain. Energy, emotional wellbeing and social functioning ratings rose within the R0175 group but not the placebo group, yet none of these ratings differed between the groups, so a benefit over placebo was not shown.
Cognitive and anxiety test scores in older adults with memory loss
In 90 older adults with mild or moderate Alzheimer's disease, some taking cholinesterase inhibitor drugs, one capsule twice daily for 12 weeks went with larger gains than placebo on two cognitive tests and an anxiety scale. This is a disease population, cited as context only; one research group ran the trial and its papers give different capsule doses.
Blood amino acid levels in older adults
A paper from the same registered trial, reporting 20 people per group, found that serum total, branched-chain and aromatic amino acids rose more on R0175 than on placebo over 12 weeks. These are blood markers in a disease population, and the paper's participant count differs from the 90 reported in the earlier paper.
Absorption of orange juice flavanones
In healthy volunteers, taking microencapsulated R0175 once with orange juice did not change how much of the juice's flavanones were absorbed. After 4 weeks of daily intake, urinary excretion of flavanones and their breakdown products rose from about 43% to 70% of intake. Stool bacteria and short-chain fatty acids did not change.
Role inside Cerebiome® and other blends
Most human studies give R0175 with a partner: with L. helveticus R0052 in Cerebiome® (Lactobacillus helveticus R0052 and Bifidobacterium longum R0175), studied for mood and stress, and with oligofructose in a synbiotic that did not change insulin sensitivity in a 4-week trial. Their results cannot be credited to R0175 alone.
Mechanism of action
Behavior after a heart attack in rats (animal work only)
Rats given R0175 for 14 days before an induced heart attack spent more time socializing, learned an avoidance test faster and were less immobile in a swim test than untreated rats, with lower brain caspase-3 activity and lower CRP. R0052 alone did not show these effects. Two authors work for Lallemand. Animal results do not show effects in people.
Liver injury model in rats (animal work only)
In rats given the liver toxin d-galactosamine, oral R0175 lowered blood AST, bile acids and inflammatory cytokines and partly reversed gut bacteria changes. This is an animal model and does not show liver support in people.
Passage through the gut
In an open-label study in 30 healthy adults taking a five-strain capsule containing R0175 for 2 weeks, the strains appeared in stool 1 to 2 days after the first dose. R0175 stayed detectable for about 8.5 days on average after intake stopped in people with intermediate gut transit, and 15 days or more in 6 of those 13. Six authors work for Lallemand.
Clinical trials
Randomized, double-blind, placebo-controlled three-arm trial (NCT02213172) after a 2-week run-in; one capsule a day of 10 billion CFU of B. longum R0175 or L. paracasei HA-196, or placebo, for 8 weeks; primary outcome the IBS Symptom Severity Score; sponsored by KGK Science and funded by Lallemand Health Solutions, which owns both strains and took part in the design; three authors (Piano A, Bhardwaj R, Tompkins TA) are Lallemand employees (Lewis et al. 2020, Nutrients)
Adults with irritable bowel syndrome (Rome III) in Ontario, Canada: 285 randomized, 95 per arm; 251 in the per-protocol analysis, of whom the abstract lists 83 on R0175 and the figures 86
Symptom severity fell in all groups with no between-group difference: by 22% on R0175 and 31% on placebo at week 8. In the diarrhea subgroup (15 on R0175, 12 on placebo), weekly bowel movements fell more than on placebo at week 4 only. HADS anxiety and depression scores did not change, and SF-36 energy, emotional wellbeing and social functioning rose within the R0175 group without differing from placebo. The number of people with adverse events did not differ between groups.
Randomized, double-blind, placebo-controlled three-arm trial (IRCT20210513051277N1); B. longum R0175, L. rhamnosus HA-114 or placebo capsules twice daily for 12 weeks; primary outcomes MMSE and categorical verbal fluency; capsules coded and supplied by Lallemand; funded by Tehran University of Medical Sciences, with no competing interests declared and no Lallemand employee among the authors; the capsule dose is printed as 10^15 CFU (Akhgarjand et al. 2022, Front Aging Neurosci)
90 adults aged 50 to 90 with mild or moderate Alzheimer's disease, 30 per group, all completing; some took cholinesterase inhibitor drugs
Context only (disease population with drug co-treatment). MMSE scores rose more on R0175 than on placebo (difference 4.86 in the abstract, P < 0.0001; the paper's Table 3 gives 2.46 unadjusted and 3.86 adjusted), and verbal fluency, instrumental daily activity and GAD-7 anxiety scores improved more on both probiotics than on placebo, with no difference between the two strains. Basic daily activity scores improved more on R0175 than placebo in the unadjusted analysis but not after adjustment for education, disease type, BMI and drug use (interaction P = 0.24). No serious side effects were reported.
Report from the same 12-week randomized, double-blind, placebo-controlled trial of R0175, HA-114 or placebo, stating each probiotic dose as 7.5 x 10^9 CFU twice daily; funding is not stated in the abstract (Akhgarjand et al. 2024, Inflammopharmacology)
90 adults with mild or moderate Alzheimer's disease
Serum inflammatory and oxidative stress markers improved by the end of the trial (P < 0.05). The abstract does not separate the R0175 results from the HA-114 results or name the markers that changed.
Randomized, double-blind, placebo-controlled three-arm trial under the same registration (IRCT20210513051277N1) and the same October 2021 to May 2022 dates; one capsule of 10^9 CFU twice daily, supplied by Lallemand; primary outcomes serum total, branched-chain and aromatic amino acids; no funding and no competing interests declared (Jouni et al. 2025, Sci Rep)
60 adults aged 50 to 90 with mild or moderate Alzheimer's disease, 20 per group, all completing; the earlier paper on this registration reports 90
Compared with placebo, R0175 raised serum total amino acids (difference 2132.67 µmol/L, p = 0.01), branched-chain amino acids (255.15 µmol/L, p = 0.01) and aromatic amino acids (p = 0.02); HA-114 raised branched-chain amino acids only. Weight, BMI and food intake did not differ between groups. No serious side effects were reported.
Human feeding study: orange juice taken with and without a single dose of microencapsulated B. longum R0175, then again after 4 weeks of daily R0175, with 24-hour urine collection; the abstract does not state randomization, a placebo group or the dose; one author is from The Coca-Cola Company (Pereira-Caro et al. 2015, Free Radic Biol Med)
Healthy volunteers; the abstract does not give the number
A single dose did not change flavanone excretion (about 22% of intake, plus 21% as colon-derived phenolic and aromatic acids). After 4 weeks of daily intake, excretion rose to 27% for flavanones and 43% for phenolic acids, about 70% overall. Stool probiotic bacteria, moisture, weight, pH, short-chain fatty acids and phenols did not differ between treatments.