Synbiotics

Synbiotics are products that combine a probiotic microorganism or microorganisms with a prebiotic substrate designed to enhance the survival and activity of the probiotic and to selectively stimulate the growth or activity of beneficial gut microbiota. The term was introduced in 1995 by Gibson and Roberfroid to describe a unit designed to deliver synergistic effects through the combined action of both components.

Components and design approaches vary. Probiotics are live microorganisms with claimed health benefits when consumed in adequate amounts, while prebiotics are non-digestible substrates that are fermented by gut microbes. Synbiotics may be classified as synergistic, where the prebiotic component specifically nourishes and supports the co-delivered probiotic strain, or complementary, where the benefits arise from the combined but independent actions of the components. Common prebiotics include inulin, fructooligosaccharides (FOS), and galacto-oligosaccharides (GOS), often used with Lactobacillus and Bifidobacterium strains.

Evidence and use vary by product and condition. Some synbiotics have shown potential in reducing antibiotic-associated diarrhea, supporting gut barrier function, and modulating immune responses, but findings are often strain- and dose-dependent and not universally established. They are marketed in foods, supplements, and medical foods, with regulatory status and permitted health claims differing across jurisdictions. Safety is generally favorable for many populations, though gastrointestinal side effects such as gas and bloating can occur; caution is advised for immunocompromised individuals or those with severe illness where probiotic risk may be higher.