Bifidobacterium lactis HN019 and constipation over eight weeks in people
What it found
Taking Bifidobacterium lactis HN019 daily for 8 weeks did not increase complete bowel movements more than a placebo in people with constipation.
The probiotic group had slightly less belly pain and bloating than the placebo group.
What they found
Studies in people
Bowel movement frequency
Both groups had more complete bowel movements by the end of the study. The probiotic group went from under one per week to about 1.58, and the placebo group went to about 1.50. This difference between the two groups was too small to rule out chance.
Belly pain and bloating
Belly pain and bloating were low at the start for everyone. Over the 8 weeks, these symptoms rose slightly in the placebo group but stayed flat in the probiotic group. The difference between the groups was small but unlikely due to chance.
Stool softness and straining
Stools were moderately hard in both groups at the start and softened only a little over time. The amount of straining during bowel movements dropped slightly and equally in both groups.
Gut bacteria levels
Stool tests showed that the amount of Bifidobacterium lactis in the gut rose in the probiotic group compared with the placebo group. However, the overall mix of gut bacteria looked similar in both groups by the end.
Side effects
A small number of people in each group reported minor health complaints during the trial. None were judged to be caused by the probiotic or the placebo, and nobody dropped out because of them.
What the authors conclude
- They found that taking Bifidobacterium lactis HN019 every day for 8 weeks did not improve bowel movement frequency more than a placebo.
- The authors note that the probiotic was well tolerated by the participants.
How it was done
Constipation is common, and earlier smaller studies suggested this specific strain of gut bacteria might help adults go to the toilet more easily. The authors wanted to test this in a larger trial that focused on how often people had complete bowel movements without needing laxatives.
The researchers recruited 229 adults aged 18 to 70 with constipation at five hospitals in Shanghai, China. Participants took either a daily sachet of Bifidobacterium lactis HN019 or a lookalike placebo without the bacteria for 8 weeks. Everyone kept daily diaries about their bowel habits and symptoms.
What it can’t tell you
- This trial lasted 8 weeks, so it cannot show what happens if someone takes the probiotic for months or years.
- The study only included adults in Shanghai, China, so the results might differ for people living elsewhere or eating different diets.
- Participants ate very little fiber, averaging 9 g per day, which may have influenced how well the probiotic could work.
Who paid
- Conflicts
- Conflict of Interest Disclosures: Dr Ouwehand reported holding patent PL2839836T3 for probiotics for use in reducing symptoms of respiratory disease licensed to Dupont Nutrition & Bioscience ApS, patent WO2009048934A2 for probiotics for use in relieving symptoms associated with gastrointestinal disorders licensed to Danisco A/S, patent WO2007132359A2 for composition licensed to Danisco A/S, patent WO0238798A1 for a method for screening probiotic strains of the genus Bifidobacterium licensed to Raisio Oyj and Bioferme Oy, patent WO9730717A1 for preparation and producing adhesion inhibitors licensed to Arla Foods Group, patent AU2013201783A1 for probiotics for use in reducing the incidence and duration of illness licensed to Dupont Nutrition & Bioscience ApS, patent PL2704704T3 for probiotic bacteria for the topical treatment of skin disorders licensed to Dupont Nutrition & Bioscience ApS, patent WO2021015977A1 for oral health care treatment and related compositions licensed to Dupont Nutrition & Bioscience ApS, patent WO2009014421A1 for probiotics for inducing satiety and/or satiation licensed to Campina Nederland Holding BV, patent WO2008122892A2 for probiotics for use in reducing eosinophilia and respiratory allergies licensed to Danisco A/S, patent WO2023057454A1 for consumption of glutamate and formation of γ-aminobutyric acid by Lactiplantibacillus plantarum licensed to Dupont Nutrition & Bioscience ApS, patent PL1981516T3 for use of probiotic microorganisms for the treatment and prevention of obesity and related disorders licensed to Dupont Nutrition & Bioscience ApS, patent WO2024121103A1 for probiotics for treating and/or preventing conditions associated with Helicobacter pylori colonization licensed to International N&H Denmark ApS, patent WO2018050623A1 for bacteria licensed to Dupont Nutrition & Bioscience ApS, patent EP3821718A1 for probiotics for lactose intolerance licensed to Dupont Nutrition & Bioscience ApS, and patent WO2021203083A2 for compositions for metabolic health licensed to Dupont Nutrition & Bioscience ApS. No other disclosures were reported.
- Authors work at
- Shanghai Tongji Hospital, China; Shanghai Zhongshan Hospital, China; Shanghai Tongren Hospital, China
The paper
- Title
- Eight-Week Supplementation With Bifidobacterium lactis HN019 and Functional Constipation: A Randomized Clinical Trial
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Cheng J, Gao C, Ala-Jaakkola R, et al (2024). Eight-Week Supplementation With Bifidobacterium lactis HN019 and Functional Constipation: A Randomized Clinical Trial. JAMA network open. doi:10.1001/jamanetworkopen.2024.36888Free full textPubMed 39356506DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error