No abstract

The intestinal tract is a host to 100 trillion of microbes that have co-evolved with mammals over the millennia. These commensal organisms are critical to the host survival. The roles that symbiotic microorganisms play in the digestion, absorption, and metabolism of nutrients have been clearly demonstrated. Additionally, commensals are indispensable in regulating host immunity. This is evidenced by the poorly developed gut immune system of germ-free mice, which can be corrected by transplantation of specific commensal bacteria. Recent advances in our understanding of the mechanism of host–microbial interaction have provided the basis for this interaction. This paper reviews some of these key studies, with a specific focus on the effect of the microbiome on the immune organ development, nonspecific immunity, specific immunity, and inflammation.

Background: Soy iso avone and soy saponin are heat-stable glycosides present in soybean meal, which is the major factor restrict soy protein using in aquatic feed. This study is aimed to conduct that dietary soy iso avone and soy saponin on growth performance, intestinal structure, intestinal immunity and gut microbiota community on rice eld eel (Monopterus albus), and revealed its mechanism. Results: In current study, dietary 1g/kg soy iso avone, 2g/kg soy saponin and their mixed feed decreased growth of M. albus. Dietary 1g/kg soy iso avone signi cantly increased serum alkaline phosphatase (P < 0.05), dietary 2g/kg soy saponin remarkably declined intestinal immunoglobulin M (P < 0.05). Dietary 1g/kg soy iso avone and 2g/kg soy saponin mixed feed signi cantly decreased intestinal complement 3, complement 4 and immunoglobulin M, amounts of intestinal goblet cells per root and shannon of gut microbiota (P < 0.05). Dietary 1g/kg soy iso avone, 2g/kg soy saponin and their mixed feed down regulated intestinal tight junction protein (Interleukin-12, Interleukin-15, Tight junction protein ZO-2-like) and anti-in ammatory (Interleukin-10, Transforming growth factor beta 2) mRNA expression, up regulated pri-in ammatory factors (Interleukin-1 β, Interleukin-6, Interleukin-8, Interleukin-12 and Interleukin-15) mRNA expression. Conclusion: Based on the current results, dietary soy iso avone and soy saponin could damage the intestinal structure and changes gut bacteria community of M. albus, and destroyed the intestinal barrier, eventually induced intestinal in ammatory occurring, soy iso avone and soy saponin mixed feed has more serious effect than they single supplemented.

No abstract

The objective of this experiment was to study the effects of catalase (CAT) on growth performance, antioxidant capacity, intestinal morphology, and microbial composition of yellow broilers. Male Lingnan yellow broilers (360), aged 1 day, were randomly divided into control group (CON) (fed with a basic diet), R1 group (fed with basic diet + 150 U/kg catalase), and R2 group (fed with basic diet + 200 U/kg catalase). Each group had 8 replicates and 15 chickens in each replicate. The test is divided into the early stage (1–30 days) and the later stage (31–60 days). The results showed that compared with the control group, groups R1 and R2 significantly (p &lt; 0.05) increased the weight gain and reduced (p &lt; 0.05) the ratio of feed to gain in the early and the whole stages; prominently increased (p &lt; 0.05) the concentration of total antioxidant capacity (T-AOC), the activities of CAT, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) in livers, the activities of CAT and GSH-Px in serum, and CAT in the jejunum in the early and the later stages; markedly increased (p &lt; 0.05) the villus height and the ratio of villus height to crypt depth of the duodenum in the early and the later stages, the villus height and the villus height:crypt depth ratio of the jejunum and ileum in the early stage, and significantly lowered (p &lt; 0.05) the crypt depth of the duodenum (in the early and the later stages), jejunum, and ileum (in early stage); memorably (p &lt; 0.05) increased the number of total bacteria and Bacteroidetes in ceca, as well as the number of Lactobacillus in the jejunum (p &lt; 0.05) on the 30th; significantly (p &lt; 0.05) increased the mRNA expression of junction adhesion molecule 2 (JAM2), mucin 2 (MCU2), and occlusal protein (occludin) in the duodenum in the early stage, and increased (p &lt; 0.05) the mRNA expression of JAM2 in the jejunum in the later stage. Collectively, adding catalase (CAT) to the diet of yellow broilers can improve the growth performance and the antioxidant capacity, promoting the integrity of intestinal morphology, optimizing the composition of intestinal microorganisms, and upregulating the mRNA expression of tight junction protein.