Parkinson's: alpha-synuclein may start in gut

Most people think you need to poo every day to be healthy. You don’t. In this episode, we explain how to tell if your poo is normal, the warning signs you shouldn’t ignore, and the gut mistake you may be making on the toilet every day. 

Dr Trisha Pasricha, a leading Harvard gastroenterologist, a columnist for the Washington Post and author of the book You’ve Been Pooping All Wrong, explains how your poo, gut health, and disease risk are linked, and when you should see a doctor.

Dr Pasricha guides us through why frequency, colour, and consistency all matter, and why there is no single “normal.” You’ll learn how to spot changes that could signal disease, including early warning signs linked to cancer and long-term brain health.

You’ll hear simple advice you can use straight away. This includes how to recognise your normal pattern, what changes to look out for, and how to avoid the common toilet habit that may affect your gut.

Are you looking at your poo every day? And, if not, what might you notice if you did?

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Timecodes

00:00 Intro

03:11 Your phone on the toilet: hidden risk?

07:26 Your colon runs on a clock

10:40 The illness that changed his gut for years

13:05 Why you should look before you flush

15:25 The poo colours you should never ignore

16:25 Why this sign is rising in younger adults

18:15 The stool colour doctors treat as urgent

19:27 What “perfect” poo actually looks like

21:05 What holding it in really does

23:05 The 3 things that control your bowel movements

25:35 Why gut problems are getting worse

26:43 The posture fix most people miss

27:35 The phone habit linked to 46% higher risk

29:47 Why your phone keeps you stuck there

32:35 The hidden gut–brain connection

34:50 What stress really does to your gut

36:50 Your gut may be controlling more than you think

38:50 Is IBS really misunderstood?

41:05 The theory that changes how we see Parkinson’s

44:15 The gut damage linked to future brain disease

47:45 The simple rule for better bowel movements

49:00 The foods that changed gut health in weeks

50:22 The surprising fix for constipation

52:05 The 2 habits most people ignore

54:31 A 60-second trick to calm your gut

55:30 If you change one thing, make it this

56:10 What matters most

📚Books by our ZOE Scientists

The Food For Life Cookbook

Every Body Should Know This by Dr Federica Amati

Food For Life by Prof. Tim Spector

Ferment by Prof. Tim Spector

Good Mood Food (preorder) by Prof. Tim Spector

Free resources from ZOE

Eating for Better Brain Health: Your brain-gut blueprint

Gut Guide - For a Healthier Microbiome in Weeks 

Better Breakfast Guide

Mentioned in today's episode

You’ve Been Pooping All Wrong by Dr Trisha Pasricha

Gastrointestinal Symptoms in the United States, The American Journal of Gastroenterology (2018)

Smartphone use on the toilet and the risk of hemorrhoids, PLOS One (2025)

Impacts of Gut Bacteria on Human Health and Diseases, International Journal of Molecular Sciences (2015)

Association between Early Adverse Life Events and Irritable Bowel Syndrome, CGH (2011)

Management of Gastrointestinal Symptoms in Parkinson's Disease: A Comprehensive, National Library of Medicine (2024)

Constipation and risk of dementia in adults, Frontiers (2025)

Gastrointestinal issues and Autism Spectrum Disorder, Child and Adolescent Psychiatric Clinics of North America (2020)

Stanford fermented foods study

Ultra-Processed Food Consumption and Irritable Bowel Syndrome, Nutrients (2025)

Have feedback or a topic you'd like us to cover? Let us know here.

Episode transcripts are available here.