Today’s increasing demand for aquaculture production is accompanied by various challenges such as diseases, broodstock improvement, domestication, development of suitable pellets and feeding methods, hatchery technology, and water quality management. Thus, probiotic usage has been reported as the ideal alternative to antibiotics, other chemotherapeutics, and additional supplements to other alternative ingredients. The main beneficial roles of probiotics include the enhancement of disease and stress resistance, immunity, promotion of growth and reproduction, improvement of digestion, provide several nutrients, and enhancement of water microbial composition. To guarantee safety, the probiotics provided must be non-invasive and non-pathogenic. The use of probiotics in aquaculture, either directly or in combination with alternative materials such as plant protein diets, vitamins, microalgae, fermented products, and so on, has been shown to improve the health and growth of aquatic animals and offer significant benefits to the sustainability of the industry. There is advocacy for a systematic approach to conducting innovative research to unearth new putative strains, which is substantial in ensuring sustainable probiotic usage and, thus, can help in the continuous development of the aquaculture industry especially in China. Some examples of the probiotics found in China are mainly photosynthetic bacteria (PSB) which are autotroph bacteria capable of photosynthesis, antagonistic bacteria (Pseudoalteromonas sp., Flavobacterium sp., Alteromonas sp., Phaeobacter sp., Bacillus sp., etc.), bacteria that contribute nutrients and enzymes during digestion (lactic acid bacteria, yeasts, etc.), bacteria that improve water quality (nitrifying bacteria, denitrifying bacteria, etc.), Bdellovibrio, and other probiotics. This review also focuses on the potential use of probiotics in aquaculture, especially in China, and probiotics’ prospective future role.

This review delves into the increasing interest in probiotics and paraprobiotics as a viable alternative to antibiotics in aquaculture, highlighting their potential to enhance fish health and prevent diseases. As the aquaculture industry continues its global expansion, addressing the challenges associated with disease outbreaks in high-density fish populations becomes imperative. The review underscores the promising role of probiotics and paraprobiotics as a sustainable strategy to mitigate these challenges. The diverse positive impacts of various probiotic strains such as Arthrobacter, Bacillus, Lactobacillus, Bifidobacterium, Clostridium, and others emphasize their roles in enhancing growth, resistance to diseases (including bacterial, viral, and parasitic infections), stress reduction, water quality management, and environmental sustainability. Challenges such as stability, host specificity, and regulatory considerations must be addressed to optimize the use of probiotics in aquaculture. Additionally, paraprobiotics, or non-viable microbial cells, present a safer alternative to the criticized antibiotics and even live probiotics in environments where microbial viability poses a risk. These inactivated cells retain the ability to modulate the immune system and improve gut health, offering a promising complementary approach to fish disease prevention. The review advocates for a systematic approach combining research, innovation, and collaboration to effectively integrate probiotics and paraprobiotics into fish farming practices. Furthermore, the mechanisms by which probiotics and paraprobiotics modulate gut microbiota, produce antimicrobial compounds, and strengthen fish’s immune system have been elucidated. Moreover, the practical applications of probiotics in fish farming, including optimal administration methods and the challenges and limitations faced by the industry, have been discussed. Emphasis on the importance of continued research to explore new probiotic and paraprobiotic strains and develop innovative delivery systems to ensure the sustainability of aquaculture has been discussed. By enhancing fish health, reducing the need for antibiotics, and improving water quality, probiotics, and paraprobiotics contribute to more sustainable and environmentally responsible aquaculture operations.

The use of antibiotics and therapeutics for Nile tilapia has increased along with its increased production and intensification. Probiotics have been studied as an alternative to the excessive use of antibiotics in fish diets. Studies have demonstrated that dietary Bacillus probiotic inclusion promotes faster growth and disease resistance in farmed fish species. Despite advances in research, there is still uncertainty about the mechanisms controlling the immune response of fish. In this review, we summarize and discuss recent research on the immune responses of Nile tilapia to Bacillus probiotics. Through the use of immunological information including phagocytosis, lysozyme activity, respiratory activity, antioxidant proteins, complement activity, and immune-related gene expression, researchers hope to develop effective strategies for successfully using Bacillus probiotics in Oreochromis niloticus farming.

The issue of antimicrobial resistance in farm-raised fish presents a significant challenge for aquaculture operations. Long-term antibiotic treatment of fish for bacterial infections has led to bacteria thriving in the aquatic ecosystem and developing resistance to antibiotics. On the other hand, increasing research suggests that probiotics and prebiotics may be viable alternatives to antibiotics in regulating the immune system. Probiotics and prebiotics interact with fish metabolism in complex ways. These interactions offer promising alternatives to reduce antibiotic use in aquaculture. Introducing live microorganisms, known as probiotics, into an organism’s system can help improve overall health by altering the microflora and boosting immunity. Acting as immunostimulants, prebiotics directly impact the fish’s innate immune system. When used together, probiotics and prebiotics enhance immunomodulatory activity, providing numerous health benefits to aquatic animals. However, successfully replacing antibiotics with probiotics and prebiotics requires a deep understanding of metabolic pathways, optimization strategies, and innovative approaches. There has been a lack of extensive research on how probiotics and prebiotics impact lipid metabolism in various types of fish. This review aims to explore the intricate relationship between probiotics, prebiotics, and fish metabolism, with a specific focus on how these beneficial microorganisms and dietary fibers interact with fish antioxidant systems. We have also discussed the challenges faced by farmers when using probiotics and prebiotics. This review analyzes metabolic and antioxidant interactions mediated by probiotics and prebiotics in cultured fish species. It synthesizes findings on histological effects, enzymatic activity, and microbial interactions, with emphasis on lipid metabolism and immune modulation, and also discusses the practical implications for sustainable aquaculture.

As aquaculture takes on a major role in global seafood production, the industry has encountered several hurdles, notably in disease management and overharvesting in natural habitats challenges. Vaccination is a critical component of immunological preventive strategy essential for the health management of animals. Over the past two decades, vaccines have revolutionized the sector by addressing these issues while enhancing productivity and ecological balance. Advanced vaccine technologies, including DNA, recombinant, and inactivated vaccines, have demonstrated their potential to transform aquaculture and sea ranching. Innovations like the recombinant DNA vaccine for goldfish using the G protein expressed by baculovirus for spring viremia for carp and the ME-VAC Aqua Strept vaccine for tilapia highlight their ability to reduce antibiotic dependence and support greener practices. Multivalent vaccines in salmon farming further showcase their effectiveness in improving fish health and productivity. Emerging solutions such as plant-based and mucosal vaccines offer scalable, cost-effective options for immunizing large fish populations, reducing disease-related losses, and stabilizing seafood supply chains. Vaccines also improve the survival rates of hatchery-reared fish in natural habitats, supporting long-term sustainability. By integrating vaccination with selective breeding for disease resistance, aquaculture can achieve enhanced productivity and reduced environmental impact. The article highlights the impact vaccines can have on technology leap forward and research cooperation that will allow for collective mobilization to prevent aquatic disease. Not only that, this review also discusses the challenges and opportunities of using vaccines to increase fish resilience for surviving in open waters. Emphasis on the transformative role of vaccines in enabling technological advancements, fostering research collaborations, and addressing economic and environmental challenges to ensure a sustainable future for aquaculture and sea ranching have been highlighted as well. Future research directions and economic implications of widespread vaccine adoption in aquaculture are also discussed.