Bifidobacterium Longum

Bifidobacterium Longum (Bifidobacterium longum) is a Gram-positive, non-spore-forming, anaerobic bacterium that represents one of the earliest and most significant colonizers of the human gastrointestinal tract. First isolated from the feces of a breast-fed infant by Henry Tissier in 1899, it has since become one of the most extensively researched “psychobiotics.” It plays a fundamental role in human health from infancy through adulthood, contributing to the fermentation of complex carbohydrates and the maintenance of the intestinal mucosal barrier.

Clinical Benefits & Mechanism of Action

Bifidobacterium longum functions through several complex physiological pathways, primarily involving the modulation of the gut-brain axis and the regulation of the systemic immune response:

1. Short-Chain Fatty Acid (SCFA) Production: B. longum ferments dietary fibers and oligosaccharides to produce acetate and lactate. These SCFAs support an optimal intestinal pH, promoting a favorable environment for beneficial flora, and serve as signaling molecules that maintain the integrity of the intestinal epithelial barrier.
2. HPA Axis Regulation: Specific strains, such as B. longum 1714, have been shown to modulate the hypothalamic-pituitary-adrenal (HPA) axis. By supporting balanced cortisol secretion, the bacterium helps manage the physiological impact of everyday stress.
3. Neurotransmitter Modulation: It influences the production and bioavailability of key neurotransmitters, including gamma-aminobutyric acid (GABA) and serotonin precursors, which are critical for emotional well-being and cognitive function.
4. Cytokine Balancing: B. longum promotes a balanced immune environment by supporting the production of Interleukin-10 (IL-10) and helping to maintain normal, healthy levels of cytokines such as TNF-α and IL-6, which are critical for systemic comfort and resilience.
5. Competitive Exclusion: It adheres to the intestinal epithelium, creating a physical presence that favors a healthy microbial balance and competes for essential nutrients, thereby stabilizing the microbiome.

Scientific Sources & Clinical Trials

• Assessing the Safety and Probiotic Potential of Bifidobacterium longum subsp. infantis BI45: A Comprehensive Study from Genomic Analysis to Randomized Controlled Clinical Trial in Healthy Adults.
• Effects of Live and Heat-Treated Bifidobacterium longum CECT 7347 in Adults With Allergic Rhinitis: A Randomised, Double-Blind, Placebo-Controlled Trial.
• Effects of Bifidobacterium longum 1714 on low mood and related symptoms: A randomized, double-blind, placebo-controlled trial.