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Effect of a biological response modifier, PSK, on intestinal flora of tumor-bearing mice
K Sakurai1, I Motokawa, T Ando
1Biomedical Research Laboratories, Kureha Chemical Industry Co., Ltd., Tokyo, Japan.
Abstract:
PSK, a protein-bound polysaccharide derived from basidiomycetes, is a biological response modifier that exhibits a variety of activities following oral administration, including prevention of infection. In this study, the effects of oral administration of this drug on microbial flora of tumor-bearing mice were examined. Numbers of Staphylococcus, Streptococcus and Pseudomonas were increased, and those of Bifidobacterium and Lactobacillus were reduced in fresh feces of mice from later than 9 weeks after inoculation of sarcoma 180. However, these changes were prevented by oral administration of PSK. In mice bearing sarcoma 180, the increases in numbers of Staphylococcus and Pseudomonas and the decrease in those of Bifidobacterium were further enhanced by intraperitoneal administration of anticancer agent mitomycin C, but such changes were suppressed by oral administration of PSK. These results suggest that PSK has a preventive effect against abnormal conditions of the intestinal flora induced by tumor inoculation or the administration of anticancer agents.
Insights
Protein-bound polysaccharide (PSK) prevents intestinal flora disruption in tumor-bearing mice. PSK administration counteracted negative microbial changes caused by cancer and chemotherapy, supporting its role in maintaining gut health.
Area of Science:
- Microbiology
- Immunology
- Pharmacology
Background:
- Protein-bound polysaccharide (PSK), derived from basidiomycetes, is a biological response modifier.
- PSK demonstrates various activities, including infection prevention, upon oral administration.
- Tumor inoculation can significantly alter the gut microbial flora.
Purpose of the Study:
- To investigate the effects of oral PSK administration on the gut microbial flora of tumor-bearing mice.
- To determine if PSK can prevent or reverse microbial dysbiosis induced by tumor growth and anticancer agents.
Main Methods:
- Mice were inoculated with sarcoma 180 to induce tumors.
- Fecal samples were analyzed for microbial flora composition at different time points.
- PSK was administered orally, and mitomycin C was administered intraperitoneally to assess combined effects.
Main Results:
- Tumor-bearing mice showed increased Staphylococcus, Streptococcus, and Pseudomonas, with decreased Bifidobacterium and Lactobacillus.
- Oral PSK administration prevented these abnormal microbial changes.
- PSK suppressed the exacerbation of microbial dysbiosis caused by mitomycin C in tumor-bearing mice.
Conclusions:
- PSK exhibits a preventive effect against abnormal intestinal flora induced by tumor inoculation.
- PSK can counteract microbial alterations associated with anticancer agent administration.
- These findings suggest PSK's potential in managing gut dysbiosis in cancer patients.