Probiotics and prebiotics — is there any difference?

Often, food advertisements have the following phrases: “enriched with probiotic” or “contains prebiotics.” These two words differ in only one letter, but is there any meaning behind this different spelling?

According to WHO definition probiotics are nonpathogenic to human bacteria that have antagonistic activity against pathogenic and opportunistic bacteria and restoring normal microflora.

It appears from the definition that probiotics cannot include disease-causing (pathogenic) microorganisms (MOs) (e.g., Yersenia pestis — the pathogen of bubonic plague).  The main role of probiotic MOs is to combat disease-causing MOs as well as those MOs that live in humans but may cause diseases under certain conditions. For example, part of the opportunistic MOs, when body's immune system becomes weak, colonizes the airway from the gastrointestinal tract (e.g., Pseudomonas sp., Candida).

Probiotic MOs include predominantly lactobacteria and bifidobacteria. Saccharomyces cerevisiae yeast and certain strains of E. coli may also serve this role.

When entered into the gut, probiotics begin actively multiply and attach themselves to the intestinal wall, providing a reliable barrier to penetration of disease-causing MOs, as well as controlling their growth and reproduction.

Probiotics are part of food products such as dairy products and may also have the status of a biologically active supplement or drug within the Russian Federation.

Prebiotics are substances (mostly composed of non-starch polysaccharides and oligosaccharides poorly digested by human enzymes), which is food for a specific group of intestinal microorganisms. Essentially, it's a food for “good” microorganisms, such as lactobacteria and bifidobacteria.

Unlike probiotics, most prebiotics are used as dietary additives — in biscuits, porridries, chocolate, pasty and dairy products.

The best-known prebiotics are:

• Oligofructose
• Inulin
• Galacto oligosaccharides
• Lactulose
• Breast milk oligosaccharides

In addition to probiotics and prebiotics, there are also synbiotics, which are a combination of pre- and probiotics.

It is worth noting that over the years there are growing doubts about the effectiveness of probiotics. Thus, when conducting an experiment with a cocktail of 11 probiotic crops, a team of Israeli scientists found that in half of the cases, beneficial bacteria entered the body with food immediately left it naturally. In the remaining cases, they lingered briefly in the body.

Because of this, so-called autoprobiotics are becoming increasingly popular. Autoprobiotics include selected MOs of the patient with proven positive functionality.