The combined effects of microplastics and bisphenol-A on the innate immune system response and intestinal microflora of the swimming crab Portunus trituberculatus

Microplastics (MPs) and bisphenol-A (BPA) have been shown to have toxic effects on aquatic organisms. However, data on the combined effects of MPs and BPA on the innate immune system response and intestinal microorganisms of crabs are limited. Here, Portunus trituberculatus were exposed to BPA (at a concentration of 100 μg/L), MPs (microbeads of polystyrene with a particle size of 1 µm and at a concentration of 1 × 106 particles/L) or BPA+MPs for 21 days were tested at the tissue, cellular, and molecular levels. The results showed that neither the single nor combined exposure of MPs and BPA had a significant impact on the growth of crabs. However, intestinal histology study found that the intestinal villi of crabs in the BPA treated group, MP treated group and MP+BPA treated group appeared abnormal. Overall, compared with the control group and the single pollutant exposure group, co-exposure to the MP and BPA generally led to a significant increase in MDA and SOD activity and a significant decrease in CAT activity, and the activation of MyD88, Crustin-1, TARF6, Cu/Zn-SOD, Lyz, Toll-2 and NOX gene expression levels were significantly up-regulated. Co-exposure induced disorders of the intestinal microbial community of crabs, resulting in an increase in the abundance of harmful bacteria and a decrease in the abundance of beneficial bacteria. This study shows that the combined exposure of MPs and BPA can exacerbate the intestinal toxicity of a single pollutant to P. trituberculatus.

Effects of heatwave events on the seagrass-dwelling crustacean Pandalus latirostris in a subarctic lagoon

Heatwaves often cause mass mortality of organisms in seagrass areas, and they eventually alter some ecological functions of seagrass ecosystems. In subarctic regions, however, the effects of heatwaves on seagrass areas are still unclear. In a subarctic lagoon of northern Japan, we examined the effects of heatwaves on the Hokkai shrimp, Pandalus latirostris, a commercially exploited species distributed in seagrass areas of northern Japan and eastern Russia. A long-term survey of the surface water temperature in the lagoon clarified a gradual increase in the frequency and intensity of heatwave events since 1999. Surveys of the water temperature at a seagrass area in the lagoon during summer have also demonstrated that the maximum water temperature had been exceeding 25 °C, unusually high for this location, regardless of water depth. These results indicate that the effects of heatwaves in seagrass areas in a subarctic region had become as severe as those in tropical and temperate regions. We also experimentally evaluated the effects of this unusually high water temperature (25 °C) on the survival of P. latirostris by changing the length of exposure time. Some individuals suffered damage to their intestinal mucosal structure after exposure for 12 h or longer, and all individuals died after exposure for 120 h. Our results suggest that heatwaves possibly cause mass mortality in P. latirostris in the following sequence: heat stress, damage to the intestinal epithelial mucosal structure, degradation of nutrient absorption and immunological function of the intestine, energy deficiency and disease infection, and finally mortality. This study, conducted in subarctic closed waters, concludes that it is essential to become familiar with not only trends in heatwaves but also the intermittent occurrence of unusually high water temperature in seagrass areas in order to better understand the process of mortality of organisms that inhabit these ecosystems.

Effects of high temperature stress on the intestinal histology and microbiota in Yesso scallop Patinopecten yessoensis

High temperature stress posed by global warming is considered as one of the greatest threats to marine ectotherms by altering their behavior and physiological functions. The intestine and its associated microbiota constitute the first defensive line for the animals against environmental stresses, but their responses to high temperature stress in mollusks are largely unknown. In the present study, the changes of intestinal histology and microbiota were investigated in Yesso scallop Patinopecten yessoensis, a cold-water bivalve species, after high temperature stress. The shrinkage of intestinal lumen, shortening of intestinal villi and increased goblet cells were observed in the intestines of scallops exposed to seawater temperatures of 20 °C (T20 group) and 23 °C (T23 group), compared to the control group (15 °C). High-throughput sequencing of 16S rRNA gene showed that the composition of intestinal microbiota rather than the alpha diversity indices changed significantly after high temperature stress. At the phylum level, the relative abundances of Proteobacteria and Firmicutes decreased progressively with increasing temperature, while that of Bacteroidetes increased by 1.18-fold in the T20 group and 0.95-fold in the T23 group. At the genus level, Tenacibaculum and Mycoplasma were significantly enriched after high temperature stress, and Mycoplasma exhibited highest abundance of 39.43% in the T23 group. Functional prediction revealed that the pathways related to amino acid biosynthesis were blocked after high temperature stress, while that of phospholipases showed the opposite trend. According to the results of network analysis, the network connectivity decreased with increasing temperature, while the percentages of negative correlations in the two high temperature groups were higher than that in the control group. Collectively, the intestinal histology and microbial community of P. yessoensis changed significantly after high temperature stress, which would hinder the nutrient absorption and promote the proliferation of pathogenic microorganisms in the intestine of scallops. Our results will provide novel insights into the occurrence mechanism of mass summer mortality in marine mollusks.

Ameliorative role of dietary acidifier potassium formate on growth metrics, blood chemistry, gut health and well-being indices of rohu, Labeo rohita fingerlings

Organic acids and their derivatives have been attributed to growth and well-being improvement in fish when supplemented in their diets. Therefore, this study was conducted to evaluate the ameliorative role of potassium formate (PF) in rohu Labeo rohita fingerlings. A total of 240 healthy rohu fingerlings (9.0 ± 0.5 g ± SE) were randomly divided into four equal groups in triplicates. Fish were fed with isonitrogenous feeds: PF10 (10 g PF/kg), PF20 (20 g PF/kg) and PF30 (30 g PF/kg). Feed without PF supplementation served as control. The results indicated that the specific growth rate (SGR) and feed conversion ratio (FCR) were significantly (p<0.05) higher in PF10. Total serum globulin content was found significantly (p<0.05) elevated in PF10 after the bacterial challenge. Non-specific lysozyme activity was significantly higher (p<0.05) after the challenge. The digestive protease enzyme activity was significantly (p<0.05) improved in PF10 treatment. Additionally, the digestive morphology of the treated fish was seen to be improved. Greater villus area, increased villus number, reduced lumen space in the hindgut, reduced vacuolation in mucosal folds and proliferation of goblet cells-like changes were observed in the PF-supplemented fish. Significantly (p<0.05), a higher relative percentage of survival (RPS) was observed in PF10 and PF20 treatments. The study revealed that the dietary supplementation of rohu fingerlings with lower levels of potassium formate could enhance the nutritional efficiency and physiological activities of rohu fingerlings. This study serves as a baseline for future research on the application of formic acid derivatives and other acidifiers in carp culture.

Atrazine exposure and recovery alter the intestinal structure, bacterial composition and intestinal metabolites of male Pelophylax nigromaculatus

The pesticide atrazine poses a potential threat to the health of frogs living in farmland areas. The exposure concentration in traditional pesticide experiments is usually constant, while pesticide pollution in actual water may fluctuate due to periodic or seasonal application. We examined the effects of different concentrations of atrazine (50, 100 and 500 μg/L) over a 14-day exposure and a 7-day recovery on intestinal histology, bacterial composition and intestinal metabolites of male Pelophylax nigromaculatus. HE staining revealed that after a 14-day atrazine exposure, the 100 μg/L and 500 μg/L groups showed obvious cysts and significantly decreased intestinal crypt depth and villus height. After a 7-day recovery, the damaged intestine in the 100 μg/L group was partially recovered, while in the 500 μg/L exposure group there was no improvement. 16S rRNA gene analysis of intestinal bacteria showed that 500 μg/L atrazine exposure significantly caused a persistent decrease in bacterial α diversity. Compared to the control and other atrazine exposure groups, the 500 μg/L group showed significant changes in the relative abundance of predominant bacteria. In addition, most dominant bacteria in the 500 μg/L recovery group showed significant differences with the 50 μg/L and 100 μg/L recovery groups. Nontargeted metabolomics profiling based on UPLC/MS analysis showed that atrazine exposure and recovery induced changes in the intestinal metabolic profile. The changes in metabolites were mainly related to purine/pyrimidine metabolism, glycine, serine and threonine metabolism, and arginine and proline metabolism. In general, these pathways were closely related to energy metabolism and amino acid metabolism. These results suggest that the short-term exposure to 500 μg/L atrazine causes persistent harm to intestinal health. This study is an important step toward a better understanding of the toxic effects of atrazine exposure and recovery in frog intestines.

Dietary effects of Clostridium autoethanogenum protein substituting fish meal on growth, intestinal histology and immunity of Pacific white shrimp (Litopenaeus vannamei) based on transcriptome analysis

The study investigated the dietary effects of Clostridium autoethanogenum protein (CAP) substituting fish meal on the growth, intestinal histology, serum immune indexes and transcriptome of Pacific white shrimp, Litopenaeus vannamei. Four isonitrogenous and isolipidic diets were designed as the control diet (CON) containing 560 g/kg fish meal, and three fish meal-substituted diets in which 30% (CAP-30), 45% (CAP-45) and 70% (CAP-70) fish meal were replaced with CAP, respectively. The four diets were fed to shrimp with initial body weight of 2.78 ± 0.13 g for 8 weeks. The results showed that the weight gain, feed intake, survival and intestinal villus height in CAP-45 and CAP-70 groups were lower than those of the control and CAP-30 groups (P < 0.05). In addition, the serum aspartate aminotransferase and phenol oxidase activities in all fish meal-substituted groups, and the lysozyme activity in CAP-45 and CAP-70 groups were increased, while the total protein content in CAP-45 and CAP-70 groups was decreased when compared with the control (P < 0.05). Transcriptome profiling of hepatopancreas indicated that high inclusion of CAP negatively affected the protein synthesis and the utilization of nutrients by regulating pancreas secretion, protein digestion and absorption, ribosome pathways, and disturbed the immune system and metabolic processes by phagosomes and lysosomes pathways, thereby affecting the growth performance and immune function of shrimp. In conclusion, CAP could substitute 30% fish meal in a diet containing 560 g/kg fish meal without adverse effects on the growth, intestinal histology and immunity of Pacific white shrimp.

Growth performance, intestinal histomorphology, gut microflora and ghrelin gene expression analysis of broiler by supplementing natural growth promoters: A nutrigenomics approach

In an epoch of escalating number of antibiotic-resistance bacteria, there is a dire need to develop efficient and novel feeding strategies for animal nutrition as alternatives to antibiotics. Here, implicating nutrigenomic approach, phytobiotics and organic acids were used to evaluate ghrelin gene expression levels, gut microflora composition, performance parameters and intestinal histomorphological changes in broiler chickens. One-day-old chicks (n = 315) were reared for 42 days and distributed randomly into five experimental groups; each with three replicates (21 birds per replicate). Experimental groups were control: basal diet only, antimicrobial growth promoter: 40 g/metric ton of basal diet (virginiamycin), organic acids: 4 kg/metric ton of basal diet, phytobiotics: 3 kg/metric ton of basal diet, combination: 7 kg/metric ton of basal diet (organic acids 4 kg and phytobiotics 3 kg metric ton of feed). Growth performance, histological and ghrelin gene expression analysis were executed on 21 and 42 days while, quantitative bacterial analysis of cecum and ileum was performed on day 42. Increased feed intake and body weight (p < 0.05) were noticed in phytobiotics group. Addition of phytobiotics significantly improved (p < 0.05) villus height and ratio of villus height/crypt depth in ileum, jejunum, and duodenum and down-regulated ghrelin gene expression levels. Total coliform and Escherichia coli in cecal and ileal digesta were decreased significantly (p < 0.05) in organic acids group. Correlation analysis revealed Lactobacillus spp. were positively correlated to villus height/crypt depth ration in duodenum. The findings indicated the importance of gene-nutrient-microbiota interactions based on nutrigenomics approach. Hence, phytobiotics and organic acids might be suitable alternatives to antibiotics for improved performance and immunity, along with healthier meat production in poultry.

Effects of dietary synbiotics supplementation methods on growth, intestinal health, non-specific immunity and disease resistance of Pacific white shrimp, Litopenaeus vannamei

The present study aims to investigate the effects of dietary synbiotics supplementation methods on growth, feed utilization, hepatopancreas and intestinal histology, non-specific immunity and microbiota community of Pacific white shrimp (Litopenaeus vannamei). A control diet was designed to contain 18% fish meal (CON), and then 3 g kg^-1 synbiotics (Bioture, consisting of Bacillus subtilis, Saccharomyces cerevisiae, β-glucan and mannan oligosaccharide, etc) was supplemented to the control diet with three methods, directly adding in diets for pelleting (DAP), spraying diets after pelleting at once (SDA), spraying diets before feeding every day (SDE). Shrimp with initial body weight of 1.5 ± 0.12 g were fed one of the four diets for 56 days. The results showed that dietary synbiotics significantly increased the weight gain (WG), apparent digestibility coefficient (ADC) of crude protein (CP) and dry matter (DM), hepatopancreatic protease activity and decreased feed conversion ratio (FCR) (P < 0.05). Among the three synbiotics-added diets, SDE group showed the best growth with significantly higher WG than DAP group (P < 0.05). Serum activities of total superoxide dismutase, catalase, acid phosphatase, lysozyme and alkaline phosphatase of synbiotics-added groups were significantly higher, and serum malondialdehyde level was significantly lower than those of the control (P < 0.05). The intestinal villus width and villus number were also increased by the supplementation of synbiotics. The cumulative mortality was reduced in the three synbiotics-added groups after challenging with Vibrio parahaemolyticus (P < 0.05), and SDE group showed a significantly lower mortality than the control and DAP groups (P < 0.05). In intestinal microbiota composition, the abundance of Lactococcus tended to increase and Vibro tended to decreased in SDA and SDE groups. In conclusion, dietary synbiotics improved the growth, feed utilization, intestine health and non-specific immunity of Pacific white shrimp, and spraying synbiotics on diet presented better performance than adding synbiotics in diet for pelleting.

Dietary supplementation of yeast cell wall improves the gastrointestinal development of weaned calves

The purpose of this study was to investigate the potential benefits of yeast cell wall (YCW) on the gastrointestinal development of weaned calves. Twenty healthy Holstein male calves (BW = 92 ± 8.29 kg and 60 ± 5 d of age) were randomly allocated into 2 groups: CON with no YCW, and YCW (accounted for 0.16% of the basal diet). The dietary concentrate-to-roughage ratio was 40:60. All the calves were fed regularly twice a day at 09:00 and 16:00 and had free access to water. The experiment lasted for 60 d. The results showed that calves fed YCW showed higher (P < 0.05) length, width, and surface area of papillae in the ventral sac of the rumen as compared to CON. For the dorsal sac of the rumen, the muscularis thickness was thicker (P < 0.05) in the YCW group when compared with CON group. The villus height of YCW calves was higher (P < 0.05) than that of CON in the ileum. Calves supplemented with YCW also showed a higher (P < 0.05) villus height-to-crypt depth ratio in the ileum. The YCW calves exhibited a greater (P < 0.05) thickness of the wall in the duodenum and jejunum. Calves supplemented with YCW improved (P < 0.05) the claudin 1 mRNA expression in the ileum and occludin mRNA expression in the jejunum and ileum. The YCW increased (P < 0.05) the contents of secretory immunoglobulin A in the jejunum and ileum of calves. In conclusion, dietary supplementation with YCW could improve the gastrointestinal development of weaned calves.

Effects of cadmium on intestinal histology and microbiota in freshwater crayfish (Procambarus clarkii)

In this study, Procambarus clarkii (P. clarkii) were exposed to different concentrations (0, 2, 5 and 10 mg/L) of cadmium (Cd). We studied the effects of Cd exposure on intestinal histology and microbiota in P. clarkii. The results demonstrated that exposure to Cd caused histological alterations in the intestines of P. clarkii. Meanwhile, high-throughput sequencing analysis revealed that Cd exposure could alter the richness, diversity, and composition of intestinal microbiota in P. clarkii. At the phylum level, the relative abundances of the prevalent phyla Firmicutes, Proteobacteria, Bacteroidetes, Fusobacteria, and Actinobacteria changed significantly after exposure to Cd. At the genus level, the most prevalent genera with significant difference in relative abundance were Bacteroides, Clostridium XlVb, Hafnia, Buttiauxella, Shewanella, Anaerorhabdus, Alistipes, Arcobacter, Azoarcus, Chryseobacterium, and so on. Furthermore, functional prediction analysis of intestinal microbial communities showed that Cd exposure could significantly alter the pathways related to metabolism, diseases, cellular processes, and so on. Taken together, exposure to Cd could induce intestinal histological damage and affect intestinal microbiota composition and functions of P. clarkii. Our study can be an important step toward a better understanding of the toxic effects of Cd on aquatic crustaceans.

Comparative effects of Bacillus subtilis and Bacillus licheniformis on live performance, blood metabolites and intestinal features in broiler inoculated with Salmonella infection during the finisher phase

Free of Salmonella infection, a total of 300 broiler chicks (Ross 308) were randomly allotted to six dietary treatments (10 replicates) as follows: Negative control (only the basal diet); positive control (infected only); T1, infection + antibiotic (avilamycin); T2, infection + Bacillus subtilis and T3, Salmonella infection + Bacillus licheniformis. The results revealed that production performance was severely affected in the infected group. Also the supplementation of Bacillus subtilis (T2) significantly (P < 0.01) improved feed intake, body weight and performance efficiency factor as compared to the positive control. In addition, feed conversion ratio was significantly (P < 0.01) improved in T2 and T3 compared to the positive control. The results of intestinal health showed that significantly (P < 0.01) higher villus height and total surface area were found in T2 compared to positive control. The results of blood cholesterol, glucose, globulin and total protein concentration were significantly (P < 0.05) higher in T3 compared to the infected birds (positive control). It was concluded that Bacillus subtilis produced superior results in comparison with Bacillus licheniformis in term of growth and intestinal features in broiler by mitigating the deleterious effects of Salmonella infection.

Effects of partial replacement of fish meal by yeast hydrolysate on antioxidant capability, intestinal morphology, and inflammation-related gene expression of juvenile Jian carp (Cyprinus carpio var. Jian)

This study aimed to evaluate the effects of fish meal (FM) replacement by yeast hydrolysate (YH) on liver antioxidant capability, intestinal morphology, and inflammation-related genes of juvenile Jian carp (Cyprinus carpio var. Jian). A total of 600 fish (average initial weight 19.44 ± 0.06 g) were randomly selected and divided into five groups. Five isonitrogenous and isocaloric diets replacing FM by YH 0% (YH0), 1% (YH1), 3% (YH3), 5% (YH5), and 7% (YH7) were formulated. Each diet was tested in four replicates for 10 weeks. The results have shown that, compared to the control group (YH0), liver total superoxide dismutase (t-SOD), catalase (CAT), glutathione peroxidase (GPX), and glutathione (GSH) activities of fish fed YH1 and YH3 diets were significantly higher (P < 0.05). Liver malondialdehyde (MDA) concentration significantly increased as supplementation levels of YH increased from 1 to 7% (P < 0.05). Moreover, intestinal microvillus length of juvenile Jian carp fed YH diets were significantly higher than that of fish fed the control diet (P < 0.05). In proximal intestine, the relative expression levels of inflammation-related genes (ALP, IL-1β, and TNF-α) in YH7 were significantly higher than that in the control group (P < 0.05). However, in midintestine, the expression levels of these genes in YH3 were significantly lower compared to the control group (P < 0.05). The results of this study indicated that dietary replacement of FM by 3%YH could improve antioxidant capability and intestinal microvillus morphology, as well as enhance the non-specific immunity of juvenile Jian carp.

Beneficial effects of killed Tsukamurella inchonensis on rainbow trout (Oncorhynchus mykiss) growth, intestinal histology, immunological, and biochemical parameters

Present study was conducted to investigate the effects of heat-killed Tsukamurella inchonensis on growth performance, gastrointestinal structure, immune response, and biochemical parameters in rainbow trout. Fish (mean weight 25 g) were fed basal diet (control), diets containing 2.48 × 10⁸ colony-forming units (low-dose group) or 1.24 × 10⁹ colony-forming units (high-dose group) of heat-killed Tsukamurella inchonensis per 1 kg of feed for 90 days. Results showed that growth performance was significantly enhanced in both treatment groups compared to the control group. The intestinal villus length and pyloric cecal fold length were mainly enhanced in the high-dose group. On the other hand, higher goblet cell percentage was shown with administration of dead Tsukamurella inchonensis in both treatment groups. Immune parameters such as alternative complement activity, immunoglobulin level, and hemagglutination titer were significantly higher in treatment groups than in fish fed in the control diet. Meanwhile, feeding heat-killed Tsukamurella inchonensis especially at higher dose caused a decrease in the levels of total cholesterol, uric acid, and lipid peroxidation product whereas no significant changes were noted in serum-specific marker enzymes levels, namely alanine aminotransferase (ALT), alkaline phosphatase (ALP), and aspartate aminotransferase (AST) by feeding both treatment diets compared to the control group. This study suggests that heat-killed Tsukamurella inchonensis especially at 1.24 × 10⁹ colony-forming units had more potential to enhance growth, immunological parameters, and intestinal structure in rainbow trout.

Impacts of supplementing growing rabbit diets with whey powder and citric acid on growth performance, nutrient digestibility, meat and bone analysis, and gut health

The present study evaluated the impact of supplementing the rabbit diet with graded levels of whey powder and citric acid. The dietary treatments were as follows: T1, control diet (basal diet); T2, basal diet + 10 g/kg citric acid; T3, T2 + whey powder (7.5 g/kg); T4, T2 + whey powder (15 g/kg); and T5, T2 + whey powder (22.5 g/kg). Results, the T5 diet resulted in the best (P < 0.05) final body weight, body weight gain, feed conversion ratio, protein efficiency, relative growth rate, and dressed weight. The best (P < 0.05) digestion coefficients were associated with the T4 and T5 diets. Rabbits fed diets supplemented with citric acid alone or with addition of graded levels of whey powder showed significantly lower (P < 0.05) intestinal pH than those fed the T1 diet. The T4 and T5 diets resulted in greater CP and ash in the thigh muscle compared with the T1 and T2 diets. Calcium content in the femur bone was higher (P < 0.05) in the T5 group followed by T4 and T3. The wall of different parts of the small intestine improved in the T4 and T5 groups, showing the greatest increase in the small intestinal villi, intestinal glands, and amount of goblet cells. In conclusion, addition of whey powder (1.5, and 2.25%) increased the growth performance, nutrient digestibility and crude protein content of the thigh muscle, and improved the gut health of growing rabbits and the best level was 2.25% whey powder. Citric acid addition had no positive effect on growth performance, nutrient digestibility, crude protein content of the thigh muscle, and the gut health.

Effects of dietary Panax notoginseng extract on growth performance, fish composition, immune responses, intestinal histology and immune related genes expression of hybrid grouper (Epinephelus lanceolatus ♂ × Epinephelus fuscoguttatus ♀) fed high lipid diets

Growth, plasma biochemical parameters, fish composition, immune parameters, intestinal histology, and expressions of immune-related genes were examined in hybrid grouper (Epinephelus lanceolatus ♂ × Epinephelus fuscoguttatus ♀) that fed respectively six diets containing Panax notoginseng extract (PNE) at 0, 0.5, 1, 2, 4, and 10 g kg^-1 after 8 weeks. Results indicated that dietary PNE significantly improved growth, feed efficiency ratio, protein efficiency ratio, and protein deposit rate, and significantly increased crude protein and crude lipid levels of whole body and crude protein level of muscle. Dietary PNE significantly increased plasma total protein, alkaline phosphatase, immunoglobulin, complement 3 and complement 4 contents, but significantly decreased cholesterol, triglyceride, glucose, and low density lipoprotein cholesterol contents. Furthermore, dietary PNE increased villus length and muscle thickness in foregut, midgut, and hindgut, activities of hepatic superoxide dismutase and total antioxidant capacity, and increased the expression levels of immune related genes (IL-10, TGF-β1, TOR, MHC2 and TLR3) in the head kidney and the expression levels of antioxidant genes (CAT and GR) in fish that fed PNE at 0.5-4 g kg^-1. In conclusion, grouper fed high lipid diets supplemented with PNE at 0.5-10 g kg^-1 improved growth, feed utilization, blood immune parameters, hepatic antioxidant status, intestine morphology and expression levels of immune related genes in the head kidney.

A difficult diagnosis of coeliac disease: Repeat duodenal histology increases diagnostic yield in patients with concomitant causes of villous atrophy

Villous atrophy in absence of coeliac disease (CD)-specific antibodies represents a diagnostic dilemma. We report a case of a woman with anaemia, weight loss and diarrhoea with an initial diagnosis of seronegative CD and a histological documented villous atrophy who did not improve on gluten-free diet due to the concomitant presence of common variable immunodeficiency (CVID) and Giardia lamblia infection. This case report confirms that CD diagnosis in CVID patients is difficult; the combination of anti-endomysial antibodies (EmA-IgA), anti-tissue transglutaminase antibodies (tTG-IgAb) antibodies and total IgA is obligatory in basic diagnostic of CD but in CVID are negative. Furthermore, the typical histological aspects of the intestinal mucosa in CVID (absence of plasma cells and switch to the IgD immunoglobulins), cannot rule out a concomitant CD diagnosis. HLA typing in this setting has a low positive predictive value but should be considered. Histological response to a gluten-free diet on repeat biopsy and the concomitant treatment of other causes of villous atrophy leads to a definite diagnosis of CD.

Effect of dietary chitosan on growth performance, hematological parameters, intestinal histology and stress resistance of Caspian kutum (Rutilus frisii kutum Kamenskii, 1901) fingerlings

This study was conducted to investigate the effects of dietary chitosan on growth performance, hematological parameters, intestinal histology, stress resistance and body composition in the Caspian kutum (Rutilus frisii kutum, Kamenskii, 1901) fingerlings. Fish (1.7 ± 0.15 g) were fed diets containing chitosan at different levels (0, 0.25, 0.5, 1 and 2 g kg(-1) diet) for a period of 60 days. Results showed that the feed conversion ratio significantly decreased in fish fed diet containing 1 g kg(-1) of chitosan compared to the other groups (P < 0.05), but there were no significant differences between treatments in terms of specific growth rate and condition factor (P > 0.05). Leukocyte increased in fish fed diet containing 2 g kg(-1) of chitosan compared to the other groups (P < 0.05). Lymphocytes, eosinophils and neutrophils did not significantly change among dietary treatments (P > 0.05). Also, the chitosan supplementation did not affect the whole-fish body composition (P > 0.05). Light microscopy demonstrated that the intestinal villus length increased in fish fed diet containing 1 g kg(-1) of chitosan compared to control group (P < 0.05). While 11 and 13 ‰ salinity and 30 °C thermal stress had no effect, 1 g kg(-1) of chitosan (P < 0.05) showed highest survival rate (70 %) in 34 °C thermal stress. The results showed that chitosan in the diet of the Caspian kutum fingerlings could improve feed conversion ratio, the nonspecific defense mechanisms and resistance to some of the environmental stresses.

Gut morphology and hepatic oxidative status of European sea bass (Dicentrarchus labrax) juveniles fed plant feedstuffs or fishmeal-based diets supplemented with short-chain fructo-oligosaccharides and xylo-oligosaccharides

The effects of short-chain fructo-oligosaccharides (scFOS) and xylo-oligosaccharides (XOS) on gut morphology and hepatic oxidative status were studied in European sea bass juveniles weighing 60 g. Fish were fed diets including fishmeal (FM diets) or plant feedstuffs (PF diets; 30 FM:70 PF) as main protein sources (control diets). Four other diets were formulated similar to the control diets but including 1 % scFOS or 1 % XOS. At the end of the trial, fish fed PF-based diets presented histomorphological alterations in the distal intestine, whereas only transient alterations were observed in the pyloric caeca. Comparatively to fish fed FM-based diets, fish fed PF diets had higher liver lipid peroxidation (LPO), superoxide dismutase (SOD) and catalase (CAT) activities, and lower glutathione peroxidase, glutathione reductase and glucose 6-phosphate dehydrogenase activities. In fish fed the PF diets, prebiotic supplementation decreased SOD activity and XOS supplementation further decreased CAT activity. In fish fed the FM diets, XOS supplementation promoted a reduction of all antioxidant enzyme activities. Overall, dietary XOS and scFOS supplementation had only minor effects on gut morphology or LPO levels. However, dietary XOS reduced antioxidant enzymatic activity in both PF and FM diets, which indicate a positive effect on reduction of hepatic reactive oxygen species production.

Effects of dietary Astragalus polysaccharides (APS) on growth performance, immunological parameters, digestive enzymes, and intestinal morphology of Nile tilapia (Oreochromis niloticus)

This work investigated the potential immunomodulatory and growth-promoting effects of Astragalus polysaccharides (APS) in Nile tilapia (Oreochromis niloticus). The dietary supplementation with APS (1500 mg/kg of diet) caused a significant increase in growth parameters (initial and final weight, weight gain (WG), specific growth rate (SGR), feed conversion ratio (FCR) and feed intake (FI), when compared to non-supplemented control basal diet. In addition, APS upregulated the phagocytic activity, the respiratory burst activity, plasma lysozyme, the bactericidal activity, superoxide dismutase (SOD), glutathione peroxidase (GPx), and amylase activity. However, it had no effect on serum nitric oxide (NO) or Malondialdehyde (MDA) levels. While APS had no effect of intestinal histology, a slight increase in the villi length was recorded. Collectively, our results indicate that dietary APS supplementation could improve the growth performance and the immune parameters of cultured tilapia fish.