Symbiogenesis with thousands of different bacterial genes has decisively enriched the limited metabolic potential of eukaryotic organisms, accelerating and facilitating their adaptation much more than would have been achieved by random mutation alone. - Microbiologists Sorin Sonea and Léo G. Mathieu in Sandor Katz’s The Art of Fermentation, Quotes
Prebiotics
Class of nutrients that the gut microbiota break down.
When prebiotics are ingested, gastrointestinal bacteria ferment them and bioactive postbiotics are the byproducts of this fermentation process.
Probiotics
Live microbes that provide health benefits when ingested (in sufficiency), generally by improving or restoring the gut microflora.
Probiotics are products designed to deliver potentially beneficial bacterial cells to the microbiotic ecosystem of humans and other animals. Strains of lactic acid bacteria are the most common microbes employed as probiotics, especially Lactobacillus and Bifidobacterium species, but lactococci, some enterococci and some streptococci are also included as probiotics.
Of the more than 100 Lactobacillus species, the following are commonly used probiotics: L. acidophilus, L. fermentum, L. paracasei, L. brevis, L. gasseri, L. plantarum, L. bulgaricus, L. helveticus, L. reuteri, L. casei, L. jensenii, L. rhamnosus, L. crispatus, L. johnsonii, L. salivarius.
With the new taxonomy (Zheng et al., 2020) it’s easy to remember that most probiotic lactobacilli are derived from three genera: Lactobacillus, Ligilactobacillus and Limosilactobacillus.
Among the 30+ Bifidobacterium species, the following are recognized as probiotics: B. adolescentis., B. breve, B. longum, B. animalis, B. infantis, B. thermophilum, B. bifidum
B. lactis
Postbiotics
Metabolites of probiotics.
Non-viable bacterial products or metabolic by-products produced by probiotic microorganisms. Low molecular weight soluble compounds, either secreted by the host or released after cell lysis. E.g. short-chain fatty acids (SCFA), microbial cell fragements, exopolysaccharides (EPS), teichoic acid, vitamins (K, B12, folate), enzymes, etc.
The health-improving properties or aspects of postbiotics and their bioactivities, are still unknown or unclear.
Thorakkattu et al., 2022. Postbiotics: Current Trends in Food and Pharmaceutical Industry
https://www.mdpi.com/2304-8158/11/19/3094
Foods 2022, 11(19), 3094; https://doi.org/10.3390/foods11193094
SCFA: acetate, propionate, butyrate. Anti-inflammatory.
EPS: Produced by many lactic acid bacteria. Homo- or hetero-EPS. Wide range of structural variation and therefore (potentially) wide range of bioactivities: immunomodulatory, antitumor and antimutagenicity, antioxidant, anti-inflammatory, antihypertensive activity, antibacterial
and antiviral, cholesterol-lowering, and anti-gastrointestinal activity.
Cell wall fragments: Lipoteichoic acid and teichoic acid are primary constituents of the cell walls of Gram-positive bacteria. Immunostimulatory effect.
Analysis of postbiotics: GC, HPLC,