A Review of the Mechanisms of Bacterial Colonization of the Mammal Gut.

A healthy animal intestine hosts a diverse population of bacteria in a symbiotic relationship. These bacteria utilize nutrients in the host's intestinal environment for growth and reproduction. In return, they assist the host in digesting and metabolizing nutrients, fortifying the intestinal barrier, defending against potential pathogens, and maintaining gut health. Bacterial colonization is a crucial aspect of this interaction between bacteria and the intestine and involves the attachment of bacteria to intestinal mucus or epithelial cells through nonspecific or specific interactions. This process primarily relies on adhesins. The binding of bacterial adhesins to host receptors is a prerequisite for the long-term colonization of bacteria and serves as the foundation for the pathogenicity of pathogenic bacteria. Intervening in the adhesion and colonization of bacteria in animal intestines may offer an effective approach to treating gastrointestinal diseases and preventing pathogenic infections. Therefore, this paper reviews the situation and mechanisms of bacterial colonization, the colonization characteristics of various bacteria, and the factors influencing bacterial colonization. The aim of this study was to serve as a reference for further research on bacteria-gut interactions and improving animal gut health.

Dietary supplementation with nano-composite of copper and carbon on growth performance, immunity, and antioxidant ability of yellow-feathered broilers.

New feed additives as antibiotics substitutes are in urgent need in poultry production. Nano-composite of copper and carbon (NCCC), a novel copper donor with stronger antibacterial properties, is expected to promote broiler growth and diminish the negative effects of excess copper (Cu). Hence, the purpose of this study is to investigate the effects of NCCC on growth performance, immunity, and antioxidant ability of yellow-feathered broilers. A total of 240 1-d-old male yellow-feathered broilers were selected and randomly divided into four groups, with five replications per group and 12 birds per replication. The CON group was fed corn-soybean basal diets, while the N50, N100, and N200 groups were supplemented with 50, 100, and 200 mg/kg of NCCC in basal diets, respectively. The trial lasted for 63 d. The results demonstrated that only 200 mg/kg NCCC addition significantly increased the Cu content in serum and feces, and liver Cu content linearly increased with NCCC dosage increment (P < 0.05). Meanwhile, NCCC supplementation did not alter the growth performance, slaughter performance, immune organ indexes, and liver antioxidant ability of broilers (P > 0.05), but optimized the serum cytokine pattern by elevating the level of serum IL-10 (P < 0.05), and there were linear and quadratic increases in serum IL-4 with NCCC dosage increment (P < 0.05). On the whole, in spite of no impact on growth performance, 50 mg/kg NCCC was optimal to supplement in chicken diets due to the rise of serum IL-10 level and no extra environmental pollution and tissue residues.

Livestock and poultry industries require eco-friendly antibacterial agents and growth promoters due to the ban on antibiotics in the European Union and China. High-dose copper is considered a bactericide and has the advantage of growth promotion in animals, but it also disturbs the absorption of other metal elements and causes heavy metal residues. In this experiment, a nano-composite of copper and carbon (NCCC) was chosen as an alternative copper donor, hoping to not only inherit the growth-promoting merit but also diminish the disadvantage of excess copper. Hence, the effects of NCCC on growth performance, immune function, and antioxidant capacity of yellow-feathered broilers were explored, and we discovered that there were no copper residues in liver, serum, and feces after 50 or 100 mg/kg NCCC treatment. Meanwhile, obvious increases in levels of serum IL-10 and IL-4 were observed with NCCC dosage increment, despite no notable changes in the growth performance, slaughter performance, and liver antioxidant ability of chickens. As a result, NCCC has been found to optimize serum cytokine pattern but not promote the growth of broilers.