This review systematically summarizes the core mechanisms by which probiotics modulate meat quality, feed efficiency and small intestinal and cecal health in pigs and broilers via the gut–muscle axis, nutrient metabolic axis, and immune regulatory axis and elucidates the heritable effects of host genetics on shaping the gut microbiome.
Abstract
As an eco-friendly strategy for improving intestinal health, production performance, and meat quality in livestock and poultry, live probiotic strains (Lactobacillus, Bifidobacterium, Bacillus), paraprobiotics and postbiotics have exhibited considerable application potential in monogastric livestock in animal husbandry. However, probiotic efficacy is commonly characterized by striking individual heterogeneity, and its intrinsic regulatory basis remains poorly understood. This review systematically summarizes the core mechanisms by which probiotics modulate meat quality, feed efficiency and small intestinal and cecal health in pigs and broilers via the gut–muscle axis, nutrient metabolic axis, and immune regulatory axis. We elucidate the heritable effects of host genetics on shaping the gut microbiome and the fundamental principles underlying genotype–probiotic (G×P) interactions, highlighting that host genetic background represents an important of differential responses to probiotics. Accordingly, we propose integrating microbial genome-wide association studies (mGWAS) and genomic selection to develop novel breeding programs targeting probiotic responsiveness, with the aim of establishing a precision breeding system for probiotic-friendly livestock and poultry. This review may facilitate the paradigm shift of probiotic applications from universal administration to precision intervention, and from single nutritional regulation to host–microbiome synergistic breeding, providing a conceptual framework and innovative strategies for the green, efficient, and sustainable development of animal husbandry.
The pursuit of sustainable and efficient animal production systems has intensified global interest in microbiota-targeted nutritional strategies. This review synthesizes current research on prebiotics and probiotics, selectively utilized microbial substrates and beneficial live microorganisms, respectively, that confer health benefits, across major livestock and aquaculture sectors, including poultry, swine, ruminants, fish, and shrimp. It examines the fundamental role of host-specific gut microbiomes in regulating health and productivity and elucidates how prebiotics, alone or in synergistic formulations with probiotics, modulate these microbial communities. Mechanisms of action involve enhanced nutrient digestibility, improved intestinal morphology and barrier integrity, selective stimulation of beneficial bacteria (e.g., Lactobacillus, Bifidobacterium), suppression of pathogens (e.g., Escherichia coli, Salmonella, Vibrio), and potentiation of innate and humoral immune responses. Consistent evidence demonstrates that microbiota-targeted interventions improve key zootechnical indicators, including weight gain, feed conversion ratio, and carcass quality, while enhancing animal welfare and resilience to environmental and physiological stressors. A pivotal finding is their ability to reduce reliance on antimicrobial agents, addressing antibiotic resistance and aligning with consumer demand for ethical and natural production systems. Furthermore, this review highlights the valorisation of agro-industrial by-products (e.g., fruit pomace, cereal brans) and novel substrates such as Hermetia illucens (black soldier fly) as functional, cost-effective sources that embed animal nutrition within a circular bioeconomy framework. By integrating multidisciplinary findings from terrestrial and aquatic species, this review concludes that microbiota-based functional nutrition is indispensable for advancing next-generation sustainable animal production, uniting productivity, environmental stewardship, and animal welfare while supporting safe, ethical, and climate-resilient food systems worldwide. Probiotic and prebiotic integration in swine, poultry, cattle, and aquaculture systems. Supports animal health, feed efficiency, and sustainable by-product use, aligning with SDG 2 and SDG 12. Repurposing agro-industrial residues as novel prebiotics closes the resource loop, reinforcing the circular economy.
João Victor dos Anjos Almeida, Julia Memrava Cabrera, Mauro de Medeiros Oliveira et al.· Brazilian Journal of Microbi...· 1 citation
The human gut microbiota plays a critical role in regulating host health and disease, making it a key target for the development of targeted microbial therapies. This review focuses on designer probiotics and synbiotics, which are genetically engineered microorganisms used in combination with prebiotics to modulate the gut microbiota and support personalised health outcomes. Unlike conventional probiotics, these engineered strains are designed to perform specific metabolic or signalling functions, thereby enhancing colonisation efficiency and functional efficacy. The article summarises recent advancements in systems biology, synthetic biology, and omics technologies (including genomics, proteomics, and metabolomics) that facilitate the design and optimisation of next-generation microbial formulations. Their significance lies in enabling precision nutrition and the development of functional foods tailored to individual host requirements. This review also discusses strategies for microbial strain engineering, synbiotic formulation, and the application of high-throughput omics approaches to better understand host-microbe interactions. Furthermore, it highlights applications in managing gut-related disorders and improving food quality. While addressing challenges such as biosafety concerns, regulatory limitations, and environmental implications, the review emphasises the potential of designer probiotics and synbiotics as innovative tools for precision-guided health through dietary interventions. Overall, this emerging field provides a sustainable approach to advancing nutrition and microbiome-based therapies by bridging precision health with food science.
Nishi Patel, M. Hajoori· Exploration of Foods and Foo...· 0 citations
The search for effective antibiotic alternatives has intensified in broiler production as consumer expectations, regulatory pressures, and disease challenges continue to shape modern poultry systems. Bacillus-based probiotics have gained particular interest because their spore-forming ability ensures feed stability and survival through feed processing and gastrointestinal transit. This review consolidates current knowledge on how Bacillus probiotics influence gut ecology, physiology, and productivity in broilers, while also emphasizing their practical relevance in commercial settings. Evidence from controlled trials shows that well-characterized Bacillus strains act through multiple coordinated mechanisms, although their efficacy is highly strain-specific. These include modulation and stabilization of the intestinal microbiota, suppression of pathogenic bacteria via competition and antimicrobial metabolite production, enhancement of digestive efficiency through enzyme secretion, and stimulation of beneficial fermentation processes. These effects are often linked to improved villus structure, strengthened epithelial barrier function, and modulation of local and systemic immune responses. Improvements in growth performance and feed efficiency have been reported in numerous studies, particularly under disease challenge or environmental stress, although responses vary with probiotic strain, supplementation strategy, and production conditions. Additionally, these probiotics have shown protective effects during necrotic enteritis challenge, reducing lesion severity and pathogen load. However, results vary across studies, influenced by strain type, dose, diet, challenge status, and farm conditions. Proper strain selection, quality control, verification of spore viability, and safety assessment are essential for reliable commercial application. In summary, current evidence supports the use of well-characterized Bacillus-based probiotics as safe and biologically effective feed additives that promote gut health, improve production efficiency, and contribute to sustainable antibiotic-reduced broiler production. Their multifaceted activity profile fits well with antibiotic-free nutrition strategies, although further research is needed to clarify strain-specific actions and optimize application protocols.
M. Naeem, D. Bourassa· Probiotics and Antimicrobial...· 0 citations
Background and Aim: The widespread restriction of antibiotic growth promoters (AGPs) in poultry production has accelerated the search for sustainable nutritional strategies that enhance bird health while maintaining productivity. Among these alternatives, probiotics have emerged as promising functional feed additives because of their ability to modulate the gut–immune axis, improve intestinal homeostasis, and strengthen host defense mechanisms. This review provides a comprehensive synthesis of current evidence regarding the immunomodulatory mechanisms of probiotics and their potential as sustainable alternatives to AGPs in poultry production. Relevant peer-reviewed studies published between 2000 and 2025 were critically evaluated to summarize the effects of probiotic supplementation on gut microbiota composition, intestinal barrier integrity, innate and adaptive immune responses, disease resistance, and production performance. The review highlights the strain-specific actions of commonly used probiotic genera, including Lactobacillus, Bacillus, Bifidobacterium, Enterococcus, and Saccharomyces, emphasizing their roles in competitive exclusion of pathogens, production of antimicrobial metabolites, regulation of cytokine expression, enhancement of mucosal and systemic antibody responses, and maintenance of immune homeostasis. Emerging evidence on postbiotics, paraprobiotics, synbiotics, and precision nutritional approaches is also discussed as part of next-generation strategies for improving poultry health. Although numerous studies demonstrate beneficial effects of probiotics on intestinal morphology, immune function, vaccine responsiveness, oxidative stress, and resistance to enteric pathogens, considerable variability remains due to differences in probiotic strains, dosage, supplementation period, bird genotype, management practices, and experimental conditions. These inconsistencies highlight the need for standardized strain characterization, optimized administration protocols, and long-term commercial validation to improve reproducibility and field application. Overall, probiotics represent an effective and environmentally sustainable approach for supporting poultry health while reducing dependence on antibiotics. Continued advances in molecular biology, microbiome research, precision livestock farming, and artificial intelligence are expected to facilitate the development of targeted probiotic interventions that enhance disease resistance, improve production efficiency, promote animal welfare, and contribute to sustainable poultry production systems.
Keywords: antibiotic alternatives, disease resistance, gut health, immune modulation, microbiota, poultry, probiotics, sustainable production.
A. Yulianto, A. Khairullah, W. Lokapirnasari et al.· Veterinary World· 0 citations
Probiotics are live microorganisms, which when administered in adequate amounts confer a health benefit on the host. Over the past two decades, there has been tremendous progress in elucidating probiotic mechanisms and function owing to advances in microbiome science, molecular biology, and clinical research. This review summarises the current state of probiotic research across mechanisms of action, clinical preclinical studies and future perspectives. Probiotics confer their benefits through diverse mechanisms of action, including modification of gut microbiota and fecal metabolite profiles, improvement in intestinal permeability, production of antimicrobial agents and short chain fatty acids (SCFAs), competitive inhibition against pathogenic microorganisms colonisation from attaching to epithelial cells; signalling pathways that mediate innate immunity or adaptive immune responses . The most recent evidence also shows their involvement in gut–brain interaction, regulation of metabolism homeostasis and signaling pathways involved with inflammation.
That's why clinical studies have shown that certain strains of probiotics are effective for prevention and management of gastrointestinal diseases, including antibiotic-associated diarrhea, irritable bowel syndrome (IBS), inflammatory bowel disease (IBD) as well as Clostridioides difficile infection. Apart from gastrointestinal health, probiotics have demonstrated favorable effects in metabolic disorders and allergies using microbiome-based mechanisms as well. Nevertheless, the applicability of probiotics to human medicine is extremely strain-specific and greatly influenced by dosage, duration of treatment and host factors such as genetics diet age comorbidities or microbiome composition. Despite the wealth of research publications on prostate cancer screening, variability in clinical trial design requirements and evolving regulatory guidelines have constrained broad application or enforcement across large populations as well as limited access to long-term safety data.
Recent advances in technology, such as multi-omics, metagenomics and metabolomics approaches combined with artificial intelligence (AI) machine learning tools and synthetic biology are expediting the quest for next-generation probiotics discovery towards microbiome-based personalized therapy. New formulations, such as synbiotics, postbiotics and engineered probiotics (along with mathematical modelling- or site-specific delivery systems), are further broadening the therapeutic scope. Key steps for future research should be the establishment of large-scale, multicenter randomized controlled trials; standardization and characterization of probiotic strains; precision interventions with probiotics tailored to patients potentially benefiting from such treatments (e.g., driven by nutrigenomic interactions) and harmonized regulatory guidelines to optimize safety vs beneficial clinical outcomes in both adults and children.
In summary, probiotics represent an evolving field that holds great promise for novel approaches to improve preventive medicine and disease management through personalized healthcare. Ongoing interdisciplinary research linking microbiology, immunology, genomics and biotechnology with clinical sciences will be critical to realizing the full therapeutic potential of probiotics as well as furthering evidence-based microbiome medicine.
Keywords: probiotics, gut microbiota, microbiome; mechanisms of action; clinical applications; health benefits or adverse effects on healthy subjects & patients (immunomodulation) ,synbiotics.
Assit.Prof.RADHIKA C.WARADE· International Journal of Cre...· 0 citations
Probiotics, defined as live microorganisms, provide health advantages when ingested in sufficient quantities. They have progressed from Élie Metchnikoff’s early hypothesis of lactic acid bacteria promoting longevity to a scientifically grounded field spanning clinical, nutritional, and environmental domains. Traditionally associated with Lactobacillus, Bifidobacterium, probiotics now include strains of Bacillus, Pediococcus, and Saccharomyces boulardii, expanding their functional repertoire. Contemporary evidence highlights their roles not only in maintaining gastrointestinal balance but also in allergy management, metabolic regulation, skin health, and modulation of the gut–brain axis. These benefits are mediated through immune modulation, enhancement of intestinal barrier function, and support of microbial diversity. Despite this progress, several challenges remain unresolved, including strain-specific variability, inconsistent efficacy across populations, and safety considerations in vulnerable groups. Additionally, fragmented global regulatory frameworks limit standardization of claims, labeling, and clinical adoption, while the ecological implications and sustainability of large-scale probiotic production are emerging concerns. This review provides a structured synthesis of probiotics in four domains: natural and engineered sources, mechanisms of action, contributions to human health, and broader implications for food safety, public health, and environmental sustainability. Integrating classical insights with recent advances highlights the promise of probiotics as broad-spectrum tools for preventive and therapeutic health. Looking forward, developments in microbiome science, bioengineering, and personalized nutrition offer opportunities to refine probiotic applications. Systematic attention to regulatory harmonization, safety, and sustainability will be critical to unlocking their full potential as cornerstones of modern health strategies.
C. Ohia, O. Falodun, C. Ezemba· Journal of Health Science an...· 0 citations