Bifidobacterium longum 35624 and IBS symptoms over 8 weeks
What it found
In 37 adults with IBS, an 8-week course of Bifidobacterium longum 35624 was linked to a 43.5% fall in a total symptom score.
The study had no placebo group, so some of this may reflect the well-known placebo effect in IBS.
What they found
Studies in people
Total symptom score
The total IBS symptom score fell from a mean of 12.3 at the start to 6.97 after 8 weeks, a 43.5% reduction. The score had already dropped significantly by week 2.
Individual symptoms
Bloating, gas, diarrhoea and abdominal pain all improved significantly over the 8 weeks. Constipation fell slightly but not significantly.
Clinically meaningful relief
Over 60% of participants had a clinically meaningful drop in the total symptom score (more than 30%) by the end of the study. At 8 weeks, 64.5% had a clinically meaningful drop in the IBS severity score (more than 50 points).
Quality of life
The share of participants saying IBS interfered greatly with their life fell from 45.2% at the start to 22.6% on day 57.
Safety and tolerability
One mild adverse event (nausea) was potentially linked to the product. Tolerability was rated very good or good by 89.3% of participants and 83.4% of doctors.
What the authors conclude
“We conclude that an 8-week course of B. longum 35624 ® was associated with significant, clinically meaningful symptom relief in a typical population of adult patients with IBS.”
Also in their conclusions
- They conclude that an 8-week course of B. longum 35624 was associated with significant, clinically meaningful symptom relief in a typical population of adult patients with IBS.
- They say the response rates were markedly greater than the average placebo response seen in IBS trials.
- They suggest that additional observational studies with larger numbers of patients might further support the real-world evidence for this strain.
How it was done
The authors wanted to see how well Bifidobacterium longum 35624 works for IBS in everyday practice, outside the tightly controlled setting of randomised trials. They also wanted data on safety and tolerability in a typical group of patients.
They recruited 37 adults with IBS, diagnosed by the Rome IV criteria, through 15 family doctors in Germany. Participants took Bifidobacterium longum 35624 for 8 weeks and filled in weekly online questionnaires about their symptoms. There was no placebo group and no blinding.
What it can’t tell you
- This study had no placebo group, so it cannot prove that the improvements were caused by the probiotic rather than by the placebo effect or the natural ups and downs of IBS.
- The results come from 37 adults in Germany, so they may not apply to other countries or groups of people.
- The study did not follow participants after they stopped taking the product, so it cannot show whether any benefits lasted.
Who paid
- Conflicts
- Declarations. Conflict of Interest: At the time of the study, Marion Lenoir was a salaried employee of Biocodex SAS. As a study physician, Jörg Wienke received fees from MEDICE Arzneimittel Pütter GmbH & Co KG for his medical services during the study. Frédérique Fardao-Beyler is salaried employee of Biocodex SAS. Nadine Roese is a salaried employee of MEDICE Arzneimittel Pütter GmbH & Co KG.
The paper
- Title
- An 8-Week Course of Bifidobacterium longum 35624 ® Is Associated with a Reduction in the Symptoms of Irritable Bowel Syndrome
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Full text
- Licence
- CC BY. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- Lenoir M, Wienke J, Fardao-Beyler F, Roese N (2025). An 8-Week Course of Bifidobacterium longum 35624 ® Is Associated with a Reduction in the Symptoms of Irritable Bowel Syndrome. Probiotics and antimicrobial proteins. doi:10.1007/s12602-023-10151-wFree full textPubMed 37702965DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error