Intestinal Villi Research Articles

Enteric α-Defensin Contributes to Recovery of Radiation-Induced Intestinal Injury by Modulating Gut Microbiota and Fecal Metabolites.

The effect of ionizing radiation on the gastrointestinal tract is a common complication of abdominal and pelvic radiotherapy. However, the pathological features of radiation enteropathy and its effective medical intervention regimen is still a global challenge. Here, we explored the role and mechanism of enteric alpha-defensins (EαDs) in protecting against radiation enteropathy. To address this, we utilized EαDs-deficiency mice, in which the matrix metallopeptidase 7 to activate Paneth cell α-defensins was knockout (KO) mice, and the complementary wild-type (WT) control mice for this study. Remarkably, the KO mice were more susceptible to 5.0 Gy total-body irradiation, resulting in worse clinic scores and lower survival rate, compared with the wild-type mice. Histological examination indicated that the KO mice were subjected to slow recovery of intestinal villus and mucosa function, characterized by the reduced expression of TFF3, Glut1 and Muc2. In addition, compared with the wild-type controls, the KO mice experienced serious inflammation response in intestinal tissue, indicated by the remarkably increased expression level of IL-1β, IL-6 and IL-12. Using high-throughput sequencing analysis, we found that the intestinal bacterial community of the KO mice was more prone to dysbiosis than that of the WT mice, with significantly increased abundance of opportunistic pathogenic bacteria, such as Streptococcus sp. and Escherichia-Shigella sp., whereas remarkably decreased probiotics harboring Lactobacillus sp., Desulfovibrio sp. etc. Fecal metabolomics analysis indicated that the relative abundance of 31 metabolites arose significantly different between WT and KO mice on day 10 after radiation exposure. A subset of differential metabolites to regulate host metabolism and immunity, such as acetic acid, acetate, butanoic acid, was negatively correlated with the alteration of gut microbiota in the irradiated KO mice. This study provides new insight into EαDs contribution to the recovery of radiation-induced intestinal damage, and suggests a potential novel target to prevent the adverse effects of radiotherapy.

Optimization of Selenium Inclusion Level in the Larval Diet of Labeo rohita.

The nutritional requirement of fish larvae remains a limiting factor in advanced aquaculture. Micronutrients are crucial for early development, but their dietary inclusion level in the larval feed of carps has not been standardized. The present study was executed to determine the optimum dietary inclusion level of organic and inorganic selenium in the larval feed of Rohu, Labeo rohita. A 35-day feeding trial in triplicate under semi-control conditions was conducted in 21 troughs divided into seven groups. Each trough (capacity 4.0 L) contained 200 larvae (average body weight 0.4mg). The first group (control) was reared on nano-particulate basal diet (CP 50%), while three groups Se-Na(0.5), Se-Na(1), and Se-Na(1.5) were fed basal diet supplemented with graded levels (0.5-1.5mg/kg diet) of inorganic form of Se, sodium selenite (Se-Na). The last three groups (Se-Met(0.5), Se-Met(1), and Se-Met(1.5)) were fed organic form of dietary Se, selenium methionine (Se-Met) at the same inclusion level as Se-Na. Results indicated the curvilinear relationship of dietary Se levels with body weight, activity of digestive enzymes (protease, amylase, lipases, and trypsin), and antioxidant enzymes (SOD, CAT, POD, and GSH-Px) activity, intestinal villi, width, and absorptive area. A positive correlation was observed with up to 0.5 and 1mg/kg diet of Se-Na and Se-Met, respectively; however, above these levels, a negative impact was observed. The upregulation of growth hormone mediator (IGF-1) and downregulation of heat shock protein (HSP-70) also followed a similar trend in response to Se-Na and Se-Met inclusion. Based on the results, 1mg/kg diet Se-Met could be considered the optimum level and is recommended for the early rearing of rohu larvae.

Reparative effect of different dietary additives on soybean meal-induced intestinal injury in yellow drum (Nibea albiflora).

Soybean meal (SBM) is an acceptable replacement for unsustainable marine fish meal (FM) in aquaculture. However, we previously reported that high dietary SBM supplementation causes intestinal inflammatory injury in yellow drum (Nibea albiflora). Accordingly, a 4-week SBM-induced enteritis (SBMIE) in yellow drum trial was conducted first, followed by a 4-week additive-supplemented reparative experiment to evaluate the reparative effect of five additives on SBMIE in yellow drum. The control diet comprised 50% FM protein substituted with SBM. The additive-supplemented diet was added with 0.02% curcumin (SBMC), 0.05% berberine (SBM-BBR), 0.5% tea polyphenols (SBM-TPS), 1% taurine (SBM-TAU), or 0.8% glutamine (SBM-GLU) based on the control diet, respectively. The weight gain (WG), specific growth rate (SGR), feed efficiency ratio (FER), and survival rate (SR) of fish fed the additive-supplemented diets were significantly higher than those of fish fed the SBM diet. The WG, SGR, and FER of fish fed the SBMC, SBM-GLU and SBM-TAU diets were significantly higher than those of fish fed other diets. Moreover, fish fed the additive-supplemented diets SBMC and SBM-GLU, exhibited significantly increased intestinal villus height (IVH), intestinal muscular thickness (IMRT), and intestinal mucosal thickness (IMLT) and significantly decreased crypt depth (CD) in comparison with those fed the SBM diets. The relative expression of intestinal tight junction factors (ocln, zo1), cytoskeletal factors (f-actin, arp2/3), and anti-inflammatory cytokines (il10, tgfb) mRNA was remarkably elevated in fish fed additive-supplemented diets than those of fish fed the SBM diet. Whereas, the relative expression of intestinal myosin light chain kinase (mlck) and pro-inflammatory cytokines (il1, il6, tnfa) mRNA was markedly lower in fish fed the additive-supplemented diets. The highest relative expression of intestinal ocln, f-actin, and arp2/3 and the lowest relative expression of intestinal mlck were found in fish fed the SBMC diet. Hence, all five dietary additives effectively repaired the intestinal injury induced by SBM, with curcumin exhibiting the strongest repair effect for SBMIE in yellow drum.

Microalgal biomass-assisted delivery of probiotics for modulation of gut homeostasis and alleviation of intestinal inflammation

The clinical application of orally delivered probiotics as live therapeutics in the treatment of colitis is hampered by suboptimal bacterial bioactivity and inadequate gut retention. Here, we present a novel symbiotic approach that combines Spirulina microalgae and probiotics (SP@BC) to enhance the therapeutic efficacy of bacteriotherapy. The SP@BC is established by attaching chitosan-coated probiotic strains (BCCS) on Spirulina platensis (SP) via electrostatic self-assembly. Following oral administration, the natural antioxidative bioenzymes present in SP can persistently protect probiotics from oxidative damage in inflamed intestines. Furthermore, the helical-shaped SP can be easily trapped by the intestinal villi, resulting in a significantly enhanced gut retention of the SP@BC system. In a mouse model of colitis, orally administrated SP@BC distinctly improves intestinal permeability, reduces gut inflammation, and restores intestinal microbial homeostasis. The microalgae-assisted delivery of probiotics is highly effective, safe, and easily manufacturable, showcasing promising potential for the clinical translation of probiotic therapies.

The impact of gut microbiota on vascularization of the small intestine

The commensal microbiota resides in a mutualistic relationship within the mammalian gut. It significantly influences the formation of capillary networks in the small intestine, not only during development but also in adulthood. Mucosal capillaries in small intestinal villus structures play a critical role for the uptake of dietary nutrients and immune regulation. Emerging studies have elucidated how the composition of gut microbiota can influence not only postnatal gut development regarding immune tolerance, nutrient absorption, and morphology but also the development and maintenance of blood and lymphatic capillaries within the small intestine. In particular, the analysis of gnotobiotic mouse models affirmed the importance of the gut microbiota, or even only single gut bacteria, in the remodeling of the small intestinal capillaries. Here, different epithelial-to-endothelial cross talk pathways, e.g. Paneth cell-derived signals, Toll-like receptor signaling, or tissue factor–protease activated receptor-1 signaling, have been reported to affect intestinal villus vascular remodeling in a microbiota-dependent fashion. In this review article, we will provide a comprehensive overview on the relevant microbiota–host interaction pathways, which have been revealed to influence angiogenesis and vascular remodeling in the small intestine.

Effects of LED Light Colors on the Growth Performance, Intestinal Morphology, Cecal Short-Chain Fatty Acid Concentrations and Microbiota in Broilers

This study aimed to explore the effects of light-emitting diode (LED) light colors on growth, intestinal morphology, and cecal microbiota in broilers. A total of 360 healthy male Arbor Acres (AA) broilers with similar weights were selected and divided into four groups with six replicates in each group and 15 broilers in each replicate: LED white light (W), LED green light (G), LED blue light (B), and LED blue–green composite light (BG). The experimental period was 42 d, the light cycle of each treatment group was 23L:1D (23 h of light, one hour of darkness) from 1 to 3 d, and the light cycle from 4 to 42 d was 16L:8D; light intensity was 20 Lux. The results showed that the average daily feed intake and final weight of broilers receiving the B group were the highest in 21 d and 42 d compared with other groups. The average daily feed intake of the BG group was lower than that of the B group. In the same light color, small intestine villus height grows with age. On days 21 and 42, compared with other groups, the ileal villus height was higher, the crypt depth was lower, and the V/C ratio (villus to crypt ratio) was higher in the BG group. The combination of blue–green composite light was beneficial to increase the content of propionate, isobutyrate, butyrate, isovalerate, and valerate in the cecum of 21-day-old broilers and the content of isobutyrate in the cecum of 42-day-old broilers, and a decrease in cecal short-chain fatty acid concentrations with age. The B group and the BG group had higher abundances of Bacteroidetes at day 21 of age and lower abundances of Phascolarctobacterium at day 42. However, no cecal microbiota differences were detected by the Bonferroni-corrected test. In general, our research results showed that light color could promote the growth of broilers by affecting intestinal morphology, microbiota abundance (needs to be validated by further experiments), and cecal short-chain fatty acid concentrations. And blue and blue–green composite lights are more suitable for broiler growth.

Synergetic Role of Energy and Oat with Enzymes on Physiological Performance of Broiler

This study was conducted in poultry fields at College of Agriculture / University of Anbar’s Animal Production Department from 2/9/2022 to 14/10/2022 (42 days). This study examined the physiological effects of high energy and oats on grill performance. Three hundred one-day-old (unsexed) chicks were distributed in a completely randomised design to ten treatments with three replicates (10 chicks per replicate). All diets were designed to meet the same requirements. Broilers received water and feed ad libitum. Treatments were as follows: T1 birds fed diets for three phases (starter, grower, and finisher) without any addition, T2 birds fed diet (starter 3100 Kcal /kg feed) + 5% oat + 0.01 mg multienzyme, T3 birds fed diet (starter 3000 Kcal/kg feed) + 5% oat + 200 mg multienzyme, T4 birds fed starter 2900 Kcal/kg feed + 5% oat + 200 mg multienzyme, T5 birds fed diet (grower 3200 Kcal/kg feed) + 5% oat + 200 mg multienzyme, and T6 birds fed diet The 5% oat hull groups had higher small intestine villus height and CD than the control group (p < 0.05). T6 group glucose is higher than control group glucose. T10 group and control group total protein differ significantly (P>0.05). The control group’s albumin, MDA, and GPT levels are not significantly different from the other groups. Dietary oat hull increased Glutamic-Oxaloacetic Transaminase (GOT) activity in T6 compared to control group, but control group had higher ALP activity.

Exploring fibrous ingredients for fish: The case of feeding sugar beet pulp to tambaquí (Colossoma macropomum)

For a long time, co-products of food processing have been used in animal feed, but far less in fish because of their assumed inability to cope with high-fiber diets. Research on feeding co-products to fish species that naturally consume fibrous diets are yet lacking. We here evaluated the impact of sugar beet pulp in the diet of tambaquí on nutrient metabolism, oxidative stress, inflammation, and intestinal histomorphometry. A total of 18 tambaquí fish (1616 ± 107 g; 2 years old) were randomly divided over 6 similar tanks with 3 fish per tank and randomly attributed to one of the six dietary treatments 0, 5, 10, 15, 20 and 25 % beet pulp addition and reared for 8 weeks. Water quality parameters (pH, NH3–N, EC, TDS, DO, and temperature) were assessed and recorded twice a week for each tank. A quadratic increase in intestinal villus length, paravilli and absorptive surface were observed with beet pulp addition. Ammonia and pH as quality indicators were significantly changing with beet pulp addition. A higher supply of glucogenic substrate to the citric acid cycle was noticed with beet pulp addition due to the positive correlation with blood propionylcarnitine: acetylcarnitine ratio while there was no effect on ketone body synthesis as measured through the 3-hydroxybutyrylcarnitine: acetylcarnitine ratio. No pronounced change of serum and whole fish histamine and lowered concentrations of serum malondialdehyde were observed with beet pulp addition. In conclusion, beet pulp induced a marked increase in intestinal villus architecture without signs of inflammation or oxidative stress. Large-scale studies need to clarify if these features lead to improved growth performance but this work opens options for further study. The non-linear pattern of some blood components with increasing beet pulp may call for future optimal dosing and feed form of beet pulp together.

Effects of adding spermidine carbon quantum dots in feed on growth, intestinal morphology, immunity and disease resistance of Anguilla japonica and Anguilla marmorata

Japanese eel (Anguilla japonica) and giant mottled eel (Anguilla marmorata) are the main eel species reared in recirculating aquaculture system (RAS) in Taiwan. RAS increases the rearing density of eel. On the other hand, it spreads pathogens and diseases more efficiently and uncontrollably. Currently, eel farmers use antibiotics to control disease in RAS, but their misuse can lead to resistance and food-safety issues. Spermidine carbon quantum dots (CQDSpds), a newly developed carbon nanomaterial with positive charges on the surface, can bind to the negatively charged bacterial cell membrane to destroy bacteria and not cause drug resistance. This research investigated the effects of different concentrations of CQDSpds as paste feed additives on the growth performance, intestinal morphology, immune-related gene expression, and disease resistance of Japanese and giant marble eels. The results showed the highest final body weight, weight gain, and specific growth rate of Japanese eel and giant mottled eel fed with 1 ppm and 0.5 ppm CQDSpds added. Compared with the control group, 1 ppm CQDSpds group showed higher lysozyme expression in Japanese eels. In the part of intestinal morphology, there was not a significant difference in intestinal villus height and intestinal morphology between the CQDSpds groups and the control group in both eel species. The survival rate of each group supplemented with CQDSpds was higher than the control group after the E. tarda challenge test, among which the highest were found at 1 ppm group in Japanese eel and 0.5 ppm group in giant mottled eel. By this research, the additive of CQDSpds in eel culturing could improve the growth and immune performance with not caused an impact on the intestine of both eels, which can be a potential feed additive in intensive eel farming.

Glutathione-rich yeast hydrolysate makes the contributions to growth performance, healthy of Pacific white shrimp (Litopenaeus vannamei), and helps shrimp resist nitrite stress

Seven diets were formulated to investigate the effects of glutathione-rich yeast hydrolysate (GYH) on growth performance, antioxidant capacity, and innate immunity of Litopenaeus vannamei. Based on the control diet (28% fishmeal content, CON), six diets supplement with GYH 0% (G0), 0.3% (G0.3), 0.5% (G0.5), 0.7% (G0.7), 0.9% (G0.9) and 1.1% (G1.1) were prepared after cottonseed protein concentrate replacing fishmeal 28.5% of the CON. After the 8 weeks feeding experiment, the shrimp fed diet containing 0.5%− 0.9% GYH obtained better growth performance compared to the CON and G0 groups, as well as the significantly lower feed conversion rate (P < 0.05). The intestinal villus height of shrimp fed diet with 0.3–0.9% GYH was significantly higher than the G0 group (P < 0.05). Decreased serum malondialdehyde content and significantly increased total antioxidant capacity, reduced glutathione content, activity of glutathione peroxidase and phenoloxidase in the hepatopancreas were found in shrimp fed diet with 0.7–0.9% GYH (P < 0.05). In addition, supplement 0.5–0.9% GYH significantly upregulated the expression levels of genes igf-1, pi3k, akt, tor, s6k1, and 4ebp1 in muscle and increased the crude protein content of the whole shrimp (P < 0.05). The expression levels of genes lgbp, proPO and lzm in the hepatopancreas were significantly upregulated in shrimp fed 0.7% GYH supplement (P < 0.05). Serum CAT activity in the G0.9 group was significantly higher than that of the G0 group before and after nitrite stress (P < 0.05). The shrimp fed diet supplemented with 0.5–1.1% GYH exhibited better intestinal tissue structure compared to groups CON and G0 after nitrite stress. In conclusion, the optimum level of dietary GYH was 0.67% based on the analysis of the quadratic term fitting results of weight gain rate. The diets supplemented with appropriate GYH could contribute to the growth and health of shrimp.

The effects of Capsicum annuum oleoresin, as a dietary carotenoid, on growth, gut microbiome, intestinal histomorphometry, and sensory characteristics of Oncorhynchus mykiss

AbstractThis study was designed to explore the dietary effects of Capsicum annuum oleoresin (CAO) on growth, body composition, sensory characteristics, gut microbiome, and intestinal histomorphometry of rainbow trout. Fish (195.13 ± 1.55 g) were fed diets with various CAO levels (0.0‐Control, 7.0‐ g kg −1 C7, 14.0 g kg −1 ‐C14, 21.0 g kg −1‐C21, and 28.0 g kg −1‐C28) for a 30‐day period. Results revealed that the maximum growth was achieved in C7 and C14 groups. Nevertheless, the growth parameters were similar in other groups compared to the control. Moreover, there were significant increases in dry matter and crude lipid contents in all CAO groups compared with the controls. The mean abundances (%) of the prevalent bacteria at the genus level in the intestinal trout samples presented no significant changes among the test groups. Dietary CAO significantly changed the intestinal histological structure, and was manifested by an increased number of goblet cells in the CAO‐supplied groups. However, there were intestinal villus epithelial deformations associated with increasing dietary CAO, and were most prominent in the C28 group. The sensory attributes of cooked trout fillets showed that capsicum's pungent odor and taste was evident in the C14 group and subsequently increased with increasing dietary CAO levels. Accordingly, the results showed, for the first time, that dietary CAO at levels (7–14 g kg−1) can enhance the growth of rainbow trout without negative effects on the sensory characters and gut health.

Effects of Fermented Soybean Meal Substituting Plant Protein and Fish Meal on Growth, Flesh Quality, and Intestinal Microbiota of Largemouth Bass (Micropterus salmoides)

This study investigated the effects of replacing soybean meal (SM), corn gluten meal (CGM), and fish meal (FM) with fermented soybean meal (FSM) on growth performance, flesh quality, and intestinal microbiota of largemouth bass. In a diet with 400 g/kg FM inclusion (FSM-0), FSM was used to substitute 120 g/kg SM, 120 g/kg SM + 80 g/kg CGM, and 65 g/kg FM at the inclusion of 100 g/kg (FSM-10-SM), 200 g/kg (FSM-20), and 100 g/kg (FSM-10-FM), respectively. Then, largemouth bass weighing 225.7 ± 2.6 g was fed the four diets for 60 days. The WG of FSM-20 group was increased by 11.8% ( P &lt; 0.05 ), while FSM-10-SM and FSM-10-FM groups did not differ significantly from FSM-0 group in growth performance. Compared with the FSM-0 group, the flesh hardness, shear force, total collagen, hot soluble collagen, and total free amino acid contents of FSM-20 group were significantly increased, and FSM-10-SM group also presented higher flesh hardness and shear force. The flesh superoxide dismutase (SOD) and total antioxidant capacity (TAOC) activities in FSM-20 and FSM-10-FM groups and glutathione peroxidase (GSH-Px) activity in FSM-10-FM group were increased ( P &lt; 0.05 ), while the lactic acid content in FSM-20 group was decreased, when compared to FSM-0 group ( P &lt; 0.05 ). In serum biochemical indexes, the glucose, total protein, cholesterol and malondialdehyde contents in the three FSM groups, and the triglyceride content in FSM-10-SM and FSM-20 groups were significantly lower than those of FSM-0 group ( P &lt; 0.05 ). In intestinal histology, the intestinal villus width, muscle thickness in FSM-10-SM group and intestinal villus width in FSM-20 group were significantly higher than those of FSM-0 group. In intestinal microbiota, the three FSM groups showed higher abundance of Firmicutes and lower abundance of Proteobacteria than FSM-0 group. In summary, the replacement of 120 g/kg SM or 65 g/kg FM with 100 g/kg FSM (FSM-10-SM and FSM-10-FM groups) did not exhibit significant effect on growth performance, but partially improved the flesh quality of largemouth bass. The substitution of 120 g/kg SM + 80 g/kg CGM with 200 g/kg FSM (FSM-20 group) significantly improved weight gain and flesh quality of largemouth bass.

Dietary effects of supplementing Clostridium butyricum culture or sodium butyrate in low fishmeal diet on growth, serum indicators, intestinal histology and microbiota of largemouth bass (Micropterus salmoides)

The present study aimed to evaluate the dietary effects of Clostridium butyricum culture (CC) or sodium butyrate (SB) on the growth, feed utilization, serum indicators, intestinal histology and microbiota of largemouth bass (Micropterus salmoides). CC and coated SB (50%) were supplemented to a low fish meal diet (245 g/kg) (control diet) at the inclusion levels of 1 g/kg and 2 g/kg, to form five iso-nitrogenous and iso-lipidic diets (control, CC-1, CC-2, SB-1, and SB-2). Then, the five diets were fed to largemouth bass with initial body weight of 70.2 ± 0.1 g. After 8 weeks of feeding, dietary supplementation of 1 g/kg CC increased the weight gain (WG) by 7.4% (P < 0.05), and decreased the feed conversion ratio by 0.09 (P < 0.05), while dietary SB just numerically improved the WG (P > 0.05), when compared to the control. The muscle composition was not significantly affected by the inclusion of CC or SB (P > 0.05). Dietary inclusion of CC or SB significantly reduced serum diamine oxidase activity and increased lysozyme activity (P < 0.05), while the decreased D-lactic acid level was observed only in the two SB groups (P < 0.05). In intestinal histology, the 1.0 g/kg CC group presented significantly higher intestinal villus height, width and muscle layer thickness than the control group (P < 0.05). The intestinal microbiota analysis showed that dietary CC or SB (1 g/kg) increased the abundance of Fusobacteriota and Cetobacterium, decreased the abundance of Proteobacteria and Aeromonas. In conclusion, the supplementation of CC in low fish meal diet promoted the growth performance, feed utilization, and both CC and SB supplementation positively modulated the intestinal microorganism community of largemouth bass.

Retinol is involved in the intestinal regeneration and strengthens the intestinal barrier during refeeding in broiler chickens

Fasting is typically used before feeding metabolizable energy assessment in broilers. Previous studies have shown that fasting cause atrophy of the intestinal villus. Whether fasting affects intestinal permeability during refeeding by altering barrier function and nutrient absorption is of concern. Here, 23-d-old broilers were randomly assigned to 5 treatments, fasted for 0, 12, 24, 36, and 48 h, respectively, and then refed for 2 d, to study the impact of different duration of fasting on the intestinal regeneration and barrier function during refeeding. Results showed that the intestinal morphology in fasted birds was recovered in 2 d of refeeding at most. As fasting durations increased, enterocytes per intestinal villus were linearly and quadratically increased (both P<0.05), whereas goblet cells per intestinal villus was linearly decreased (both P<0.05). Besides, the mRNA level of lysozyme was linearly decreased as fasting durations increased during refeeding (both P<0.05), while quadratically increased mucin 2 was observed only after 1 d of refeeding (P<0.05). Linear increase effects were observed for claudin 2 and zonula occludens-1 with increased fasting durations after 1 d of refeeding (all P<0.05), and linear and quadratical effects were observed for claudin 2 at 2 d of refeeding (both P<0.05). Besides, we found that intestinal permeability to creatinine, 4 and 70 kD dextran were linearly and quadratically decreased with increased fasting durations at 6 h and 1 d of refeeding (all P<0.05). Furthermore, jejunum proteomic from birds refed for 6 h showed that birds fasted for 36 h showed increased antimicrobial peptides and upregulated retinol metabolism when compared to the nonfasted birds (P<0.05). Further study showed that retinyl ester catabolism was inhibited during fasting and enhanced during refeeding. Results of intestinal organoid culture showed that retinol benefits the cell proliferation and enterocyte differentiation. In conclusion, the intestinal permeability to small and large molecules was decreased during refeeding by strengthening the intestinal barrier function, and the activated retinol metabolism during refeeding is involved in the intestinal regeneration and strengthens the intestinal barrier.

Preliminary Study to Assess the Impact of Dietary Rutin on Growth, Antioxidant Capacity, and Intestinal Health of Yellow Catfish, Pelteobagrus fulvidraco

This research aimed to examine the effects of dietary rutin supplementation on growth, body composition, serum biochemical indexes, liver enzyme activities and antioxidant-related genes expression, intestinal morphology, and microbiota composition of juvenile yellow catfish (Pelteobagrus fulvidraco). Rutin was added to the basal diets at doses of 0 (control), 100 mg/kg, and 500 mg/kg. Each diet was fed randomly into three tanks, each tank containing 30 fish with an initial body mass of (10.27 ± 0.62) g. The feeding trial was conducted in an indoor recirculating aquiculture system at 28 °C for 56 days. According to the findings, the inclusion of 100 mg/kg rutin significantly improved the growth performance of yellow catfish and reduced the feed conversion ratio; however, the growth promotion effect was diminished when the diet was supplemented with 500 mg/kg of rutin. The inclusion of 500 mg/kg rutin in the diet significantly reduced the level of crude lipid and protein of the whole fish. Serum activities of alkaline phosphatase, albumin, and total protein were all significantly increased when fish were fed the diet supplemented with 500 mg/kg rutin, while serum glucose was significantly lower compared to the control group. Meanwhile, dietary rutin at a concentration of 500 mg/kg significantly induced the hepatic mRNA expressions of antioxidant-related genes (including Cu/Zn-SOD, Mn-SOD, CAT, GPx) and inflammatory-associated genes (including TNFα, IL-10, LYZ). Incorporating rutin at doses of 100 mg/kg and 500 mg/kg into the diets resulted in a notable increase in superoxide dismutase (SOD) activity, while simultaneously reducing malondiadehyde (MDA) content in the liver and intestine. Intestinal villus height, villus width, muscular thickness, and lumen diameter were significantly increased with the administration of 500 mg/kg of dietary rutin. Gut microbial diversity analysis indicated that supplementing diets with 100 mg/kg and 500 mg/kg rutin significantly enhanced the abundance of Cetobacterium while decreasing Plesiomonas richness. In conclusion, dietary rutin levels at 100 mg/kg could enhance the growth, antioxidant capability, and intestinal health of yellow catfish under present experimental conditions.

Effect of multi-enzyme supplementation on growth performance, digestibility, blood profile, intestinal villus height, and faecal gas emission in weaning pigs

Effect of multi-enzyme supplementation on growth performance, digestibility, blood profile, intestinal villus height, and faecal gas emission in weaning pigs

Effects of dietary arachidonic acid supplementation in low fishmeal and fish oil-free diets on growth performance, inflammatory response, gut histology, and non-specific immunity in sub-adult rainbow trout, Oncorhynchus mykiss

Arachidonic acid (ARA) is becoming increasingly important due to significant reductions in fishmeal (FM) and fish oil (FO), the primary sources of ARA, in aquafeeds. ARA is an essential omega-6 fatty acid in some fish species and plays a wide range of physiological roles. However, studies reported to date have demonstrated contrasting findings concerning the effects of ARA in fish growth and health, regardless of the fish's trophic level. Additionally, limited research has addressed energy allocation during reproduction and growth in sub-adult rainbow trout as they approach reproductive maturity. Therefore, a study was conducted to evaluate the effects of different levels of ARA on growth performance, the fatty acid composition of whole-body and ovary, intestinal inflammatory gene expression, gut histology, antioxidant activity, and non-specific immunity in sub-adult rainbow trout (Oncorhynchus mykiss). Four isonitrogenous (51% crude protein), isolipidic (15% crude lipid), and isocaloric (23 MJ/kg) diets were formulated and supplemented with ARA-enriched oil (40%), resulting in analyzed ARA levels of 0.10 (ARA0.10), 3.95 (ARA3.95), 7.67 ARA(7.67), and 14.8% (ARA14.8) of total fatty acid, respectively. Rainbow trout (307 ± 3.64 g) were fed to apparent satiation three times a day for 12 weeks to assess growth performance, feed utilization, and intestinal inflammatory response. The fish were then exposed to acute stress to evaluate circulating cortisol, prostaglandin E2, antioxidant activity, and non-specific immune response. The 12-week growth trial demonstrated that dietary ARA did not affect rainbow trout growth performance and feed utilization during the final grow-out. Whole-body fatty acid profiles reflected those of the diets except for eicosapentaenoic acid (EPA) content being significantly lower in the ARA14.8 group than in the ARA0.10 and ARA3.95 groups. EPA and docosahexaenoic acid (DHA) contents in the ovary were less affected by dietary ARA supplementation, likely reflecting the selective deposition of those fatty acids in embryonic development. The expression of tnf-α was significantly downregulated in ARA7.67 and ARA14.8 groups relative to other treatment groups, and only distal intestinal villus height was significantly increased in the ARA3.95 group, suggesting that dietary ARA supported intestinal health. Plasma superoxide dismutase, catalase, and lysozyme activity significantly increased in both pre- and post-stress groups due to incremental increases in dietary ARA. These results suggest that a moderate level of dietary ARA in low FM and FO-free enhances innate immune function and antioxidant responses while supporting intestinal health in sub-adult rainbow trout.

Effects of Trichinella spiralis and its serine protease inhibitors on autophagy of host small intestinal cells.

In eukaryotes, autophagy is induced as an innate defense mechanism against pathogenic microorganisms by self-degradation. Although trichinellosis is a foodborne zoonotic disease, there are few reports on the interplay between Trichinella spiralissurvival strategies and autophagy-mediated host defense. Therefore, this study focused on the association between T. spiralis and autophagy of host small intestinal cells. In this study, the autophagy-related indexes of host small intestinal cells after T. spiralis infection were detected using transmission electron microscopy, hematoxylin and eosin staining, immunohistochemistry, quantitative real-time polymerase chain reaction, and Western blotting. The results showed that autophagosomes and autolysosomes were formed in small intestinal cells, intestinal villi appeared edema, epithelial compactness was decreased, microtubule-associated protein 1A/1B-light chain 3B (LC3B) was expressed in lamina propria stromal cells of small intestine, and the expression of autophagy-related genes and proteins was changed significantly, indicating that T. spiralis induced autophagy of host small intestinal cells. Then, the effect of T. spiralis on autophagy-related pathways was explored by Western blotting. The results showed that the expression of autophagy-related pathway proteins was changed, indicating that T. spiralis regulated autophagy by affecting autophagy-related pathways. Finally, the roles of T. spiralis serine protease inhibitors (TsSPIs), such as T. spiralis Kazal-type SPI (TsKaSPI) and T. spiralis Serpin-type SPI (TsAdSPI), were further discussed in vitro and in vivo experiments. The results revealed that TsSPIs induced autophagy by influencing autophagy-related pathways, and TsAdSPI has more advantages. Overall, our results indicated that T. spiralis induced autophagy of host small intestinal cells, and its TsSPIs play an important role in enhancing autophagy flux by affecting autophagy-related pathways. These findings lay a foundation for further exploring the pathogenesis of intestinal dysfunction of host after T. spiralis infection, and also provide some experimental and theoretical basis for the prevention and treatment of trichinellosis.

Yeast extract improves growth in rainbow trout (Oncorhynchus mykiss) fed a fishmeal-free diet and modulates the hepatic and distal intestine transcriptomic profile

Replacing fishmeal with alternative protein sources and improving new ingredients diets with feed additives are major objectives in aquaculture. The aim of this study was to evaluate benefits for rainbow trout (Oncorhynchus mykiss) of supplementing a fishmeal-free diet, composed of processed animal proteins (dehydrated poultry protein, hydrolyzed feather meal, poultry and pork blood meal), with yeast extract. Juvenile rainbow trout (initial weight 37 ± 2 g) were fed either with a control diet (19% fishmeal) or with a diet based on terrestrial animal by-products (17%) supplemented or not with 3% of yeast extract. Effects of the diets were evaluated in a 4-week digestibility trial and a 12-week growth experiment. Fish health was investigated by measuring plasma immune markers and performing histological study of the gut. Underlying molecular responses were investigated using unbiased transcriptomic analysis of the liver and distal intestine. Results indicated that supplementing with 3% yeast extract did not influence nutrient digestibility substantially. Nevertheless, fish fed the yeast supplemented fishmeal-free diet grew more than those fed the non-supplemented processed animal protein diet (final body weight of 206.7 ± 14.2 g vs 182.3 ± 13.5 g) but less than their counterparts fed the fishmeal diet (230.5 ± 7.6 g). Plasma and structural parameters indicated no exacerbated immune response or signs of intestinal inflammation in fish fed the fishmeal-free diets. However, plasma total immunoglobulin M levels and intestinal villi were significantly higher in fish fed the diet supplemented with yeast extract. The transcriptomic analysis revealed that the diets influenced immune, inflammatory, pathogen fighting and coagulation gene-related expressions. These results suggest that the dietary inclusion of yeast can enhance a fishmeal-free diet by improving rainbow trout performances and potentially their robustness.

Lactobacillus plantarum E2 regulates intestinal microbiota and alleviates Pseudomonas plecoglossicida induced inflammation and apoptosis in zebrafish (Danio rerio)

Pseudomonas plecoglossicida infection is a highly contagious epidemic in aquaculture, causing significant mortality among teleost. Our previous research has demonstrated that Lactobacillus plantarum E2 is beneficial for large yellow croaker in resisting infections caused by P. plecoglossicida. However, the relevant mechanisms remain largely unclear. In the present study, we used zebrafish (Danio rerio) to further explore the function of L. plantarum E2 and its mechanisms for resisting P. plecoglossicida infection. E2 supplementation diet significantly improved the growth rates and α-amylase and trypsin activities of the liver in zebrafish. After challenge with P. plecoglossicida strain PQLYC4, the survival rates of zebrafish were improved, and immune-related genes expression (IL-1β, TNF-α, IL-8, Ig-Z, TLR-22 and IL-12α) were down-regulated. Histological analysis showed that E2 group had a longer intestinal villus and thicker intestinal walls after 30 days of feeding and healthier intestinal structure after challenge with P. plecoglossicida strain PQLYC4. Furthermore, co-incubation of zebrafish embryo fibroblast (ZF-4 cells) with L. plantarum E2 reduced apoptosis of ZF-4 cells after exposed to P. plecoglossicida. Intestinal microbiota analysis showed that E2 strain significantly increased the relative abundance of Lactobacillus and Pseudomonas, and PCoA analysis revealed a noticeable divergence in the intestinal microbial communities after E2 supplement. Together, our results suggested that E2 strain may promote zebrafish survival against P. plecoglossicida infection by regulating the intestinal microbiota and alleviating inflammatory response and apoptosis, thus exhibiting the potential as a probiotic.