Probiotics
Digestive Health
Overview
- Probiotics are live microorganisms, mainly bacteria from the Lactobacillus and Bifidobacterium genera and the yeast Saccharomyces boulardii.
- When ingested in adequate amounts, they confer health benefits.
- Their primary function is modulating the gut microbiota, influencing digestion, immune function, and metabolic pathways.
Chemistry
- Probiotics are living microbial cells, lacking a single molecular formula or IUPAC name.
- Chemical architecture:
- Cell wall: Gram-positive bacteria have a thick peptidoglycan layer (N-acetyl-glucosamine-N-acetyl-muramic acid polymer) cross-linked by peptide bridges; Gram-negative strains have an outer lipopolysaccharide (LPS) layer.
- Surface proteins: Adhesion proteins (MUB, pili), teichoic acids (poly-glycerol-phosphate), and lipoteichoic acids contribute to host-cell interaction.
- Metabolites: Short-chain fatty acids (C2–C4), bacteriocins (proteinaceous antimicrobial peptides), and exopolysaccharides are produced during fermentation. These macromolecules are responsible for the functional effects.
- CFU (colony-forming unit) quantifies viable cells.
Sources & Quality
- Commercial probiotic strains are isolated from diverse sources:
- Human gastrointestinal tract: (e.g., L. acidophilus from infant feces).
- Fermented foods: (yogurt, kefir, kimchi, sauerkraut) yielding Lactobacillus spp.
- Environmental sources: (soil, fermented vegetables) for Bifidobacterium spp.
- Yeast: (S. boulardii) from tropical fruit fermentations.
- Isolation involves anaerobic culture, 16S rRNA sequencing for strain identification, and verification of functional traits (acid tolerance, bile resistance).
- Manufacturing: Freeze-drying (lyophilization) or micro-encapsulation preserves viability; final products must meet ≥90% viability at end-of-shelf-life.
- Quality control: Includes strain-specific genetic confirmation, absence of pathogenic genes (e.g., antibiotic-resistance markers), and compliance with GMP and USP <1021> microbial limits. High-quality supplements list the exact strain, CFU count, and storage conditions.
Where to Buy Probiotics
Affiliate Disclosure: We earn a commission if you purchase through these links at no additional cost to you. This helps us maintain our research and provides you with the best supplement information.