Justine Pattison - The Healthy Gut Handbook: Lose Weight and Boost Your Health with this 28-Day Plan

by Professor Tim Spector

While on holiday a few years ago, I was struck down with a rare illness that suddenly left me with double vision, dizziness and high blood pressure. The symptoms resolved over the following months, but I was left needing a daily dosage of tablets and, crucially, was forced to re-evaluate my diet. As a practising doctor for over thirty years and the author of hundreds of research papers, many on obesity and weight, I considered myself well versed on nutrition and dieting. However, once I began to pick apart my seemingly healthy diet I realised that it was high in sugar, low in fat and most startlingly lacking in diversity. And I began a journey to discover the health repercussions that this lack of diversity can lead to.

Diets dont work

We have in the last two generations become obsessed with dieting, but its increasingly clear that faddish regimes and strict calorie counting dont work. Most people will have dipped their toe in and tried a diet at some point, but after an initial weight loss or burst of enthusiasm, the inevitable happens and the diet falls by the wayside. Despite doctors advice over the last thirty years to eat less and exercise more, our waistlines are increasing, obesity is rising fast across the globe and weight-related diseases are more prevalent. But this is not simply a collective failure of willpower, as babies and infants have also been getting bigger. At the same time food allergy has become an epidemic and, despite the first modern case only being reported in 1969, it now affects nearly one in ten children. What research has shown is that our health, and in particular our weight, is governed by the key role of an until recently overlooked and outwardly invisible component: our microbiome.

The importance of our microbiome

Microbes describe any living creature that you need a powerful lens or microscope to see. We are surrounded by them in the air we breathe and the soil we garden with and play in; they are on our skin and in the food we eat. But we actually carry most of them around inside us in our intestines.

The four to five feet of the adult colon contains around 100 trillion microbes; these weigh as much as our liver and should be thought of as a newly discovered organ. Our microbes outnumber our own human cells ten to one (if you discount our borning non-replicating red blood cells) and have over 150 times more genes than we do.

We share about a third of our genes with our microbes, the original inhabitants of our planet from whom we slowly evolved millions of years ago. Since then we have provided them with a safe place to live plus a steady source of food. In return they have kept us healthy by controlling our immune systems, protecting us from invading aggressive microbes and helping us digest our food by extracting key chemicals and vitamins we require.

What do microbes do?

Control our immune systems

Protect us from invading aggressive microbes

Help us digest food by extracting key chemicals and vitamins

Produce chemicals altering our mood and appetite

The traditional view of microbes is based on stories of extreme food poisoning (such as salmonella), infections like pneumonia or potentially lethal diseases like gangrene. More recently so-called superbugs (like MRSA or C. difficile) have hit the headlines because they have acquired resistance to antibiotics. By decimating the normal microbe community in the blood or bowel they dominate with fatal consequences. Yet these potentially bad microbes make up less than 1 per cent of our microbiome (the combined set of our individual microbes) and usually exist in small numbers without harm to us.

Over the past fifty or so years we have been systematically destroying our microbiome by eating an increasingly processed and limited diet, becoming obsessed with cleanliness and hygiene and by the high instances of caesarean sections.