Prebiotics, probiotics or postbiotics?

Inside our digestive tract live billions of microorganisms (particularly bacteria) that make up the so-called intestinal microbiota .

This population of “friendly microbes” is essential for the well-being of our intestines and, more generally, of our body . In fact , when the intestinal microbiota is in a state of disequilibrium ( dysbiosis ) it opens the way to various pathologies , which can affect not only the digestive tract but also other organs .

A specific microbiota is also present in the mouth , called the oral microbiota . When the oral microbiota is in optimal condition (eubiosis), it helps to protect the oral mucosa and upper respiratory tract , and tooth enamel .

Fortunately, there are some substances that can help keep the intestinal and oral microbiota healthy, and restore their balance in case of alterations. Among these, we find prebiotics , probiotics and postbiotics .

Prebiotics

Prebiotics are non-digestible dietary fibers capable of promoting the growth of the “good” bacteria of the intestinal microbiota.

Among the foods rich in prebiotics we find some vegetables (such as chicory, artichokes, asparagus, leeks, garlic and onions), cereals (wheat, oats and barley), soy and honey . 

In addition to diet, prebiotics can also be introduced by taking supplements . These preparations contain substances belonging to the group of carbohydrates (i.e. sugars), capable of promoting the fermentation of intestinal bacteria. This group includes inulin , FOS ( fructo-oligosaccharides), GOS (galacto-oligosaccharides) and lactulose .

Probiotics

According to the definition of FAO and WHO, probiotics are ” live microorganisms which, when administered in adequate quantities, exert a  beneficial effect on the health  of the host”.

According to the Italian Ministry of Health, in accordance with the provisions of the EFSA, they are instead ” microorganisms capable of favoring the balance of the intestinal microflora “, while other more specific beneficial effects on individual aspects of health must be demonstrated for each specific probiotic.

The main food sources of probiotics are represented by some milk derivatives, such as yoghurt : for this reason, these microorganisms are often referred to with the generic term “lactic ferments” . As we will see later, however, this denomination is not always correct.

In addition, probiotics can also be taken through specific commercially available supplements , offered in various forms (drops, tablets or sachets).

Some probiotics, such as Streptococcus salivarius K12 , have the ability to modify the oral microbiota and reduce disorders and diseases of the mouth (such as caries, abscesses, gingivitis or halitosis) and of the respiratory tract (such as pharyngitis, tonsillitis, sinusitis and otitis).

Postbiotics

The term postbiotics defines a group of products of bacterial origin , derived from the fermentation of certain foods, which have an effect similar to that of probiotics .

Postbiotics are present in the fermented matrices of many foods undergoing the fermentation process (such as yogurt, kefir, miso, sourdough bread and sauerkraut).

What is the difference between probiotics and lactic ferments?

The generic term “lactic ferments” refers to a group of bacteria capable of metabolizing lactose (a sugar found mainly in milk and some of its derivatives). These bacteria are mainly used industrially, for the fermentation of milk and the production of yoghurt .

Although probiotics actually belong to the class of lactic ferments, being able to digest lactose, it is important to underline that not all lactic ferments are probiotics . Some of them, in fact, do not have the ability to pass through the gastric juices unscathed and to maintain their vitality: therefore, they have no beneficial effect on the intestinal microbiota .