Effects of Pediococcus acidilactici on growth, blood physiology, health and gene expression in red tilapia.

PubMed: 41288812
DOI: 10.1186/s13568-025-01954-x

Study Design

Type: Clinical Trial
Sample size: n = 180
Population: 180 tilapia fingerlings (average weight 17.10 ± 0.46 g) red tilapia (Oreochromis niloticus × O. mossambicus)
Methods: Fish were distributed into four groups and fed a basal diet supplemented with 0 (PCA0), 1 (PCA1), 2 (PCA2), and 3 (PCA3) g of Pediococcus acidilactici per kg of diet for 63 days; then challenged with the bacterial pathogen Aeromonas hydrophila

Despite the widespread practice of using probiotics in aquaculture for their potential benefits, the consistency of their impact on disease resistance in fish is still being scrutinized. This study aimed to address this gap by investigating the influence of the probiotic Pediococcus acidilactici (PCA) on hematological indices, body composition, serum metabolites, water quality, growth metrics, the transcriptomic profile of genes related to immune function, and the ability of red tilapia (Oreochromis niloticus × O. mossambicus) to resist challenge with the bacterial pathogen Aeromonas hydrophila. A total of 180 tilapia fingerlings (average weight 17.10 ± 0.46 g) were distributed into four groups and fed a basal diet supplemented with 0 (PCA0), 1 (PCA1), 2 (PCA2), and 3 (PCA3) g of PCA per kg of diet for 63 days. Water quality analysis indicated a significant decrease in both salinity and dissolved oxygen concentrations in all PCA-supplemented groups compared to a PCA-free diet (P < 0.05). Fish fed diets having 2 or 3 PCA had superior FBW, SGR, and ADG, while these levels significantly improved the FCR compared to the untreated diet (P < 0.001). In fish supplemented with PCA, body composition analysis showed a statistically significant increase in protein and ash content, accompanied by a statistically significant decrease in lipid content (P < 0.05). Furthermore, dietary PCA significantly enhanced phagocytic index, and serum IgG and IgM levels in a dose-dependent response. Notable improvements in hematological variables and blood protein fractions were observed in the PCA2 and PCA3 groups compared to other groups (P < 0.05). Dietary PCA administration sustained liver enzymes and kidney functions (P < 0.05). Dietary supplementation with PCA resulted in a significant upregulation (P < 0.05) of growth-related genes (GH, IGF-1, and IGF1-R) and immunity-associated genes (CXC chemokine, IL8, and IL1β) in a dose-dependent manner. Furthermore, dietary PCA improved the histological structure of the liver and enhanced intestinal integrity in Tilapia. Following pathogen challenge, the survival rate was significantly higher in all PCA-supplemented groups compared to the control group, with the highest survival observed in the PCA3 group. In summary, this research highlights the significant benefits of dietary Pediococcus acidilactici supplementation at 2 and 3 g/kg for improving growth, blood physiology, immunity, and disease resistance in red tilapia. These findings underscore the potential of Pediococcus acidilactici as a practical and effective strategy for enhancing productivity and sustainability in red tilapia aquaculture.

Research Insights

Supplement	Dose	Health Outcome	Effect Type	Effect Size	Source
Pediococcus acidilactici	—	Enhanced Disease Resistance	Beneficial	Large	View source Following pathogen challenge, the survival rate was significantly higher in all PCA-supplemented groups compared to the control group, with the highest survival observed in the PCA3 group.
Pediococcus acidilactici	—	Improved Body Composition	Beneficial	Moderate	View source body composition analysis showed a statistically significant increase in protein and ash content, accompanied by a statistically significant decrease in lipid content (P<0.05).
Pediococcus acidilactici	—	Improved Growth Performance	Beneficial	Large	View source Fish fed diets having 2 or 3 PCA had superior FBW, SGR, and ADG, while these levels significantly improved the FCR compared to the untreated diet (P<0.001).
Pediococcus acidilactici	—	Improved Hematological Health	Beneficial	Moderate	View source Notable improvements in hematological variables and blood protein fractions were observed in the PCA2 and PCA3 groups compared to other groups (P<0.05).
Pediococcus acidilactici	—	Improved Immune Function	Beneficial	Large	View source Dietary PCA significantly enhanced phagocytic index, and serum IgG and IgM levels in a dose-dependent response.