Probiotici

Probiotici, or probiotics, are live microorganisms that, when consumed in adequate amounts, confer health benefits to the host. Most commonly used are bacteria from the genera Lactobacillus and Bifidobacterium, but certain yeasts such as Saccharomyces boulardii are also included. Probiotics occur naturally in fermented foods like yogurt, kefir, sauerkraut, and miso, and are also sold as dietary supplements. To be effective, they must survive manufacturing, storage, and passage through the stomach and small intestine, and many products specify the dose in colony forming units (CFU).

The effects of probiotics are strain-specific and not all products have the same evidence base. Mechanisms attributed to probiotics include reducing colonization by pathogens, strengthening the intestinal barrier, modulating the immune system, and producing beneficial metabolites such as short‑chain fatty acids. They may also influence the composition and activity of the gut microbiota and, in some cases, the gut-brain axis.

Evidence for clinical use varies by strain and condition. There is moderate support for reducing the risk of antibiotic-associated diarrhea and for some relief of symptoms in irritable bowel syndrome. Results are mixed for inflammatory bowel disease and other conditions. Probiotics are generally considered safe for healthy individuals, but rare infections can occur in severely immunocompromised people or those with certain medical devices. Quality and viability of products can vary, so consumers should consult healthcare professionals, especially in pregnancy, infancy, or illness.

In addition to probiotics, prebiotics are non-digestible fibers that feed beneficial bacteria, and synbiotics combine both approaches.