Bifidobacterium longum 1714 for Stress and Anxiety: A Focused Look at a Leading Psychobiotic

Psychobiotics and Mental Health (Supporting Article)

Headline topic: Bifidobacterium longum 1714 for stress and anxiety

Overview

Psychobiotics are probiotic strains that may influence mood, stress, and cognitive processes through the gut–brain axis. Among the most studied candidates is Bifidobacterium longum, particularly the 1714 and NCC3001 strains. This focused review examines what research suggests about these strains and stress- and anxiety-related outcomes, how they might work, and how traditional fermented foods fit into the bigger picture.

Key takeaways at a glance

• Human trials of B. longum 1714 in healthy adults report reduced perceived stress and brain activity changes consistent with calmer arousal states (Evidence: moderate; randomized controlled trial)
• In people with irritable bowel syndrome (IBS), B. longum NCC3001 reduced depressive symptoms and altered brain activity in regions linked to emotion (Evidence: strong for this population; randomized controlled trial)
• Meta-analyses of probiotics overall show small but significant benefits for depressive and anxiety symptoms, with strain-specific effects (Evidence: moderate; systematic reviews/meta-analyses)
• Mechanisms may involve vagus nerve signaling, immune modulation, and neurotransmitter/tryptophan pathways (Evidence: emerging; translational studies)
• Traditional fermented foods do not typically supply B. longum strains directly, but they may support gut-brain health and mood via microbial diversity and bioactive metabolites (Evidence: emerging/traditional)

What is Bifidobacterium longum 1714?

B. longum is a commensal gut bacterium broadly associated with human health. The 1714 strain has been investigated as a “psychobiotic” because preclinical and clinical studies suggest effects on stress reactivity and cognitive performance. Strains are not interchangeable; findings for one B. longum strain do not automatically apply to others (Evidence: strong consensus in microbiome science).

What do human trials show?

• Healthy adults under everyday stress: In a double-blind, randomized, placebo-controlled trial, healthy volunteers receiving B. longum 1714 for several weeks reported lower perceived daily stress and showed neurophysiological changes consistent with reduced arousal; aspects of memory performance also improved compared with placebo (Evidence: moderate; RCT) [Allen et al., 2016]. While promising, studies are few, sample sizes are modest, and replication is needed.

• IBS with comorbid mood symptoms: In a randomized controlled trial of adults with IBS, B. longum NCC3001 led to a clinically meaningful reduction in depressive symptoms compared with placebo and altered functional brain activity in limbic areas involved in emotion regulation (Evidence: strong for IBS-related mood symptoms; RCT) [Pinto-Sanchez et al., 2017]. Notably, improvements occurred without major changes in IBS severity for some participants, hinting at a direct gut–brain effect.

• Combination formulas: A formulation combining Bifidobacterium longum R0175 with Lactobacillus helveticus R0052 reduced psychological distress and lowered urinary free cortisol in healthy adults in randomized trials (Evidence: moderate; RCTs, combo product) [Messaoudi et al., 2011]. Because these are blends, it is difficult to attribute effects to one strain.

What do meta-analyses say about probiotics and mood?

Systematic reviews and meta-analyses pooling clinical trials of probiotics for depression and anxiety generally report small but statistically significant benefits versus placebo, with substantial heterogeneity and strain-dependent effects (Evidence: moderate; meta-analyses) [Ng et al., 2018; Wallace & Milev, 2017]. Bifidobacterium and Lactobacillus species feature prominently among the contributing strains, but authors consistently caution that results vary by strain, population, and outcome measure.

How might B. longum influence the gut–brain axis?

• Vagus nerve signaling: Animal work shows that certain Lactobacillus strains exert anxiolytic-like effects that disappear when the vagus nerve is severed, indicating a neural signaling route from gut to brain (Evidence: emerging; preclinical) [Bravo et al., 2011]. While this specific experiment used Lactobacillus rhamnosus JB-1, it illustrates a plausible mechanism that may also be relevant to Bifidobacterium strains.

• Immune and inflammatory tone: Probiotics can modulate cytokines and barrier integrity, potentially lowering peripheral inflammation that is linked to stress-related symptoms (Evidence: emerging; translational and human biomarker data) [Wastyk et al., 2021 (fermented foods reduce inflammatory markers)].

• Neurotransmitter and tryptophan pathways: Gut microbes influence GABA and serotonin pathways and the availability of tryptophan, a serotonin precursor (Evidence: emerging; mechanistic studies and reviews). Some Bifidobacterium species can impact kynurenine–tryptophan metabolism, which is implicated in mood regulation.

• Microbial metabolites: Short-chain fatty acids (SCFAs) such as butyrate may support blood–brain barrier integrity and microglial function, indirectly affecting stress responsiveness (Evidence: emerging; preclinical to early clinical translation).

Where do fermented foods fit in?

Traditional fermented foods—yogurt, kefir, kimchi, sauerkraut, miso, tempeh—do not typically contain B. longum 1714 or NCC3001 specifically. However, they introduce live microbes and bioactive metabolites that may shape the gut environment in ways that support endogenous Bifidobacterium and broader gut–brain communication (Evidence: emerging/traditional). Notable findings include:

• A randomized dietary intervention showed that increasing fermented foods for 10 weeks boosted microbiome diversity and reduced multiple inflammatory markers compared with a high-fiber diet (Evidence: strong for immune effects; RCT) [Wastyk et al., 2021]. Mood was not the primary outcome, but inflammation is closely linked to stress and depression biology.
• Observational research in young adults associated higher fermented food intake with fewer social anxiety symptoms, particularly among individuals with higher neuroticism (Evidence: emerging; observational) [Hilimire et al., 2015]. These data are correlational and cannot prove causation.

Taken together, traditional fermentation practices can be viewed as “proto-psychobiotic” strategies that may help maintain a gut ecosystem conducive to mental well-being, even if they do not deliver the exact strains studied in clinical psychobiotic trials.

Safety and practical considerations

• General safety: Probiotic use in healthy adults is generally well tolerated (Evidence: strong; post-marketing and clinical trial experience). Mild gastrointestinal symptoms may occur. Individuals with compromised immunity, critical illness, or central venous catheters should discuss probiotics with a clinician due to rare risks of infection (Evidence: strong; clinical guidance).
• Strain specificity: Benefits are strain- and condition-specific. Findings for B. longum 1714 or NCC3001 may not apply to other B. longum strains or to different populations (Evidence: strong; consensus).
• Not a stand-alone treatment: Research suggests psychobiotics may be adjunctive tools rather than replacements for established mental health care (Evidence: moderate; clinical reviews). People experiencing significant anxiety or depression should seek qualified care.

Bridging Western and Eastern perspectives

Western clinical research is beginning to validate aspects of traditional dietary wisdom: regular consumption of fermented foods—common in East Asian (kimchi, miso), Middle Eastern (labneh), and Eastern European (kefir, sauerkraut) cuisines—may support the gut ecosystem and, by extension, stress resilience. Psychobiotic trials with defined strains provide precision tools that complement the broader, food-based approach rooted in culinary traditions (Evidence: emerging to moderate, depending on outcome).

Bottom line

• Bifidobacterium longum 1714 shows early human evidence for reducing perceived stress and altering brain activity in healthy adults, while B. longum NCC3001 has stronger evidence for improving depressive symptoms in IBS alongside brain imaging changes.
• Meta-analyses indicate small, strain-dependent benefits of probiotics on depression and anxiety outcomes overall.
• Mechanisms likely involve gut–brain signaling via the vagus nerve, immune modulation, and microbial metabolites.
• Traditional fermented foods may not deliver these exact strains but can support a favorable gut environment tied to mental well-being.
• Psychobiotics may help as part of a broader lifestyle and clinical care plan; strain specificity and individual response matter.

Key studies cited

• Allen AP et al. Bifidobacterium longum 1714 as a psychobiotic in healthy volunteers: randomized, double-blind, placebo-controlled trial. 2016. (RCT)
• Pinto-Sanchez MI et al. Bifidobacterium longum NCC3001 reduces depression scores and alters brain activity in IBS. Gastroenterology. 2017. (RCT with fMRI)
• Messaoudi M et al. Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 reduce psychological distress. 2011. (RCT, combination)
• Ng QX et al. A meta-analysis of probiotics for depressive symptoms. Journal of Affective Disorders. 2018. (Meta-analysis)
• Wallace CJK & Milev R. The effects of probiotics on depressive symptoms: a systematic review. Ann Gen Psychiatry. 2017. (Systematic review)
• Bravo JA et al. Ingestion of Lactobacillus rhamnosus modulates GABA and reduces stress via the vagus nerve in mice. PNAS. 2011. (Preclinical)
• Wastyk HC et al. Gut-microbiota–targeted diets modulate human immune status. Cell. 2021. (RCT, fermented foods)