Trillions of bacteria and other microbes live in our gut and make up its microbiome. These microbes influence many aspects of our health, from our immune system to making certain vitamins and helping to digest the food we eat (1).
Research has shown that the foods you eat have a major influence on your gut microbiome.
Each type of bacteria or strain performs a different role in our body, and each strain likes different types of plant foods and fibres. We call these prebiotics. Prebiotics are nutrients in plant foods that we can’t digest ourselves. The prebiotics in plants include different types of fibre and other carbohydrates, as well as chemicals called polyphenols. These prebiotics provide food for our gut microbes and encourage their growth. Our gut microbes transform these foods into thousands of different metabolites which have many benefits for our health. So by eating a broader range of plant foods, we encourage a greater diversity of gut microbes to thrive, which in turn are better able to support our health.
Where is the research from?
In 2018, results from the American Gut Project (2), a collaboration of researchers and more than 10,000 participants in the study showed that those who ate a wider variety of plants had more diverse gut microbiomes. Participants who ate 30 or more different plants per week were more likely to have certain beneficial gut microbes than those who ate just 10. These participants also had higher levels of healthy metabolites, the chemicals produced by the microbes. These beneficial bacteria are responsible for numerous functions in the body:
The brain: the brain is connected to the gut through various neuronal and hormonal pathways. This provides communication between emotional and cognitive regions of the brain and the gut, meaning both have influence over one another. Various studies have highlighted the link between diet, mood, and mental health, with research indicating a diet higher in plants could be used as a tool to help manage and support mental wellbeing (3, 4).
Immunity and disease: with almost 70% of our immune cells residing in our gut, it is no surprise that our gut microbes can influence our immune response. Further human studies are needed to understand the role and extent our gut bacteria has on our immunity, however, research indicates that the diversity of our gut microbiota is involved in the prevention of numerous chronic diseases, and some cancers (5)
Metabolism: our body cannot fully break down fibre, which is why it continues through to our large intestine where it reaches our gut bugs. Here, the gut bacteria are able to ferment and break down these fibres and produce something called short chain fatty acids (SCFAs). These SCFAs help communicate to our body when we are full and influence the production of hunger/fullness and other appetite regulation hormones. This highlights the role that our gut bacteria play in appetite and blood sugar control (6, 7).
So you can see that by eating 30 or more different plants a week, not only can you improve the diversity and balance of your gut microbes, you can also nourish your body and mind and improve your overall health and wellbeing.
What is the Thomas Franks Plant 30 Challenge?
The aim of the Plant 30 Challenge is to eat 30 different plants each week. This can include fruits, vegetables, wholegrains, legumes, nuts and seeds, and herbs and spices; these are often referred to as the Super Six. It is easy for us to stick to the same meals and snacks on rotation each week. By aiming to consume 30 different plants each week, not only will you be providing a wide range of foods for our gut microbes, you may also discover new foods you enjoy.
Where to start?
It may seem overwhelming to consume 30 different plants a week, especially if you’ve not taken much notice of your plant intake before. However, it can be surprisingly easy by making small tweaks to your every day meals. If you don’t already consume 5-a-day (5 different fruits and vegetables), this is a great place to start. A portion is roughly the size of your fist, and eating a rainbow of colours each day can help ensure you’re upping your plant varieties. Frozen, dried and tinned fruits and vegetables also count (just be mindful of added salt and sugar), which are handy staples you can use in every day meals.
Begin by thinking about your current meals and identify any ways you could bulk them up with a few more plants, here are some handy tips:
- Add a handful of berries, nuts and seeds to your breakfast cereal and ensure your cereal of choice includes a wholegrain.
- You could swap your morning snack to one that includes a fruit or vegetable, such as carrot sticks with houmous or fruit and yoghurt.
- Try out some plant proteins. Legumes (beans and pulses) make excellent additions to pasta sauces, stews and curries, this will provide additional plants and protein… double win!
- Swap to wholegrain items for your common staples, such as bread, pasta and rice. You could also try out some other grains such as quinoa, bulgur, buckwheat and more!
- Add a flavour boost by including more herbs and spices. Whilst you may not consume a large portion, every little helps when it comes to increasing variety.
- Keep a checklist. This can help you keep track of how many different plants you currently eat, and monitor how it improves throughout the challenge. Use our weekly planner to track how many different plants you are eating.
Before you know it you’ll be on your way to eating 30 different plants each and every week. For many, this can provide noticeable improvements in overall wellbeing and soon becomes second nature. If you are someone who currently eats very little plants, start slowly and work your way up. You will find lots of tasty recipes on our Plant 30 webpage to help inspire you along the way, as well as some handy tips to reach 30 different plants within our article section.
References
- Zheng, D., Liwinski, T. & Elinav, E. Interaction between microbiota and immunity in health and disease. Cell Res30, 492–506 (2020). https://doi.org/10.1038/s41422-020-0332-7
- McDonald, D., et al (2018). American Gut: an Open Platform for Citizen Science Microbiome Research. mSystems, 3(3), e00031-18.
- https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-017-0791-y
- https://ajph.aphapublications.org/doi/abs/10.2105/AJPH.2014.302110?journalCode=ajph
- https://www.nature.com/articles/s41430-021-00991-6
- https://www.cambridge.org/core/journals/proceedings-of-the-nutrition-society/article/control-of-appetite-and-energy-intake-by-scfa-what-are-the-potential-underlying-mechanisms/A1EFBE12AD6F9838EBE3D7314D1EE1B4
- https://diabetesjournals.org/diabetes/article/71/11/2438/147445/Butyrate-Producing-Bacteria-and-Insulin
