POSTBIOTICS, innovation in animal nutrition

This article will try to answer the following questions: what are postbiotics, what are their advantages over other bioactive compounds, what are their mechanisms of action, and what are their benefits for production animals?


In animal production, the need to seek new strategies to reduce the use of antimicrobials has led to a great interest in the use of functional compounds. Prebiotics, probiotics and the combination of both, synbiotics, are very common products on the market and their use is widespread in the field of animal nutrition. However, postbiotics, the newest member of the family of bioactive compounds, called “-biotics”, is not yet well known.

Table 1 – Definitions of bioactive compounds mentioned and accepted by the current scientific community.



Postbiotics are bioactive metabolic products or by-products, secreted by live bacteria or released from bacterial cell membrane lysis, that can be used to improve host health (2, 3). This concept, by definition, is quite broad and is currently under revision (2, 4), as it may encompass some other terms that have other specific names, such as paraprobiotics. Paraprobiotics or “phantom probiotics” are inactivated microbial cells that confer a health benefit to the host when administered in adequate amounts (3). In this article, no distinction will be made between the two terms, considering that paraprobiotics are a specific type of postbiotics, despite the fact that there is no global consensus in the current scientific community (4).

Postbiotics are soluble factors released during fermentation or bacterial lysis and may include metabolites such as enzymes, peptides, proteins, exopolysaccharides, organic acids and lipids (short-chain fatty acids – SCFA); and structural components, mainly of the bacterial cell wall, such as teichoic and lipoteichoic acids, peptidoglycan, bacterial surface coat proteins and other polysaccharides (2,3).

Scientific studies published to date have mainly considered postbiotics of bacterial origin, especially those produced by species of the genus Lactobacillus, but there are also other bacterial and yeast species with the capacity to produce bioactive metabolites (3).



The process of elaboration of a postbiotic consists of the generation of bioactive compounds in a matrix during microbial fermentation, under a series of controlled conditions that are specific for each microorganism(2). After this process, a final product made from bioactive ingredients is obtained, which can be called a formula or functional feed (5). These functional ingredients manage to mimic and optimize the effects of probiotics without the need to administer live bacteria, which confers numerous advantages.

In the case of probiotics, for the product to be effective it is necessary for the live microorganisms to colonize the intestine, which is a great technological challenge. A number of factors have been described that could hinder this process and that are difficult to control, such as the host’s own microbiota characteristics, the consumption of antibiotics or other drugs, and interindividual differences related to the genetics of each subject(6). On the other hand, it is very difficult to know whether, once they reach their site of action, the necessary conditions exist for the probiotic microorganisms to produce the beneficial substances in the desired quantity. The great advance of postbiotics is that bioactive metabolites are produced under optimal conditions and delivered directly in controlled doses to their site of action without the need for microbial colonization (5).

Another major technological advantage is that the shelf life of postbiotics is longer and the storage and transport conditions of the final product are simplified (2,3,5). This is especially important when ideal conditions for probiotic preservation are not present, as might occur under field conditions.

Finally, the administration of postbiotics decreases the likelihood of adverse effects such as resistance gene transfer and bacteremia, which occur sporadically after probiotic administration, although serious complications are very rarely observed (3).



In general, postbiotics have local effects (microbiota modulator, antimicrobial and immunomodulatory) and derived systemic effects, which promote animal physiological processes and confer enormous health benefit to the host (2,3).

The modulation of the microbiota is carried out by signaling molecules that induce complex cellular communication systems (7). For example, extracellular vesicles (EVs) contain a great diversity of substances such as proteins, nucleic acids, phospholipids, glycolipids and polysaccharides, which interact with the host microbiota by transferring genetic material and proteins and participating in signaling processes (2). In this way, the composition of microbial populations is modified, creating a favorable balance between beneficial and potentially harmful species.

The antimicrobial activity of postbiotics is due to the presence of compounds that inhibit the growth of pathogenic microorganisms, especially Gram-positive and Gram-negative bacteria. These compounds are mainly small proteins and peptides, such as bacteriocins, and organic acids, such as lactate or acetate (2,3). Enzymes and other low molecular weight molecules with antimicrobial activity have also been described (3).

The interaction of bioactive metabolites produced by microorganisms with the host immune system is generating increasing interest in the scientific community. The immunomodulatory effect of postbiotics is related to their ability to induce or suppress the immune system and regulate the production of proinflammatory and anti-inflammatory cytokines (2,3,5). Some metabolites involved in this process are SCFA, such as acetate or propionate, which enhance intestinal barrier function, promoting mucosal immunity and have an effect on macrophage and dendritic cell differentiation (2). Several proteins and polysaccharides, such as lipopolysaccharide, have also been described with various effects on immune pathways and cytokine production (3,5).



Postbiotics are able to increase the productive performance and profitability of animals and improve health indicators, reducing the processes that cause high mortality and morbidity, especially during critical phases of production. Several studies in lambs, pigs and broilers have shown that the administration of postbiotics increases the average daily gain and final weight of the animals (8-11) and a study in laying hens found an improvement in egg production and quality (12).

The use of these supplements during the phases of higher nutritional requirements facilitates the digestibility and utilization of nutrients, favoring the production and absorption of substances that are essential to increase the growth rate of animals and the efficiency in the transformation of food (3,8,9). In addition, modulation of the intestinal microbiota increases beneficial populations of bacteria such as Lactobacillus and Bi-fidobacterium to the detriment of coliforms and other potentially pathogenic enterobacteria, including E. coli and Clostridium spp (3).

Undoubtedly, the great potential of postbiotics in animal nutrition lies in the reduction of the use of antimicrobials. This is achieved, on the one hand, because they are a novel alternative to the use of antibiotic growth promoters, which have been banned in the European Union since 2006. On the other hand, by boosting the immune system, livestock can cope more effectively with certain diseases, reducing the amount of antibiotics to be administered and, in some cases, avoiding their use (9).



INGULADOS has a collection of Lactic Acid Bacteria(BAL-INGULATES), isolated from the microbiota of animals in exceptional health, genetically characterized and selected for their immunomodulatory and antimicrobial properties. These strains are registered for restricted use in the Spanish Type Culture Collection and meet the requirements for inclusion in food products according to the Qualified Presumption of Safety (QPS) established by the European Food Safety Authority (EFSA).

INGULADOS markets a range of postbiotic products made from these strains and used in animals, improving parameters related to animal health and welfare.



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