Protective Effects of Lactobacillus curvatus Against Acute Lead and Cadmium Toxicity in Caspian Kutum (Rutilus frisii, Nordmann, 1840): Growth Performance, Chemical Composition, Hematological Characteristics, Serum Biochemical Parameters, and Immune Response.

2025-07-04
Biological trace element research 204(1)

PubMed: 40615769
DOI: 10.1007/s12011-025-04677-z

Study Design

Type: Clinical Trial
Population: Caspian Kutum (Rutilus frisii) fingerlings
Methods: Fish with an average initial weight of 8.05 ± 1.58 g were allocated to 40-L polyethylene tanks, with six fish per tank, and divided into six treatment groups: a control group, a Lactobacillus curvatus only group (10^8 CFU/g), a Pb exposure group (12 mg/L), a Cd exposure group (4 mg/L), a Pb + Lactobacillus curvatus group, and a Cadmium + Lactobacillus curvatus group; each treatment was conducted in triplicate and fish were fed three times daily at 6% of body weight

Animal Study

In this study, we explored the efficacy of the probiotic Lactobacillus curvatus in growth performance, chemical composition, hematological characteristics, serum biochemical parameters, and immune response of Caspian Kutum (Rutilus frisii) under HMs stress. Fish with an average initial weight of 8.05 ± 1.58 g were allocated to 40-L polyethylene tanks, with six fish per tank. These fish were divided into six treatment groups: a control group, a Lactobacillus curvatus only group (10⁸ CFU/g), a Pb exposure group (12 mg/L), a Cd exposure group (4 mg/L), a Pb + Lactobacillus curvatus group (10⁸ CFU/g with Pb), and a Cadmium + Lactobacillus curvatus group (10⁸ CFU/g with Cadmium). Each treatment was conducted in triplicate, with the fish being fed three times daily at 6% of their body weight over. The outcomes demonstrated that growth indices in fish treated with probiotic strain had a considerable enhancement compared with the control treatment (p < 0.05). The addition of 3 g of probiotics to the diet caused a remarkable growth in white blood cells, neutrophils, a reduction in lysozyme and complement, which showed a significant difference compared with the control treatment. In general, probiotic Lactobacillus curvatus have a considerable effect on the growth, blood, and immunity, and it plays an effective role in reducing injuries caused by lead and cadmium poisoning of Caspian Sea fish fingerlings (Rutilus frisii). The administration of Lactobacillus curvatus resulted in significant improvements in growth parameters compared to the control group (p < 0.05). Lactobacillus curvatus treatment Pb to a substantial increase in white blood cells and neutrophils, along with a reduction in lysozyme and complement levels, indicating an enhanced immune response. Moreover, Lactobacillus curvatus effectively mitigated the adverse effects of Pb and Cd exposure, underscoring its potential as a protective agent against heavy metal toxicity in Caspian kutum.

Research Insights

Supplement	Dose	Health Outcome	Effect Type	Effect Size	Source
Lactobacillus curvatus	—	Improved Growth Performance	Beneficial	Moderate	View source The outcomes demonstrated that growth indices in fish treated with probiotic strain had a considerable enhancement compared with the control treatment (p < 0.05).
Lactobacillus curvatus	—	Improved Hematological Parameters	Beneficial	Moderate	View source The addition of 3 g of probiotics to the diet caused a remarkable growth in white blood cells, neutrophils... compared with the control treatment.
Lactobacillus curvatus	—	Improved Immune Response	Beneficial	Moderate	View source Lactobacillus curvatus treatment Pb to a substantial increase in white blood cells and neutrophils, along with a reduction in lysozyme and complement levels, indicating an enhanced immune response.
Lactobacillus curvatus	—	Reduced Toxicity	Beneficial	Moderate	View source Lactobacillus curvatus effectively mitigated the adverse effects of Pb and Cd exposure, underscoring its potential as a protective agent against heavy metal toxicity in Caspian kutum.