Effect of Lyophilized, Encapsulated Lactobacillus fermentum and Lactulose Feeding on Growth Performance, Heavy Metals, and Trace Element Residues in Rainbow Trout (Oncorhynchus mykiss) Tissues

Guardians of the Gut: Harnessing the Power of Probiotic Microbiota and Their Exopolysaccharides to Mitigate Heavy Metal Toxicity in Human for Better Health

Heavy metal pollution is a significant global health concern, posing risks to both the environment and human health. Exposure to heavy metals happens through various channels like contaminated water, food, air, and workplaces, resulting in severe health implications. Heavy metals also disrupt the gut's microbial balance, leading to dysbiosis characterized by a decrease in beneficial microorganisms and proliferation in harmful ones, ultimately exacerbating health problems. Probiotic microorganisms have demonstrated their ability to adsorb and sequester heavy metals, while their exopolysaccharides (EPS) exhibit chelating properties, aiding in mitigating heavy metal toxicity. These beneficial microorganisms aid in restoring gut integrity through processes like biosorption, bioaccumulation, and biotransformation of heavy metals. Incorporating probiotic strains with high affinity for heavy metals into functional foods and supplements presents a practical approach to mitigating heavy metal toxicity while enhancing gut health. Utilizing probiotic microbiota and their exopolysaccharides to address heavy metal toxicity offers a novel method for improving human health through modulation of the gut microbiome. By combining probiotics and exopolysaccharides, a distinctive strategy emerges for mitigating heavy metal toxicity, highlighting promising avenues for therapeutic interventions and health improvements. Further exploration in this domain could lead to groundbreaking therapies and preventive measures, underscoring probiotic microbiota and exopolysaccharides as natural and environmentally friendly solutions to heavy metal toxicity. This, in turn, could enhance public health by safeguarding the gut from environmental contaminants.

Metal(loid)-gut microbiota interactions and microbiota-related protective strategies: A review

Human exposure to metal(loid)s has dramatically increased over the past five decades, which has triggered public concern worldwide. Recently, gut microbiota has been considered a target for metal(loid)s, and some literature has reviewed the interactions between gut microbiota and heavy metal(loid)s (HMs) with high toxicity. However, whether there is an interaction between gut microbiota and metal(loid)s with essential roles or some normal functions are far from clear to date. Importantly, in addition to traditional probiotics that have been clarified to alleviate the adverse effect of HMs on the body, some novel probiotics, prebiotics, synbiotics, and postbiotics may also exhibit comparable or even better abilities of metal(loid) remediation. In this review, we mainly outline and discuss recent research findings on the metal(loid)-gut microbiota interactions and microbiota-related protective strategies.

Probiotics in addressing heavy metal toxicities in fish farming: Current progress and perspective

Heavy metal contamination of aquatic environments adversely affects the health of aquatic organisms and consumption of fish contaminated with heavy metals poses serious health risks to humans. Among various strategies, probiotics (living microorganisms known to have beneficial effects on the host), which have been extensively applied in the aquaculture industry, could be helpful for heavy metal detoxification and remediation. Several probiotics, including Lactobacillus strains, exhibit heavy metal binding, high heavy metal tolerance, and other beneficial characteristics for the host. Notably, numerous probiotics have been reported to bind heavy metals and excrete them from the host. Various probiotic strains (Lactobacillus, Bacillus, Lactococcus, etc.) show beneficial effects in alleviating heavy metal toxicity in cultured fish species. Certain probiotic bacteria reduce the absorption and bioavailability of heavy metals by enhancing heavy metal detoxification and sequestration while preserving gut barrier function. This review summarises the toxic effects of selected heavy metals on the health of farmed fish and discusses the role of probiotic strains in remediating the consequential exposure-induced immune toxicity and oxidative stress. Moreover, we discussed the protective strategies of probiotics against heavy metal accumulation in various tissues and gut dysbiosis in fish to alleviate heavy metal toxicity in fish farming, thereby promoting a sustainable blue economy worldwide.

Probiotic Supplementation as an Emerging Alternative to Chemical Therapeutics in Finfish Aquaculture: a Review

Aquaculture is a promising food sector to fulfil nutritional requirements of growing human population. Live weight aquaculture production reached up to 114.5 million tonnes in 2018 and it is further expected to grow by 32% by year 2030. Among total aquaculture production, major product harvested is finfish and its contribution has reached 46% in recent years. Frequent outbreaks of infectious diseases create obstacle in finfish production, result in economic losses to the farmers and threaten the sustainability of aquaculture industry itself. In spite of following the best management practices, the use of antibiotics, chemotherapeutics and phytochemicals often become the method of choice in finfish culture. Among these, phytochemicals have shown lesser effect in animal welfare while antibiotics and other chemotherapeutics have led to negative consequences like emergence of drug-resistant bacteria, and accumulation of residues in host and culture system, resulting in quality degradation of aqua products. Making use of probiotics as viable alternative has paved a way for sustainable aquaculture and minimise the use of antibiotics and other chemotherapeutics that pose adverse effect on host and culture system. This review paper elucidates the knowledge about antibiotics and other chemicals, compilation of probiotics and their effects on health status of finfish as well as overall culture environment. Besides, concoction of probiotics and prebiotics for simultaneous application has also been discussed briefly.

An Overview of the Use and Applications of Limosilactobacillus fermentum in Broiler Chickens

The implementation of government regulations on antibiotic use, along with the public's concern for drug resistance, has strengthened interest in developing alternatives not only aimed at preserving animal production but also at reducing the effects of pathogenic infections. Probiotics, in particular, are considered microorganisms that induce health benefits in the host after consumption of adequate amounts; they have been established as a potential strategy for improving growth, especially by stimulating intestinal homeostasis. Probiotics are commonly associated with lactic acid bacteria, and Limosilactobacillus fermentum is a well-studied species recognized for its favorable characteristics, including adhesion to epithelial cells, production of antimicrobial compounds, and activation of receptors that prompt the transcription of immune-associated genes. Recently, this species has been used in animal production. Different studies have shown that the application of L. fermentum strains not only improves the intestinal ecosystem but also reduces the effects caused by potentially pathogenic microorganisms. These studies have also revealed key insights into the mechanisms behind the actions exerted by this probiotic. In this manuscript, we aim to provide a concise overview of the effects of L. fermentum administration on broiler chicken health and performance.

Rosmarinic acid alone or in combination with Lactobacillus rhamnosus ameliorated ammonia stress in the rainbow trout, Oncorhynchus mykiss: growth, immunity, antioxidant defense and liver functions

Rosmarinic acid (RS) and Lactobacillus rhamnosus (LR) were added singularly or in combination to rainbow trout (Oncorhynchus mykiss) diets to test their efficacy in the protection against ammonia stress. Fish (31.4±0.6 g) were randomly allocated to six groups in three replicates, as follows: T1: basic food as control, T2: LR with a concentration of 1.5 × 108 CFU/g, T3: LR with a concentration of 3 × 108 CFU/g, T4: 1 g RS/kg, T5: 3 g RS/kg, and T6: 1.5 × 108 CFU/g LR + 1 g RS/kg and T7: 3 × 108 CFU/g LR + 3 g RS/kg. After 60 days feeding, fish exposed to 0ammonia stress. After the feeding period, the supplemented fish had the highest final body weight (FW), weight gain (WG), and specific growth rate (SGR), and the lowest feed conversion ratio (FCR) as compared with the control group (P<0.05). Amylase, protease and lipase activities were noticed markedly higher in fish supplemented with 1.5 × 108 CFU/g LR + 1 g RS/kg and 1.5 × 108 CFU/g LR diets compared to the control (P<0.05). Generally, fish in supplemented diets, particularly T2 and T6 groups, had the highest lysozyme, alternative complement activity (ACH50), total Ig, nitroblue tetrazolium test (NBT), myeloperoxidase (MPO), complement component 3 (C3), complement component 4 (C4), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx). On the other hand, T2 and T6 groups had the lowest malondialdehyde (MDA), glucose, and cortisol concentrations as well as alanine aminotransferase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) enzyme levels when were compared with the control (P<0.05). After ammonia stress, fish in the supplemented groups, particularly T2 and T6, generally showed significantly higher values of lysozyme, ACH50, total Ig, NBT, MPO, C3, C4, SOD, CAT, GPx and lower levels of MDA, glucose, cortisol, ALT, ALP, LDH when compared with the control (P<0.05). In conclusion, a combined administration of RS and L. rhamnosus effectively improved growth performance and health status as well as enhanced the resistance of rainbow trout against ammonia toxicity.

Micro-/bio-/nano-/syn-encapsulations and co-treatments of bioactive microbial feed supplementation in augmenting finfish health and aquaculture nutrition: a review

Finfish and fish products are globally the most acknowledged health-promoting foods. The rising incidence of pathogenic and disease outbreaks have had a sizeable impact on aquaculture. Microbial supplementation of food in the form of probiotics, prebiotics, and their controlled release combinations (=co-encapsulations) as 'synbiotics' is noted for its significant biotherapeutic and health benefits. Supplementation of probiotic microbial feed additives in the fish diet claims to improve fish health by modulation of resident intestinal microbiota and by introducing healthy microbiota procured from an exogenous source, capable of combating pathogens, improving nutrient uptake, assimilation, growth as well as survival. Prebiotics are selectively digestible substrates beneficially used by host gut microbes to enhance probiotic effects. Formulating a fish diet with augmented probiotics and prebiotic microbial bio-supplements can ensure a sustainable alternative for establishing fish health in a naturally susceptible aquaculture scenario. Micro-encapsulation, co-encapsulation, and nano-encapsulation are novel strategies of biotechnical interventions in functional feeds for finfish. These aim to improve probiotic persistence, survivability, and efficacy in commercial formulations during probiotic transit through the host-gut environment. This review discusses the importance of co-treatment and encapsulation strategies for improving probiotic and prebiotic potential in aquafeed formulations, reliably improving finfish health and nutritional returns from aquaculture, and, consequently, for consumers.

Biotherapeutic microbial supplementation for ameliorating fish health: developing trends in probiotics, prebiotics, and synbiotics use in finfish aquaculture

Nutrition demands in aquaculture can be realized through quality aquafeeds as compounded diets that contribute to the growth and health of aquaculture species. Functional additives in feed, notably probiotics, prebiotics, and their admixture synbiotics, have been recently recognized for their biotherapeutic role as immunostimulants capable of conferring disease resistance, stress tolerance, and gastrointestinal health; counteracting the negative effects of anti-nutrients, pathogenic prevalence, and antimicrobials in finfish aquaculture. Formulated diets based on probiotics, prebiotics, and as a supplemental combination for synbiotics can significantly influence fish gut microbiomes, establishing the modalities of microbial dynamics to maximize host-associated benefits. These microbial functional-feed supplements are acclaimed to be biocompatible, biodegradable, and safe for dietary consumption as well as the environment. In fed fish aquaculture, prebiotic appended probiotic diet 'synbiotic' has propounded larger attention for its additional health and nutritional benefits. Synbiotic, prebiotic, and probiotic usage as functional feeds for finfish aquaculture thus provides promising prospects. Developing trends in their intended application are reviewed here forth.

Biodetoxification and Protective Properties of Probiotics

Probiotic consumption is recognized as being generally safe and correlates with multiple and valuable health benefits. However, the mechanism by which it helps detoxify the body and its anti-carcinogenic and antimutagenic potential is less discussed. A widely known fact is that globalization and mass food production/cultivation make it impossible to keep all possible risks under control. Scientists associate the multitude of diseases in the days when we live with these risks that threaten the population’s safety in terms of food. This review aims to explore whether the use of probiotics may be a safe, economically viable, and versatile tool in biodetoxification despite the numerous risks associated with food and the limited possibility to evaluate the contaminants. Based on scientific data, this paper focuses on the aspects mentioned above and demonstrates the probiotics’ possible risks, as well as their anti-carcinogenic and antimutagenic potential. After reviewing the probiotic capacity to react with pathogens, fungi infection, mycotoxins, acrylamide toxicity, benzopyrene, and heavy metals, we can conclude that the specific probiotic strain and probiotic combinations bring significant health outcomes. Furthermore, the biodetoxification maximization process can be performed using probiotic-bioactive compound association.

Effects of a Trans-Galactooligosaccharide on Minerals Content of Common Carp (Cyprinus carpio L.) Tissues

Common carp (Cyprinus carpio L.) is a dominant fish species in aquaculture, and as it is a stomachless species, absorption and digestion of nutrients take place in the intestine. The aim of the study was to evaluate the effects of a prebiotic on the content of selected minerals found in the meat, gills, and skeleton of common carp. The research applied trans-galactooligosaccharide (GOS) prebiotic produced by enzymatic transgalactosylation of milk lactose by whole cells of Bifidobacterium bifidum. The following diets have been applied: control diet without feed additives (C), diet 2 (B1) with 1% of GOS, and diet 3 (B2) with 2% of GOS. In the freeze-dried samples, concentrations of the analyzed metals were determined using atomic absorption spectroscopy (AAS). The content of phosphorus was determined using colorimetric method. The analyses confirmed that the highest level of Mg was detected in the skeleton of fish fed with 1% GOS (2.51 g kg-1) and was significantly higher compared the control treatment (2.11 g kg-1) (P < 0.05). Zn content in fish meat fed with 1% GOS (35.41 mg kg-1) was significantly higher (P < 0.05) than in the control group (24.59 mg kg-1). The tissue that accumulated the greatest amount of Zn was the gills. GOS had a positive effect on Fe accumulation in the meat, gills, and skeleton. It has been concluded that supplementation of feed with 2% GOS significantly influenced the positive correlations between Mg and P in the meat and skeleton, Fe-Ca correlation in gills, and Fe-Zn correlation in the skeleton.

Microencapsulated and Lyophilized Lactobacillus acidophilus Improved Gut Health and Immune Status of Preruminant Calves

The present study was conducted to study the effect of microencapsulated, lyophilized, or fermented milk using Lactobacillus acidophilus NCDC15 as a probiotic to improve gut health, growth, nutrient utilization, and immunity status of young crossbred calves. The viable culture of L. acidophilus was used for preparation of different probiotic forms/products. To compare the efficacy of probiotic products, twenty crossbred calves (3-day old) were divided into four groups (n = 5), control (C), fed only milk and basal diet, and treatment groups, supplemented with microencapsulated, fermented, and lyophilized probiotic at 10⁸ colony-forming units, respectively. Probiotic-supplemented groups showed reduction in faecal score, faecal pH, and ammonia concentration as compared to control indicating decreased diarrheal incidence. There was an increase (P < 0.05) in the concentration of faecal lactate and butyrate in the probiotic-supplemented groups. The faecal count (log10 (CFU)/g of fresh faeces) of lactobacilli and bifidobacteria was higher (P < 0.05), whereas faecal coliforms and clostridia count were reduced (P < 0.001) in all the probiotic fed groups as compared to control. The cell-mediated immunity was improved (P < 0.05) in the microencapsulated and fermented probiotic groups. However, there was no effect on the nutrient utilization, average daily gain, and blood biochemical profile. Therefore, it is concluded that the fermented, microencapsulated and lyophilized probiotic products were superior in improving the gut health in terms of its microbiota and metabolites and cell-mediated immunity response in calves, irrespective of form of probiotic. The increased population of Lactobacillus and Bifidobacterium decreased the colonization of the gut by pathogens such as Escherichia coli and Clostridium by exclusion and production of organic acids in the intestine. This decreased the diarrhoeal incidence (1.3 vs 1.8) and days in diarrhoea (3.9 vs 5.8) in calves in probiotic fed groups as compared to control.

Protective effects of non-encapsulated and microencapsulated Lactobacillus delbrueckii subsp. bulgaricus in rainbow trout (Oncorhynchus mykiss) exposed to lead (Pb) via diet

The present study was designed to investigate the effects of dietary non-encapsulated and microencapsulated Lactobacillus delbrueckii subsp. bulgaricus on growth performance, intestinal enzymatic activities, antioxidant capacity and hepato-biochemical parameters of rainbow trout before or after exposure to lead via diet. Fingerling fish (16 ± 4 g) were divided into four groups: negative control (NC), positive control (PC), probiotic (PR) and encapsulated probiotic (EN-PR). During the pre-exposure period (days 0-45), fish in the NC and PC groups received the basal diet, whereas fish in the PR and EN-PR groups were fed with basal diet containing 108 CFU g−1 feed of non-encapsulated and microencapsulated probiotic, respectively. During the exposure period (days 46-66), the fish in the probiotic and PC groups were co-treated with 500 μg g−1 feed of lead nitrate. Blood, liver and gut samples were taken at days 0, 45, 52, 59 and 66. The results revealed that growth performance and intestinal enzymatic activities were significantly (p< 0.05) improved in the probiotic groups compared to the NC group (day 45). Dietary exposure to lead resulted in the highest levels of liver aspartate aminotransferase (AST), liver alkaline phosphatase (ALP) and serum malondialdehyde (MDA), and the lowest activities of serum superoxide dismutase (SOD) and catalase (CAT) in the PC group (day 66). The levels of liver ALP were significantly (p< 0.05) lower in the probiotic groups compared to the NC and PC groups prior to and after exposure to dietary lead. Serum levels of total protein, albumin, SOD, CAT and glutathione (GSH) were significantly increased in fish fed with both non-encapsulated and microencapsulated probiotics (p< 0.05). However, microencapsulated probiotic showed the greatest potential for alleviation of the disturbed activities of intestinal and hepatic enzymes, and improvement of serum biochemical and antioxidant parameters. Our findings suggest that L. delbrueckii subsp. bulgaricus, particularly in the microencapsulated form, can be used as a potential probiotic to protect rainbow trout from dietborne lead toxicity.

Development of a microencapsulated probiotic delivery system for New Zealand black-footed abalone (Haliotis iris)

Conventional methods of probiotics delivery to farmed aquatic animals are not efficient due to loss of probiotic's viability before the probiotics can reach their site of action. This study aims to develop a microencapsulated probiotic delivery system for black-footed abalone (Haliotis iris). An emulsion technique was used to encapsulate probiotic bacteria within chitosan-coated alginate microparticles (CALG). The efficacy of CALG microparticles in delivering probiotics to abalone was assessed using ex vivo and in vivo experiments. Microparticles (113 ± 4 µm) with encapsulation efficiency of more than 75% were developed using an internal gelation formulation approach. The ex vivo release experiments revealed the lack of probiotic discharge in the first 6 h of incubating CALG in seawater followed by a slight bacterial release within the next 20 h. The exposure of CALG microparticles to simulated gastric and intestinal media showed a significantly higher release of encapsulated bacteria in the simulated intestinal medium. The results of feeding trial revealed that the number of probiotic bacteria in probiotic-fed abalone was significantly higher than the one in the control animals. The results suggest that CALG microparticles can be used as a controlled release system for delivering viable probiotic bacteria to the gastrointestinal tract of abalone.