What if boosting your immune system is the wrong goal? 

Today, Dr Giulia Enders explains how boosting immunity may increase inflammation and why your symptoms are often part of your body’s defence. Your immune system is not failing when you feel sick. It is trying to protect you. So what should you focus on instead?

That’s the idea at the very heart of Giulia’s new book, Organ Speak. Giulia is a gastroenterologist and author whose previous book, Gut, sold eight million copies and helped convince the world that gut health was worth taking seriously.

She explains how the immune system really works and why symptoms like a runny nose, cough, or fever come from your body, not the infection itself. You’ll learn how sugar may push the immune system toward inflammation, how stress can weaken it, and why sleep is key for producing immune cells. This episode also explores how exercise helps regulate your immune response. The core idea is simple: health is not about making your immune system stronger. It is about keeping it balanced.

By the end of this episode, you will have practical ways to support that balance and habits to help your immune system respond in the right way.

If the sneezing, runny nose, fever - all of it - are actually the whole point, how much energy should you spend in suppressing them?

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Timecodes

00:00 Intro

02:45 Why being sick feels like failure

04:30 The problem with only treating the gut

07:16 Why your body is not broken

10:25 When your immune system gets overprotective

13:28 The virus may not cause your symptoms

15:36 Should you stop cold symptoms?

16:40 When diarrhoea medicine can backfire

18:05 Should you take painkillers when sick?

18:52 Why immunity is not a war

20:46 The invisible microbe cloak protecting you

22:49 How your body clears bacteria from skin

24:10 Your microbiome is part of immunity

26:58 Is your immune system like AI?

28:00 Why boosting immunity can go wrong

30:36 Are immune supplements worth taking?

31:45 How stress weakens your gut barrier

34:25 The one-minute breathing reset

37:48 Why sleep builds immune cells

39:27 The most important half of sleep

44:16 Do naps help your immune system?

46:40 What to eat for immune balance

48:00 How exercise moves immune cells

49:10 Why exercise when sick can be risky

54:26 Strength vs cardio for immunity

56:00 The immune system takeaway everyone needs

📚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

The Hormone Harmony Guide: Tuning Your Body’s Internal Orchestra

Eating for Better Brain Health: Your brain-gut blueprint

How to eat in 2026 - Discover ZOE’s 8 nutrition principles for long-term health

Live Healthier: Top 10 Tips From ZOE Science & Nutrition

Gut Guide - For a Healthier Microbiome in Weeks 

Better Breakfast Guide

Mentioned in today's episode

Organ Speak: What it really means to listen to our bodies by Giulia Enders

Gut by Giulia Enders

Association of Stress-Related Disorders With Autoimmune Disease, JAMA (2018)

Sugar-sweetened soda consumption and risk of developing rheumatoid arthritis, AJCN (2014)

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

Episode transcripts are available here.