Show Notes
One bacterium causes roughly 1 in 20 cancer cases worldwide. It’s the most cancer-causing pathogen we’ve found—and the main cause of peptic ulcers. Its discovery overturned an ironclad medical dogma that the stomach was sterile. Despite infecting about half of humanity, Helicobacter pylori wasn't discovered until 1979 and shown to cause gastritis and peptic ulcer disease in the early 1980s. Why did it evade detection for so long—and what finally broke through the consensus? I went to Perth, Australia—where H. pylori was first discovered—to chat with Barry Marshall, gastroenterologist and co-recipient (with Robin Warren) of the 2005 Nobel Prize in Physiology or Medicine for discovering H. pylori and proving that it causes gastritis and peptic ulcer disease. Marshall famously infected himself with the bacterium to demonstrate causality and later helped develop clinical diagnostics like the urea breath test, which we demo live in the episode. We discuss: the rise and fall of stomach cancer in the West;
whether Darwin’s dyspepsia and Napoleon's stomach cancer trace to H. pylori;
the ulcer–cancer paradox;
Correa’s cascade: what H. pylori eradication reverses—and what it doesn’t;
the “H. pylori enigmas” (Africa, India, Costa Rica);
eradication prospects and an oral vaccine timeline;
how the field missed the discovery;
how the primitive internet enabled the discovery;
what the H. pylori discovery teaches us about how knowledge diffuses;
lessons from manufacturing millions of tests in Perth;
and much, much more.
Episode sponsors: Eucalyptus: the Aussie startup providing digital healthcare clinics to help patients around the world take control of their quality of life. Euc is looking to hire ambitious young Aussies and Brits. You can check out their open roles at eucalyptus.health/careers. Vanta: helps businesses automate security and compliance needs. For a limited time, get one thousand dollars off Vanta at vanta.com/joe. Use the discount code "JOE". See omnystudio.com/listener for privacy information.
More from The Joe Walker Podcast
This is the second episode in a multi-part series called 'Compute in Australia'. Series announcement here. More episodes to follow over the coming month. [Recorded 24 August 2026.] Janet Egan is Senior Fellow and Deputy Director of the Technology and National Security Program at the Center for a New American Security in Washington, DC. Her research focuses on the national security implications of artificial intelligence. She was previously the inaugural director of policy in Australia's Office of Supply Chain Resilience.
This is the first episode in a multi-part series called 'Compute in Australia'. Series announcement here. More episodes to follow over the coming month. [Recorded 7 August 2026.] Dr Andrew Charlton MP is an Australian economist, entrepreneur and politician. As Cabinet Secretary and Australia's Assistant Minister for Science, Technology and the Digital Economy, he is one of the key leaders shaping the Australian government's AI strategy. Andrew shares his internal model for how AI plays out economically and what a middle power like Australia should do about it. We discuss whether data centres will yield large economic rents, the geostrategic case for a compute industry, and how the government plans to use compute to climb the stack to "sovereign AI". Sponsors e61: a non-partisan economic research institute focused on Australian public policy. To receive a copy of the new essay I co-authored with e61 on data centres and the compute economy, go to https://www.e61.in/joewalker. Vanta: helps businesses automate security and compliance needs. For a limited time, get one thousand dollars off Vanta at https://www.vanta.com/joe. Use the discount code "JOE". To sponsor a future episode, go to https://josephnoelwalker.com/sponsor/ See omnystudio.com/listener for privacy information.
https://josephnoelwalker.com/ See omnystudio.com/listener for privacy information.
Patrick Weller is emeritus professor of politics and public policy at Griffith University and the author or editor of some forty books. Pat wrote what was the first (and may still be the only) Westminster-system equivalent to Robert Caro's epic meditation on Lyndon Johnson: a detailed study of how Australian Prime Minister Malcolm Fraser wielded power. First published in 1989, it's a fascinating study of how one individual climbed into the hermit-crab-shell that is the prime ministership and made it his own. Pat is also the author of two other detailed studies of Australian political leaders, and the definitive history of cabinet government in Australia. Pat's work offers a picture of how human institutions – in this case, Westminster cabinets – work in practice and on a day-to-day level. Understanding the messiness, the beautiful malleability of the institutions, and their human bottlenecks has helped me build a more accurate model of the world – useful for predicting how governments may both respond to and utilise powerful new technologies. Sponsors Effective Altruism Australia: how Australians give to GiveWell's top charities — tax-deductibly, and with 100% pass-through. Until June 30, 2026, EAA is matching new donations up to $300,000. Donate at https://www.eaa.org.au/joewalker. e61: a non-partisan economic research institute focused on Australian public policy. To receive a copy of the new essay I co-authored with e61 on data centres and the compute economy, go to https://www.e61.in/joewalker. To sponsor a future episode, go to https://josephnoelwalker.com/sponsor/ See omnystudio.com/listener for privacy information.
Danielle Wood is an Australian economist and the current chair of the Australian Productivity Commission. Had a lot of fun chatting with Dani about how she's making sense of AI and its implications for policy. We discuss: whether AI will be more like the internet or the Industrial Revolution, where in the AI stack the profits will ultimately flow (and why it might not be the model layer), why diffusion is the "main game" for Australian policymakers, whether there's a case for government support of data centres, why the AI jobpocalypse story is too crude (and why humans may still have jobs even under transformative AI), whether AI will turn out to be a normal or abnormal technology, or both, and why in either case Australia shouldn't follow the EU in legislating an AI Act. Sponsors Effective Altruism Australia: how Australians give to GiveWell's top charities — tax-deductibly, and with 100% pass-through. Until June 30, 2026, EAA is matching new donations up to $300,000. Donate at https://www.eaa.org.au/joewalker. e61: a non-partisan economic research institute focused on Australian public policy. To receive a copy of the new essay I co-authored with e61 on data centres and the compute economy, go to https://www.e61.in/joewalker. Vanta: helps businesses automate security and compliance needs. For a limited time, get one thousand dollars off Vanta at https://www.vanta.com/joe. Use the discount code "JOE". To sponsor a future episode, go to https://josephnoelwalker.com/sponsor/ See omnystudio.com/listener for privacy information.