Effects of Dietary Lactobacillus plantarum on Growth Performance, Digestive Enzymes and Gut Morphology of Litopenaeus vannamei

Microencapsulated Lactobacillus plantarum promotes intestinal development through gut colonization of layer chicks

The effects of Lactobacillus plantarum in microencapsulation (LPM) on intestinal development in layer chicks were investigated in this study, as well as the colonization of L. plantarum in the gut. A total of 480 healthy Hy-Line Brown layer chicks at 0 d old were randomly divided into 4 groups (8 replicates each treatment), and the diets of these birds were supplemented with nothing (control), L. plantarum (0.02 g/kg feed; 109 CFU/kg feed), LPM (1.0 g/kg feed; 109 CFU/kg feed) and wall material of LPM (WM; 0.98 g/kg feed), respectively. Compared to control, LPM improved growth performance and intestinal development of layer chicks, evidenced by significantly increased body weight, average daily gain, average daily feed intake, villus height, villus height/crypt depth, as well as weight and length of the duodenum, jejunum and ileum (P < 0.05). These results could be attributed to the increased colonization of L. plantarum in the gut, which was verified by significant increases in lactic acid content, viable counts in chyme and mucosa (P < 0.05), as well as a visible rise in number of strains labeled with fluorescein isothiocyanate. Meanwhile, the relative abundances of Lactobacillus and Bifidobacterium significantly increased in response to microencapsulated L. plantarum supplementation (P < 0.05), accompanied by the significant up-regulation of colonization related genes (P < 0.05), encoding solute carrier family, monocarboxylate transporter, activin A receptor, succinate receptor and secretogranin II. To sum up, microencapsulated L. plantarum supplementation promoted intestinal development, which could be attributed to the enhancement of L. plantarum colonization in the intestine through the mutual assistance of Bifidobacterium and interactions with colonization related transmembrane proteins.

A novel Lactiplantibacillus plantarum strain: probiotic properties and optimization of the growth conditions by response surface methodology

The objective of this study is to explore the probiotic properties and optimal growth conditions of Lactiplantibacillus plantarum BG24. L. plantarum BG24 exhibited a remarkable ability to utilize lactose, and to grow under acidic conditions and in the presence of high levels of bile salts. The strain showed the highest antibacterial activity against L. monocytogenes Scott A (zone of inhibition: 26 mm). L. plantarum BG24 was found to be resistant to 8 of the tested 19 antibiotics using the disc diffusion method.and its multiple antibiotic resistance (MAR) index was calculated as 0.421. The adhesion rate to human intestinal epithelial Caco-2 cells was determined as 37.51%. The enzyme profile of L. plantarum BG24 was investigated using API ZYM test kit and the highest enzymatic activities were found for Leucine arylamidase, β-glucosidase, Valine arylamidase, β-galactosidase and N-acetyl-β-glucosaminidase. L. plantarum BG24 strain showed higher microbial growth under static conditions (6.60 OD600) compared to 100 rpm (5.73 OD600) and 200 rpm (5.02 OD600) shaking speed due to its facultative anaerobic characteristic. However, different inoculation rates and glucose addition did not make a statistically significant difference on biomass formation (p > 0.05). The specific growth rate of L. plantarum BG24 was 0.416 h-1, the doubling time was 1.67 h, and the biomass productivity value was 0.14 gL-1 h-1 in the original MRS broth (pH 5.7) while higher values were found as 0.483 h-1, 1.43 h and 0.17 gL-1 h-1, respectively, in MRS broth (pH 6.5) medium enriched with 5 g/L yeast extract. The stirred tank bioreactor was used to optimise the growth of BG24 strain. The process variables was optimized at 0.05 vvm of aeration rate, 479 rpm of agitation speed, 3% of inoculation rate and 18 h of incubation time. The maximum biomass (g/L) production was obtained as 3.84 g/L at the optimized conditions.

Current Status of Probiotics in European Sea Bass Aquaculture as One Important Mediterranean and Atlantic Commercial Species: A Review

European sea bass production has increased in recent decades. This increase is associated with an annually rising demand for sea bass, which encourages the aquaculture industries to increase their production to meet that demand. However, this intensification has repercussions on the animals, causing stress that is usually accompanied by dysbiosis, low feed-conversion rates, and immunodepression, among other factors. Therefore, the appearance of pathogenic diseases is common in these industries after immunodepression. Seeking to enhance animal welfare, researchers have focused on alternative approaches such as probiotic application. The use of probiotics in European sea bass production is presented as an ecological, safe, and viable alternative in addition to enhancing different host parameters such as growth performance, feed utilization, immunity, disease resistance, and fish survival against different pathogens through inclusion in fish diets through vectors and/or in water columns. Accordingly, the aim of this review is to present recent research findings on the application of probiotics in European sea bass aquaculture and their effect on growth performance, microbial diversity, enzyme production, immunity, disease resistance, and survival in order to help future research.

Effects of Astragalus membranaceus Polysaccharides on Growth Performance, Physiological and Biochemical Parameters, and Expression of Genes Related to Lipid Metabolism of Spotted Sea Bass, Lateolabrax maculatus

This experiment investigated the effects of Astragalus membranaceus polysaccharides (AMP) on growth, physiological and biochemical parameters, and the expression of lipid metabolism-related genes in spotted sea bass, Lateolabrax maculatus. A total of 450 spotted sea bass (10.44 ± 0.09 g) were divided into six groups and were given diets with different levels of AMP (0, 0.2, 0.4, 0.6, 0.8, and 1.0 g/kg) for 28 days, respectively. Results indicated that dietary intake of AMP significantly improved fish weight gain, specific growth rate, feed conversion, and trypsin activity. Meanwhile, fish fed with AMP manifested significantly higher serum total antioxidant capacity and activity of hepatic superoxide dismutase, catalase, and lysozyme. Lower triglyceride and total cholesterol were noted in fish fed with AMP (P < 0.05). Moreover, hepatic ACC1 and ACC2 were downregulated by dietary intake of AMP, and PPAR-α, CPT1, and HSL were upregulated accordingly (P < 0.05). Parameters with significant difference were analyzed by quadratic regression analysis, and results showed that 0.6881 g/kg of AMP is the optimal dosage for spotted sea bass in size (10.44 ± 0.09 g). In conclusion, dietary intake of AMP can improve the growth, physiological status, and lipid metabolism of spotted sea bass, thereby indicating its promise as a potential dietary supplement.

Lycium barbarum polysaccharides improve lipid metabolism disorders of spotted sea bass Lateolabrax maculatus induced by high lipid diet

This experiment explored the effects of Lycium barbarum polysaccharides (LBP) on lipid metabolism of spotted sea bass Lateolabrax maculatus. Blank and experimental control diets with 100 and 150 g/kg lipid were designed, respectively, and three dosages of LBP (0.75, 1.00, 1.25 g/kg) were supplemented in the experimental control diet. A total 375 of spotted sea bass (19.33 ± 0.15) g were divided into 5 groups, and were given experimental diets for 56 days, respectively. Results showed fish were induced to lipid metabolism disorders with dietary 150 g/kg lipid intake, which manifested in reduced feeding, oxidative stress, elevated serum lipid, and more severe hepatic damage. Dietary LBP improved the lipid metabolism disorders of fish, as indicated by significant enhancements in weight gain, digestion, superoxide dismutase activity, and decreases in malonaldehyde content, and activity of alanine aminotransferase and aspartate aminotransferase. Accordingly, an improvement in the hepatic morphological and expression of lipid metabolism related genes, including FAS, PPAR-α, CPT1 and ATGL, was observed. Nevertheless, no significant variation in serum triglyceride and total cholesterol was observed. Overall, dietary LBP can improve the growth, digestion, antioxidant capacity, and liver health of spotted sea bass, thereby improving the lipid metabolism disorders induced by 150 g/kg dietary lipid intake.

A comparative study on effects of dietary three strains of lactic acid bacteria on the growth performance, immune responses, disease resistance and intestinal microbiota of Pacific white shrimp, Penaeus vannamei

The present study evaluated the growth performance, immune responses, disease resistance and intestinal microbiota in Penaeus vannamei fed diets supplemented with three strains of lactic acid bacteria (LAB). The basal diet (control, CO) supplemented with Lactobacillus plantarum W2 (LA), Pediococcus acidilactici Nj (PE), Enterococcus faecium LYB (EN) and florfenicol (FL), respectively, formed three LAB diets (1 × 10¹⁰ cfu kg^-1) and a florfenicol diet (15 mg kg^-1, positive control), were fed to shrimp for 42 days. Results indicated that specific growth rate, feed efficiency rate, and disease resistance of shrimp against Vibrio parahaemolyticus in the treatment groups were significantly improved versus the control (P < 0.05). Compared with the control, acid phosphatase, alkaline phosphatase, phenonoloxidase, total nitric oxide synthase, peroxidase, superoxide dismutase activities, total antioxidant capacity, and lysozyme content in the serum and the relative expression levels of SOD, LZM, proPO, LGBP, HSP70, Imd, Toll, Relish, TOR, 4E-BP, eIF4E1α and eIF4E2 genes in the hepatopancreas of LAB groups were enhanced to various extents. Intestinal microbiota analysis showed that the LA and EN groups significantly improved microbial diversity and richness, and LAB groups significantly altered intestinal microbial structure of shrimp. At the phylum level, the Verrucomicrobiota in the LA and PE groups, the Firmicutes in the EN group, and the Actinobacteriota in the PE and EN groups were enriched. Moreover, the CO group increased the proportion of potential pathogens (Vibrionaceae and Flavobacteriaceae). The potential pathogen (Vibrio) was reduced, and potential beneficial bacteria (Tenacibaculum, Ruegeria and Bdellovibrio) were enriched in response to dietary three strains of LAB. When the intestinal microbiota homeostasis of shrimp is considered, L. plantarum and E. faecium showed better effects than P. acidilactici. However, due to the concerns on the possible potential risks of E. faecium strains to human health, L. plantarum W2 is more suitable for application in aquaculture than E. faecium LYB. Considering collectively the above, Lactobacillus plantarum W2 could be applied as better probiotic to improve the growth performance, non-specific immunity, disease resistance and promote intestinal health of P. vannamei.

Effect of Probiotics on Tenebrio molitor Larval Development and Resistance against the Fungal Pathogen Metarhizium brunneum

In recent years, the yellow mealworm (Tenebrio molitor L.) has demonstrated its potential as a mass-produced edible insect for food and feed. However, challenges brought on by pathogens in intensive production systems are unavoidable and require the development of new solutions. One potential solution is the supplementation of probiotics in the insect's diet to obtain the double benefits of improved growth and enhanced immune response. The aim of this study was to evaluate the effects of diet-based probiotic supplementation on T. molitor larval survival, growth, and resistance against a fungal pathogen. Three probiotic strains, namely Pediococcus pentosacceus KVL-B19-01 isolated from T. molitor and two commercialized strains for traditional livestock, Enterococcus faecium 669 and Bacillus subtilis 597, were tested. Additionally, when larvae were 9 weeks old, a pathogen challenge experiment was conducted with the fungus Metarhizium brunneum. Results showed that both P. pentosaceus and E. faecium improved larval growth and larval survival following fungal exposure compared to the non-supplemented control diet. Since B. subtilis did not improve larval performance in terms of either development or protection against M. brunneum, this study suggests the need for further research and evaluation of probiotic strains and their modes of action when considered as a supplement in T. molitor's diet.

Dietary SYNSEA probiotic improves the growth of white shrimp, Litopenaeus vannamei and reduces the risk of Vibrio infection via improving immunity and intestinal microbiota of shrimp

The growth performance, immunological status, and intestinal microbiology of white shrimp, Litopenaeus vannamei, were evaluated after dietary administration of the commercial probiotic SYNSEA. Shrimp were fed a control diet (without probiotic supplement) and two levels of SYNSEA probiotic, a low concentration of SYNSEA (LSL) containing 10⁵ CFU (g diet)^-1Bacillus subtilis and 10⁵ CFU (g diet)^-1 lactic acid bacteria (LAB), and a high concentration of SYNSEA (LSH) containing 10⁶ CFU (g diet)^-1B. subtilis and 10⁶ CFU (g diet)^-1 LAB, for 12 weeks. Shrimp fed with the LSL diet significantly increased growth performance as well as final weight and feed efficiency compared to the control, but not the LSH diet. After being orally challenged with Vibrio parahaemolyticus, shrimp fed with LSL diet prior to the challenge or fed with LSL and pathogen simultaneously showed significantly lower mortality compared to the control. SYNSEA probiotic significantly improved shrimp immune response, including lysozyme activity in LSL and LSH groups, and phagocytic activity in the LSL group in comparison to the control. In addition, the gene expressions of anti-lipopolysaccharide factor 2 in LSL and LSH groups, and penaeidin 4 in LSL were also up-regulated. Although there was no significant difference among groups for hepatopancreas and intestinal morphology, the muscular layer thickness and villi height were slightly improved in the intestines of shrimp fed SYNSEA. The 16S rDNA gene amplicon sequence analysis using next-generation sequencing revealed a significant decrease in α-diversity (Margalef's species richness) after oral administration of SYNSEA due to an increase in the relative abundance of beneficial bacteria in the gut flora of shrimp, such as Lactobacillus, Shewanella, and Bradymonadales and a decrease in harmful bacteria, such as Vibrio, Candidatus_Berkiella, and Acinetobacter baumannii. Together the data suggest that the provision of SYNSEA probiotic at 10⁵ CFU (g diet)^-1B. subtilis and 10⁵ CFU (g diet)^-1 LAB can improve shrimp growth, enhance immunity, and disease resistance status of the host. In addition, these findings conclude that SYNSEA probiotic has great preventive and therapeutic potential for Vibrio infection in shrimp aquaculture.

Assessing the Influence of Dietary Pediococcus acidilactici Probiotic Supplementation in the Feed of European Sea Bass (Dicentrarchus labrax L.) (Linnaeus, 1758) on Farm Water Quality, Growth, Feed Utilization, Survival Rate, Body Composition, Blood Biochemical Parameters, and Intestinal Histology

The probiotics are being used as ecofriendly and bioremediation tools for developing sustainability to aquaculture. The present study was conducted to explore the practical capability of using dietary lactic acid bacteria (Pediococcus acidilactici) probiotics and see how its dose variation affected the water quality, growth performance, survival rate, body composition, blood biochemical parameters, and intestinal histology of European sea bass (Dicentrarchus labrax L.). A total of 120 fingerlings with an initial weight of $9\pm 0.2$  g were divided into four groups, each with three replicates. The feeding experiment lasted for 60 days. In addition to the control (without probiotics) (T0), fish were fed diets containing (T1) 2.0, (T2) 2.5, and (T3) 3.0 g of probiotics per kg of diet twice a day. When compared to the control, sea bass fed probiotic-supplemented diets had significantly higher growth parameters, fish body “crude lipid,” and villi height ( $p<0.05$ , $p<0.01$ , and $p<0.001$ ). The P. acidilactici probiotic treatments improved survival rate, feed conversion ratio, body composition, and blood biochemical markers, but not statistically significant ( $p>0.05$ ). Also, in regard to water quality, P. acidilactici drastically reduced ammonia and pH levels. In this experiment, fish fed with a dosage of 3.0 g of this commercial probiotic per kg of probiotics performed better. The study found that including probiotics in the diets of European sea bass improved growth, body composition, survival rate, blood biochemical markers, intestinal histology, and some water quality parameters.

Exploring Sexual Dimorphism in the Intestinal Microbiota of the Yellow Drum (Nibea albiflora, Sciaenidae)

Most of fish species exhibit striking sexual dimorphism, particularly during growth. There are also sexual dimorphisms of internal organs and biological functions, including those of intestinal microbiota, which likely plays a key role in growth. In this study, the growth and intestinal microbiota of the female, male, and all-female Nibea albiflora (yellow drums) were comprehensively analyzed. The caged culture female and all-female yellow drums showed higher growth rates than males. A further analysis of the intestinal microbiota showed a significant difference in diversity between females and males in the summer, whereas there were no significant differences in the diversity and richness between females and males in the winter. In contrast, a significant difference in richness was observed between all-female and male fish, regardless of the season. Although the main composition of the intestinal microbiota showed no significant sex differences, the community structure of the intestinal microbiota of yellow drums did. Furthermore, the correlations between intestinal microbial communities are likely to be influenced by sex. The ecological processes of the intestinal microbial communities of the yellow drums showed clear sexual dimorphism. Further network analysis revealed that, although the main components of the network in the intestinal microbiota of female, male, and all-female fish were similar, the network structures showed significant sex differences. The negative interactions among microbial species were the dominant relationships in the intestinal ecosystem, and Bacteroidetes, Firmicutes, and Proteobacteria were identified as the functional keystone microbes. In addition, the functional pathways in the intestinal microbiota of yellow drums showed no significant sexual or seasonal differences. Based on the findings of this study, we gain a comprehensive understanding of the interactions between sex, growth, and intestinal microbiota in yellow drums.

Probiotics, prebiotics and synbiotics improved the functionality of aquafeed: Upgrading growth, reproduction, immunity and disease resistance in fish

Aquaculture plays an increasingly significant role in improving the sustainability of global fish production. This sector has been intensified with the advent of new husbandry practices and the development of new technology. However, the increasing intensification and indiscriminate commercialized farming has enhanced the vulnerability of cultivated aquatic species to damage from pathogens. In efforts to confront these various diseases, frequent use of drugs, antibiotics, chemotherapeutics, and agents for sterilization have unintentionally added to the risk of transmission of pathogens and harmful chemical compounds to consumers. Some natural dietary supplements are believed to have the potential to offset this setback in aquaculture. Application of bio-friendly feed additives such as probiotics, prebiotics and synbiotics are becoming popular dietary supplements with the potential to not only improve growth performance, but in some cases can also enhance immune competence and the overall well-being of fish and crustaceans. The present review discusses and summarizes the effects of probiotics, prebiotics and synbiotics application on growth, stress mitigation, microbial composition of intestine, immune system and health condition of aquatic animals in association with existing constraints and future perspectives in aquaculture.

Profiling intestinal microbiota of Metaplax longipes and Helice japonica and their co-occurrence relationships with habitat microbes

Intestinal microbiota plays key roles in maintaining the health and homeostasis of the host. However, information about whether the formation of intestinal microbiota of wild aquatic animals is associated with habitat microbes is not fully understood. Here, intestine samples were collected from two wild crab species and sediment samples were collected from the habitat environment. The total DNA of each sample was extracted, and the V3–V4 regions of 16S rRNA were sequenced using the MiSeq platform. The purpose of this study was to investigate the composition and diversity of intestinal microbiota and habitat microbes, and bacterial community relationships between wild crab intestine and habitat sediment. In the present study, the composition and diversity of intestinal microbiota of the two crab species were different from the habitat microbes. In contrast, a similar composition and diversity of the intestinal microbiota were observed between two crab species. Moreover, the bacterial community relationships between crab intestine and habitat sediment were associated with intestinal regions. Further network analysis revealed that the network structure of the intestinal microbiota was not only associated with intestinal regions, but also with the crab species. Additionally, although the compositions of bacterial functions were similar between crab intestine and sediment, no significant correlation in bacterial functions was observed between crab intestine and sediment. The findings of the present study would contribute to understanding the relationship between intestinal microbiota of wild aquatic animal and habitat microbes, and providing new insights into the intestinal microbiota of wild aquatic animals.

Effects of Supplementing Intestinal Autochthonous Bacteria in Plant-Based Diets on Growth, Nutrient Digestibility, and Gut Health of Bullfrogs (Lithobates catesbeianus)

Poor utilization efficiency of plant protein diets always leads to intestinal barrier dysfunction and growth inhibition in animals. Probiotics have shown promise in improving growth performance and gut health of the host. However, obtaining the host-beneficial probiotic from thousands of bacterial phylotypes is challenging. Here, four intestinal autochthonous bacteria were isolated from fast-growing bullfrog after a 60-day feeding on a soybean meal (SM)-based diet. Another feeding trial was conducted to evaluate the effects of supplementing these strains in an SM-based diet on growth, nutrient digestibility, immunity, and gut health of bullfrog. A high-SM basal diet was used as a non-supplemented control group (NC), and four other diets were prepared by supplementing the basal diet with 1 × 10⁷ CFU/g of Bacillus siamensis, Bacillus tequilensis (BT), Bacillus velezensis, and Lactococcus lactis (LL). Results showed that weight gain, feed efficiency, nitrogen retention, and apparent digestibility coefficients of dry matter and protein were significantly higher in the LL group compared with the NC group (p < 0.05). Furthermore, compared with the NC group, both BT and LL groups showed markedly higher jejunal protease and amylase activities, serum complement 4 and immunoglobulin M levels, jejunal muscularis thickness (p < 0.05), and up-regulated expression of il-10 and zo-1 genes (p < 0.05). High-throughput sequencing revealed higher abundances of Bacillus and Cetobacterium in BT and LL groups, respectively, accompanied with decreased abundances of Enterobacter and Escherichia-Shigella. Besides, KEGG pathways related to metabolisms were significantly enhanced by the LL diet relative to the NC diet (p < 0.05). Overall, the beneficial effects of two frog-derived probiotics were determined: supplementation of L. lactis in SM-based diet promoted growth and nutrient digestibility; both B. tequilensis and L. lactis supplementation improved immune response and intestinal barrier function of bullfrogs.

Limosilactobacillus fermentum SWP-AFFS02 Improves the Growth and Survival Rate of White Shrimp via Regulating Immunity and Intestinal Microbiota

White shrimp Litopenaeus vannamei is an important species of farmed shrimp. Intestinal bacterial composition and immune activity play important roles in regulating the health condition of shrimp. Lactic acid bacteria Limosilactobacillus fermentum SWP-AFFS02 was isolated from the intestine of sea fish Rachycentron canadum, and the potential of its effect on growth, immunity, and intestinal microbiota of L. vannamei shrimp was investigated. Shrimps received feed with or without the addition of 8 log CFU/g L. fermentum SWP-AFFS02 thrice a day for 8 weeks. After 8-week treatment, weight gain, feed conversion rate, and survival rate of shrimp were greater in the L. fermentum SWP-AFFS02-feed group than in the control group. L. fermentum SWP-AFFS02 treatment increased the number of granular cells and semi-granular cells and decreased hyaline cell number when compared to the control group. L. fermentum SWP-AFFS02 promoted prophenoloxidase (PO) activity through increasing immune-associated gene expression in the hepatopancreas of shrimp. In addition, administration of feed containing L. fermentum SWP-AFFS02 regulated intestinal microbiota via decreasing the ratio of pathogenic bacteria, such as Vibrionaceae and Enterobacteriaceae, in the intestine of shrimp. This study demonstrated that administration of L. fermentum SWP-AFFS02 effectively prevented infection of L. vannamei shrimp by regulating intestinal microbiota and enhancing immunity in shrimp to increase the growth and improve their health status, which acted as a probiotic and provided beneficial effects on shrimp.

Probiotics Improve Eating Disorders in Mandarin Fish (Siniperca chuatsi) Induced by a Pellet Feed Diet via Stimulating Immunity and Regulating Gut Microbiota

Eating disorders are directly or indirectly influenced by gut microbiota and innate immunity. Probiotics have been shown to regulate gut microbiota and stimulate immunity in a variety of species. In this study, three kinds of probiotics, namely, Lactobacillus plantarum, Lactobacillus rhamnosus and Clostridium butyricum, were selected for the experiment. The results showed that the addition of three probiotics at a concentration of 10⁸ colony forming unit/mL to the culture water significantly increased the ratio of the pellet feed recipients and survival rate of mandarin fish (Siniperca chuatsi) under pellet-feed feeding. In addition, the three kinds of probiotics reversed the decrease in serum lysozyme and immunoglobulin M content, the decrease in the activity of antioxidant enzymes glutathione and catalase and the decrease in the expression of the appetite-stimulating regulator agouti gene-related protein of mandarin fish caused by pellet-feed feeding. In terms of intestinal health, the three probiotics reduced the abundance of pathogenic bacteria Aeromonas in the gut microbiota and increased the height of intestinal villi and the thickness of foregut basement membrane of mandarin fish under pellet-feed feeding. In general, the addition of the three probiotics can significantly improve eating disorders of mandarin fish caused by pellet feeding.

Lactobacillus reuteri KT260178 Supplementation Reduced Morbidity of Piglets Through Its Targeted Colonization, Improvement of Cecal Microbiota Profile, and Immune Functions

Supplementing suckling piglets with Lactobacillus reuteri isolated from a homologous source improves L. reuteri colonization number in the gastrointestinal tract, which can have health benefits. This study investigated dietary L. reuteri supplementation on the growth and health-including immune status-of piglets, as well as its colonization. A total of 60 sows with similar parity and body weight were allocated into one of three groups after secretion (n = 20 each, with 10 neonatal piglets of each): untreated control, L. reuteri supplementation, and antibiotic treatment. The experimental duration was 28 days, from birth of piglets to their group transferred. For the first 7 days after birth, all neonatal piglets were fed by sows. Piglets in the L. reuteri supplementation group were administered with 1.0 ml L. reuteri fermentation broth containing 5.0 × 10⁷ CFU. From 7 to 28 days, piglets were given basal feed (control), basal feed supplemented with L. reuteri (1.0 × 10⁷ CFU/g), or aureomycin (150 mg/kg). L. reuteri colonization in the distal jejunum and ileum was increased in piglets in the L. reuteri-supplemented as compared to the control group after 28 days, as determined by fluorescence in situ hybridization and real-time PCR analysis. Total Lactobacillus and Bifidobacterium counts in the cecum were higher whereas total aerobic bacteria (Escherichia coli and Staphylococcus) counts were lower in the L. reuteri as compared to the control group. L. reuteri supplementation also improved body antioxidant status and immune function relative to control animals. Strain-specific L. reuteri administered to piglets colonizes the intestinal mucosa and improves cecal microbiota profile and whole-body antioxidant and immune status, leading to better growth and lower morbidity and mortality rates.

Effects of Feed Mixed with Lactic Acid Bacteria and Carbon, Nitrogen, Phosphorus Supplied to the Water on the Growth and Survival Rate of White Leg Shrimp (Penaeus vannamei) Infected with Acute Hepatopancreatic Necrosis Disease Caused by Vibrio parahaemolyticus

Simple Summary

This study aimed to evaluate the growth, survival rate, and resistance to Acute hepatopancreatic Necrosis Disease (AHPND) of white leg shrimp (Penaeus vannamei) by using Lactobacillus plantarum, Lactobacillus fermentum, and Pediococcus pentosaceus mixed with feed, and at the same time supplying CNP in a ratio of 15:1:0.1 to the water. The result showed that shrimps were fed with feed containing lactic acid bacteria (LAB), especially L. plantarum have an effective to increased shrimp growth, stimulated non-specific immune system such as total hemocyte cells, granulocyte cells, hyaline cells, and protected shrimp to ANPND. The supply of CNP to the water have increased the intensity of V. parahaemolyticus effects on shrimp health; significantly decreased non-specific immune parameters of shrimp by 30–50%, therefore increased the AHPND infected rate and mortality of shrimp compared with without CNP group. In summary, LAB has a good effect to shrimp and the supply of CNP had significantly reduced the shrimp’s immune response and increased the susceptibility of shrimp to AHPND in both cases of use with and without LAB-containing diets.

Abstract

This study aimed to evaluate the growth, survival rate, and resistance to acute hepatopancreatic necrosis disease (AHPND) of white leg shrimp (Penaeus vannamei) by using Lactobacillus plantarum, Lactobacillus fermentum, and Pediococcus pentosaceus mixed with feed, and at the same time supplying CNP in a ratio of 15:1:0.1 to the water. As a result, the treatments that shrimp were fed with feed containing lactic acid bacteria (LAB), especially L. plantarum, have increased shrimp growth, total hemocyte cells, granulocyte cells, and hyaline cells significantly (p < 0.05) in comparison to the control group. The supply of CNP to the water has promoted the intensity of V. parahaemolyticus effects on shrimp health and significantly decreased total hemocyte cells, granulocyte cells, and hyaline cells by 30–50% in the period after three days of the challenge, except in L. plantarum treatment, which had only a 20% decrease compared to other treatments. In CNP supplying treatments, the AHPND infected rate and mortality of shrimp were higher than those in other treatments. In summary, the supply of CNP had significantly reduced the shrimp’s immune response and promoted the susceptibility of shrimp to AHPND in both cases of use with and without LAB-containing diets.

Probiotics inspired from natural ecosystem to inhibit the growth of Vibrio spp. causing white gut syndrome in Litopenaeus vannamei

Probiotics inspired by host-microbe interactions in the natural ecosystem are propitious in controlling bacterial infections in aquaculture and veterinary systems. Here we report the isolation and characterization of pathogenic Vibrio spp. and lactic acid bacteria from an intensive culture system of Litopenaeus vannamei and natural ecosystem, respectively. The pathogen isolated from the gut of L. vannamei showing the symptoms of white gut disease were identified as V. parahaemolyticus and V. campbelli. Both the pathogens expressed the virulence genes, rtxA, and tcpA and were showing multiple antibiotic resistance (MAR) index of more than 0.5. The lactic acid bacteria isolated from the sediment and gut of benthic organisms (shrimp and polychaetes) collected from a tropical estuary were classified as member of 9 OTUs such as Pediococcus stilessi, Lactobacillus fermentum, L. rhamnosus, Weissella cibaria, Enterococcus durans, E. fecalis, Streptococcus gallolyticus and L. garvieae. Majority of these isolates were facultative in nature and were able to tolerate gastric juice and bile salt. Out of 83 bacteria isolated from sediment and gut, 36 showed abilities to reduce the pH of culture medium to less than five. Many of these isolates (34 Nos.) showed production of hydrolytic enzymes and secondary metabolites with antagonistic activity against both the pathogens (1 No.) or separately toward V. parahaemolyticus (9 Nos.) and V. campbelli (11 Nos.). Overall, the current study proposes a natural ecosystem as a potential source of lactic acid bacteria with probiotic potentials to prevent the vibriosis disease outbreaks in shrimp aquaculture systems. Further studies are required to understand the abilities of lactic acid bacteria to colonize shrimp intestine, stimulate immune system and manipulate microbiome.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13205-020-02618-2.

Effects of probiotic and alpha-lipoic acid supplements, separately or in combination on the anthropometric indicators and maintenance of weight in overweight individuals

BACKGROUND & AIMS

Weight loss after proper diet is one of the main topics in nutrition. This study was designed to evaluate the effects of probiotic and alpha-Lipoic acid (ALA) supplements on the anthropometric indicators and maintenance of weight in overweight individuals.

METHODS

This study consisted of two phases of weight loss (8 weeks) and weight maintenance (16 weeks). Eighty-eight overweight participants were randomly divided into 4 groups in phase 1: isocaloric diet with probiotic (500 mg), an isocaloric diet with ALA (600 mg) and probiotic, an isocaloric diet with ALA and isocaloric diet with placebo. In phase 2, participants received a normal diet with the mentioned supplements. In the beginning, end of the phase 1, and at the end of phase 2, weight, body mass index (BMI), waist circumference (WC), hip circumference (HC), body fat percentage, and blood pressure (BP) were measured. Also, 10 cc blood samples were taken from subjects to measure C-reactive protein (CRP). Data was analyzed using SPSS software.

RESULTS

At the end of the two phases, the differences of changes in the probiotic + ALA group was significant in weight, WC, and CRP factors when compared to the other groups (P < 0.05). Also, at the end of the study, maintain a reduced weight was significantly higher in the probiotic + ALA group than in the other groups (P < 0.05).

CONCLUSION

According to findings, probiotics and ALA supplementation with normal diet help to maintain decreased weight after adhering to a weight loss diet. This may be due to the reduction of inflammation.

TRIAL REGISTRATION

(IRCT20141025019669N10).

Lactobacillus johnsonii BS15 Prevents Psychological Stress-Induced Memory Dysfunction in Mice by Modulating the Gut-Brain Axis

Researchers are attempting to harness the advantages of the gut–brain axis to prevent neurocognitive disorders by enhancing intestinal health. In this study, four groups of ICR mice were orally gavaged with either phosphate-buffered saline (control and CW groups) or the probiotic strain Lactobacillus johnsonii BS15 (P and PW group; daily amounts of 2 × 10⁸ colony-forming units) for 28 days. From days 22 to 28, the mice in the CW and PW groups were subjected to water-avoidance stress (WAS). The issue of whether psychological stress–induced memory dysfunction can be prevented via L. johnsonii BS15 pretreatment to modulate the gut–brain axis was investigated. Results show that L. johnsonii BS15 enhanced gut development by increasing villus height in the jejunum and ileum as well as villus height:crypt depth ratio in the ileum. L. johnsonii BS15 increased the activities of digestive enzymes, including trypsin and lipase in the jejunum and ileum. The intestinal goblet cell number was also increased by L. johnsonii BS15 pretreatment. Moreover, L. johnsonii BS15 balanced the gut microbiota by increasing the log₁₀ DNA gene copies of Lactobacillus spp. and L. johnsonii and decreasing that of Enterobacteriaceae in the cecum. L. johnsonii BS15 also exerted preventive effects on intestinal permeability WAS by modulating diamine oxidase and _D-lactate levels in the serum and mRNA expression levels of the tight junction proteins claudin-1, occludin, and ZO-1 in the jejunum and ileum. L. johnsonii BS15 pretreatment modulated inflammatory factors, specifically tumor necrosis factor-alpha, interferon-gamma, and interleukin-10. L. johnsonii BS15 pretreatment improved their performance in two behavioral tests, namely the novel object and T-maze tests. This result indicates that psychological stress–induced memory dysfunction possibly could be prevented through the gut–brain axis. In addition, L. johnsonii BS15 exerted beneficial effects on the hippocampus by modulating memory-related functional proteins, especially those related to synaptic plasticity, such as brain-derived neurotrophic factor and stem cell factor. Moreover, L. johnsonii BS15 recovered antioxidant capacity and exerted protective effects on mitochondrion-mediated apoptosis in the hippocampus. Collectively, the modulation of the gut–brain axis by L. johnsonii BS15 could be considered a promising non-invasive treatment modality for psychological stress–induced memory dysfunction.

Probiotics, lactic acid bacteria and bacilli: interesting supplementation for aquaculture

Probiotics administration in aquafeed is known to increase feed consumption and absorption due to their capacity to release a wide range of digestive enzymes and nutrients which can participate in digestion process and feed utilization, along with the absorption of diet components led to an increase in host's health and well-being. Furthermore, probiotics improve gut maturation, prevention of intestinal disorders, predigestion of antinutrient factors found in the feed ingredients, gut microbiota, disease resistance against pathogens and metabolism. The beneficial immune effects of probiotics are well established in finfish. However, in comparison, similar studies are less abundant in the shellfish. In this review, the discussions will mainly focus on studies reported the last 2 years. In recent studies, native probiotic bacteria were isolated and fed back to their hosts. Although beneficial effects were demonstrated, some studies showed adverse effects when treated with a high concentration. This adverse effect may be due to the imbalance of the gut microbiota caused by the replenished commensal probiotics. Probiotics revealed greatest effect on the shrimp digestive system particularly in the larval and early post-larval stages, and stimulate the production of endogenous enzymes in shrimp and contribute with improved the enzyme activities in the gut, as well as disease resistance.

Effects of dietary Pediococcus acidilactici GY2 single or combined with Saccharomyces cerevisiae or/and β-glucan on the growth, innate immunity response and disease resistance of Macrobrachium rosenbergii

One Pediococcus acidilactici strain, named PA-GY2 was isolated from the gut of cultured Macrobrachium rosenbergii. In order to better examine the potential scope and applicability of this strain in M. rosenbergii culture, based on the control diet, four experimental diets containing single or combined immunostimulants were produced by supplementing with yeast (Saccharomyces cerevisiae, SC) or/and β-glucan (G), then fed to the prawns (6.70 g ± 0.74) in five groups, which were named as group C (control group), P (PA-GY2), PS (PA-GY2 + SC, 1:1), PG (PA-GY2 + G) and PGS (PA-GY2 + SC + G), respectively. After a 60-day feeding trial, growth performance, feed utilization, immune response and disease resistance of prawns were evaluated in the present study. Results indicated that (1) The growth performance of the prawns in group PS and PGS were significantly improved. The prawns in group PGS presented the lowest feed coefficiency (FC), while prawns in group C presented the highest FC. (2) The protease activity was significantly improved by dietary immunostimulants supplementation, meanwhile, prawns in the group PS presented the highest lipase activity. (3) The highest total hemocyte count and respiratory burst activity were found in the group P and PG, respectively. The phagocytic index of the prawns in the group C was significantly lower than those in group P and PGS. (4) Dietary PA-GY2 single or combined with SC or/and β-glucan increased the immune related genes expression, including some antibacterial and antioxidant enzymes, while decreased the tumor necrosis factor-α gene expression, which led to the decreased cumulative mortality rate of prawns during the Aeromonas hydrophila challenge test. Based on the results of growth performance, digestive enzymes activity and immune response of M. rosenbergii, PA-GY2 supplementation, single or combined with SC or/and β-glucan could be suggested as promising immunostimulants in prawns farming.

Evaluation of Potential Probiotics Bacillus subtilis WB60, Pediococcus pentosaceus, and Lactococcus lactis on Growth Performance, Immune Response, Gut Histology and Immune-Related Genes in Whiteleg Shrimp, Litopenaeus vannamei

An eight-week feeding trial was conducted to evaluate the effects of different dietary probiotic supplements in juvenile whiteleg shrimp, Litopenaeus vannamei. A basal control diet without probiotics (CON), and five other diets by supplementing Bacillus subtilis at 10⁷ CFU/g diet (BS₇), B. subtilis (BS₈), Pediococcus pentosaceus (PP₈), and Lactococcus lactis (LL₈) at 10⁸ CFU/g diet, and oxytetracycline (OTC) at 4 g/kg diet were used. Whiteleg shrimp with initial body weights of 1.41 ± 0.05 g (mean ± SD) were fed with these diets. Growth of shrimp fed BS₈ and LL₈ diets was significantly higher than those of shrimp fed the CON diet (p < 0.05). Superoxide dismutase activity in shrimp fed PP₈ and LL₈ diets was significantly higher than that of shrimp fed the CON diet (p < 0.05). Lysozyme activity of shrimp fed probiotics and OTC diets significantly improved compared to those on the CON diet (p < 0.05). The intestinal histology showed healthier guts for shrimp fed the probiotic diets (p < 0.05). Immune-related gene expression in shrimp fed BS₈, PP₈ and LL₈ diets was recorded as significantly higher than that of shrimp fed CON and OTC diets (p < 0.05). Also, results of the challenge test for 7 days and the digestive enzyme activity of shrimp fed BS₈, PP₈, and LL₈ were significantly improved compared to those on the CON diet (p < 0.05). Therefore, these results indicated that L. lactis at 10⁸ CFU/g could be an ideal probiotic for whiteleg shrimp, and also B. subtilis WB60 and P. pentosaceus at 10⁸ CFU/g could improve the growth, immunity, histology, gene expression, digestive enzyme activity, and disease resistance, while replacing antibiotics.

Effect of Dietary Supplementation of Lactobacillus Casei YYL3 and L. Plantarum YYL5 on Growth, Immune Response and Intestinal Microbiota in Channel Catfish

Simple Summary

Channel catfish became one of the most efficient aquaculture species due to its fast growth and considerable commercial importance, however, the intensive farming of these fish resulted in disease pressure and the eutrophic conditions. In this study, we isolated two strains of lactobacillus, Lactobacilluscasei YYL3 and L. plantarum YYL5, which can be potentially used as feed additives to promote the growth performance, disease resistance against Edwardsiellaictaluri, and dramatically change the composition of intestinal microbiota of channel catfish.

Abstract

The purpose of this study is to investigate the effect of probiotics L. casei YYL3 (Lc) and L. plantarum YYL5 (Lp) on growth performance, innate immunity, disease resistance and intestinal microbiota of channel catfish. A total of 252 catfish (67.20 ± 1.46 g) were randomly divided into 3 groups which were fed with basal diet, Lc-added (3.0 × 10⁸ cfu/g) or Lp-added (3.0 × 10⁸ cfu/g) diets, respectively. After 4 weeks of feeding, Lc significantly enhanced the growth and feed utilization of channel catfish compared with the control group (CG). Following that, the catfish were challenged with an intraperitoneal injection of 200 μL of the pathogenic E.ictaluri (2.0 × 10⁶ cfu/mL), the relative percent survival of Lc and Lp were 38.28% and 12.76%, respectively. High-throughput sequencing indicated Lc and Lp reduced the alpha diversity of the intestinal microbiota in channel catfish. Lactobacillus were overwhelming in the guts during probiotics treatment, but almost vanished away after 2 weeks post-cessation of probiotics administration. Compared to CG, Lc and Lp resulted in an increased abundance of Pseudomonas and decreased amount of Aeromonas. Functional analysis revealed that Lc treatment upregulated the relative abundance of Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways including lipid metabolism, metabolism of other amino acids, metabolism of terpenoids and polyketides, xenobiotics biodegradation and metabolism, and nucleotide metabolism. Combined, our data revealed that Lc, as a feed additive at 3.0 × 10⁸ cfu/g, could promote the growth performance, disease resistance and dramatically change the composition of intestinal microbiota of channel catfish.

Effect of Clostridium butyricum in different forms on growth performance, disease resistance, expression of genes involved in immune responses and mTOR signaling pathway of Litopenaeus vannamai

A 42-day feeding trial was conducted to evaluate the effects of diet supplemented with various additives from Clostridium butyricum (fermentation supernatant, FS; live cells, LC; cell-free extract, CE; spray-dried spores, DS; mixture of live cells and supernatant, LCS) on the growth, intestinal morphology, disease resistance, immune gene expression and mTOR signaling-related gene expression in Litopenaeus vannamai. The feeding trial showed that the final weight and specific growth rate of the shrimp were improved significantly while the feed conversion ratio were reduced significantly in LC, CE, DS and LCS groups compared to the control. The villus height and intestinal wall thickness of shrimp's mid-intestine in LC, DS and LCS group increased significantly. After challenge test to Vibrio parahaemolyticus, the cumulative mortalities of the shrimp in LC, CE, DS and LCS groups were significantly lower than that of the control. As compared to the control, the relative expression levels of superoxide dismutase, lysozyme, prophenoloxidase (proPO), Toll, Immune deficiency (Imd), Relish, TOR, 4E-BP, eIF4E1α and eIF4E2 genes in the shrimp of DS and LCS groups enhanced significantly, whereas the relative expression levels of proPO, SOD, Toll, Imd, Relish, elF4E1α and elF4E2 genes were statistically the same between FS group and the control. These results suggested that the spray-dried spores and mixture of live cells and supernatant of C. butyricum exerted better probiotic benefits in modulating immune responses of shrimp. In addition, single supernatant could not be helpful to shrimp while mixture of live cells and supernatant could better improve the immune responses of shrimp in comparison to single live cells. The integration of C. butyricum and their metabolites supplemented into feed could significantly improve growth performance, intestinal morphology, immunity capacity and resistance against V. parahaemolyticus of L. vannamei.

Use of probiotics in aquaculture of China-a review of the past decade

China is the largest aquaculture producer in the world. Antibiotics were extensively used to ensure the development of the intensive aquaculture; however, the use of antibiotics causes safety- and environment-associated problems. As an alternative strategy to antibiotics, aquatic probiotics have attracted attention. The microbial organisms used as probiotics or tested as potential probiotics in Chinese aquaculture belong to various taxonomic divisions, including Actinobacteria, Bacteroidetes, Firmicutes, Proteobacteria and yeast. Moreover, the mixture of probiotic strains and synbiotics are also widely used. Studies on the mode of action of aquatic probiotics have extended our understanding of the probiotic effects, and novel mechanisms have been discovered, such as interference of quorum sensing. However, use of probiotics in Chinese aquaculture is still at an initial stage, and there are potential risks for some probiotic applications in aquaculture. Further regulation and management are required to normalize the production and usage of aquatic probiotics. In this review, we discuss species, effects, and mode of actions of probiotics in Chinese aquaculture since 2008. Challenges and future directions for research are also discussed.