The Main Concept Behind Eating 30 Different Plants a Week Explained

October 11, 2025 •

4 min read

According to the American Gut Project, individuals who consumed 30 or more different plants each week had a significantly more diverse gut microbiome than those who ate fewer than 10. This finding is the central principle behind the concept of eating 30 different plants a week, focusing on diversity over mere quantity to nurture a flourishing inner ecosystem.

Quick Summary

The principle of eating 30 different plants weekly is centered on increasing gut microbiome diversity through a varied intake of plant-based foods. This approach provides a wide array of fibers and phytochemicals to feed a larger, healthier community of gut microbes, which supports overall well-being. It is a modern, variety-focused update to older dietary guidelines.

Key Points

Microbiome Diversity: The core concept is that a wide variety of plant foods fosters a more diverse and resilient gut microbiome, crucial for overall health.
Prebiotic Fuel: Different plant types contain unique fibers and starches that act as prebiotics, feeding different species of beneficial gut bacteria.
Polyphenol Power: A diverse plant intake provides a broad range of polyphenols and other phytochemicals, which have antioxidant and anti-inflammatory effects that benefit gut health.
Small Changes, Big Impact: Even if you don't reach 30 plants immediately, increasing your dietary variety incrementally still provides significant health benefits and improves microbial diversity.
More Than Fruits & Veggies: The 30-plant count includes all plant categories, such as nuts, seeds, legumes, whole grains, herbs, and spices, making the target more achievable.
Focus on Variety, Not Volume: The emphasis is on counting unique plant types, not portion size. Eating a wider variety of foods is the priority over large quantities of a few types.

The Science of Microbiome Diversity

At the core of the main concept behind eating 30 different plants a week is the symbiotic relationship between humans and their gut microbiome—the trillions of microorganisms living in our digestive tract. A diverse microbiome, rich with different species of bacteria, is strongly linked to numerous health benefits, including enhanced immune function, improved metabolic health, and even better mental well-being. Conversely, a low-diversity microbiome can increase the risk of chronic diseases and inflammation.

How Plant Diversity Feeds Your Gut

Different species of gut bacteria thrive on different food sources, primarily various types of fiber and plant compounds known as polyphenols. By consuming a wide variety of plants—including fruits, vegetables, whole grains, legumes, nuts, seeds, herbs, and spices—you introduce a broader spectrum of these fermentable fibers and phytochemicals into your diet. This provides a banquet of nutrients for a wider array of microbial species, encouraging them to flourish and diversify. This variety-driven approach contrasts with simply consuming large quantities of a few plant types, which would only feed a limited number of microbial species.

The Role of Fibers and Polyphenols

Plants are packed with different types of fiber, both soluble and insoluble, that serve as prebiotics—fuel for your beneficial gut bacteria. These bacteria ferment the fibers to produce beneficial compounds called short-chain fatty acids (SCFAs), such as butyrate, which is a primary energy source for your colon's cells and has anti-inflammatory properties. Beyond fiber, plants contain thousands of different phytochemicals, including polyphenols, which are natural compounds with antioxidant and anti-inflammatory effects. Different colors in fruits and vegetables, for example, often indicate different types of polyphenols, reinforcing the “eat the rainbow” philosophy. By diversifying your plant intake, you ensure a wider range of these protective compounds reach your gut.

Practical Ways to Increase Your Plant Intake

Achieving the goal of 30 different plants a week may seem daunting at first, but it is easier than you might think when you consider all the different plant-based foods that count.

Getting creative in the kitchen can dramatically increase your tally:

Breakfast Boosters: Add different berries, nuts (almonds, walnuts), and seeds (chia, flax) to your oatmeal or yogurt. A sprinkle of cinnamon or turmeric adds an extra point.
Salad Supercharge: Go beyond just lettuce and tomatoes. Incorporate chickpeas, kidney beans, quinoa, avocado, and a variety of colorful vegetables like red onion and bell peppers. Top with a mixed seed sprinkle and fresh herbs like cilantro or dill.
Soups and Stews: When making a base, include a mix of vegetables like carrots, celery, and leeks. Add lentils or different types of beans (black beans, butter beans) for extra fiber and texture. Season with a range of spices for flavor and extra points.
Snack Smart: Swap processed snacks for mixed nuts, veggie sticks with hummus, or an apple with a handful of sunflower seeds.
Herbs and Spices: Don't underestimate the power of herbs and spices. Different herbs like basil, oregano, and thyme, plus spices like cumin, paprika, and ginger, all count. Even coffee and dark chocolate (over 70% cocoa) contribute.

Comparison Table: 30 Plants a Week vs. 5-a-Day


Feature	30 Plants a Week Approach	5-a-Day Approach (traditional)
Primary Goal	Maximize dietary diversity for gut microbiome health.	Meet a minimum intake quantity of fruits and vegetables for general nutrition.
What Counts?	All plants count: fruits, vegetables, whole grains, legumes, nuts, seeds, herbs, and spices.	Focus primarily on fruits and vegetables.
Focus	Variety is the priority; quantity is secondary.	Quantity is the priority; variety is encouraged but not tracked.
Underlying Principle	Different plants feed different microbes, promoting a diverse and resilient gut.	Ensures a baseline intake of essential vitamins, minerals, and fiber.
Measurement	Tracking the number of different plants consumed in a week.	Tracking the number of portions of fruits and vegetables consumed in a day.

Making the Change: Small Steps to Big Results

For many, shifting to this mindset is a gradual process. If you are currently eating fewer than 10 plants a week, aiming for 30 immediately can be overwhelming. The key is to start small and incrementally increase variety. Add one new vegetable to your dinner each night, swap white rice for brown rice or quinoa, and start sprinkling a seed mix on your salads. Small, sustainable changes can lead to a lasting health impact, as the goal is progress, not perfection. Even simply incorporating a greater variety of plants can naturally displace less nutritious, processed food choices, leading to overall improved health.

Conclusion: Nurturing Your Inner Ecosystem

Ultimately, the main concept behind eating 30 different plants a week is to recognize and actively support the complex ecosystem within your gut. It's a modern dietary philosophy rooted in science, emphasizing the profound connection between dietary variety and a robust, diverse microbiome. By broadening your palate to include a wide array of plant-based foods—from obvious fruits and vegetables to often-forgotten herbs and seeds—you are proactively building a resilient inner system that can contribute to a healthier, happier life. The 30-plant goal is a powerful and achievable target, encouraging a positive and expansive approach to eating that reaps long-term rewards for your overall well-being.

Visit the ZOE website for more information and tips on the 30 plants challenge.

Scientific Backing

The American Gut Project's 2018 research, which involved over 10,000 participants, revealed the link between a diverse plant-rich diet and a more diverse gut microbiome. The study found that individuals who consumed 30 or more different plants per week showed greater microbial diversity compared to those who ate 10 or fewer. This diversity is crucial for overall health due to its impact on gut function, immune response, and metabolic processes. While other diets may improve gut health, the emphasis on variety in the 30-plant goal is a distinguishing and highly beneficial factor.

Frequently Asked Questions

The number 30 originates from the 2018 American Gut Project study, which found that participants consuming 30 or more plant types per week had significantly higher gut microbiome diversity compared to those eating fewer than 10. While not a rigid rule, it represents a beneficial threshold for diversity.

A 'plant' can be any fruit, vegetable, whole grain, legume (beans, lentils), nut, seed, herb, or spice. Different colors of the same fruit or vegetable can count as separate points.

Yes, different colors of the same type of fruit or vegetable, such as red and yellow bell peppers, can count as separate points because they contain different beneficial compounds.

Herbs and spices count towards the weekly goal and are an easy way to add variety. For example, using basil in one meal and oregano in another adds two distinct plants to your count.

Both recommendations are beneficial, but they have different focuses. The 5-a-day goal emphasizes minimum quantity, while the 30-plant goal prioritizes maximum variety. The increased variety in the 30-plant approach offers greater benefits for microbiome diversity.

Highly processed or refined plant products, such as fruit juices and white bread, generally do not count. The goal is to consume whole or minimally processed plant-based foods to maximize fiber and nutrient intake.

The goal is progress, not perfection. Even gradually increasing your intake from your current level will improve your gut microbiome diversity. Every new plant food adds valuable fiber and nutrients that benefit your gut health.