Pancreatic Cancer and the Mycobiome

A brief post today as I find myself way behind on, well, everything!

I found this really interesting and I don’t often get to write about the mycobiome. New research has just come out which shows that a particular form of pancreatic cancer – which, as you may know, is one of the deadliest  that exist – may be the result of fungi moving into the pancreas from the gut.[i]  Scientists have k nown for some time that bacteria, viruses and parasites may play a role, but until now, fungi/yeasts were not suspect.

Pancreatic ductal adenocarcinoma is cancer of the tube of the pancreas, which allows its digestive juices to flow into the small intestine.  This appears to be the exchange site for the movement of fungi into the pancreas.

The scientists treated mice that already had pancreatic tumors with antifungals, and the tumor shrank 20-40% in 30 weeks.  They then looked at the species of fungi in the intestines of mice with and without pancreatic cancer in order to figure out which kind were moving into the pancreas of those affected.  They found that certain types of fungi moved at a much higher rate, including one called Malassezia, which is usually found on the skin and scalp and is responsible for dandruff and some kinds of eczema.  However, this species has also been linked to colon and skin cancers.  Incredibly, when Malassezia was allowed to grow unchecked, pancreatic cancers grew 20% faster in mice.  Candida, Saccharomyces, Aspergillus did not have this same effect.[ii]

They believe the mechanism of action is that the fungi stimulate the immune system in such a way as to lead to the growth of abnormal tissue.

As you know, abnormalities of the mycobiome are associated with other illnesses including autism and inflammatory bowel disease, and even perpetuating C.difficile infections.  You have to believe that with the explosion of research into the human biome, this list is going to get longer and longer.

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[i] https://www.webmd.com/cancer/pancreatic-cancer/news/20191004/fungal-invasion-may-drive-some-pancreatic-cancers#2

[ii] Aykut, B, et. al. The fungal mycobiome promotes pancreatic oncogenesis via activation of MBL.  Nature. 2019;574:264-267.