What are the Uses of Probiotics in Aquaculture?
There was an increased risk of infectious diseases and losses for farmers when culture systems were strengthened to satisfy rising requirements. Because of the numerous problems associated with prophylactic antibiotic administration, rigorous laws have been enacted to prohibit or limit their use in aquaculture. Dietary administration of feed additives has gotten a lot of interest in the last three decades as an alternative to antibiotics. Aquaculture probiotics, prebiotics, synbiotics, and medicinal plants were among the most promising feed additions for bacterial, viral, and parasite illness management and therapy in fish and shellfish.
Lilly and Stillwell coined the term probiotics in 1965. The microbiological origin element that stimulates the growth of other organisms is known as a probiotic. Roy Fuller proposed the hypothesis that probiotics have a beneficial effect on the host in 1989. He described probiotics as live bacteria that, when given in sufficient proportions, promote the host’s health by improving the microbiota balance in the intestine.
Probiotics are “live microorganisms that impart a health benefit on the host when provided in suitable proportions,” according to the Food and Agriculture Organization/World Health Organization.
Its objective is to install, improve, or compensate for the functions of the indigenous microbiota that lives in the digestive tract or on the body’s surface.
The use of fermented foods for health advantages is not a new concept; it is also described in the Persian translation of the Old Testament.
A scientific approach that recognizes the beneficial role of certain microorganisms was applied in the first decades of the 20th century suggesting the use of Lactobacillus; Bifidobacterium; and Saccharomyces boulardii.
Probiotics have been found to be beneficial to human health in several clinical studies such as lactose intolerance, diarrhea, allergies, irritable bowel syndrome, and cancer, to name a few.
Animals’ production performance can be improved by using growth boosters. To increase the performance of chickens, pigs, and cattle, a wide range of antibiotic-like compounds, particularly penicillin and tetracycline, were initially utilized.
Antibiotics as feed additives provided significant benefits to animal husbandry, primarily in the form of increased weight gain and feed conversion.
Probiotics have been included in the diet of animals in order to preserve the balance of their intestinal flora, avoid digestive tract disorders, improve feed digestibility, boost nutrient utilization, and improve zootechnical performance.
Probiotics: Definition and History
Several types of beneficial feed additives, like probiotics, prebiotics, and synbiotics, are being employed in aquaculture to increase growth performance, immunological responses, and disease resistance, as well as serve as an antibiotic substitute. The term “probiotics” comes from the Greek words “pro” and “bios,” which both mean “for life,” and refers to microbial feed additives that confer host organisms through modulating the intestinal microbiota. The other half of the probiotics were identified as organisms and chemicals that influence bacteria in the intestine by the first researcher. Probiotics are live bacteria that are consumed orally and provide substantial health advantages to the host, according to the Food and Agriculture Organization (FAO) and the World Health Organization (WHO).
Probiotic organisms
The following are the requirements that a liquid probiotic organism must meet:
Resistance to acid, bile, and pancreatic enzymes;
Resistance to acid, bile, and pancreatic enzymes; Access to intestinal mucosa cells;
The ability to colonize;
Staying alive for an extended period of time during transport and storage in order to efficiently colonize the host;
Antimicrobial compounds are produced against harmful bacteria, and there is no transfer.
Non-pathogenic normal microflora such as lactic-acid bacteria (Bifidobacterium, Lactobacillus, Lactococcus, Streptococcus, and Enterococcus) and yeasts such as Saccharomyces spp. are commonly utilised as probiotics in animal nutrition.
Mechanisms of action
Although not entirely understood, the mechanisms of action of bacteria are employed as probiotics.
Competition for binding sites, also known as “competitive exclusion,” occurs when probiotic bacteria bind to binding sites in the intestinal mucosa, producing a physical barrier that prevents harmful bacteria from connecting.
Antibacterial substance production: probiotic bacteria produce antibacterial substances such as hydrogen peroxide and bacteriocins, which are mostly used against pathogenic bacteria. They also create organic acids that reduce the pH of the gastrointestinal tract’s environment, inhibiting pathogen growth and the development of certain Lactobacillus species.
Competition for nutrition: the scarcity of nutrients that pathogenic bacteria can consume is a limiting factor in their survival.
Immune system stimulation: certain probiotic bacteria are directly associated with immune response stimulation by enhancing antibody synthesis, macrophage activation, T-cell proliferation, and interferon production.
