Vivek Srivastava, Madhu C Lingaraju, Mohanapriya K, Thakur Uttam Singh, Kesavan MDivision of Pharmacology and Toxicology, Indian Veterinary Research Institute, Izatnagar
The term ‘Probiotics’ was first used by Lilly and Stillwell (1965) to designate unknown growth promoting substances produced by a ciliate protozoan that stimulated the growth of another ciliate. The joint Food and Agriculture Organization of the United Nations (FAO) and World Health Organization (WHO) Working Group defined Probiotics as “live micro-organisms which when administered in adequate amounts in diet confer a health benefit on the host”. Probiotics are living microbial feed supplements which beneficially affect the host by improving its intestinal microbial balance.
Development of Probiotics
A Russian scientist and Nobel laureate Eli Metchnikoff (1907), in the beginning of the 20th century, first noticed the beneficial role of certain bacteria and suggested that it would be possible to modulate the micro flora of GIT and to replace harmful microbes with useful microbes. Milk fermented by common types of bacteria, such as lactic acid bacteria inhibits the growth of proteolytic bacteria because of the low pH produced by the fermentation of lactose. Based on these facts, Metchnikoff proposed that consumption of fermented milk by lactic acid bacteria shows beneficial role of harmless lactic-acid bacteria and decrease the intestinal pH and that this would suppress the growth of proteolytic bacteria. Metchnikoff himself introduced in his diet sour milk fermented with the bacteria he called “Bulgarian Bacillus” and found this milk has beneficial for health.
There is an array of micro-organisms used as probiotics, which can be classified as follows.
- Bacterial vs Non-bacterial Probiotics.
- Spore forming vs Non-spore forming Probiotics.
- Multi-species (or multi-strain) probiotics vs Single-species (or single-strain) Probiotics.
- Allochthonous Probiotics vs Autochthonous Probiotics
Beneficial effects of Probiotics for farm animals-
- Greater resistance to infectious disease.
- Improved feed conversion
- Increased growth rate
- Improved digestion
- Improved milk yield & quality
- Increased egg production
Health benefits on consumption of Probiotics
(Begum PS, Madhavi G, Rajagopal S, Viswanath B, Razak MA, Venkataratnamma V. Probiotics as Functional Foods: Potential Effects on Human Health and its Impact on Neurological Diseases. Int J Nutr Pharmacol Neurol Dis 2017; 7:23-33.)
There is a significant rise in the adoption of Probiotics in animal feed for farm animals like swine, cattle, horse, ruminants, and poultry. Using probiotics in cattle feed has shown beneficial results in animal performance, digestion, and the immune system.When introduced to feed in an appropriate quantity, live probiotic microorganisms can show health benefits. Ruminants see numerous benefits when probiotics are included in feed during weaning and at the beginning of lactation.
Another example: yeast helps stabilize pH and reduce the risk of acidosis among ruminants. Today, yeast is commonly used among swine, poultry, and monogastric animals. Yeast-based probiotics target the animal’s colon, caecum, and other areas—a hideout for diverse microbial populations.
The shift towards antibiotic-free meat is also expected to be a major factor driving businesses to discover safe and reliable tools for farmers. However, not all probiotics reduce food borne diseases. The most commonly used bacteria used as Probiotics are Lactobacillus, Bacillus, Streptococcus, Pediococcus, Enterococcus & Bifidobacterium.
Selection of Probiotics
Not all strains of Lb. acidophilus, Bifidobacterium species and Lb. casei are suitable for use as probiotics. The following criteria have been used or suggested for use in strain selection: –
- Origin -Strain should have originated from the human GI-tract
- Safety- Strain should be non-pathogenic and it should also be sensitive to common antibiotics.
- Withstand host’s natural barriers – Essentially be able to survive transit through the GI tract and resistance to bile salts, low pH and proteases.
- Adherence to intestinal epithelium- The ability to adhere to intestinal cells and effectively block sites that could be occupied by pathogens.
- Commercial propagation- Strain must be able to grow in under commercial conditions and should retain viability under normal commercial storage conditions.
- Functional properties- The strain should meet the definition of a probiotic in clinical trials
Feed Probiotics Market
Global feed probiotics market is classified on the basis of bacteria, livestock and region. Based on the bacteria present diet of farm animal’s probiotics market is isolated into Lactobacillus, Bacillus, Streptococcus, Pediococcus, Enterococcus & Bifidobacterium .Of which, lactobacillus is the largest market as compared to other segments of probiotics market and is expected to exhibit significant growth during the forecast period. On the basis of livestock feed probiotics market includes cattle feed, swine feed, poultry feed and pet feed. Based on the region global feed probiotics market is isolated into North America, Latin America, Eastern Europe, Western Europe, Asia Pacific excluding Japan, Middle East and Africa and Japan.
Future Prospects of Probiotics
High demand of probiotic products from cattle farmers and the companion animal sectors are expected to increase the adoption of advanced probiotic technologies. Many companies are investing lot of amounts in research and development to discover entirely new probiotics products and applications. Nano-encapsulated probiotics are expected to create numerous opportunities for the industry in near future. Apart from Probiotics act as gut flora stabilizers, probiotics are expected to be utilized for more applications in animals, including for increased immunity and reduced stress levels. Probiotics will also continue to be used to improve the quality & quantity of Milk, eggs, meat etc. And, overall, the microorganisms used in probiotics are approved for animal nutrition and do not constitute a major hazard for animal health. They do not affect metabolic processes of animals as they are not transferred from intestines to other body parts.
Conclusion The improvements in productive performance of all livestock animals are fed with probiotics were mostly due to the fact that probiotics promote the metabolic processes of digestion, and nutrient utilization. Experimental studies have shown that probiotic dietary supplementation can change the microbial population dynamics in the GIT eventually creating a more favourable microbial population due to a shift in the balance of beneficial and harmful microbes. It is believed that the improvement in metabolic processes that were observed as a result of probiotic supplementation were due to modification of micro flora of GIT and to replace harmful microbes with useful microbes. The reduction of pathogenic microorganism in gut is due to production of anti microbial substances like bacteriocin & adhesion of healthy, or probiotic microbes to intestinal epithelium. Healthy micro flora of GIT enhances process of digestion, improved immunity & animal performance.