Probiotic
    Moderate Evidence

    Bifidobacterium Longum

    Bifidobacterium longum

    TL;DR

    One of the dominant species in the infant and adult colon, with the strongest supplement evidence in IBS and a genuinely interesting but early signal for anxiety and stress via the gut-brain axis. Strain identity is decisive: NCC3001 and 1714 are the ones with human trial data.

    Ideal For

    • IBS with abdominal pain or low mood
    • Rebuilding flora after a course of antibiotics
    • People interested in the gut-brain axis with realistic expectations

    Avoid If

    • You are severely immunocompromised
    • You have a central venous catheter
    • You have short bowel syndrome

    Overview

    Bifidobacterium longum is a native resident of the human gut, abundant in breastfed infants and persisting through adulthood. Unlike many probiotics marketed on general "gut health", B. longum has been studied against defined endpoints, and the two best-characterised strains behave quite differently.

    NCC3001 has been tested in IBS with comorbid low mood. A controlled trial reported reduced depression scores and altered brain activity on functional MRI in amygdala and fronto-limbic regions, without a large change in IBS symptom severity itself — a striking result that has not yet been replicated at scale. Strain 1714 has been studied in healthy volunteers under acute stress, where it modestly reduced perceived stress and altered EEG measures. Separately, B. longum blends show consistent small benefits in overall IBS symptom scores and in restoring flora after antibiotics.

    Two caveats keep this from being a stronger recommendation. Trials are small, often 40-90 participants, and the gut-brain findings rest on a handful of studies from closely related research groups. And like most probiotics, B. longum does not durably engraft in an established adult microbiome, so effects depend on continued dosing.

    How It Works

    • Ferments non-digestible oligosaccharides into short-chain fatty acids, chiefly acetate, which supports colonocyte energy and barrier integrity
    • Competitive exclusion of pathogens through nutrient competition and adhesion-site occupancy
    • Downregulates pro-inflammatory cytokines in gut-associated lymphoid tissue
    • Vagal and metabolite signalling to the CNS is the proposed route for the observed mood and stress effects
    • Reduces visceral hypersensitivity in animal models, which fits the IBS pain findings

    Benefits & Outcomes

    Gut-Brain Axis Support

    Digestive
    Mixed evidence
    Preliminary
    Effectiveness 3/5

    B. longum has produced two of the more credible human gut-brain results in the field: reduced depression scores with measurable fMRI changes (NCC3001) and modest stress reduction in healthy adults (strain 1714). Both rest on small, single-site trials that have not been independently replicated.

    Health Concerns Addressed

    IBS (Irritable Bowel Syndrome)

    condition
    Mixed evidence
    Preliminary
    Effectiveness 6/5

    B. longum NCC3001 produced a striking reduction in depression scores and measurable changes in brain activity in IBS patients, but its effect on IBS symptoms themselves was modest and inconsistent. It is a reasonable option when low mood accompanies IBS, and a weak one for gut symptoms alone.

    Supporting Research
    11 studies

    Probiotic Bifidobacterium longum NCC3001 Reduces Depression Scores and Alters Brain Activity: A Pilot Study in Patients With Irritable Bowel Syndrome

    Score: 7/10
    2017
    rct
    n=44

    Pinto-Sanchez MI, Hall GB, Ghajar K +1 more

    B. longum NCC3001 reduced depression scores in IBS patients versus placebo at 6 weeks and altered limbic brain responses, but did not significantly reduce anxiety or core IBS symptoms.

    View source

    Bifidobacterium longum 1714 as a translational psychobiotic: modulation of stress, electrophysiology and neurocognition in healthy volunteers

    Score: 6/10
    2016
    crossover
    n=22

    Allen AP, Hutch W, Borre YE +7 more

    B. longum 1714 reduced cumulative daily stress and subjective anxiety and improved hippocampus-dependent visuospatial memory relative to placebo in healthy volunteers.

    View source

    Bifidobacterium longum 1714 modulates brain activity and stress responses in healthy volunteers: neuroimaging evidence

    Score: 6/10
    2019
    crossover
    n=40

    Wang H, Braun C, Murphy EF +1 more

    B. longum 1714 altered resting-state neural oscillations and reduced subjective stress during social stress testing, without changing gut symptoms.

    View source

    A randomized double-blind, placebo-controlled trial to evaluate the safety and efficacy of live Bifidobacterium longum CECT 7347 (ES1) and heat-treated Bifidobacterium longum CECT 7347 (HT-ES1) in participants with diarrhea-predominant irritable bowel syndrome

    Score: 8/10
    2024
    rct
    n=200

    Srivastava S, Basak U, Naghibi M +2 more

    The decrease in mean IBS-SSS score from baseline to Day 84 was: ES1 (-173.70) vs placebo (-60.44) (p < .0001).

    View source

    Bifidobacterium and Lactobacillus Probiotics and Gut Dysbiosis in Preterm Infants: The PRIMAL Randomized Clinical Trial

    Score: 8/10
    2024
    rct
    n=618

    Van Rossum T, Haiss A, Knoll RL +2 more

    Probiotics did not prevent colonization with multidrug-resistant organisms or highly epidemic bacteria at day 30 of life.

    View source

    Usefulness of Bifidobacterium longum BB536 in Elderly Individuals With Chronic Constipation: A Randomized Controlled Trial

    Score: 7/10
    2023
    rct
    n=80

    Takeda T, Asaoka D, Nojiri S +2 more

    The primary end point was not significant (P = 0.074), although there was significant improvement (P < 0.01) in the BB536 group from baseline to week 4.

    View source

    Psychobiotic Effects on Anxiety Are Modulated by Lifestyle Behaviors: A Randomized Placebo-Controlled Trial on Healthy Adults

    Score: 7/10
    2023
    rct
    n=135

    Morales-Torres R, Carrasco-Gubernatis C, Grasso-Cladera A +2 more

    Results showed no significant effects of probiotic intake in whole sample outcomes.

    View source

    Effect of Postbiotic Bifidobacterium longum CECT 7347 on Gastrointestinal Symptoms, Serum Biochemistry, and Intestinal Microbiota in Healthy Adults: A Randomised, Placebo-Controlled Pilot Study

    Score: 6/10
    2024
    rct
    n=60

    Naghibi M, Pont-Beltran A, Lamelas A +2 more

    While minimal changes were observed in gastrointestinal (GI) symptoms, the HT-ES1 group showed a significant decrease in total and non-HDL cholesterol compared to the placebo.

    View source

    The Potential Immunomodulatory Effect of Bifidobacterium longum subsp. longum BB536 on Healthy Adults through Plasmacytoid Dendritic Cell Activation

    Score: 6/10
    2023
    rct
    n=97

    Li Y, Arai S, Kato K +2 more

    Compared to placebo (n = 48), a significant increase in the expression of CD86 on peripheral pDCs was detected at week 4 of live BB536 intake.

    View source

    Early Probiotic Supplementation of Healthy Term Infants with Bifidobacterium longum subsp. infantis M-63 Is Safe and Leads to the Development of Bifidobacterium-Predominant Gut Microbiota

    Score: 6/10
    2023
    rct
    n=110

    Hiraku A, Nakata S, Murata M +2 more

    Supplementation with B. infantis M-63 significantly increased the relative abundance of Bifidobacterium compared with the placebo group.

    View source

    Probiotic Supplementation Improves Cognitive Function and Mood with Changes in Gut Microbiota in Community-Dwelling Older Adults

    Score: 6/10
    2021
    rct

    Sixty-three healthy elders consumed either placebo or probiotics containing Bifidobacterium bifidum BGN4 and Bifidobacterium longum BORI for 12 weeks.

    View source

    Safety Information

    Potential Side Effects

    Transient gas, bloating, or stool changes during the first one to two weeks.

    Contraindications

    Caution in severe immunosuppression, short bowel syndrome, or with indwelling central lines.

    Drug Interactions

    • Antibiotics (separate doses by 2-3 hours)
    • Immunosuppressants

    Pregnancy & Breastfeeding

    Pregnancy: likely_safe

    Breastfeeding: likely_safe

    Dosage Guidelines

    Dosage Used in Studies

    Consult healthcare provider

    Best Time to Take

    With breakfast or the evening meal

    Best Form

    Enteric-coated or acid-protected capsule, strain identified on the label

    Bioavailability

    Acid-sensitive. Survival depends heavily on enteric protection and dosing with food.

    Food & Timing

    With or shortly after a meal; food buffers stomach acid and improves survival of vegetative probiotics.

    Medical Disclaimer

    The information provided on this website is for educational and informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any supplement regimen.

    Individual results may vary. The statements on this website have not been evaluated by the Food and Drug Administration. Products and information are not intended to diagnose, treat, cure, or prevent any disease.