Postbiotics
As the understanding of gut health evolves, postbiotics have emerged as a promising addition to promoting gut health. Unlike probiotics, which are live bacteria, or prebiotics, which are food for those bacteria, postbiotics are the beneficial byproducts of probiotic fermentation.
This article provides you with a comprehensive overview of postbiotics, and delves into what postbiotics are, their types, health benefits, and how you can incorporate them into your diet.
What are Postbiotics?
According to the International Scientific Association for Probiotics and Prebiotics (ISAPP), postbiotics are defined as a “preparation of inanimate microorganisms and/or their components that confers a health benefit to the host.” This means that live microorganisms have been intentionally inactivated, leaving behind the components that provide the benefit [1].
These components include:
- Short-chain fatty acids (SCFAs): these are produced through the fermentation of dietary fibers by gut bacteria. The most common SCFAs include butyrate, acetate, and propionate, which play a pivotal role in maintaining gut health, reducing inflammation, and supporting the gut barrier [2].
- Enzymes: enzymes such as peptidases, lipases, amylases, proteases, ureases, and antioxidants catalyze various biological processes. They aid in digestion and bioavailability by breaking down carbohydrates, fats, and proteins [3].
- Bacteriocins: a group of antimicrobial peptides produced by Gram-positive and Gram-negative bacteria with a broad spectrum of effects, including inhibition of the growth and development of gastrointestinal infections [4].
- Vitamins: including vitamins such as B and K, which play a crucial role in various physiological processes, such as bone health, brain function, and blood clotting [3].
- Exopolysaccharides (EPS): a group of substances produced during bacterial growth, and have biofunctional properties, such as antioxidant and immunomodulatory effects, regulation of intestinal microbiota, and impact on lipid metabolism by inhibiting cholesterol absorption [4].
- Bacterial lysates: these are fragments of bacterial cells that result from the breakdown of probiotics, and can stimulate the immune system, enhance gut barrier function, and have anti-inflammatory effects [2].
- Cell wall fragments: bacterial cell walls contain teichoic acids (WTA), lipoteichoic acids (LTA), and other compounds that have immunomodulatory effects [5].
- Cell-free supernatants: these are a broad category of residual biomolecular and active metabolites secreted by bacteria and yeasts, that have antibacterial, antibiofilm, anti-inflammatory, and antioxidant activities [5].
Health Benefits of Postbiotics
Research has uncovered numerous benefits associated with postbiotics:
1. Immune System Support: postbiotics significantly enhance immune function by promoting the differentiation of regulatory T cells (Tregs) to inhibit harmful bacteria and increasing the production of anti-inflammatory cytokines to help reduce inflammation and promote immune responses [2].
2. Improved Gut Barrier Function and Resident Microbiota Regulation: postbiotics contribute to the integrity and functionality of the gut barrier by helping in the modulation of immune, metabolic, and neuronal responses through the production of various compounds, including vitamins and metabolites from aromatic amino acids (AAA). In addition, they enhance gut health by inhibiting the growth and virulence of pathogens through the production of SCFAs, which bind to epithelial cells, preventing infections and reducing intestinal permeability [4].
3. Antioxidant Properties: postbiotics have potent antioxidant properties that protect against oxidative stress by neutralizing harmful reactive oxygen species (ROS). Key antioxidant enzymes include superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). These enzymes convert ROS into harmless molecules, preventing cellular damage and supporting overall health. By reducing oxidative damage, postbiotics help maintain cellular integrity and contribute to disease prevention [4].
4. Anti-inflammatory Properties: postbiotics can modulate inflammatory pathways by influencing the transcription of pro-inflammatory genes and the expression of related proteins. Key mechanisms include inhibiting NF-κB nuclear translocation, preventing IκB phosphorylation, and reducing proteasomal degradation [5].
How to Add Postbiotics into your Diet
Incorporating postbiotics into your diet can be achieved by focusing on foods rich in prebiotics and probiotics. Here’s how:
- Fermented foods and beverages: include kimchi, kefir, tempeh, yogurt, and kombucha, which are rich in beneficial bacteria and their metabolites.
- Prebiotic-rich foods: garlic, onions, bananas, apples, oats, beans, and lentils, are good sources to provide fibers that help produce more probiotics.
- Nuts and seeds: nuts and seeds are a combination of prebiotic fibers and phytonutrients that can be added to diets for a prebiotic effect boost.
- Raw Cheeses: opt for raw, unpasteurized cheeses, which contain beneficial bacteria and postbiotics.
These foods can significantly contribute to your postbiotic intake, supporting gut health and overall well-being. But for a guaranteed daily dose, consider supplements or fortified foods.
The Bottom Line
Postbiotics offer a unique beneficial addition to our gut, complementing the roles of probiotics and prebiotics. As the inanimate byproducts of probiotic fermentation, they encompass a wide range of beneficial compounds that work together to promote various health benefits. Incorporating postbiotics into your diet can be as simple as consuming a variety of fermented foods, prebiotic-rich foods, and specific dairy products like raw cheeses. While these dietary sources can provide substantial benefits, supplements or fortified foods can ensure a consistent and adequate intake of postbiotics.
References
- Salminen, Seppo et al. “The International Scientific Association of Probiotics and Prebiotics (ISAPP) consensus statement on the definition and scope of postbiotics.” Nature reviews. Gastroenterology & hepatology 18,9 (2021): 649-667. Available on: https://www.nature.com/articles/s41575-021-00440-6
- Żółkiewicz, Jakub et al. “Postbiotics-A Step Beyond Pre- and Probiotics.” Nutrients 12, 8 2189. Available on: https://www.mdpi.com/2072-6643/12/8/2189
- Hijová, Emília. “Postbiotics as Metabolites and Their Biotherapeutic Potential.” International journal of molecular sciences 25,10 5441. Available on: https://www.mdpi.com/1422-0067/25/10/5441
- Prajapati, Nidhi et al. “Postbiotic production: harnessing the power of microbial metabolites for health applications.” Frontiers in microbiology 14 1306192. Available on: https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1306192/full