How to eat 30 plant foods a week

The power of 30 plants a week

What is the microbiome?

Put simply, the microbiome is a collection of many different microorganisms which are found in specific environments throughout the body, such as our skin, mouth and gut. The microbiome includes bacteria, fungi, yeast and viruses and is individualised to each human, making it more unique than DNA cells or even our fingerprints. Even genetically identical twins have different microbiomes.

There are many factors that influence the microbiome – not only genetic factors, but also things like your diet, the pollution in your environment, whether you were born vaginally or by C-section, and whether you were breastfed.

Why should we eat 30 plants a week?

The American Gut Project conducted a large study in 2018 with people from the US, UK and Australia. It revealed that those who had a diet with more plant diversity – specifically 30 different plant foods a week – had better gut health and better gut microbe diversity than those who consumed fewer than ten.

They also found that people who were consuming more fibre, as well as more fermented foods, had better gut health.

Read about the impact of fibre on your gut health in our guide.

The importance of plant diversity

The quality and diversity of plants is key, and it's important to consume different colours as well as different species. For example, if you had a bag of mixed salad leaves, each different leaf would count as a separate plant.

Eating a varied diet means that our bodies are taking in different types of dietary fibre and a variety of antioxidants, as well as polyphenols, which are plant chemicals that are beneficial to gut health.

Getting enough 'plant points'

In essence, plant points are a way of measuring the diversity of plant-based foods. Each variety of plant will count as one plant point. The six main plant groups, or 'super six', are: vegetables; fruit; wholegrains; beans and pulses; nuts and seeds; and herbs and spices – and they all count.

Each different colour gives a different plant point. For example, if you have both a red and a green pepper, this will count as two plant points. Different varieties of veg also count, such as long-stemmed broccoli versus regular broccoli.

Herbs and spices are classed as plant points as they're derived from a whole food such as a root or leaf. Adding lots of herbs and spices into food is a great way of boosting your diet, although they only equal a quarter of a plant point at a time. Some hidden heroes are dark chocolate (if it's more than 75% cocoa), good quality coffee, and green tea.

If you are worried about your access to fresh fruit and vegetables, spices, beans, pulses, legumes, dried fruits and frozen veg all count too. Frozen options can be a great way to avoid food waste as you can typically use exactly how much you need and keep the rest frozen.

Eating the rainbow

The different colours in foods provide different properties which protect the gut due to their antioxidant, anti-inflammatory and antimicrobial activities. They improve overall health, and can also support gut health because they help to defend against harmful pathogens, reduce inflammation in the gut and reduce oxidative damage, which can be linked to chronic disease.

Berries, for example, are full of polyphenols, as are tomatoes. Whole grains like brown rice, oats, quinoa, nuts and seeds are all really good sources of polyphenols too.

The key to fibre

Fibre is crucially important for gut health, and digestive health in particular, supporting the digestion and removal of waste products in our bodies. In the UK we consume on average 18-20g of fibre a day, but we should be aiming for about 30g. Fibre consumption has been shown to reduce the risk of type 2 diabetes and cardiovascular disease. It also provides fuel to the gut microbiome.

Prebiotics are types of dietary fibre that the beneficial gut microbes feed off. By aiming for 30g of fibre a day, we can ensure that we're supporting these microbes. Having that balance within the gut also supports the digestive system.

Fruits, vegetables and wholegrains are high in fibre (check here for a list of high-fibre foods). To incorporate more fibre in your diet, you could add desiccated coconut, nuts and seeds to your morning oats at breakfast. When it comes to pasta or bread, opt for a wholewheat version.

The gut-brain connection

Other factors such as stress can play a really big part in our gut health, due to the gut-brain axis: the communication between the gut and the brain via the vagus nerve. That's why before an interview you may have nervous butterflies in your stomach or feel nauseous. If you're very anxious or stressed, there can be a miscommunication between the gut and the brain, so the gut doesn't know how to function properly.

Sleep also plays a huge part because our gut microbes work on a circadian rhythm. They operate on a 24-hour cycle and know the difference between day and night. If you're not getting enough sleep, the gut microbes are also disrupted.

Movement and getting outdoors is really important in maintaining a healthy gut. Studies have shown that simply being outdoors more can benefit microbial diversity – even if it's just going for a stroll or taking your dog for a walk. Even doing household chores can improve digestion.