Inuits and the Microbiome: How a Change in Diet Contributes to Cancer Risk
In pursuit of their studies into how diet and the microbiome affect colorectal cancer risk, James Kinross and his collaborators have to keep some very antisocial hours: with conference calls between collaborators based in London, Pittsburgh, Northern Alaska, and Stellenbosch, amongst others, at least one group tends to be communing with either the larks or the owls at their end of the phone.
The reasons for these global collaborations are entirely clear: to investigate how what we eat can predispose us to colorectal cancer, researchers need to study and compare populations who are at unusually high, or unusually low risk of developing cancer and which have distinct, less westernised diets. Quite often, these will be communities that can be rather remote and isolated.
James recently co-authored an international study that compared the effects of a typical high-fat, low fibre ‘westernised’ diet in African Americans, versus a low-fat, high fibre diet of rural Africans, on the composition of their gut health and bacteria—the microbiome. The results were startling. When African Americans and rural Africans—who share a genetic heritage, but have very high versus very low incidences of colorectal cancer—swapped diets for two weeks, they also swapped gut health; the high-fat low-fibre diet promoted an increase in cancer biomarkers and a switch towards a more ‘cancer-friendly’ microbiome.
James is currently collaborating on a study involving the Inuit population of Alaska and the circumpolar region. The Inuit community eat a diet very high in animal fat and low in fibre, and as their traditional lifestyles erode, they are suffering an epidemic of cancers, including colon cancer.
Unravelling how nutrition interweaves with the many other factors that contribute to the Inuit’s increasing cancer incidence requires expertise in cancer biology, oncology and metabolomics, which James’s group has. However, it also requires the involvement of clinicians and health workers on the ground, experts in nutrition and diet, the microbiome and microbial ecology, as well as bioinformaticians to deal with the huge amounts of very diverse data being generated. There’s also a huge issue of cultural and ethnic sensitivity, as James highlights: “Every publication has to be signed off by the local cultural committee, as historically, their identity, culture and data has been exploited by outsiders,” he says. “We have to be very sensitive to our partners and adapt the way we do our work, if necessary.”
Studying the links between microbiome-dietary interactions and cancer risk is incredibly complicated ... you need a global overview—just the UK is not enough
“This whole project happened because I got talking to my Pittsburgh collaborator at a meeting, and found we were working on the same problem but from a different standpoint,” says James. ‘Studying the links between microbiome-dietary interactions and cancer risk is incredibly complicated, so to make any headway, you need teams of people who bring particular expertise to the table, and you need a global overview—just the UK is not enough.”
For a busy colorectal surgeon, James manages to juggle a lot of other collaborations: in addition to his work on diet and cancer, he is also taking part in a trial of the iKnife (invented by his Imperial colleague Zoltan Takats) as a way of improving precision in colon cancer surgery and endoscopy, and is part of a team-building virtual reality simulators for use in major incidents and trauma training.
If you want to have a successful research career in surgery where your work is translational in nature, you can only succeed if you collaborate
James has a solid justification for his hectic schedule: “If you want to have a successful research career in surgery where your work is translational in nature, you can only succeed if you collaborate. And it’s an amazing luxury to work with some of the best scientists in the world,” he adds. “They’re brilliant people and I work with them every day—I absolutely love it!”