Background: The use of total parenteral nutrition (TPN) is commonly associated with mucosal lining of the intestinal tract, causing degenerative changes within the gut-associated lymphoid tissue (GALT). These phenomena are probably caused by the translocation of indigenous intestinal bacteria into other organs and tissues where they induce infections.

Methods: Using TPN model rats, this paper looks at the result of the investigation of the action of PSK (proteoglycan), a biological response modifier, which appears to suppress bacterial translocation and maintain local immunity activity.

Results: Culture of mesenteric lymph nodes obtained post-TPN demonstrate a bacterial rate as high as 60%. Immunohistochemical examination indicates a reduction in the number of plasma cells and a decrease in S-IgA production and secretion. A similar reduction in S-IgA within bile and portal venous blood was also confirmed. Continuous oral administration of PSK in a daily dose of 1,000 mg/kg had a protective effect against the degeneration of GALT. A staining in immunocytes of Peyer’s patches using immunohistochemical study was performed after administration of PSK and revealed constant levels of MHC-I, MHC-II, T helper cells, and interleukin-2 producing cells, supporting the protective role of PSK against degeneration of GALT with a subsequent reduction in bacterial translocation.

Conclusions: Proteoglycan can restore the impaired local immunity in the intestinal tract to normal levels and suppression of the bacterial translocation to provide an important function for patients receiving TPN treatment.