Tokyo-based ingredient supplier House Wellness Foods, the makers of a probiotic ingredient called Immuno-LP20, recently announced the results of a study which concluded that an aquaculture feed version of this probiotic, sourced from the strain Lactobacillus Plantarum, strain L-137, had immunological benefits against piscine disease factors when used in the setting of catfish aquaculture – specifically river farming of the juvenile striped catfish, which comprises 35% of Vietnam’s aquacultural activity.
 
“Vietnam’s story is one of many that expose the dual edge of farming to emerging populations,” the company said in the announcement. “It’s been the keystone of civilization’s advancement since the dawn of humankind, but where resources are limited and need is great, farming’s potential hazards become viciously clear. Overstocked waters turn hazardous to human life due to excessive waste production and a rise in bacteria, parasites, fungi, and viruses. Overstocked waters produce fish that are increasingly malnourished, enervated, injured, and unable to reproduce.”
 
The response in the aquacultural system has been to use antibiotics to keep weakened fish populations alive, however, disease-inducing microbes become resistant to these treatments, while antibiotics turn up in the food chain to an unpredictable, deleterious effect, the authors of the study said.
 
Researchers involved with the study fed test stocks a diet supplemented with Feed LP20, a heat-killed version of the probiotic strain. Heat treatment hardens bacillary cell walls and fixes their genetic material, the researchers said, which enables the bacteria to resist initial breakdown in the upper gastric system, and can be administered in an aquatic environment without compromising potency. The probiotic’s ability to stimulate immune cytokine interleukin 12, along with its long shelf life, are better than that of any living lactobacillus strain supplement, House Wellness Foods said.
 
According to the study authors, juvenile striped catfish fed HK-L137-supplemented diets exhibited higher final weight and specific growth rate than controlled stock given ordinary feed. The fish showed higher survival rate, longer lifespan, better feed conversion ratios, weight gain, better protein efficiency ratios, and increased reproductive capacity. Further, a test sub-group was administered a bacterial challenge mirroring a real-life scenario in Vietnamese river farms of their most devastating bacterial threat, bacillary necrosis disease, caused by the bacterial agent Edwardsiella ictalurid. Part of the test group was injected with this agent, and in every case the cumulative mortality of HK L-137-supplemented group was lower than the group fed control diet.
 
Immunobiotics, probiotics formulated to support immune health, do so by triggering immune responses in the mucosa. House Wellness Foods began working with immunobiotics and conducting research over three decades ago, resulting in the development of its flagship ingredient Immuno-LP20. The strain has been substantiated to initiate production of signal molecule IL-12 and IFN-B cells, which results in inhibiting viral multiplication, stimulate T cell activity and the production of NK and cytotoxic T effector cells, boost innate immunity, and foster antibody creation as an adjunct to the adaptive immune response, House Wellness Foods said. Following Immuno-LP20, the company developed Feed LP20 as an antibiotics alternative candidate, and an alternative to the costly, unreliable, and lengthy process of cultivating disease-resistant strains of livestock.
 
Prior to the present study, researchers have found the probiotic to be effective in aquaculture stocks of white leg shrimp and Nile tilapia as well, the company said – Feed LP20 is also being marketed in the EU as a complementary feed for poultry, swine, and salmon.