# Benefits of Probiotics--Biodetoxification
## 3. Probiotics--Detoxification in the Human Body
### Modulation of Intestinal Microbiota and Immunomodulation
The production of slgA is one of the main functions of GALT and significantly correlates with the presence and activity of the pro-health intestinal microbiota. Secretory IgA is an immunoglobulin secreted on most mucous membranes of our body and is one of the most important elements of mucosal defense. slgA can flatten and agglutinate microorganisms, exerts a bacteriostatic effect, and prevents the adhesion of antigens to the epithelium, and thus their penetration into the mucous membranes, as well as neutralizing bacterial toxins [94; 128; 129]. It is also important that the intestinal microbiota is involved in building immunity by creating a natural barrier on the surface of the intestinal epithelium. Beneficial bacteria take up space on the receptors, thus preventing them from being occupied by pathogenic bacteria. In addition, they compete for nutrients with pathogens. Intestinal bacteria, through the production of bacteriocins, including hydrogen peroxide, are capable of direct bacteriostatic and bactericidal action. In addition, by synthesizing lactic acid, they lower the pH within the intestines, which changes the environment to one that is less hospitable for pathogenic bacteria [130; 131; 132]. Regular consumption of products with probiotics or supplementation with probiotic preparations may contribute to a more effective biodetoxification process, supporting the natural functions of the body that are responsible for the removal of toxins [121; 128; 129]. The gut microbiota plays a major role in the human body's capacity to maintain homeostasis. Probiotics are becoming more and more significant in the medical profession because of their beneficial effects on the human body and their ability to prevent and treat a number of chronic illnesses, including cancer, without having any harmful side effects [106]. Probiotics' anticarcinogenic activity stems from the following: (1) altering the composition of the intestinal microbiota; (2) altering the intestinal microbiota's metabolic activity; (3) producing anticarcinogenic compounds like conjugated linoleic acid and short-chain fatty acids; (4) inhibiting cell proliferation and inducing apoptosis in cancer cells; (5) influencing other mutagenic and carcinogenic factors (they can alter the activity of certain enzymes involved in the cellular detoxification process, preventing the activity of free radicals and carcinogenic substances); (6) binding and degradation of carcinogenic compounds present in the intestinal lumen; (7) immunomodulation promoting the production of antibodies, NK cells (natural killer cells), and macrophages; (8) improvement of the intestinal barrier; and (9) support for the production of anti-inflammatory cytokines, such as IL-10, which can prevent inflammation that leads to the development of cancer [133; 134; 135; 136]. In Table 2, examples of antimutagenic and anticarcinogenic probiotic activity are shown. The innate immune response is extremely important in the context of cancer. The first line of defense of the body against the development of cancer is NK cells, dendritic cells (DC), T-lymphocytes, cytokines (IFN, TNF, IL-12, and IL-18), chemokines (RANTES, MIP-1a, MIP-1b), chemokines, oxygen radicals, and nitrogen oxides and granulocytes (mainly neutrophils). NK cells are the first to destroy cancer cells that do not express molecules of the main MHC (Major Histocompatibility Complex) tissue compatibility system. NK cells destroy cancer cells by releasing cytotoxic proteins such as performs and granzymes that lead to cell lysis. Lysis of cancer cells releases their antigens, then they activate DC cells, which then present antigens to CD8+ T cells. In addition, NK cells, in response to cellular stress, increase the expression of ligands for NK cells on cancer cells, which activate other NK cells. Cytokines, such as interferons IL-12, IL-18, and IL-15, affect the faster maturation of NK cells. Most of the T cell subpopulation of TCR receptors is able to recognize phosphoantigens, antigens expressed on cancer cells.