What specific effects does Bacillus subtilis have on the immune function of anim

Bacillus subtilis has the following specific effects on animal immune function:

1、 Stimulate the development of immune organs

Promoting lymphatic organ growth: In young animals, Bacillus subtilis can stimulate the growth and development of lymphatic organs such as spleen and thymus. For example, in chicken feeding experiments, it was found that the feed group supplemented with Bacillus subtilis had significantly higher spleen index and thymus index (the ratio of organ weight to body weight) than the non supplemented group. This is because the metabolites of Bacillus subtilis or the bacterial cells themselves can act as signaling molecules to activate some growth factors and cytokines in animals, promote the proliferation of immune organ cells, and enable these organs to develop and mature faster, providing animals with a more complete immune function foundation.

Increase the number of lymphocytes: It helps to increase the number of B lymphocytes and T lymphocytes. B lymphocytes are mainly responsible for humoral immunity and can produce antibodies to fight against pathogens; T lymphocytes play a crucial role in cellular immunity, such as recognizing and killing virus-infected cells. Bacillus subtilis can stimulate hematopoietic tissues such as animal bone marrow to produce more lymphocyte precursor cells, and guide these precursor cells to differentiate into mature and immunologically active lymphocytes, thereby increasing the reserve of lymphocytes in the animal body and enhancing the ability of immune response.

2、 Enhance immune cell activity

Activate macrophages: Macrophages are the "scavengers" in the animal immune system, capable of engulfing and clearing invading pathogens, cell debris, and other foreign substances. Bacillus subtilis can activate macrophages and enhance their phagocytic ability. When macrophages are activated, the expression of phagocytic receptors on their surface increases, enabling them to more effectively recognize and bind to pathogens. For example, in aquaculture, adding Bacillus subtilis can significantly increase the phagocytic rate of bacteria by macrophages in fish, thereby enhancing their resistance to bacterial diseases.

Enhance the activity of natural killer cells (NK cells): NK cells are important immune cells in the body that can directly recognize and kill abnormal cells such as tumor cells and virus-infected cells. Bacillus subtilis can upregulate the expression of NK cell surface activated receptors and promote the release of cytotoxic particles by regulating intracellular signaling pathways, enhancing their killing activity. In some mouse experiments, it has been shown that after consuming food containing Bacillus subtilis, the killing activity of NK cells against tumor cells in mice is significantly enhanced.

3、 Regulating the production of cytokines

Inducing the production of immune enhancing factors: Bacillus subtilis can induce various immune enhancing factors in animal bodies, such as interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF - α). These cytokines play a crucial role in initiating immune responses, regulating inflammatory responses, and other processes. For example, IL-1 can activate T lymphocytes, promote their proliferation and differentiation; IL-6 can stimulate B lymphocytes to produce antibodies; TNF - α can enhance the phagocytic activity and bactericidal ability of macrophages.

Balancing anti-inflammatory and pro-inflammatory factors: At the same time, it can regulate the production of anti-inflammatory cytokines such as interleukin-10 (IL-10), maintaining the balance of anti-inflammatory and pro-inflammatory cytokines in the body. If the inflammatory response is excessive, it can cause damage to the animal's own tissues, and IL-10 can inhibit the excessive inflammatory response. Bacillus subtilis regulates this balance, allowing animals to effectively initiate immune responses to eliminate pathogens while avoiding damage caused by uncontrolled inflammatory reactions when responding to pathogen invasion.

4、 Improve mucosal immune function

Strengthening the intestinal mucosal barrier: In animal intestines, Bacillus subtilis can promote the expression of tight junction proteins in intestinal mucosal epithelial cells. These tight junction proteins act like "glue" that tightly connects intestinal epithelial cells together, preventing pathogens and harmful substances from entering the body through intercellular spaces. For example, adding Bacillus subtilis to the intestine of piglets can increase the expression level of tight junction proteins such as ZO-1 in the intestinal mucosa, enhancing intestinal barrier function.

Stimulating the production of secreted immunoglobulin A (sIgA): sIgA is the main antibody in mucosal immunity, which can prevent pathogens from adhering and invading on the mucosal surface. Bacillus subtilis can stimulate plasma cells in intestinal and other mucosal tissues to produce more sIgA. In the respiratory mucosa of poultry, Bacillus subtilis can induce the secretion of sIgA by respiratory epithelial cells, enhance the respiratory resistance to pathogens, and effectively prevent respiratory infections.