AUTHOR=Hoseinifar Seyed Hossein , Hoseini Seyyed Morteza , Taheri Mirghaed Ali , Ghelichpour Melika , Shirzad-Aski Hesamaddin , Van Doan Hien , El-Haroun Ehab , Safari Roghieh , Khanzadeh Majid TITLE=Comparison of the effects of host-associated (autochthonous) and commercial probiotics on immune responses, growth parameters and intestinal microbiota of Caspian whitefish (Rutilus frisii kutum) fry JOURNAL=Frontiers in Marine Science VOLUME=11 YEAR=2024 URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2024.1446927 DOI=10.3389/fmars.2024.1446927 ISSN=2296-7745 ABSTRACT=

Probiotics are helpful bacteria that safeguard host animals from harmful pathogens. In fish farming, the primary aim of using probiotics is to preserve or reestablish a balance between pathogenic microorganisms and the native bacteria that constitute the intestinal and skin microbial communities of fish. This study investigates the effects of host-associated probiotic (HAP) vs commercial probiotic (CP) on the growth performance, antioxidant defense and immunity of Caspian whitefish fry. Three hundred whitefish fry (1.15 ± 0.03 g) were randomly divided into five treatments in triplicate. Treatments included feeding with the control group (zero), P. acidilactici as a commercial probiotic (CP) at 6 × 108 CFU g -1, and HA Pediococcus pentosaceus at 106, 107 and 108 CFU g-1 for eight weeks. Dietary HAP and CP did not have significant effects on growth indices compared to the control group (P > 0.05). However, HAP at 107 and 108 CFU g-1 and CP significantly increased protein in whitefish carcasses compared to the control group (P < 0.05). Different levels of HAP and CP had a significant effect on whole-body extract (WBE) lysozyme (LZM) activity (P < 0.05). HAP treatment significantly increased WBE ACH50 and bactericidal activity compared to the control and CP group (P < 0.05). Also, in the case of mucosal immune response, different levels of HAP could significantly increase LZM, total immunoglobulin (Ig), agglutination titer, protease and alkaline phosphatase activity compared to the control group (P < 0.05). Whitefish fed HAP showed a significant increase in the activity of WBE antioxidant parameters (SOD, CAT and GPx) compared to the control group (P < 0.05). Also, feeding with HAP could significantly increase autochthonous LAB levels compared control group (P < 0.05); while the total count of intestinal heterotrophic bacteria was not affected (P > 0.05). Overall, the present study showed HA Pediococcus pentosaceus can be considered as beneficial feed additive for whitefish.