Secretion Of Digestive Enzymes Research Articles

Alleviative effects of C60 fullerene nanoparticles on arsenate transformation and toxicity to Danio rerio

Widely-used C60 fullerene nanoparticles (C60) result in their release into the aquatic environment, which may affect the distribution and toxicity of pollutants such as arsenic (As), to aquatic organism. In this study, arsenate (As(V)) accumulation, speciation and subcellular distribution was determined in Danio rerio (zebrafish) intestine, head and muscle tissues in the presence of C60. Meanwhile we compared how single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNTs), graphene oxide (GO) and graphene (GN) nanoparticles alter the behaviors of As(V). Results showed that C60 significantly inhibited As accumulation and toxicity in D. rerio, due to a decrease in total As and monomethylarsonic acid (MMA) and As(V) species concentrations, a lower relative distribution in the metal-sensitive fraction (MSF). It was attributed that C60 may coat As(V) ion channels and consequently, affect the secretion of digestive enzymes in the gut, favoring As excretion and inhibiting As methylation. Similarly, MWCNTs reduced the species concentration of MMA and As(V) in the intestines, low GSH (glutathione) contents in the intestine. Due to the disparity of other carbon-based nanomaterial morphologies, SWCNTs, GO and GN exhibited the various effects on the toxicity of As(V). In addition, the possible pathway of arsenobetaine (AsB) biosynthesis included migration from the intestine to muscle in D. rerio, with the precursor of AsB likely to be 2-dimethylarsinylacetic acid (DMAA). The results of this study suggest that C60 is beneficial for controlling As(V) pollution and reducing the impact of As(V) biogeochemical cycles throughout the ecosystem.

Probiotic functional gene explorations in the genome of Limosilactobacillus fermentum GD5MG

Limosilactobacillus fermentum is an isolate obtained from oral gingival samples of healthy human individuals. The whole genome of Lb. fermentum GD5MG is composed of a circular DNA molecule containing 1,834,134 bp and exhibits a GC content of 52.80 %. The sequencing effort produced 38.6 million reads, each 150 bp in length, resulting in a sequencing depth of 2912.48x. Our examination unveiled a total of 1961 protein-coding genes, 27 rRNA genes, 24 tRNA genes, 3 non-coding RNA genes, and 63 pseudogenes with the use of gene annotations in NCBI Prokaryotic Genome Annotation tool. RAST revealed 1863 coding genes distributed across 209 subsystems, with a predominant involvement in amino acid, carbohydrate, and protein metabolism. Phylogenetic analysis infers that the Lb. fermentum GD5MG shares 281 gene clusters. Furthermore, the genome features showed a single CRISPR locus of 45 bp in length. Three genes associated with adhesion ability (strA, dltD, and dltA) and 26 genes related to acid tolerance, digestive enzyme secretion, and bile salt resistance were identified. Numerous genes associated with oral probiotic properties, comprising adhesion, acid and bile salt tolerance, oxidative stress tolerance, and sugar metabolism, were identified in the genome. Our findings shed light on the genomic characteristics of Lb. fermentum GD5MG, which are probable probiotics with functional benefits in humans.

Pancreatic Diseases: Genetics and Modeling Using Human Pluripotent Stem Cells.

Pancreas serves endocrine and exocrine functions in the body; thus, their pathology can cause a broad range of irreparable consequences. Endocrine functions include the production of hormones such as insulin and glucagon, while exocrine functions involve the secretion of digestive enzymes. Disruption of these functions can lead to conditions like diabetes mellitus and exocrine pancreatic insufficiency. Also, the symptoms and causality of pancreatic cancer very greatly depends on their origin: pancreatic ductal adenocarcinoma is one of the most fatal cancer; however, most of tumor derived from endocrine part of pancreas are benign. Pancreatitis, an inflammation of the pancreatic tissues, is caused by excessive alcohol consumption, the bile duct obstruction by gallstones, and the premature activation of digestive enzymes in the pancreas. Hereditary pancreatic diseases, such as maturity-onset diabetes of the young and hereditary pancreatitis, can be a candidate for disease modeling using human pluripotent stem cells (hPSCs), due to their strong genetic influence. hPSC-derived pancreatic differentiation has been established for cell replacement therapy for diabetic patients and is robustly used for disease modeling. The disease modeling platform that allows interactions between immune cells and pancreatic cells is necessary to perform in-depth investigation of disease pathogenesis.

Systemic Effects of a Phage Cocktail on Healthy Weaned Piglets.

Numerous studies have demonstrated that bacteriophages (phages) can effectively treat intestinal bacterial infections. However, research on the impact of phages on overall body health once they enter the intestine is limited. This study utilized weaned piglets as subjects to evaluate the systemic effects of an orally administered phage cocktail on their health. Twelve 21-day-old weaned piglets were divided into control (CON) and phage gavage (Phages) groups. The phage cocktail consisted of five lytic phages, targeting Salmonella enterica serovar Choleraesuis (S. choleraesuis), Enteropathogenic Escherichia coli (EPEC), and Shiga tox-in-producing Escherichia coli (STEC). The phages group received 10 mL of phage cocktail orally for 20 consecutive days. The results show that the phage gavage did not affect the piglets' growth performance, serum biochemical indices, or most organ indices, except for the pancreas. However, the impact on the intestine was complex. Firstly, although the pancreatic index decreased, it did not affect the secretion of digestive enzymes in the intestine. Secondly, phages increased the pH of jejunum chyme and relative weight of the ileum, and enhanced intestinal barrier function without affecting the morphology of the intestine. Thirdly, phages did not proliferate in the intestine, but altered the intestinal microbiota structure and increased concentrations of microbial metabolites isobutyric acid and isovaleric acid in the colonic chyme. In addition, phages impacted the immune status, significantly increasing serum IgA, IgG, and IgM, as well as serum and intestinal mucosal IFN-γ, IL-1β, IL-17, and TGF-β, and decreasing IL-4 and IL-10. They also activated toll-like receptors TLR-4 and TLR-9. Apart from an increase in basophil numbers, the counts of other immune cells in the blood did not change. This study indicates that the impact of phages on body health is complex, especially regarding immune status, warranting further attention. Short-term phage gavage did not have significant negative effects on health but could enhance intestinal barrier function.

Comparative study of leucine on digestive enzyme secretion, ISR and mTOR pathway in cattle and porcine pancreas in vitro

ABSTRACT This experiment is to investigate whether interspecies differences exist in the effects of leucine (Leu) on digestive enzyme secretion in pancreatic tissues through in vitro. Five healthy Simmental cattle and Duroc × Landrace × Yorkshire growing-finishing pigs were selected, and pancreatic tissues were taken for culture after slaughter. Leu levels of 0, 2.62, 5.24, 10.48 mg/mL. Leu levels of 0, 5.24 mg/mL were selected to determine the expression of mRNA and proteins in the signaling pathways. The results showed that Leu increased the activity of digestive enzyme in cattle and pig, and there was an interaction was found on trypsin and chymotrypsin (P < 0.05). Leu had a significant effect on the mRNA (PKB, S6K1, 4E-BP1 and ATF4) and protein expression (PKB and 4E-BP1) and the phosphorylation (PKB, S6K1 and ATF4) levels (P < 0.05). Animal species had significant effects on the mRNA (PKB, S6K1 and ATF4) and protein (S6K1 and 4E-BP1) expression, and the phosphorylation (4E-BP1) levels (P < 0.05). There was an interaction between animal species and Leu on the expression of protein (PKB and S6K1) (P < 0.05). In summary, interspecies differences exist in the regulation of Leu on digestive enzyme secretion in pancreatic tissues in vitro of different animals.

Pyrazole derivative Z10 ameliorates acute pancreatitis by inhibiting the ERK/Ddt pathway

Acute pancreatitis (AP) can lead to death; however, there is no specific treatment for AP. Screening of drugs for AP treatment is rarely performed. Compounds were screened in a primary pancreatic acinar cell and peritoneal macrophage coculture system. Compounds were used in vitro and in vivo. Compound targets were predicted and validated. Among the 18 nitrogen-containing heterocycles, Z10 was shown to decrease the cerulein plus lipopolysaccharide (CL)–induced secretion of both acinar digestive enzymes and macrophage cytokines. Z10 was also shown to ameliorate CL-induced or sodium taurocholate–induced AP in mice. Proteomics analysis and enzyme linked immunosorbent assay (ELISA) revealed that Z10 decreased the levels of D-dopachrome tautomerase (Ddt) within macrophages and those in the extracellular milieu under CL treatment. Z10 also decreased Ddt expression in AP mice. Moreover, exogenous Ddt induced cytokine and digestive enzyme secretion, which could be inhibited by Z10. Ddt knockdown inhibited CL-induced cytokine secretion. Medium from CL-treated macrophages induced the release of amylase by acinar cells, and Ddt knockdown medium decreased amylase secretion. The target of Z10 was predicted to be ERK2. Z10 increased the thermostability of ERK1/2 but not ERK1 K72A/ERK2 K52A. The docking poses of ERK1 and ERK2 with Z10 were similar. Z10 inhibited ERK1/2 phosphorylation, and Ddt levels and cytokines were regulated by ERK1/2 during AP. Additionally, Z10 could not further inhibit cytokines under ERK1/2 knockdown with CL. Thus, this study revealed that Z10-mediated ERK1/2 inhibition decreased Ddt expression and secretion by macrophages. Ddt inhibition decreased cytokine release and digestive enzyme secretion.

Exocrine pancreatic insufficiency as a possible predictor of pancreatic cancer development.

679 Background: Chronic and acute pancreatitis are established risk factors for pancreatic cancer. Chronic pancreatitis and pancreatic cancer are also common causes of exocrine pancreatic insufficiency (EPI), which is characterized by inadequate pancreatic secretion of exocrine digestive enzymes. Although the association between EPI and pancreatic cancer has been thought to be linked by preceding chronic pancreatitis, it is unclear if EPI, regardless of etiology, is a risk factor or early marker for pancreatic cancer or cancer in general. Methods: This is a retrospective observational study utilizing the electronic health records of Ochsner Health System, Louisiana, over a 3-year period from January 2017 to January 2020 to identify patients with a diagnosis of EPI by ICD-10 codes. Two cohorts were reviewed: patients with EPI (n=677) and patients with pancreatitis (n=1852). Both history of acute and/or chronic pancreatitis were included in the pancreatitis cohort. The cohorts were compared based on cancer prevalence at the start and end of the 3 year observation period. Results: In the EPI cohort, the cancer prevalence was 15.95% (108) at start, and 43.9% (297) at end, (p&lt;0.05); and pancreatic cancer prevalence at start was 6.65% (123) and 29.8% (552) at end (p&lt;0.05). In the pancreatitis cohort, the cancer prevalence was 5.4% (100) at start and 15.9% (294) at end (p&lt;0.05); and pancreatic cancer 0.8% at start and 5% at end (p&lt;0.05). Conclusions: Over a 3 year period, the rise in prevalence of general cancer and pancreatic cancer was higher in the EPI cohort compared to the pancreatitis cohort. Additionally, there was a statistically significant 2.8-fold increase in prevalence of cancer diagnosis and 4.5-fold increase in prevalence of pancreatic cancer diagnosis in the EPI cohort over the 3 year observation period. Though this is an observational study, it suggests the possibility that EPI, regardless of etiology, may be an independent predictor/risk factor for the development of future cancer in general and pancreatic cancer in particular. In addition it appears that this risk potential is substantively greater than that from a history of pancreatitis alone.

Cardiometabolic risk comorbidities in exocrine pancreatic insufficiency compared to patients with cancer: A single centered observational retrospective cohort study.

642 Background: Exocrine pancreatic insufficiency (EPI) is characterized by inadequate secretion of digestive enzymes. EPI is associated with increased risk for pancreatic cancer as well as increased risk for diabetes and consequently cardiometabolic (CM) risk equivalents. Emerging data suggest patients with cancer also have increased CM risk equivalents. To explore the cardiovascular risk associated with both EPI and cancer, we sought to describe and compare CM comorbidities and surrogates in patients with EPI vs cancer. Methods: A retrospective observational electronic chart analysis was done at Ochsner Health, Louisiana, spanning records from January 2017-2020 comparing two cohorts: patients with EPI (n=677) and patients with Cancer (n=1432). Results: The Cancer cohort was older (65.1 ± 11.9 yrs) than the EPI cohort (54.2 ± 17.6 yrs) (p &lt; 0.05). The Cancer cohort had higher AST levels (63.2 ± 106.2 U/L [nl 8-33 U/L] at start, 84.9 ± 447.3 U/L at end) vs the EPI cohort (50.2 ± 86.9 U/L at start, 65.4 ± 368.9 U/L at end) (p &lt; 0.05). The Cancer cohort also had higher ALT levels (69 ± 111.4 U/L (nl 7-55 U/L) at start, 58.5 ± 141.2 U/L at end) vs the EPI cohort (48.7 ± 79.5 U/L at start, 41.4 ± 100.3 U/L at end) (p &lt; 0.05). No significant differences were seen in Cancer cohort vs EPI cohort for A1c, TG, amylase, lipase, cholesterol, uric acid, tobacco/alcohol use, or blood pressure levels. Within the Cancer cohort, there was an increase in neuropathy (11% at the start vs 26.9% at end [p &lt; 0.05]), CHF (3.63% at the start vs 11.5% at end [p &lt; 0.05]), and HTN prevalence (29.9% at the start vs 66.1% at end [p &lt; 0.05]). Cancer patients also had decreased weight (175.2 ± 46.5 lbs at start, 163.8 ± 43.4 lbs at end [p &lt; 0.05]) and BMI (27.3 ± 6.5 at start, 25.7 ± 6.4 at end [p &lt; 0.05]). Among the general cancer cohort, no statistically different changes were seen in hypoglycemia, DKA, retinopathy, nephropathy, ESRD, dialysis, HLD, NAFLD, OSA, CAD, CVD, PAD, hyperuricemia, or gout prevalence over the period of observation or in comparison to EPI cohort. Conclusions: Patients in the Cancer cohort in this study have some indices of greater CM risk compared to those with EPI. Though older, they had significantly higher AST and ALT levels compared to EPI cohort. Over the 3 years of observation, cancer patients developed a statistically significant increase in neuropathy, CHF, and HTN prevalence, and decrease in weight and BMI. These changes may reflect consequent morbidity related both to natural disease progression and/or effects of cancer treatments such as chemotherapy.

The Localization of Cell Wall Components in the Quadrifids of Whole-Mount Immunolabeled Utricularia dichotoma Traps.

Utricularia (bladderworts) are carnivorous plants. They produce small hollow vesicles, which function as suction traps that work underwater and capture fine organisms. Inside the traps, there are numerous glandular trichomes (quadrifids), which take part in the secretion of digestive enzymes, the resorption of released nutrients, and likely the pumping out of water. Due to the extreme specialization of quadrifids, they are an interesting model for studying the cell walls. This aim of the study was to fill in the gap in the literature concerning the immunocytochemistry of quadrifids in the major cell wall polysaccharides and glycoproteins. To do this, the localization of the cell wall components in the quadrifids was performed using whole-mount immunolabeled Utricularia traps. It was observed that only parts (arms) of the terminal cells had enough discontinuous cuticle to be permeable to antibodies. There were different patterns of the cell wall components in the arms of the terminal cells of the quadrifids. The cell walls of the arms were especially rich in low-methyl-esterified homogalacturonan. Moreover, various arabinogalactan proteins also occurred. Cell walls in glandular cells of quadrifids were rich in low-methyl-esterified homogalacturonan; in contrast, in the aquatic carnivorous plant Aldrovanda vesiculosa, cell walls in the glandular cells of digestive glands were poor in low-methyl-esterified homogalacturonan. Arabinogalactan proteins were found in the cell walls of trap gland cells in all studied carnivorous plants: Utricularia, and members of Droseraceae and Drosophyllaceae.

Evaluation of Anti-Foodborne Bacterial Activity, Digestive Enzyme Secretion, and Antimicrobial Resistant Genes as Probiotic Strains Selection for Industrial Interest

Beneficial microbes, such as probiotic bacteria, are increasingly in demand in the food and feed industry. Lactic acid bacteria and bifidobacteria are commonly used as commercial probiotics, only a few species have been isolated from Southeast Asia areas. This study employed criteria including antimicrobial activity, the release of digestive enzymes, and the absence of antibiotic-resistant (AMR) genes to screen potential local isolates. The results revealed that 4 out of 16 isolates met these criteria, displaying anti-foodborne bacterial activities and a lack of fifty-one tested AMR genes. Furthermore, the four selected isolates demonstrated the production of extracellular digestive enzymes, including amylase, lipase, protease, β-glucanase, and cellulase, with enzyme indices ranging from 1.09–1.31. Among these isolates, two potential probiotics were identified as Bifidobacterium animalis subsp. lactis (strain H9-01) and Lactobacillus reuteri (strain P4-S03). Importantly, both species are approved for use as food and feed supplements in accordance with Thai regulations. This research outlines an approach for screening potential probiotics for industrial-scale applications.

Exploring the Role of Hyperinsulinemia in Obesity-Associated Tumor Development.

Although there has been a long-standing connection between hyperinsulinemia and cancer development, there is a lack of understanding of the role of the insulin receptor on cells that can become cancerous. In a recent issue of Cell Metabolism, Zhang and colleagues, using a diet-induced obesity mouse model, identified a direct function of insulin receptors on pancreatic acinar cells expressing a KRASG12D mutation in promoting obesity-associated pancreatic cancer. Furthermore, insulin receptor signaling from hyperinsulinemia promoted the secretion of digestive enzymes that contributed to acinar to ductal metaplasia. These findings highlight an important connection between obesity, diabetes, and pancreatic tumor development and suggest potential strategies for obesity-associated cancer prevention targeting the insulin receptor signaling pathways.

Exocrine pancreatic insufficiency in dogs and cats.

Exocrine pancreatic insufficiency (EPI) is a malabsorptive syndrome caused by insufficient secretion of digestive enzymes from pancreatic acini. The most common causes of EPI in dogs and cats are pancreatic acinar atrophy and chronic pancreatitis. EPI is diagnosed by measurement of species-specific immunoassays for serum trypsin-like immunoreactivity, the concentration of which directly reflects the mass of functioning pancreatic acinar tissue. EPI is treated by pancreatic enzyme replacement therapy, nutritional management (low-residue diets with moderate fat content), and supplementation of cobalamin. Some dogs and cats have persistent clinical signs despite these treatments. Growing evidence suggests that these clinical signs may be due to enteric microbiota dysbiosis or the presence of concurrent diseases such as chronic enteropathies. Management of these abnormalities may improve outcome in dogs and cats with EPI. The long-term prognosis for dogs and cats with EPI is generally good if high-quality medical therapy is provided. Future studies are needed to further understand the causes of persistent dysbiosis in animals with EPI following initiation of pancreatic enzyme replacement therapy and assess the efficacy of treatments to ameliorate these abnormalities.

Impact of predigestion feed on the growth of tilapia (Oreochromis niloticus)

The addition of simplified feed or predigestion feed is one of the alternative solutions in helping the process of utilizing feed by tilapia seeds with incomplete digestive tract conditions or limited secretion of digestive enzymes. The purpose of this study was to analyze the impact of predigestion feed on the growth of tilapia (Oreochromis niloticus). The design used in this study was a completely randomized design (CRD) with treatments in the form of differences in pancreatic enzyme concentrations (0%, 3%, 6%, and 9%) with 3 replications each. Parameters observed include the coefficient of diversity, specific growth rate (SGR), and feed efficiency. The results of this study showed that the lowest coefficient of diversity, the highest specific growth rate, and the highest feed efficiency were owned by the 9% treatment with a value of 16.07%, 4.95 %/day, and 84.02%, respectively. Provision of predigestion feed on tilapia fry significantly affected the growth of tilapia (Oreochromis niloticus). Provision of predigestion feed with an enzyme concentration of 9% gave optimal results.

Starvation induces hepatopancreas atrophy in Chinese mitten crab (Eriocheir sinensis) by inhibiting angiogenesis

BackgroundThe hepatopancreas of crustaceans serves as a significant organ for both the synthesis and secretion of digestive enzymes, as well as energy storage. In the event of food shortage, the hepatopancreas can provide energy for survival. To investigate the potential regulatory mechanisms of the hepatopancreas in response to starvation in Eriocheir Sinensis, transcriptome analysis, histological study and qRT-PCR were performed.ResultsThe results showed that starvation caused a decrease in the hepatopancreas index of E. sinensis, which had certain effects on the tissue structure, metabolism and angiogenesis in the hepatopancreas. In addition, WGCNA and linear regression analysis showed that the genes significantly related to the hepatopancreas index were mainly enriched in the angiogenesis pathway, in which AKT signaling played an important role. Starvation may inhibit AKT signaling pathway by reducing the expression of TGFBI, HSP27, HHEX, and EsPVF1, thereby hindering angiogenesis, promoting apoptosis, and leading to hepatopancreas atrophy.ConclusionThese results indicate that AKT plays an important role in the angiogenesis pathway and apoptosis of the starvation induced hepatopancreas index reduction, which is beneficial to further understand the effect of starvation stress on hepatopancreas of Chinese mitten crab.

Digestive exophagy of biofilms by intestinal amoeba and its impact on stress tolerance and cytotoxicity

The human protozoan parasite Entamoeba histolytica is responsible for amebiasis, a disease endemic to developing countries. E. histolytica trophozoites colonize the large intestine, primarily feeding on bacteria. However, in the gastrointestinal tract, bacterial cells form aggregates or structured communities called biofilms too large for phagocytosis. Remarkably, trophozoites are still able to invade and degrade established biofilms, utilizing a mechanism that mimics digestive exophagy. Digestive exophagy refers to the secretion of digestive enzymes that promote the digestion of objects too large for direct phagocytosis by phagocytes. E. histolytica cysteine proteinases (CPs) play a crucial role in the degradation process of Bacillus subtilis biofilm. These proteinases target TasA, a major component of the B. subtilis biofilm matrix, also contributing to the adhesion of the parasite to the biofilm. In addition, they are also involved in the degradation of biofilms formed by Gram-negative and Gram-positive enteric pathogens. Furthermore, biofilms also play an important role in protecting trophozoites against oxidative stress. This specific mechanism suggests that the amoeba has adapted to prey on biofilms, potentially serving as an untapped reservoir for novel therapeutic approaches to treat biofilms. Consistently, products derived from the amoeba have been shown to restore antibiotic sensitivity to biofilm cells. In addition, our findings reveal that probiotic biofilms can act as a protective shield for mammalian cells, hindering the progression of the parasite towards them.

High-efficiency expression of a novel antimicrobial peptide I20 with superior bactericidal ability and biocompatibility in Pichia pastoris and its efficiency enhancement to aquaculture

One of the major constraints on aquaculture is the susceptibility of farmed fish to diseases or slow growing. Antimicrobial peptide I20, as a novel feed additive, is used to cope with these limiting factors. In the current study, the Pichia pastoris expression system was used to produce I20 in large quantities, thereby reducing its application cost. In terms of molecular strategy, the I20 expression codon was optimized according to the preference of P. pastoris codon. Through traditional strategy optimization (expression strain, time, methanol concentration, temperature, and pH), the expression level of I20 in shaking bottles was 21.09 ± 1.10 mg/L. Surprisingly, the expression level of I20 in a 20 L high-cell-density cultivation was 514.78 ± 22.07 mg/L after methanol induction of 72 h. Comprehensive analyses using a series of fluorescence and microscopy revealed that I20 killed bacteria by increasing bacterial membrane permeability and binding bacterial DNA. I20 effectively killed a variety of pathogenic bacteria (Aeromonas hydrophila, Aeromonas veronii, Elizabethkingia miricola, Flavobacterium columnare, Edwardsiella ictaluri, Vibrio parahaemolyticus, Streptococcus agalactiae, Nocardia seriolae, Escherichia coli, and Staphylococcus aureus). I20 was found to have excellent biocompatibility after both feeding and injection studies. Grass carp were fed I20 diet supplemented with 200 mg/Kg I20 for 8 weeks. I20 can effectively promote intestinal villus length, secretion of digestive enzymes, and expression of growth genes to improve growth performance. I20 significantly promotes immune response to reduce tissue damage and bacterial load, enhancing survival after Aeromonas hydrophila infection. In conclusion, we systematically optimized the expression of antimicrobial peptide I20 in P. pastoris, and achieved a satisfactory efficiency for producing antimicrobial peptide I20 by integrating several strategies. The results herein showed that I20-feed promoted growth performance and disease resistance in fish, suggesting a feed supplement with great potential applications for aquaculture.

The growth and probiotic characteristics of Bacillus velezensis BS in soybean meal used as synbiotic-like preparations for Litopenaeus vannamei culture

Soybean meal (SBM) is the by-product of soybean oil extraction. It is well known to contain at least 47% protein and more than 6% crude fiber. This study showed that Bacillus velezensis BS grew well in medium containing 1% SBM and gained the prebiotic index and activity score of 15.40 ± 4.10 and 0.85 ± 0.22, respectively. In this medium, B. velezensis BS showed various probiotic characteristics, such as digestive enzyme secretion (α-amylase, cellulase, and protease), anti-Vibrio parahaemolyticus, biofilm formation on the solid surface after 24 h of interaction and the ability to grow in a broad range of environmental conditions (pH 6-9, temperature of 20-45ºC, salinity of 4%). In addition, SBM fermented with B. velezensis BS significantly reduced 79.7 ± 1.9% of the trypsin inhibitor content. Dietary supplement of the fermented product in Litopenaeus vannamei culture improved the specific growth rate of shrimp by approximately 7 times and concomitantly decreased the density of V. parahaemolitycus pathogen by 10 times compared to the group without synbiotic-like fed. Hence, the B. velezensis BS and its SBM fermented product were suggested as a potential feed additive in aquaculture applications.

Immunotoxicity and the mechanisms of aflatoxin B1-induced growth retardation in shrimp and alleviating effects of bile acids

Aflatoxin B1 (AFB1) is one of the most toxic mycotoxins prevalent in the environment and food chain, posing severe health risks to humans and animals. Bile acids are natural detergents synthesized from cholesterol and play a key role in the excretion of toxins in vertebrates. Here, pacific white shrimp (Litopenaeus vannamei) served as an animal model to examine the toxicity mechanisms of AFB1 and assess the potential alleviating effects of bile acids against AFB1. Our results revealed that AFB1 exposure significantly inhibited the growth performance and immune response of shrimp, accompanied by AFB1 accumulation and histological damage. Mechanistically, AFB1-induced DNA damage activated DNA repair mechanisms and induced the arrest of cell cycle via the ATR-cyclin B/cdc2 pathway. Additionally, AFB1 directly suppressed the immune response and growth performance of shrimp by inhibiting Toll and IMD pathways and the secretion of digestive enzymes. Notably, dietary bile acids significantly reduced AFB1 accumulation and alleviated AFB1-induced growth retardation and immunotoxicity in shrimp, and CCKAR, ATR, and Relish may be key mediators of the alleviating effects of bile acids. Our study provided new insights into the toxicity mechanisms of AFB1 in invertebrates and highlighted the potential of bile acids to alleviate AFB1 toxicity.

Nutritional innovations in superior gilthead seabream (Sparus aurata) genotypes: Implications in the utilization of emerging new ingredients through the study of the patterns of secretion of digestive enzymes

To promote sustainability and efficiency for aquaculture production, there are two key actions: i) The implementation of novel nutritional strategies with more sustainable raw materials, that aim to reduce the dependence on fishmeal (FM) and fish oil (FO) in the feeds, and ii) the implementation of a successful breeding program addressed to improve fish growth, feed utilization, and health. Different studies performed on salmonids and European sea bass (Dicentrarchus labrax) support the existence of genetic variability for the utilization of plant or non-marine-based diets. Nevertheless, those studies do not consider that the better zootechnical performance obtained in selected fish can be associated with differences in digestive biochemistry. Therefore, the present study aimed to evaluate the changes in the levels of the activities of different digestive enzymes present in two populations of gilthead seabream (Sparus aurata): reference or selected for high growth. Furthermore, the effect of different diets including a variety of protein ingredients partially substituting FM (poultry meal, insect meal, and bacterial single-cell protein) was assessed on the digestive enzyme profile of both fish genotypes, after 90 days of feeding. Higher levels of certain protein-related enzymes (pepsin and chymotrypsin) were found in selected sea bream fish compared with reference fish. Selected fish also revealed higher ADCs for dietary amino acids, irrespective of the diet fed, compared with the reference group. These results, added to the better growth and feed utilization of selected sea bream compared with reference fish, suggest that selected fish are more able to utilize the combination of emergent ingredients for aquafeeds, showing changes in the pattern of digestive enzymes to face the different ingredients in diets, which indicates a higher plasticity of the digestive enzymes to face changes in dietary ingredients. Those changes could be reflecting a compensatory mechanism to improve the digestibility of the ingredient.

Untargeted Analysis of Serum Metabolomes in Dogs with Exocrine Pancreatic Insufficiency.

Exocrine pancreatic insufficiency (EPI) is a malabsorptive syndrome resulting from insufficient secretion of pancreatic digestive enzymes. EPI is treated with pancreatic enzyme replacement therapy (PERT), but the persistence of clinical signs, especially diarrhea, is common after treatment. We used untargeted metabolomics of serum to identify metabolic disturbances associated with EPI and generate novel hypotheses related to its pathophysiology. Fasted serum samples were collected from dogs with EPI (n = 20) and healthy controls (n = 10), all receiving PERT. Serum metabolomes were generated using UPLC-MS/MS, and differences in relative metabolite abundances were compared between the groups. Of the 759 serum metabolites detected, 114 varied significantly (p < 0.05, q < 0.2) between dogs with EPI and healthy controls. Differences in amino acids (arginate, homoarginine, 2-oxoarginine, N-acetyl-cadaverine, and α-ketoglutaramate) and lipids (free fatty acids and docosahexaenoylcarnitine) were consistent with increased proteolysis and lipolysis, indicating a persistent catabolic state in dogs with EPI. Relative abundances of gut microbial metabolites (phenyllactate, 4-hydroxyphenylacetate, phenylacetyl-amino acids, catechol sulfates, and o-cresol-sulfate) were altered in dogs with EPI, consistent with disruptions in gut microbial communities. Increased kynurenine is consistent with the presence of intestinal inflammation in dogs with EPI. Whether these metabolic disturbances participate in the pathophysiology of EPI or contribute to the persistence of clinical signs after treatment is unknown, but they are targets for future investigations.