Prebiotics, Probiotics and Postbiotics

Prebiotics are dietary components that confer health benefits on the host (4, 9). They’re carbohydrates that our stomach enzymes can’t hydrolyze. This means that they’re still intact when they reach the small intestine, where they’re fermented by gut bacteria (4, 9). This helps stimulate the growth and metabolism of beneficial bacteria (4, 9). Prebiotics are therefore considered a nutritional tool for modifying the gut microbiota (4).

Prebiotics are divided into groups such as fructo-oligosaccharides (FOSs), galacto-oligosaccharides (GOSs), gluco-oligosaccharides, inulin, and resistant starch (4, 9). Studies have shown that prebiotics have many positive effects on the microbiota, such as increasing beneficial bacteria and short-chain fatty acids (SCFAs) and maintaining intestinal barrier integrity (2, 5). For example, inulin and FOSs promote the growth of Bifidobacterium and Lactobacillus (3).

Food sources of prebiotics: beets, asparagus, garlic, onions, legumes, green bananas, whole grains, oats, potatoes, nuts, seeds, berries, coffee, tea

Scientists are also investigating the health effects of prebiotic supplements. These can influence appetite perception, energy homeostasis and SCFA production (4, 9). For example, studies show that inulin supplementation appears to affect hunger and satiety hormones—such as GLP-1 and ghrelin—and increase Akkermansia muciniphila (4, 9). Further studies are needed to confirm the benefits and determine the optimal duration and doses for supplementation.

Probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host (6, 7). The most common genera are Lactobacillus and Bifidobacterium (4, 6, 7). Probiotics can help balance the gut microbiota, modulate the immune response, maintain the intestinal barrier, compete with pathogens for adhesion sites, promote the production of SCFAs and neurotransmitter molecules, improve gastrointestinal symptoms, and boost mood (4, 6, 7).

Researchers have conducted trials to assess the effectiveness of probiotics in weight management, depression, and rheumatic diseases, among other things. However, it’s difficult to make recommendations due to the high degree of heterogeneity in the reported outcomes and the many factors that influence an individual’s response, such as diet and pre-existing microbiota (6, 7).

Probiotic bacteria are found in fermented foods such as yogurt, kefir, kimchi and miso. However, these foods don’t meet the clinical criteria for probiotics because their bacterial content isn’t standardized (1). It’s important to remember that not all bacteria are probiotics and that they need to reach the intestinal tract alive to be beneficial (6, 7).

Postbiotics are microbial metabolites—substances released by microbial metabolic activity—that directly or indirectly benefit the host (8, 10). The best-known postbiotics are SCFAs, including butyrate, acetate, propionate and pyruvate (8, 10). There are also muramyl dipeptides, long-chain polyphosphates, exopolysaccharides, and antioxidant enzymes such as glutathione peroxidase, superoxide dismutase, and catalase (8, 10). All of these postbiotics provide a range of benefits to the gut microbiota, including helping the immune system mature, soothing intestinal inflammation, and improving intestinal barrier function (8, 10). There could also be a two-way regulation and positive feedback action between postbiotics and the growth of related bacteria (8, 10). Current trials are mainly conducted in vivo, and more research on humans is needed (8, 10). The study of postbiotics shows that there’s still much to understand about the gut microbiota.

Prebiotics, probiotics and postbiotics play an important role in maintaining gut health. Incorporating prebiotic-rich foods into our daily diet can promote microbial balance, overall health, and postbiotic synthesis. It’s worth considering the clinical use of probiotic supplements depending on the cause and symptoms of the condition at hand.

Eating more fruits, vegetables, whole grains, polyphenols, and plant proteins is a good way to maintain these essential components of gut and overall health.