Probiotic supplementation affects IGF-1 and leptin levels in Nile tilapia hepatopancreatic tissue

R.S Pacheco,D.D Schleder,M.O Pereira,G.F.A Jesus,F Moreira,A Jatobá,Y.V Borges,P.H.S Ferro

doi:10.1590/1678-4162-12339

Abstract

ABSTRACT This work aimed to assess the effect of the probiotic strain, Lactobacillus plantarum, on the levels of leptin, IGF-1 and their receptors on the hepatopancreatic tissues of Nile tilapia (Oreochromis niloticus) and then correlate fish growth performance and gut microbiological parameters. Fish juveniles (±23g) were reared in a recirculation system with constant aeration and temperature (25°C). They were distributed into six polyethylene tanks (45L) and fed twice a day at 5% of the tank biomass with the respective diets: control (commercial diet without probiotic) and supplemented with L. plantarum inoculum (1 x 108 CFU mL-1), both in triplicate. After 30 days of feeding, L. plantarum-fed fishes showed greater weekly growth rate, final weight, and feed conversion rate, in addition to higher count of lactic-acid bacteria and lower count of pathogenic bacteria in the intestinal tract, when compared to the control group. The immunostaining intensity for IGF-1 and leptin hormones was lower after L. plantarum supplementation than in the control group, with no change in the level for receptors. This reduction could implicate important changes in fish metabolism and homeostasis.

Highlights

Nile tilapia (Oreochromis niloticus) is the third most cultivated fish species in the world, with 4.52 million tons produced in 2018, just behind the grass carp, Ctenopharyngodon idella (5.70 million tons), and silver carp, Hypophthalmichthys molitrix (4.79 million tons) (The State..., 2020)
Probiotics are related to the secretion of several hormones and signaling molecules such as neuropeptide Y (NPY), leptin, insulin, growth hormone (GH), and the cytokines TNF-a, IL6, and IL-1b (Bagarolli et al, 2017; Procaccini et al, 2017)
Tilapia juveniles fed the diet supplemented with probiotic bacteria had a better weekly weight gain, final weight, and feed conversion compared to the control group (p < 0.05)

Summary

Introduction

Nile tilapia (Oreochromis niloticus) is the third most cultivated fish species in the world, with 4.52 million tons produced in 2018, just behind the grass carp, Ctenopharyngodon idella (5.70 million tons), and silver carp, Hypophthalmichthys molitrix (4.79 million tons) (The State..., 2020). Tilapia farming suffers from the emergence and spread of diseases, especially parasitic and bacterial diseases (Jatobá et al, 2016; Arguedas et al, 2017). In this context, the use of the probiotic strain Lactobacillus plantarum has shown potential for application in tilapia farming. The use of the probiotic strain Lactobacillus plantarum has shown potential for application in tilapia farming This can be attributed to its high capacity to colonize the intestinal tract, inhibit pathogenic bacteria, and improve the nonspecific response of the tilapia immune system (Dotta et al, 2011; Jatobá et al, 2011). Probiotics are related to the secretion of several hormones and signaling molecules such as neuropeptide Y (NPY), leptin, insulin, growth hormone (GH), and the cytokines TNF-a, IL6, and IL-1b (Bagarolli et al, 2017; Procaccini et al, 2017)

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