Jie Feng

Phytosterols improve immunity and exert anti-inflammatory activity in weaned piglets

BACKGROUND Phytosterols (PS), plant-derived natural steroid compounds, are novel feed additives to regulate immune function and promote pig growth. This study was conducted to determine the effects of PS on the immune response of weaned piglets. RESULTS One hundred and twenty crossbred (Duroc × Landrace × Yorkshire) piglets with an average initial weight of 9.58 ± 0.26 kg were randomly allotted to three treatments. Treatments consisted of a control, PS (0.2 g kg-1 ) and polymyxin E (0.04 g kg-1 , antibiotic control) treatment. The results showed that PS or polymyxin E supplementation remarkably decreased diarrhea rate and elevated CD3+ CD4+ /CD3+ CD8+ ratio in piglets compared with the control (P < 0.05). PS increased basophil and serum interleukin-4, and caused a shift towards Th2 profile by decreasing Th1/Th2 ratios in piglets compared with control (P < 0.05). Polymyxin E contributed to an increase in interleukin-10 compared with the control (P < 0.05). No significant difference was observed in the amount of Lactobacillus, Bifidobacterium or Escherichia coli of jejunum among the three treatments (P > 0.05). CONCLUSION These results suggest that PS supplementation has no significant effect on growth but could remarkably decrease diarrhea rate, and improve immunity and anti-inflammatory activity in weaned piglets. In addition, PS supplementation had similar effects on growth, anti-inflammation and intestinal microorganisms as supplementation with polymyxin E in piglets.

Digital gene expression profiling analysis of duodenum transcriptomes in SD rats administered ferrous sulfate or ferrous glycine chelate by gavage

The absorption of different iron sources is a trending research topic. Many studies have revealed that organic iron exhibits better bioavailability than inorganic iron, but the concrete underlying mechanism is still unclear. In the present study, we examined the differences in bioavailability of ferrous sulfate and ferrous glycinate in the intestines of SD rats using Illumina sequencing technology. Digital gene expression analysis resulted in the generation of almost 128 million clean reads, with expression data for 17,089 unigenes. A total of 123 differentially expressed genes with a |log2(fold change)| >1 and q-value < 0.05 were identified between the FeSO4 and Fe-Gly groups. Gene Ontology functional analysis revealed that these genes were involved in oxidoreductase activity, iron ion binding, and heme binding. Kyoto Encyclopedia of Genes and Genomes pathway analysis also showed relevant important pathways. In addition, the expression patterns of 9 randomly selected genes were further validated by qRT-PCR, which confirmed the digital gene expression results. Our study showed that the two iron sources might share the same absorption mechanism, and that differences in bioavailability between FeSO4 and Fe-Gly were not only in the absorption process but also during the transport and utilization process.

Oral administration of liquid iron preparation containing excess iron induces intestine and liver injury, impairs intestinal barrier function and alters the gut microbiota in rats

The aim of this study was to determine the toxicological effects of excess iron in a liquid iron preparation (especially on intestinal barrier function) and the possible etiology of side effects or diseases caused by the excess iron. In study 1, forty male Sprague-Dawley rats (4-5 wk old) were subjected to oral gavage with 1 ml vehicle (0.01 mol/L HCl) or 1 ml liquid iron preparation containing 8 mg, 16 mg or 24 mg of iron for 30 d. Iron status, oxidative stress, histology (H&E staining), ultrastructure (electron microscopy) and apoptosis (TUNEL assay) in the intestines and liver were assessed. The cecal microbiota was evaluated by 16S rRNA sequencing. In study 2, twenty rats with the same profile as above were subjected to oral gavage with 1 ml vehicle or 24 mg Fe for 30 d. The intestinal barrier function was determined by in vivo studies and an Ussing chamber assay; tight junction proteins and serum pro-inflammatory cytokines were observed by enzyme-linked immunosorbent assay. In study 1, the intestinal mucosa and liver showed apparent oxidative stress. In addition, iron concentration-dependent ultrastructural alterations to duodenal enterocytes and hepatocytes and histological damage to the colonic mucosa were detected. Notably, apoptosis was increased in duodenal enterocytes and hepatocytes. Impaired intestinal barrier function and lower expression of intestinal tight junction proteins were observed, and the phenotype was more severe in the colon than in the duodenum. A trend toward higher expression of serum pro-inflammatory cytokines might indicate systemic inflammation. Furthermore, the caecal microbiota showed a significant change, with increased Defluviitaleaceae, Ruminococcaceae, and Coprococcus and reduced Lachnospiraceae and Allobaculum, which could mediate the detrimental effects of excess iron on gut health. We concluded that excessive iron exposure from liquid iron preparation induces oxidative stress and histopathological alterations in the intestine and liver. Impaired intestinal barrier function could increase iron transportation, and inflammation along with oxidative stress-enhanced liver iron deposition may cause further liver injury in a vicious circle. These effects were accompanied by lower intestinal segment damage and altered gut microbial composition of rats toward a profile with an increased risk of gut disease.

Betaine Improves Intestinal Functions by Enhancing Digestive Enzymes, Ameliorating Intestinal Morphology, and Enriching Intestinal Microbiota in High-salt stressed Rats

To investigate the role of betaine in the intestinal functions of high-salt stressed rats, 32 four-week-old male Sprague–Dawley rats weighing 128.0 (SD 5.06) g were randomly allotted to four groups. The control group was fed with standard chow diet (0.4% NaCl), while the treatment groups were fed a high-salt diet (4.0% NaCl) supplemented with betaine at 0.0%, 0.5%, and 1.0%, respectively. The experiment lasted 28 days. The results showed that rats in the high-salt stressed groups had a significant increase in both water intake and kidney index (p < 0.05). The level of cortisol (COR) was increased in the high-salt stressed rats (p < 0.05), and returned to normal levels with betaine supplementation (p < 0.05). Aldosterone (ALD) was decreased in all high-salt diet groups (p < 0.05). Betaine supplementation decreased antidiuretic hormone (ADH) levels significantly (p < 0.05). High salt stress decreased the activities of amylase, lipase, trypsin, and chymotrypsin in the small intestinal luminal contents (p < 0.05), however, these activities increased with betaine supplementation (p < 0.05). The gut villus height of small intestine was significantly decreased in the high-salt diet group (p < 0.05). However, they were higher in the betaine supplementation groups than in the control group (p < 0.05). A similar result was observed in the ratio of villus height to crypt depth (p < 0.05). Both alpha diversity indexes and beta diversity indexes showed that high salt stress decreased the diversity of intestinal microbiota, while supplementation with betaine counteracted the negative effect. In conclusion, the results indicate that betaine improves intestinal function by enhancing the digestive enzymes, ameliorating intestinal morphology, and enriching intestinal microbiota of high-salt stressed rats.

Phytosterols on growth performance, antioxidant enzymes and intestinal morphology in weaned piglets

BACKGROUND Plant extracts have been used widely to improve growth, lower cholesterol, and exert antioxidative defense and antimicrobial activities in animal production. The present study aimed to investigate the effects of dietary phytosterols (PS) on growth performance, antioxidant enzymes and intestinal morphology in weaned piglets. RESULTS A total of 120 crossbred piglets, weighing 9.58 ± 0.26 kg, were randomly allocated to three treatments: control, PS (0.2 g kg-1 ) and polymyxin E (0.04 g kg-1 , antibiotic control). Compared to the control, PS or polymyxin E supplementation decreased diarrhea rate, serum cholesterol and malondialdehyde (MDA) of the piglets (P < 0.05). Liver MDA was significantly decreased in PS-fed piglets compared to the control (P < 0.05), although there was no difference between the control and polymyxin E-fed piglets. PS increased the villous height/crypt depth ratio of the duodenum and jejunum compared to the control (P < 0.05). Polymyxin E supplementation in piglets did not alter the villous height/crypt depth ratio but raised the villous height and crypt depth of the duodenum compared to the control (P < 0.05). CONCLUSION The results of the present study indicated that PS could decrease diarrhea rate, lower serum cholesterol, reduce lipid peroxidation and ameliorate intestinal morphology in weaned piglets. In addition, PS exerted better amelioration on intestinal morphology than polymyxin E in piglets.