Could the microbiome be linked to breast cancer?

Research on the microbiome has shown for years that it has unexpected links to certain conditions, such as neurodegenerative diseases. A recent study has raised the question of its role in breast cancer.

The gut microbiota is a rapidly growing area of research. In fact, our digestive tract contains as many microorganisms as there are cells in our body. It consists of 𝐧𝐨𝐧-𝐩𝐚𝐭𝐡𝐨𝐠𝐞𝐧𝐢𝐜 𝐛𝐚𝐜𝐭𝐞𝐫𝐢𝐚, 𝐯𝐢𝐫𝐮𝐬𝐞𝐬, 𝐚𝐧𝐝 𝐟𝐮𝐧𝐠𝐢. It is primarily located in the colon and small intestine and plays a role in the body’s 𝐝𝐢𝐠𝐞𝐬𝐭𝐢𝐯𝐞, 𝐦𝐞𝐭𝐚𝐛𝐨𝐥𝐢𝐜, 𝐢𝐦𝐦𝐮𝐧𝐞, 𝐚𝐧𝐝 𝐧𝐞𝐮𝐫𝐨𝐥𝐨𝐠𝐢𝐜𝐚𝐥 𝐟𝐮𝐧𝐜𝐭𝐢𝐨𝐧𝐬. Imbalances in the gut microbiota (𝐝𝐲𝐬𝐛𝐢𝐨𝐬𝐢𝐬) are implicated in inflammatory bowel diseases, metabolic and cardiovascular diseases, neurodegenerative diseases, and developmental disorders, for example.

A study conducted by a team in Baltimore revealed that 𝐩𝐚𝐭𝐡𝐨𝐠𝐞𝐧𝐢𝐜 𝐠𝐮𝐭 𝐛𝐚𝐜𝐭𝐞𝐫𝐢𝐚 (𝐵𝑎𝑐𝑡𝑒𝑟𝑜𝑖𝑑𝑒𝑠 𝑓𝑟𝑎𝑔𝑖𝑙𝑖𝑠), which are sometimes found in tumors, may promote the activity of 𝐬𝐩𝐞𝐫𝐦𝐢𝐧𝐞 𝐨𝐱𝐢𝐝𝐚𝐬𝐞. This enzyme is known to be involved in the 𝐝𝐞𝐯𝐞𝐥𝐨𝐩𝐦𝐞𝐧𝐭 𝐚𝐧𝐝 𝐩𝐫𝐨𝐠𝐫𝐞𝐬𝐬𝐢𝐨𝐧 𝐨𝐟 𝐛𝐫𝐞𝐚𝐬𝐭 𝐜𝐚𝐧𝐜𝐞𝐫. Indeed, in this study, increased levels of spermine oxidase 𝐩𝐫𝐨𝐦𝐨𝐭𝐞𝐝 𝐨𝐱𝐢𝐝𝐚𝐭𝐢𝐯𝐞 𝐬𝐭𝐫𝐞𝐬𝐬, 𝐢𝐧𝐟𝐥𝐚𝐦𝐦𝐚𝐭𝐢𝐨𝐧, 𝐚𝐧𝐝 𝐃𝐍𝐀 𝐢𝐧𝐬𝐭𝐚𝐛𝐢𝐥𝐢𝐭𝐲. An increase in inflammatory cytokines and tumor necrosis factor alpha also amplified the expression and activity of spermine oxidase, thereby 𝐩𝐞𝐫𝐩𝐞𝐭𝐮𝐚𝐭𝐢𝐧𝐠 𝐚 𝐯𝐢𝐜𝐢𝐨𝐮𝐬 𝐜𝐲𝐜𝐥𝐞.

This finding suggests that spermine oxidase could be a 𝐩𝐨𝐭𝐞𝐧𝐭𝐢𝐚𝐥 𝐟𝐮𝐭𝐮𝐫𝐞 𝐭𝐡𝐞𝐫𝐚𝐩𝐞𝐮𝐭𝐢𝐜 𝐭𝐚𝐫𝐠𝐞𝐭, as the authors demonstrated in mice that inhibitors of this enzyme reduced tumor size and the number of metastases in animals exposed to strains of 𝐵𝑎𝑐𝑡𝑒𝑟𝑜𝑖𝑑𝑒𝑠 𝑓𝑟𝑎𝑔𝑖𝑙𝑖𝑠.