Villus Length Research Articles

Postnatal intestinal mucosa and gut microbial composition develop hand in hand: A mouse study

BackgroundDuring the early postnatal life, gut microbiota development experiences dynamic changes in their structural and functional composition. The postnatal period is the critical window to develop a host defense mechanism. The maturation of intestinal mucosal barrier integrity is one of the essential defense mechanisms to prevent the entry of pathogens. However, the co-development of intestinal microbial colonization, formation of barrier integrity, and intestinal epithelial cell layer is not entirely understood. MethodsWe studied the gut microbial composition and diversity using 16S rRNA marker gene-based sequencing in mice to understand postnatal age-dependent association kinetics between gut microbial and intestinal development. Next, we assessed the intestinal development by in vivo gut permeability assay, mRNA gene expression of different tight junction proteins and intestinal epithelial cell markers, goblet cells population, villus length, and cecal IgA quantification. ResultsOur results showed a significant shift in gut microbial structural and functional composition from postnatal day 14 onwards with early life Proteobacteria abundance. Relative abundance of Verrucomicrobia was maximum at postnatal day 14 and showed a gradual decrease over time. We also observed an age-dependent biphasic pattern in barrier integrity improvement and differentiation of intestinal epithelial cells (IECs). A significant improvement in barrier integrity between days 1 and 7 showed the host factor contribution, while that beyond day 14 revealed an association with changes in microbiota composition. Our temporal correlation analysis associated Bacteroidetes phylum with the mucosal barrier formation during postnatal development. ConclusionsThe present study revealed the importance and interplay of host factors and the microbiome in gut development and intestinal mucosal homeostasis.

Aging of intestinal stem cells.

SummaryThe intestine is one of the organs that relies on stem cell function for maintaining tissue homeostasis. Recent findings on intestinal aging show that intestinal architecture, such as villus length, crypt size, and cell composition changes in the aged crypts. The correspondent decline in the regenerative capacity of the intestine is mainly due to a decline in intestinal stem cell function upon aging, as the underlying mechanisms of aging intestinal stem cells are beginning to unravel. This review summarizes our current knowledge on stem cell-intrinsic mechanisms of aging of intestinal stem cells and their connection to extrinsic factors, such as niche cells and microbiota and will introduce recent approaches to attenuate or even revert the aging of intestinal stem cells.

Influence of increasing levels of oregano essential oil on intestinal morphology, intestinal flora and performance of Sewa sheep

The purpose of this experiment was to study the effects of oregano essential oil (OEO) on the performance, intestinal morphology and intestinal flora of fattening Sewa sheep. Sixty 20-month-old Sewa sheep with similar body weights (BWs) and in good health were randomly divided into four groups. The groups were fed a diet containing 0 mg/kg OEO (group A), 150 mg/kg (group B), 300 mg/kg (group C) or 450 mg/kg (group D). Daily gain, slaughter rate and other production performance parameters were analysed in the test sheep (mean ± standard error). Intestinal morphology was analysed by tissue sectioning, and intestinal flora was analysed by 16S rRNA genome sequencing. The indexes, including average daily gain (ADG), slaughter rate, villus length of the small intestine and number of beneficial bacteria in the intestinal flora, in group C were significantly higher than those in the other groups. Supplementation with 300 mg/kg OEO concentrate in the diets can improve the growth performance of Sewa sheep by changing their intestinal morphology and modifying their intestinal flora structure. Conclusively, these encourage to further verifying in practice positive evidence in improving growth performance of OEO supplementation in the diets for Sewa sheep. Highlights Oregano essential oil (OEO) can improve the performance of Sewa sheep by changing the intestinal morphology and regulating the intestinal flora structure.

Effect of oral cholecalciferol in a murine model of celiac disease: A dose ranging study

Previous studies have shown a relationship between vitamin D and celiac disease (CD), however little evidence is available examining the direct effects of vitamin D on pathological features of this disease. In this study we evaluated the effect of oral administration of different doses of native vitamin D3 (cholecalciferol) in enteropathic mice. Female non-obese diabetic (NOD)/ShiLt.J mice were fed standard or gluten-free diet and administered gliadin (5 μg/kg) to induce a celiac pathology. Healthy control (gluten-free diet, without gliadin) and control for pathology (standard diet, with gliadin) were administered olive oil. All other experimental groups received gliadin and standard diet plus oral cholecalciferol (5, 10, 20, 50 and 130 μg/kg). Serum levels of 25(OH)D3, calcium and zonulin and expression of vitamin D receptor (VDR), CD3 and zonula occludens-1 (ZO-1) by immunohistochemistry as well as intestinal histological and histomorphometric analyses were undertaken. Although no difference in serum levels of 25(OH)D3, calcium or zonulin was observed in cholecalciferol-treated mice vs. healthy controls, a significant improvement in intestinal mucosa pathological features in mice administered cholecalciferol was observed by histological analysis. Villi length was also significantly increased by cholecalciferol in a dose-dependent manner. Immunohistochemical staining revealed increased expression of CD3 and ZO-1 in celiac mice compared to mice receiving high dose (130 μg/kg) cholecalciferol. These findings show the effect of oral cholecalciferol on signature features of CD in a mouse model of CD. Further dose-ranging studies to investigate the efficacy of cholecalciferol for the treatment of CD are warranted.

Effects of dietary protein on gut development, microbial compositions and mucin expressions in mice.

Dietary protein, as an important macronutrient, widely participates in host growth and metabolism. In this study, effects of different protein levels (14, 20 and 26%) on the gut development, microbial compositions and mucin expressions were studied in C57BL/6mice. The results showed that body weight and the relative weight of stomach and gut were decreased in low-protein diet-fed mice, whereas high-protein diet significantly reduced the villus length and area of jejunum. Goblet cells number in the jejunum was reduced in the low-protein group, which was reversed by dietary a high-protein diet. In addition, high-protein diet notably reduced microbial diversity and changed the microbial compositions at the phylum level, such as Bacteroides, Proteobacteria, Actinomycetes and Deferribacteres. Furthermore, high-protein diet significantly increased mucin2, mucin3 and mucin4 expressions in the jejunum, but downregulated mucin1, mucin2, mucin4 and TFF3 in the ileum, indicating a tissue-dependent manner. Together, high-protein diet may impair gut development, microbial balance and mucin system, and a low-protein diet is suggested to promote a healthy lifestyle. Mucin influenced gut development (villus index and goblet cell number) through remodelling gut microbes, as low and high protein levels resulted in contrary expression levels of mucin in jejunum and ileum.

A Challenge to Conventional Fish Meal: Effects of Soy Protein Peptides on Growth, Histomorphology, Lipid Metabolism and Intestinal Health for Juvenile Pompano Trachinotus ovatus

This experiment was conducted to assess the possibility of replacing fish meal (FM) with soy protein peptide (SPP) at different levels—0% (FM), 14.29% (S5), 28.57% (S10), 57.14% (S20), 71.42%(S25)—and its effects on growth, histology, gene expression related to liver lipid metabolism and intestinal immunity in juvenile pompano Trachinotus ovatus (initial mean weight = 39.88 ± 0.15 g). 600 healthy and uniformed-size fish were distributed to five groups of three replicates, each with 40 fish in each floating cage and fed twice daily for 8 weeks. Results showed that no significant difference in the growth was observed with SPP replacing FM (P > 0.05). Serum glutathione peroxidase activity in the S10 group was significantly higher than that in the FM group, and serum malondialdehyde content significantly decreased (P < 0.05). SPP significantly improved intestinal immunity by increasing alkaline phosphatase and lysozyme activities and up-regulating interleukin 10 and complement 4 mRNA levels while simultaneously decreasing triglyceride and total cholesterol content and down-regulating interleukin 1β mRNA expression. Villus length and muscle thickness in the S10 group were significantly higher than those in the FM group (P < 0.05). SPP significantly improved liver fat metabolism by increasing carnitine palmitoyl transferase I mRNA levels, and down-regulating fatty acid synthesis mRNA expression (P < 0.05). In summary, SPP substitution for FM promoted intestinal health, liver lipid metabolism and reduced liver fat accumulation for juvenile pompano T. ovatus, with no significant effect on growth performance. Based on the second-order polynomial analysis model of LYZ activity, the optimal replacement SPP level for juvenile pompano T. ovatus was 11.82%.

Feeding Bacillus subtilis ATCC19659 to Broiler Chickens Enhances Growth Performance and Immune Function by Modulating Intestinal Morphology and Cecum Microbiota

This study investigated dietary supplementation with Bacillus subtilis (BS) ATCC19659 on growth performance, biochemical indices, intestinal morphology, and cecum microflora in broiler chicks. A total of 600 Arbor 1-day Acres broilers of either sex were allotted to 5 treatments: chicks were fed a corn- and soybean-based diet (CON); chicks were fed basal diet containing 500 mg ZnB/kg (ZnB); chicks were fed basal diet containing 1 × 108 CFU/g feed of BS-ATCC19659 (BS-1); chicks were fed basal diet containing 3 × 108 CFU/g feed of BS-ATCC19659 (BS-3); and chicks were fed basal diet containing 5 × 108 CFU/g feed of BS-ATCC19659 (BS-5). Each treatment comprised 6 replicates with 20 birds for each replicate pen. Chicks in the BS-5 and BS-3 groups had higher body weight at the 21st and 42nd days and average daily gain from 1 to 21 days than that in the CON group (p < 0.05). Chicks in the BS-5 and ZnB groups had higher serum antioxidant activities and immunity response than those in the CON group (p < 0.05). Compared with the CON group, the liver mRNA abundance of GHR, TGF-β, IGF-1, IFN-γ, SOD, CAT, and GPX of chicks in three BS groups and the ileum villus length (μm) of chicks in BS-3 and ZnB groups was increased (p < 0.05). Compared with the CON group, the villus height-to-crypt depth ratio of the ileum of chicks in the BS-5 and BS-3 groups and the crypt depth and villus height-to-crypt depth ratio of the jejunum in the BS-5 and ZnB groups were increased (p < 0.05). The abundance of the Cyanobacteria phyla in the cecum decreased in response to treatment with both BS-ATCC19659 and ZnB groups (p < 0.05). Compared with the CON group, the cecum abundance of genera GCA-900066575 (Lachnospiraceae), Anaerofustis, and Papillibacter (Firmicutes phylum) in three BS groups were increased (p < 0.05); The abundance of genus Escherichia–Shigella reduced in the BS-3 group (p < 0.05). Compared with the CON group, the cecum abundance of genus Clostridia_unclassified in ZnB and BS-5 groups was decreased (p < 0.05) of broilers. Generally, Bacillus subtilis ATCC19659 as feed additive positively affected growth performance, immunity response, and cecal microflora of broilers.

A proteolytic enzyme treatment to improve Ulva laetevirens and Solieria chordalis seaweed co-product digestibility, performance, and health in broilers

To explore the potential use of seaweed co-products for broiler diets, this study investigates whether an enzyme treatment of seaweed co-products improves performance, in vivo digestibility and health in broilers. In total, 360 Ross 308 male broilers were fed one of 5 experimental diets: a basal diet, or a basal diet including the U. laetevirens or S. chordalis co-product, with or without proteolytic enzyme treatment of the seaweed, using 6 replicate pens of 12 birds each. The starter (d 0–13) and grower (d 14–21) diet contained 5 and 10% (w/w) seaweed product, respectively. A general linear model with contrast statements was used after model assumptions and goodness of fit were evaluated through normal distribution of residuals. Inclusion of seaweed in the broiler diets increased body weight gain (+14%; P = 0.002), and feed intake (+12%; P = 0.001) in the third week of the experiment. Birds fed the U. laetevirens compared to the S. chordalis diets had a higher body weight gain (+11%; P = 0.007), and a lower feed conversion ratio (FCR; -7%; P < 0.001). Seaweed inclusion reduced apparent pre-cecal digestibility of all nutrients (P < 0.05). Birds fed U. laetevirens vs. S. chordalis diets had a 10% reduced villus length (P < 0.001). Enzymatic treatment reduced the digestibility of most nutrients, and increased crypt depth in birds fed the U. laetevirens diets, whereas the opposite was observed for the birds fed the S. chordalis diets (Seaweed × Enzyme P = 0.035). Untreated vs. treated seaweed in the diets led to lower (−60%) plasma Interleukin-13 levels (P = 0.035). In conclusion, the proteolytic enzyme treatment of the seaweed co-products did not improve performance nor health-related parameters, and reduced digestibility of the diets. Dietary inclusion of U. laetevirens co-products did improve performance based on growth and FCR, whereas inclusion of S. chordalis did not. Inclusion of U. laetevirens in broiler diets slightly reduced duodenal villus length and crypt depth. The inflammation response was strongly reduced, specifically in birds fed the untreated U. laetevirens diet, making the U. laetevirens co-product of interest for future research.

Antidiabetic Effects of Pediococcus acidilactici pA1c on HFD-Induced Mice.

Prediabetes (PreD), which is associated with impaired glucose tolerance and fasting blood glucose, is a potential risk factor for type 2 diabetes mellitus (T2D). Growing evidence suggests the role of the gastrointestinal microbiota in both PreD and T2D, which opens the possibility for a novel nutritional approach, based on probiotics, for improving glucose regulation and delaying disease progression of PreD to T2D. In this light, the present study aimed to assess the antidiabetic properties of Pediococcus acidilactici (pA1c) in a murine model of high-fat diet (HFD)-induced T2D. For that purpose, C57BL/6 mice were given HFD enriched with either probiotic (1 × 1010 CFU/day) or placebo for 12 weeks. We determined body weight, fasting blood glucose, glucose tolerance, HOMA-IR and HOMA-β index, C-peptide, GLP-1, leptin, and lipid profile. We also measured hepatic gene expression (G6P, PEPCK, GCK, IL-1β, and IL-6) and examined pancreatic and intestinal histology (% of GLP-1+ cells, % of goblet cells and villus length). We found that pA1c supplementation significantly attenuated body weight gain, mitigated glucose dysregulation by reducing fasting blood glucose levels, glucose tolerance test, leptin levels, and insulin resistance, increased C-peptide and GLP-1 levels, enhanced pancreatic function, and improved intestinal histology. These findings indicate that pA1c improved HFD-induced T2D derived insulin resistance and intestinal histology, as well as protected from body weight increase. Together, our study proposes that pA1c may be a promising new dietary management strategy to improve metabolic disorders in PreD and T2D.

Effects of bacitracin zinc, potassium diformate and lauric acid on duodenal digestive functions, intestinal morphology and caecal microflora of broilers

This study investigated the effects of bacitracin zinc, potassium diformate and lauric acid on duodenal digestive functions, intestinal morphology and caecal microflora of broilers. A total of 240 male broilers were randomly allotted to four treatments consisting of five replicates with 12 birds per replicate. The dietary treatments were CON group (basal diet), ANT group (basal diet + 40 mg/kg bacitracin zinc), KDF group (basal diet + 1 000 mg/kg potassium diformate), and LA group (basal diet + 500 mg/kg lauric acid). The results showed that the chymotrypsin activity was significantly enhanced on days 21 and 42 in KDF group compared with CON group (P &amp;lt; 0.05), but there were no effects on the activities of trypsin and amylase (P &amp;gt; 0.05). No differences in digestive enzyme activities were found between ANT and LA groups (P &amp;gt; 0.05). Compared with CON group, the villus length and the villus-to-crypt ratio were significantly increased on days 21 and 42, and the crypt depth was significantly decreased in ANT, KDF and LA groups (P &amp;lt; 0.05). Compared with CON group, the supplementation of LA increased the relative abundance of Faecalibacterium on day 21 and the relative abundance of Bacillus on day 42 in caecum, while the supplementation of KDF increased the relative abundance of Faecalibacterium and decreased the relative abundance of Dorea on day 42 in caecum (P &amp;lt; 0.05). In conclusion, the supplementation of KDF enhanced the chymotrypsin activity. Dietary KDF and LA maintained the intestinal morphology by improving the villus length and the villus-to-crypt ratio and decreasing the crypt depth, and regulated the caecal microflora.

Advanced age exacerbates intestinal epithelial permeability after burn injury in mice.

Advanced age is an independent risk factor for morbidity and mortality after burn injury. Following burn, the intestines can become permeable leading to the leakage of bacteria and their products from the lumen of the ileum to the portal and systemic circulation. Here, we sought to determine the effects of advanced age on intestinal permeability post burn injury and assess intestinal inflammatory biomarkers. Young (4-5months) and aged (18-22months) female BALB/cBy mice were subjected to a 12-15% total body surface area (TBSA) sham or burn injury. 24h after injury, mice were euthanized, and organs collected. Colony-forming units (CFU) were counted from plated mesenteric lymph nodes (MLN). Gene expression of ileal tight junctional proteins, occludin and zonula occludens 1 (ZO-1), in addition to ileal damage associated molecular pattern (DAMP) proteins, S100A8 and S100A9, as well as ileal inflammatory markers IL-6 and TNF-α were measured by qPCR. Intestinal cell death was measured by ELISA. Intestinal permeability was determined by FITC fluorescence in serum; 4kD FITC-dextran was given by oral gavage 3h before euthanasia. Aged mice subjected to burn injury had increased intestinal permeability as evidenced by a 5.8-fold higher level of FITC-dextran in their serum when compared to all other groups (p<0.05). In addition, aged burn-injured mice exhibited heightened bacterial accumulation in the MLN with a 15.5-fold increase over all other groups (p<0.05). Histology of ileum failed to show differences in villus length among all groups. Analysis of ileal tight junctional proteins and inflammatory marker gene expression revealed no difference in Ocln, Tjp1, Il6, or Tnf expression among all groups, but 2.3 and 2.9-fold upregulation of S100a8 and S100a9, respectively, in aged burn-injured mice relative to both young groups and aged sham-injured mice (p<0.05). Lastly, cell death in the ileum was elevated more than two-fold in aged burn-injured mice relative to young animals regardless of injury (p<0.05). These data demonstrate that advanced age exacerbates intestinal epithelial permeability after burn injury. Heightened apoptosis may be responsible for the elevated intestinal leakiness and accumulation of bacteria in mesenteric lymph nodes. In addition, S100a8/9 may serve as a biomarker of elevated inflammation within the intestine.

Influence of Dietary Berberine on Liver Immune Response and Intestinal Health of Black Sea Bream (Acanthopagrus schlegelii) Fed with Normal and High-Lipid Diets

This study designed the normal diet (Con), high-lipid diet (HL), and 50 mg/kg berberine supplemented Con and HL diets (named as ConB and HLB, respectively). Fingerling black sea bream (Acanthopagrus schlegelii) (initial weight 1.47 ± 0.03 g) were fed these four diets for 8 weeks, and the liver immune response and intestinal health were evaluated. Fish fed the HL diet had the lowest serum glutathione peroxidase and catalase activities, while berberine supplementation significantly improved serum catalase activity ( P &lt; 0.05 ). The expressions of tumor necrosis factor-alpha (tnfα), nuclear factor-kappa b (nf-κb), and interleukin 1 beta (il-1β) were significantly increased by the HL diet, whereas berberine supplementation significantly downregulated these proinflammation cytokine expressions ( P &lt; 0.05 ). Berberine supplementation in normal and high-lipid diets significantly promoted hepatic anti-inflammation cytokines interleukin-10 (il-10) and transforming growth factor beta-1 (tgfβ-1) expressions ( P &lt; 0.05 ). The intestinal expressions of tnfα, nf-κb, and tgfβ-1 were not significantly influenced by different treatments, while Cu/Zn-superoxide dismutase (Cu/Zn-sod) expression was significantly upregulated in the ConB group compared with the Con group. High-lipid diet reduced intestinal villus length. the thickness of muscularis mucosa, mucosal folds, and diversity and richness of intestinal microbiota but increased numbers of goblet cells and width of lamina propria. Berberine supplementation in high-lipid diet alleviated these pathological changes and rebalanced intestinal microbiota composition. At the genus level, fish fed the HL diet had significantly lower abundances of some probiotics such as Lactobacillus and Hydrogenophaga than that of the HLB group ( P &lt; 0.05 ). In conclusion, berberine supplementation in high-lipid diet reduced liver inflammation, improved the antioxidative status of fish, and alleviated intestinal damage and intestinal microbiota alteration of black sea bream.

Influences of indigenous isolates Pantoea agglomerans RCS2 on growth, proximate analysis, haematological parameters, digestive enzyme activities, serum biochemical parameters, antioxidants activities, intestinal morphology, disease resistance, and molecular immune response in juvenile's cobia fish (Rachycentron canadum)

The fast expansion and high intensity of cobia culture or, better still, farming has resulted in diseases infestation and has been recognised as a significant evolving problem for cobia culture throughout its production cycle. This study explored the possible effects of dietary additives of indigenous Pantoea agglomerans RCS2 on growth, haematological parameters, biochemical blood indices, antioxidant enzyme activities, disease resistance, digestive enzyme activities, and molecular immune response in juvenile's cobia fish. After 70 days, the growth parameters (i.e., specific growth rate, weight gain, and final weight) and feed conversion ratio significantly improved (P < 0.05) compared to those fed diets without supplementation. Also, haematological parameters such as red blood cells, white blood cells, corpuscular haemoglobin concentration, mean corpuscular volume, haemoglobin, and Mean corpuscular haemoglobin were high significantly (P < 0.05) in supplemented groups. The serum blood biochemical indices aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, triglyceride, cholesterol, and glucose recorded no significant difference (P > 0.05) while globulin, total protein, and albumin were high significantly (P < 0.05) in supplemented groups as compared to the group without supplement. The current results displayed that the activities of superoxide dismutase, glutathione peroxidase, and catalase in the liver and head kidney were affected by dietary supplements of indigenous isolated microorganisms. An exceptionally low mortality rate was observed in the treatment groups than the group without supplemented diets when challenged with pathogenic bacteria. Similarly, light microscopy revealed an increase in the intestinal villus length in fish fed with the supplemented diet compared to those without supplements. In this study, the higher digestive enzyme activities show that supplemented bacteria isolates have impacted digestive enzyme secretion in juvenile cobia. Regarding the gene expression, Interleukin-1 Beta (IL-1β), Tumour necrosis factor α (TNFα), and Interleukin-8 (IL-8) were all up-regulated by indigenous isolates. The current results show that the dietary additive of indigenous P. agglomerans RCS2 could constitute a treasured nutritional approach in the path of a sustainable cobia aquaculture. The fish immune responses enhancement and the gut morphology are vital in enhancing growth, absorption of nutrients, and disease resistance; hence the results in the present study are essential outcomes for the development and competitive aquaculture sector.

Lactobacillus rhamnosus GG colonization in early life regulates gut-brain axis and relieves anxiety-like behavior in adulthood

Evidence reveals that gut dysbiosis is involved in bidirectional interactions in gut-brain axis and participates in the progress of multiple disorders like anxiety. Gut microbes in early life are crucial for establishment of host health. We aimed to investigate whether early life probiotics Lactobacillus rhamnosus GG (LGG) colonization could relieve anxiety in adulthood through regulation of gut-brain axis. Live or fixed LGG was gavaged to C57BL/6 female mice from day 18 of pregnancy until natural birth, and newborn mice from day 1 to day 5 respectively. In this study, we found that live LGG could be effectively colonized in the intestine of offspring. LGG colonization increased intestinal villus length and colonic crypt depth, accompanied with barrier function protection before weaning. Microbiota composition by 16S rRNA sequencing showed that some beneficial bacteria, such as Akkermansia and Bifidobacteria, were abundant in LGG colonization group. The protective effect of LGG on gut microbiota persisted from weaning to adulthood. Intriguingly, behavioral results assessed by elevated plus mazed test and open field test demonstrated relief of anxiety-like behavior in adult LGG-colonized offspring. Mechanically, LGG colonization activated epithelial growth factor receptor (EGFR) and enhanced serotonin transporter (SERT) expression and modulated serotonergic system in the intestine, and increased brain-derived neurotrophic factor and γ-aminobutyric acid receptor levels in the hippocampus and amygdala. Blocking EGFR blunted LGG-induced the increased SERT and zonula occludens-1 expression. Collectively, early life LGG colonization could protect intestinal barrier of offspring and modulate gut-brain axis in association with relief of anxiety-like behavior in adulthood.

Effects of dietary supplementation with itaconic acid on the growth performance, nutrient digestibility, slaughter variables, blood biochemical parameters, and intestinal morphology of broiler chickens

Itaconic acid (IA) is a biologically based unsaturated dicarboxylic acid secreted by mammalian cells. While IA has potential for use in multiple applications, information regarding the influence of IA on animal production remains scarce. This study investigated the effects of dietary IA supplementation on the growth performance, nutrient digestibility, slaughter variables, blood parameters, and intestinal morphology of broiler chickens. A total of 360 one-day-old Arbor Acre broiler chicks were allotted to 6 groups, with 10 chicks per cage and 6 replicates per group in a randomized complete block design. Broiler chicks were fed a basal diet with 0 (control), 0.2, 0.4, 0.6, 0.8, or 1.0% IA. The experimental period lasted from 1 to 42 d of age. Dietary IA supplementation did not affect average daily gain (ADG) and feed/gain ratio (F/G) but quadratically increased average daily feed intake (ADFI) and linearly increased crude protein (CP) digestibility during the grower period (d 22–42). A higher breast and thigh muscle yield and a lower abdominal fat yield were observed in a linear and quadratic manner with the IA supplementation. Adding IA to the diet had significant effects on superoxide dismutase (SOD), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and catalase (CAT) levels in serum at d 21 and on total antioxidation capacity (T-AOC) at d 42. There were linear and quadratic increases in villus height and the villus height/crypt depth ratio (V/C) of the duodenum and villus height of the jejunum with the supplementation of IA. Regression analyses for ADFI, dressed yield, breast and thigh muscle yield, abdominal fat yield, serum ALT, CAT, and SOD levels, villus length of the duodenum and jejunum, and V/C of the duodenum indicated that the optimal dietary IA supplementation would be from 0.4 to 0.7%. From an economic perspective, a level of 0.4% IA in the broiler diet is recommended for improving the nutrient digestibility, slaughter performance, antioxidant ability, and intestinal morphology of broiler chickens.

Effects of zinc glycinate on growth, immunity, and intestinal health in broiler chickens

The objective is to investigate the effects of dietary zinc form and concentration in broiler chickens. Day-old broiler chicks (n = 6) were allotted to treatments in a 2 × 3 factorial arrangement to examine supplemental zinc from sulfate (ZS) and glycinate (ZG) and concentration (40, 80, and 120 mg/kg). In healthy conditions, no difference in poultry performances is to be expected between organic and inorganic zinc sources, supplemented at the same zinc dose to the diets. We found that on day 21, zinc supplemented at 80 mg/kg increased body weight gain (BWG) by 113 g compared to zinc supplemented at 40 mg/kg (P < 0.01). Similarly, on day 35, zinc supplemented at 120 mg/kg increased BWG by 155 g compared to zinc supplemented at 40 mg/kg (P < 0.05). On day 35, zinc supplemented at 120 mg/kg increased feed intake by 239 g compared to zinc supplemented at 40 mg/kg (P < 0.05). The villi length on day 21 was increased by 63 µm in birds supplemented at 120 mg/kg compared to 40 mg/kg (P < 0.05). On day 21, cecal tonsil gene expression of interleukin 1 beta (IL-1β) was higher by 2.5 and 2.4-fold in the ZG-80 mg/kg group than the ZG-40 mg/kg and ZS-120 mg/kg groups (P < 0.01), and interleukin 10 (IL-10) was lower by 2-fold in the ZS-120 mg/kg group than ZS-40 mg/kg, while IL-10 was lower in the ZG-40 mg/kg than ZS-40 mg/kg group (P < 0.01). On day 35, cecal tonsil gene expression of IL-1β was overall higher by 1.3-fold in the ZG group compared to ZS (P < 0.05). On day 21, spleen gene expression of transforming growth factor-beta (TGF-β) was higher by 1.4-fold in the ZG-80 mg/kg group compared to ZG-40 mg/kg (P < 0.05). On day 35 spleen gene expression of lipopolysaccharide-induced TNF factor (LITAF) was lower in the ZG-80 mg/kg group compared to ZS-80 mg/kg (P < 0.05). On day 35 jejunum gene expression of claudin-2 was higher by 2.1-fold in the ZG-80 mg/kg group than ZS-80 mg/kg (P < 0.05). This study supports that zinc supplementation at 120 mg/kg improves the growth performance of broiler chickens. This is accompanied by improvements in intestinal morphology and modulation in immunity through an altered cytokine production profile.

Effects of Antimicrobial Peptides Gal-13 on the Growth Performance, Intestinal Microbiota, Digestive Enzyme Activities, Intestinal Morphology, Antioxidative Activities, and Immunity of Broilers.

To evaluate the application effect of antimicrobial peptides Gal-13 (AMP Gal-13) instead of antibiotic feed additives, 90 7-day-old Ross 308 broilers were randomly divided into 3 groups. Group A was fed a basic diet as the control, and Groups B and C were supplemented with AMP Gal-13 (100mg/kg and 200mg/kg, respectively). After a 35-day feeding experiment, the weight and average daily gain (ADG) of the broilers in Group B were significantly higher than those of the broilers in Group A. The Enterococcus sp. and Escherichia coli counts in the ileum and cecum in Group A were significantly higher than those in Groups B and C, while the Lactic acid bacteria (LAB) and Bifidobacterium sp. counts were significantly lower. The amylase activity of the jejunum in Group B was significantly higher than that in Group A. The villus length (VL): crypt depth (CD) ratios of the jejunum and ileum in Group B were significantly higher than those in Group A. The glutathione peroxidase (GSH-Px) activities in the liver and serum in Groups B and C were significantly higher than those in Group A, while the malondialdehyde (MDA) activity was significantly lower. The titers of Newcastle disease virus (NDV)-specific antibodies were elevated significantly in Group B at the age of 42days. Additionally, the weights of the spleen and thymus were significantly increased. The expression levels of Il-2, Il-6, Tgf-β4, Tnf-α, and Mif in the spleen in Groups B and C were significantly downregulated to different degrees; Il-4 expression in Group B was significantly upregulated, while Ifn-γ expression in Group C was significantly upregulated. The results suggested that adding AMP Gal-13 to the diet could improve intestinal digestion, the antioxidant capacity, and immune function, ultimately promoting the growth of broilers.

Dietary bile acids reduce liver lipid deposition via activating farnesoid X receptor, and improve gut health by regulating gut microbiota in Chinese perch (Siniperca chuatsi)

The aim of this study is to explore the effects of dietary bile acids (BAs) supplementation on lipid metabolism and gut health of Chinese perch (Siniperca chuatsi), and its possible mechanisms. Two isonitrogenous and isolipidic diets were formulated to supplement different levels of BAs (0 and 900 mg BAs kg−1 diet, respectively). All fish (Initial mean body weight: 171.29 ± 0.77g) were randomly divided into 2 groups (triplicate, 54 fish/group) and were fed with different experimental diets for 56 days, respectively. Dietary exogenous BAs supplementation at the concentration of 900 mg kg−1 significantly increased weight gain and survival rate, and decreased feed conversion ratio. BAs could inhibit lipid synthesis and promote lipid oxidation to reduce lipid deposition by activating farnesoid X receptor (FXR). Dietary BAs supplementation increased the abundance of Lactobacilli in Firmicutes, and the increase of Lactobacillus caused the increase of lactic acid level and the decrease of pH, which might be the reason for the gut villus length and gut wall high in this study. Dietary BAs supplementation increased the levels of catalase and superoxide dismutase and decreased the level of malondialdehyde in the gut and plasma, which might be contributed to the regulating the antioxidant stress phenotype of gut microbiota by the increased abundance of Firmicutes. Then it caused the increase of the globulin level in the plasma, meaning the enhancement of immune state. The increased immunity might also be thought to be responsible for increased survival rate. These results suggest dietary BAs reduce liver lipid deposition via activating FXR, and improve gut health by regulating gut microbiota in Chinese perch.

Iron supplementation in plant-based aquafeed: Effects on growth performance, tissue composition, iron-related serum parameters and gene expression in rainbow trout (Oncorhynchus mykiss)

This study evaluated the effects of iron supplementation in plant-based aquafeed on growth performances, feed intake, nutrient composition, digestibility, iron-related serum parameters and gene expression in juvenile rainbow trout (Oncorhynchus mykiss). Triplicate groups of fish were fed for 60 days using incremental levels of iron in a ferrous sulphate heptahydrate form, as follows: 0 (group Fe0); 150 (group Fe150); 300 (group Fe300); 600 (group Fe600) mg iron/kg feed, corresponding to actual iron levels of 132, 273, 403, 741 mg iron/kg feed, respectively. As a further control, a fifth group was fed a commercial feed (CMF; 253 mg iron/kg feed). Growth performances showed that the highest specific growth rate (SGR), condition factor (CF), protein efficacy ratio (PER), feed intake (FI) and lowest feed conversion rate (FCR) were found in Fe150, Fe300 and CMF groups. Final weight and weight gain (WG) were significantly higher in CMF and Fe150 groups, followed by the Fe300, Fe600 and Fe0 groups (P < 0.05). Apparent digestibility coefficients (ADCs) of protein, lipid, ash and iron were over 90% in Fe150 and Fe300 groups, while significantly lower ADCs were observed in Fe0 and Fe600 groups. Intestinal histomorphological measurements of muscular thickness (muscularis externa; ME, inner circular layer; ICL, outer longitudinal layer; OLL) were higher in CMF and Fe150 groups, while villus length was generally similar among groups, with the exception of the Fe0 group. Serum iron levels were significantly higher in Fe150 and Fe300 groups, while total iron-binding capacity (TIBC) was highest in the Fe150 group. No significant differences were observed in either serum ferritin or liver ferritin gene expression among groups, although hepcidin gene expression was highest in the Fe300 group followed by the Fe150 group. Transferrin gene expression was the lowest in the Fe0 group. Appetite-related Leptin A1 gene expression was not affected by iron addition, but Leptin A2 was up-regulated in all groups except for the Fe0 group. In summary, the study showed that the addition of 150 mg/kg feed of iron (equivalent to ~270 mg/kg feed total) improved growth performances and feed utilization in rainbow trout, which aligns well with the iron levels in current commercial feeds.

Effects of Mulberry (Morus alba L.) Leaf Extracts on Growth, Immune Response, and Antioxidant Functions in Nile Tilapia (Oreochromis niloticus)

Abstract This study evaluates how white mulberry (Morus alba L.) leaf extracts affect the growth, antioxidant activity, and immune response in Nile tilapia Oreochromis niloticus. Mulberry leaf extracts were obtained through aqueous extraction (AE) and ethanol extraction (EE). Powder of mulberry leaf (PML) was added directly to feed and compared with the effects of feeds supplemented with the different extracts. Fish were divided into eight groups for an 8-week feeding trial where they were fed the basal diet or supplemented with 10% PML, 10% AE, 20% AE, 40% AE, 10% EE, 20% EE, or 40% EE. The inclusion of mulberry leaf extract obtained with either method showed better effects on fish growth performance, antioxidant activities and acid phosphatase activity (ACP) in serum, immune cytokine expression, and intestinal morphology as compared with controls or fish fed the 10% PML diet. The specific growth rate was significantly higher in the 10% AE, 10% EE, and 20% EE groups compared with all other groups (P&lt;0.05). Catalase activity was significantly greater in most groups fed an extract, and in the 10% PML group, when compared with controls. Similarly, ACP, interleukin (IL)-1, and IL-2 expression was significantly increased in groups fed an extract, and in the 10% PML group, when compared with controls (P&lt;0.05). IL- 1, IL-2, IL-10, and Toll-like receptor 2 expression was significantly greater in the 10% EE group than in the 10% PML and 10% AE groups (P&lt;0.05). Villus length in the middle intestine was significantly increased in the 10% AE and 10% EE groups compared with controls and the 10% PML group (P&lt;0.05). Thus, 10% mulberry leaf ethanol extract added to feed is recommended for enhancing the growth rate and health of cultured Nile tilapia.