POSTBIOTIC: A NOVEL NON-AGP IN POULTRY
Nibedita Nayak*1, Smruti Smita Mohapatra2 and Amiya Ranjan Sahu1
1Scientist, ICAR- Central Coastal Agricultural Research Institute, Goa
2Research Fellow, Institute of Rural Management Anand (IRMA), Gujarat
*Email: drnibeditavet@gmail.com
Abstract
Poultry production in India has taken a quantum leap in the last four decades emerging from an unscientific farming practice to a strong agro-based commercial activity as a result of scientific and technological revolution. The total poultry population in our country is 851.81 million numbers with the egg and meat production of around 88.14 billion and 3.46 million tons respectively. The poultry industry is now considered as one of the fastest-growing subsectors of agriculture and veterinary fields due to the increased consumption of meat and egg, making these easily accessible, with a relatively low cost, and rich in most essential nutrients. Poultry has become one of the most widespread food industries worldwide. The size is expanding faster than any other food producing animal industry. Due to the advances in the fields of avian genetics, nutrition, health and management, the broiler production has become a more popular, easy and credible enterprise to the Indian farmers with the increasing demand for this cheap source of well-balanced animal protein. Postbiotic is an alternative and a new age non-antibiotic growth promoter (AGP) in poultry. Postbiotics also known as metabiotics, biogenics, or metabolites are soluble factors (metabolic products or byproducts), secreted by live bacteria or released after bacterial lysis providing physiological benefits to the host.
Keywords: Non-AGP, Postbiotics, Poultry
Introduction
Probiotics are beneficial bacteria that are able to colonize the digestive system of poultry, increasing the natural flora and preventing colonization of pathogenic organisms and thus, securing optimal utility of the feed. Despite their proven benefits, there are many concerns about their biosafety aspects in poultry, ease of microbial production, handling and storage, route of probiotic administration, stability, and survival of the probiotic in the host and tolerance for bile (Reque et al., 2003). Probiotics are living organisms, which eventually die but they secrete postbiotics as nutritive patrimony that continue to improve the health of the host. Thus, postbiotics refers to the metabolic byproducts like enzymes, peptides, teichoic acid, peptidoglycan derived muropeptides, exopolysaccharides, cell surface and secreted proteins, bacteriocins and organic acids generated by a probiotic organism during the final or intermediate stage of its metabolic process (Tsilingiri et al., 2012; Konstantinov et al., 2013). Postbiotics avoid risks linked with the administration of live microorganisms. They are believed to have probiotic effects without living cells. Contrary to probiotics, metabolites are relatively more stable in terms of handling and storage and are unlikely to transfer antimicrobial resistance traits to other bacteria (Loh et al., 2009). Postbiotics have advantage due to their clear chemical structure, safety dose parameters and longer shelf life which can influence the physiological function of host (Shenderov, 2013). Healthy postbiotics include nutrients such as vitamins B and K, amino acids, and antimicrobial peptides that help to slow down the growth of harmful bacteria. Other postbiotics such as short-chain fatty acids help healthy bacteria flourish. Bacterial lysates, cell-free supernatants from bacteria and yeast, cell wall fragments, enzymes, exopolysaccharides and lipopolysaccharide are various postbiotics.
Need for postbiotics
Increased growth rate, improved feed efficiency and prevention of subclinical diseases are the main reasons why dietary antibiotic growth promoters (AGP) have been practiced during the last 60 years in poultry production. However, their constant use, at low dosage, leads to development of resistance in bacteria and also leaves antibiotic residues in animal products (Collignon, 2003). Despite the face of remarkable progress, concerns have been raised with regards to the safety and quality of chicken products due to the panic of transferring these antibiotic-resistant bacteria to humans via food chain (Dibner and Buttin, 2002). The emergence of antibiotic resistant pathogens through the spread of antibiotic resistance genes is an ecological problem that is exacerbated by the widespread indiscriminate use of antibiotics in livestock agriculture, veterinary and in human medicine. As a result, there has been a global effort to limit the sub-therapeutic use of feed antibiotics such as in the European Union and in the United States (Casewell et al., 2003). Debates in India in context of use of antibiotics in poultry production has sought for withdrawal of antibiotics from poultry feeds and the need for alternatives that would influence improvement of healthy production traits of chickens and safety for human consuming poultry products. This situation, therefore, compelled researchers to investigate for other non-therapeutic alternatives to antibiotics and chemical growth promoters for poultry so that the ever-increasing growth of this industry remains unaffected. Postbiotics are the metabolites of probiotics, or the components that result from probiotic activity in the gut, like fermentation. As intestinal microbes consume prebiotic fiber, the result of that fermentation or consumption is postbiotics.
Diagrammatic mechanism of action
(Source: Nataraj et al., 2020)
Uses of postbiotics
In recent times, several feed additives have been attempted to replace the use of antibiotics as growth promoters and the most common of these additives include probiotics (Jin et al., 1997; Barrow, 1992; Mountzouris et al., 2007; Sugiharto, 2016). A recent study reveals that even probiotic bacteria have acquired resistance to antimicrobials that are commonly used in the human and animal health sciences (Shalini and Rameshwar, 2005). Given their shared microbial environment in the gastrointestinal tract, a risk of pathogenic microbes acquiring antibiotic resistance genes from probiotic microbes exists and vice versa (Mater et al., 2007; Gueimonde et al., 2013). The situation is further complicated by the fact that these acquired resistance traits can be transferred easily over species and genus borders by conjugative plasmids and transposons (Varankovich et al., 2015). If improperly cooked, livestock treated with probiotics that are consumed by humans as food may also pose as a possible source of antibiotic resistance genes for the human gut microbiota. As a consequence, probiotic as live bacteria might not be used anymore in the near future. Of late, the metabolite products synthesized from probiotics known as postbiotics have attracted attention to be applied in animal feed as growth promoter as a substitution to probiotics and in-feed antibiotics (Thanh et al., 2009; Loh et al., 2010; Kareem et al., 2017).
The evidence of beneficial effects of soluble secreted products synthesized by different probiotic strains are progressively increasing and in recent years there has been an upsurge in research oriented to provide a better understanding of their underlying mechanisms, even if their precise composition is still under investigation. In this regard, most available literature concerns Lacto bacilli. The metabolites produced from Lactic acid bacteria have been suggested as feed additives in animal feeding, showing beneficial probiotic effects on growth and gut health of animals (Loh et al., 2010; Kareem et al., 2016). One of the features of postbiotics is their ability to reduce pH value thereby inhibiting opportunistic pathogens in the feed and gut of animals. Postbiotics display wide inhibitory activity against various species of pathogens such as Clostridium perfringens, Salmonella enterica and Escherichia coli (Savadogo et al., 2006; Liasi et al., 2009). In spite of its immense scope as an alternative to probiotics and antibiotic growth promoters, there is dearth of information on the use of postbiotics in chicken. Dietary supplementation of a combination of inulin and postbiotics improved growth performance and feed efficiency in broiler chickens. This observation could be attributed to the organic acids, bacteriocins, hydrogen peroxide, and vitamins produced by the postbiotics and inulin that help to modulate gut health (Ibrahim and Desouky, 2009). Postbiotics produced by L. plantarum showed an inhibitory effect against various pathogens (Kareem et al., 2014).
Benefits of postbiotics in poultry industry
- Lowers blood sugar
A lack of intestinal microbe balance has been shown to contribute to insulin resistance. A postbiotic bacterial component called muramyl dipeptide, has been shown to relieve glucose intolerance by increasing insulin sensitivity. While more trials are still needed to fully understand the mechanism, it seems that this postbiotic plays an important role in fighting pre-diabetes and Type II diabetes.
- Supports probiotics
Probiotics and postbiotics work together to exhibit beneficial effects on birds’ health. Probiotics produce postbiotics which often produce the immunomodulatory effects that have been deemed beneficial for poultry health.
- Treats diarrohea
It has been long known that probiotic foods and supplements are effective in treating diarrohea. With a closer observation it is noted that the effect is not due to a direct interaction between the “good” bacteria and the intestinal lining, but rather to the metabolic products released by probiotics.
- Antimicrobial properties
One of the main functions of probiotics and postbiotics is to populate the gut with an ecosystem that favors the growth of good bacteria, thus not allowing the population of infectious bacteria. The “replacement effect” in coordination with the direct bacteria-fighting properties of postbiotics helps fight infection. They have anticarcinogenic qualities.
- Support immune system in birds
For birds with immunodeficiency (immune system deficiency or weakness), probiotics may not be tolerable or safe. Postbiotic compounds, however, are much more tolerable, and reduce problematic inflammation.
- Reduces inflammation
Postbiotics, when administrated, may protect against inflammation caused by some infections including Salmonella.
Conclusion
Antimicrobial resistance (AMR) is a widely acknowledged as one of the most important global public health threats. The main reason behind this hazard is the irrational and indiscriminate use of antimicrobial drugs in humans, livestock, and the poultry industry. Postbiotics have been shown to have many beneficial probiotic effects on growth performances and particularly in the gut health when used as an additive in animal diets. In spite of the roles of postbiotics on growth performance, intestinal microbial ecology, and cytokine expression in broiler chickens, there is a paucity of information on the possible synergistic effects of the combination of postbiotics and prebiotics on growth performance, gut microbiota, and cytokine expression in broiler chickens. Thus, it is emphasized to examine the influence of a combination of inulin and postbiotics on growth performance, cecal bacterial population, volatile fatty acids and ileal cytokine expression in broiler chickens. With a long shelf-life, postbiotics can be easily stored, transported and reliably produced on commercial basis. They are not as sensitive to cold temperatures. Postbiotics are much less widely known than both prebiotics and probiotics, but recent research suggest that they have an equally important role, if not more important, in maintaining and improving the health of poultry. Postbiotics are potential replacements for AGP in the poultry industry. Thus, postbiotics are likely to be the next up-and-coming health-boosting component in poultry diet and digestive processes.
https://www.pashudhanpraharee.com/probiotics-effect-on-poultry-and-pig/
https://veterinaryresearch.biomedcentral.com/articles/10.1186/s13567-017-0425-6
