30 Plants a Week: What Counts, a Checklist and a Sample Week

Eating 30 different plant foods a week, not 30 portions of the same five, is linked to greater gut microbiome diversity than eating fewer than 10 types. That finding comes from the American Gut Project, one of the largest citizen-science microbiome studies ever run, and it has become one of the most repeated pieces of gut health advice for good reason.

This guide covers what actually counts as a “plant”, how herbs and spices are scored, a checklist you can tick off as you go, and a sample week that reaches 30 without turning breakfast into a spreadsheet exercise.

Updated 4 November 2026: corrected how herbs and spices are counted (a quarter point each), and added a 30 plants a week checklist and a sample week.

Where the “30 plants a week” idea comes from

The figure comes from an analysis of American Gut Project data (McDonald et al., 2018), which sequenced stool samples from thousands of participants alongside detailed diet records. People who reported eating more than 30 different plant types per week had significantly more diverse gut microbiomes than those eating 10 or fewer types.

Diversity itself is not directly a health outcome, but it is consistently associated with better markers of gut and metabolic health in other research. A more diverse microbiome generally means more bacterial species capable of fermenting a wider range of fibres into beneficial compounds.

The number 30 is not a hard biological threshold. It is the point in the data where the diversity benefit became clearly visible, and it has stuck as a practical, memorable target.

What counts as a “plant”?

This is where most people underestimate themselves. A “plant” in this context is any distinct plant-based food, not just vegetables.

In the plant points system most UK guides use, each herb or spice counts as a quarter of a point. Four different herbs or spices make one plant.

So a well-spiced curry still adds a point or more on top of its vegetables. It just won’t do the whole job on its own.

What doesn’t count, or counts less than people think

The same plant eaten multiple times in a week only counts once. Eating porridge oats every morning is one plant, not seven, however consistent the habit.

Highly refined plant-derived ingredients, white flour, sugar, and most vegetable oils, do not meaningfully contribute to microbiome diversity, even though they technically originate from plants. The whole-food fibre and micronutrient content is what matters, and refining strips most of it out.

Ultra-processed snack foods that happen to contain a plant-derived ingredient somewhere on the label are not a practical route to variety. A biscuit containing wheat flour is not doing the same job as a bowl of oats.

Why variety matters more than volume

Different plant fibres feed different bacterial species. Inulin from onions and garlic favours Bifidobacterium. Resistant starch from legumes and cooled potatoes favours butyrate-producing bacteria. Pectin from apples supports a different fermentation profile again.

Our guide to prebiotic fibre covers these mechanisms in more depth if you want the science behind why diversity, not just total fibre intake, drives a more resilient gut environment. Eating the same high-fibre food every day still leaves large parts of your microbiome under-fed.

This matters more with age. Gut microbiome diversity naturally declines from your 40s onward, which is one reason dietary variety becomes more, not less, important over time.

30 plants a week checklist

Tick each plant the first time you eat it in a week. Repeats don’t count again. Most people find they already eat 15 to 20 without trying.

Screenshot or print this section and keep it on the fridge for a week.

Vegetables (1 point each)

• ☐ Onion   ☐ Garlic   ☐ Carrot   ☐ Broccoli
• ☐ Spinach   ☐ Pepper   ☐ Courgette   ☐ Tomato
• ☐ Cucumber   ☐ Cauliflower   ☐ Kale   ☐ Leek
• ☐ Sweet potato   ☐ Peas   ☐ Beetroot

Fruit (1 point each)

• ☐ Apple   ☐ Banana   ☐ Blueberries   ☐ Raspberries
• ☐ Strawberries   ☐ Orange   ☐ Pear   ☐ Grapes
• ☐ Avocado   ☐ Kiwi

Wholegrains (1 point each)

• ☐ Oats   ☐ Brown rice   ☐ Wholemeal bread   ☐ Rye
• ☐ Quinoa   ☐ Barley   ☐ Buckwheat

Legumes and pulses (1 point each)

• ☐ Chickpeas   ☐ Lentils   ☐ Black beans   ☐ Kidney beans
• ☐ Butter beans   ☐ Edamame

Nuts and seeds (1 point each)

• ☐ Almonds   ☐ Walnuts   ☐ Hazelnuts   ☐ Chia
• ☐ Flaxseed   ☐ Pumpkin seeds   ☐ Sunflower seeds

Herbs and spices (¼ point each)

• ☐ Basil   ☐ Parsley   ☐ Coriander   ☐ Mint
• ☐ Cumin   ☐ Turmeric   ☐ Ginger   ☐ Cinnamon
• ☐ Paprika   ☐ Black pepper

Your weekly total: full plants ticked + (herbs and spices ticked ÷ 4) = plant points.

A sample week that reaches 30

This is an ordinary week of meals, not a special diet. The count only includes plants that are new that week, which is why it slows down as the days go on.

Saturday and Sunday are then a buffer for eating out, repeats, or a week that doesn’t go to plan.

The two biggest jumps came from a lentil soup and a curry. Mixed dishes do most of the work, which is why the tips below focus on them.

Simple ways to increase your plant count without extra cooking

• Buy frozen mixed vegetables rather than a single frozen vegetable. Most bags contain 4 to 6 different plants in one scoop.
• Add a spoonful of mixed seeds to porridge, yoghurt, or salad. Three or four seed types in one jar is an easy way to bank several plants at once.
• Rotate tinned beans and pulses rather than buying the same one repeatedly. Chickpeas one week, black beans the next, butter beans after that.
• Use a spice rack properly. Four different herbs or spices in a meal you already cook adds a full plant point.
• Keep a rotating fruit bowl rather than buying the same two fruits. Frozen mixed berries count as multiple plants in one bag.

Two of our other guides make this easier in practice. High fibre snacks like chickpeas, almonds, and mixed berries double as plant variety, not just fibre. And a high fibre breakfast built around oats, chia, and fruit can bank four or five plants before you’ve left the kitchen.

Plant variety and Biome Bliss

Plant variety feeds the bacteria already living in your gut. Biome Bliss works alongside that from the other direction.

It is a naturally fermented liquid that delivers six live cultures, together with the postbiotic compounds, such as organic acids, that the fermentation produces. It is made by fermenting organic ginger and 25 further organic herbs and fruits in an organic honey and apple juice base.

So it sits naturally next to a plant-varied diet rather than replacing one. You can see the six cultures and the full ingredient list in our guide to what’s in Biome Bliss.

Frequently asked questions

What counts as one of the 30 plants a week?

Any distinct plant-based food. Vegetables, fruits, wholegrains, legumes, nuts and seeds count as one point each, and herbs and spices count as a quarter point each. Eating the same food repeatedly only counts once in a week.

Is 30 plants a week actually necessary for gut health?

American Gut Project research found people eating more than 30 plant types per week had significantly more diverse gut microbiomes than those eating 10 or fewer. Thirty is not a strict biological threshold, but it reflects the range where the benefit became clearly visible in the data.

Do herbs and spices really count as separate plants?

They count, but usually as a quarter point each rather than a full plant. Four different herbs or spices add up to one plant point, so a well-spiced meal still helps, just less than the vegetables on the plate.

Can I get enough plant variety without eating more food overall?

Yes. Variety is about the number of different plants, not the total quantity eaten. Swapping which vegetables, beans, or spices you use week to week, rather than eating more food, is the more realistic route to 30.

Why does plant variety matter more than total fibre intake?

Different plant fibres feed different bacterial species. Eating a high volume of one fibre type feeds a narrower range of bacteria than eating a smaller amount of many different fibre types. Diversity of input supports diversity of the microbiome itself.

Does frozen or tinned produce count toward plant variety?

Yes. Frozen and tinned vegetables, fruit, and pulses retain most of their fibre content and count the same as fresh. Mixed frozen vegetable bags and rotating tinned beans are two of the easiest ways to add variety without extra cooking effort.

References

1. McDonald D, Hyde E, Debelius JW, et al. American Gut: an Open Platform for Citizen Science Microbiome Research. mSystems. 2018;3(3):e00031-18. pubmed.ncbi.nlm.nih.gov/29795809
2. Wastyk HC, Fragiadakis GK, Perelman D, et al. Gut-microbiota-targeted diets modulate human immune status. Cell. 2021;184(16):4137-4153. doi:10.1016/j.cell.2021.06.019

This article is for informational purposes only and does not constitute medical advice. If you have digestive symptoms or a diagnosed gut condition, speak with your GP before making significant dietary changes.