How to boost your gut health naturally
By Dr Marissa Kelaher
If you’re curious about what the science really says on improving your gut health, this post is for you! 🌱
Welcome to Part 2 of our gut health series. If you missed Part 1, be sure to check it out first—it covers the essential basics of why your gut microbiome is so important for your overall wellbeing. 😊
Now, in Part 2, we’re diving into practical, science-backed ways you can support your gut health on a daily basis!
And if you’re ready to go deeper into gut health and learn more about how to optimize it, check out our Transform Your Nutrition or Reboot Your Health courses.
These provide an in-depth look at how your gut works and how you can improve it with simple, actionable steps, as well as recipes, downloadable resources, and more.
What Makes a Healthy Gut?
First off, let’s clarify what a healthy gut really means.
When we talk about "gut health," we’re essentially referring to two key areas:
Gut Tissues: This includes the cells lining your intestines, the mucus layer that protects them, and the immune and nervous systems in your gut wall, which act as the body’s first line of defense. They are vital in helping regulate our immune health, mood, nutrition, metabolism and more.
Gut Microbiome: These are the trillions of bacteria, viruses, and fungi (both “good” and “bad”) that live in your gut. They play a crucial role in digestion, immunity, and overall health.
The fascinating thing is that these two systems—your gut tissues and microbiome—are deeply connected to each other, and in turn to your overall health.
Your gut bacteria help maintain the health of your gut lining, and in turn, a healthy gut lining supports a balanced immune and nervous system.
One of the main ways this balance is achieved is through postbiotics. These are chemical compounds produced by bacteria when they break down undigested food.
Think of postbiotics as “superfood” for your gut lining—they're essential for keeping those gut cells healthy and functioning properly.
(We go into more detail on how your microbiome works in Part 1, if you want to dive deeper!)
What Impacts Our Gut Microbiome?
Our gut health starts at birth - with some research showing it may even start in utero, based on our mothers diet while she’s pregnant! The first few years of our life are key, as this is when our gut microbiome is established - think of it like a unique fingerprint that develops. We cover this in more depth in this blog post if you want to dive into the details.
Things that impact our gut microbiome include:
the way we are born (vaginal delivery vs caesarean section)
whether we are breastfed or bottle fed
the amount of antibiotics we are exposed to
our environment (urban vs rural, and exposure to animals and dirt)
environmental toxins (exhaust fumes, cigarettes, pesticides in food, and household chemicals like BPA and phthalates)
medications (ie pain medications, acid suppressing medications and even hormonal contraceptives)
disinfectants and anti-bacterial personal products
the amount of fibre and plant foods we eat
fermented foods in our diet
the type of fat and protein in our diet (saturated fat vs unsaturated; animal protein vs plant protein)
red meat intake
additives in our food (such as emulsifiers, preservatives, artificial colors and flavors)
stress levels, and the amount of exercise and sleep we get
Our gut microbiome is literally a reflection of what we do and are exposed to on a day to day basis - and it’s changing all the time!
The Role Of Postbiotics
And our gut doesn’t just contain a few bacteria - it is home to thousands of different bacterial species—up to 30,000, in fact? That’s a lot of diversity!
But what do our gut bacteria do that makes them so special?
Our gut bacteria are amazing, as each species produces its own unique set of postbiotics, which can determine whether a particular bacterium is "good" or "bad."
Good bacteria produce "good" postbiotics, like short-chain fatty acids (SCFAs), which promote gut health and benefit other parts of your body—your heart, brain, metabolism, and even weight regulation.
Bad bacteria, on the other hand, can produce harmful compounds like endotoxins (from pathogens like salmonella or clostridium), which damage the gut lining and can even leak into your bloodstream, triggering inflammation and other health problems.
This means it’s not just the bacteria in our gut that are important - it’s actually what they do that matters most!
Short-Chain Fatty Acids: The Gut’s Superheroes
Among the many postbiotics produced by good bacteria, short-chain fatty acids (SCFAs)—particularly butyrate—are some of the most well known - and most important for your health too.
Here’s why SCFAs are so vital:
They feed the cells lining your gut, keeping your gut wall strong and intact.
They help your body absorb nutrients more efficiently from food.
They suppress the growth of harmful bacteria.
They protect the gut mucus barrier, preventing damage to gut cells.
They reduce inflammation in the gut, which can ease bloating and discomfort.
They travel through your bloodstream to other parts of your body, helping to regulate metabolism, improve heart health, and support brain function.
They even help improve how well your gut muscles contract, making digestion smoother.
In short, SCFAs are absolutely essential for maintaining overall health, and the more we learn about them, the clearer it becomes that gut health is at the root of many chronic health issues.
As the ancient physician Hippocrates wisely said over 2,000 years ago, “All disease begins in the gut.” The more we understand about the role of gut bacteria and postbiotics, the more we see just how true that is.
Boost Your SCFA Levels Naturally
So by now it’s hopefully become pretty apparent that what our gut microbes produce (AKA Short Chain Fatty Acids, or SCFA) is super important for good health.
And you’re probably wondering - how can I actually do this? Here’s the secret.
If you want to boost your levels of short-chain fatty acids (SCFAs), it’s simple:
Eat more plants!
The SCFAs we want for good health are ONLY produced when we consume plant-based foods—as plant based foods contain the vital fibre our gut bacteria need to make them.
That’s why eating a wide variety of whole plant foods is crucial for maintaining a healthy gut.
But it’s not just the fibre in plants that supports gut health either—other plant compounds like polyphenols and antioxidants also act as prebiotics, to feed our good gut bacteria.
This is reflected in research studies over and over - which show the more plant foods we eat, the healthier our gut microbiome is - and the better overall health we experience too!
In our Transform Your Nutrition and Reboot Your Health courses, we dive deep into how to feed your gut bacteria with the right foods. We explain the role of fiber, share tips on how to boost your fiber and plant intake, and provide a 6-week plant-based meal plan to make it easy for you to start!
It’s Never Too Late To Change
Here’s the exciting part: You have a huge impact on which bacteria live in your gut, and that directly influences your health. This means you have the power to improve your gut health—and, by extension, your overall wellbeing—just by changing your diet! ❤️
Research shows that your gut microbiome starts to shift within just 24 hours of changing your eating habits. So, if you start incorporating more plant foods or fermented foods, your gut bacteria will respond very quickly. In fact, eating a more diverse range of whole plants and fermented foods is the only scientifically proven way to improve gut health and increase microbiome diversity.
For instance, when you eat more fiber and fermented foods (which we cover in detail in our courses), your gut microbiome health and diversity will improve within just a few weeks. While in contrast, when you cut these out and eat a more ‘Western’ diet high in saturated fat and animal products, your good bacteria start dying off almost immediately.
Low-carb, ketogenic, or even low FODMAP diets can have a similar effect if they don’t contain enough fibre—your gut health takes a hit fast. Within 48 hours of going on a low-fiber diet, you can lose up to 50 types of beneficial bacteria. 😳
And the damage doesn’t stop there. Within just two weeks, the lack of fiber can start to harm your gut lining, causing measurable damage.
Remember, your gut bacteria are what you eat! Each bacterial strain feeds on different types of fiber, so the more diverse the fiber you consume, the more diverse and healthy your microbiome will be.
Think of it like caring for a garden. We want to feed the good gut bugs, and keep the bad bugs down, to create a healthy thriving eco-system .
And we can do this just by being aware of what we eat and drink, and how we live each day!
So, How Can We Support and Improve Our Gut Health?
Supporting and improving your gut microbiome might sound complicated, but it’s actually pretty simple when you focus on the right habits.
While our gut microbiome starts developing at birth (and potentially even before), so there are a lot of factors that shape it throughout our lives.
Here’s a list of the most effective ways to nurture and improve your gut health:
1. Vaginal Delivery & Breastfeeding
If possible, a vaginal birth and breastfeeding are both fantastic for shaping a healthy microbiome.
Breast milk, in particular, contains special compounds called human milk oligosaccharides, which are designed to feed the beneficial bacteria in our gut.
This is why supporting breastfeeding mothers and vaginal delivery where safe and possible to do so (and advocating for breastfeeding and birthing rights in our communities and hospitals) is so important.
2. Avoid Environmental Toxins
Try to avoid exposure to harmful toxins like cigarette smoke, car fumes, pesticides on food, and household chemicals like BPA and phthalates. These can disrupt the delicate balance of your gut microbiome.
In contrast, getting out in nature, and getting your hands dirty (and letting your kids do the same), is rocketfuel for a healthy gut microbiome!
3. Eat a Diverse, Plant-Rich Diet
A key to a healthy microbiome is variety!
Aim to eat a wide range of plant-based foods and focus on including different types of fiber in your diet each day.
Studies show that people who eat 30 or more different plant foods per week have the healthiest, most diverse gut microbiomes.
Swapping out saturated fats (such as fatty meat and dairy) for plant fats and omega 3 rich foods (nuts, seeds, and oily fish) is also good news for your gut microbiome.
Including legumes in your diet is also a great way to boost your gut health.
In our Transform Your Nutrition and Reboot Your Health courses, we give you all the tools to make this easy and enjoyable.
4. Include Prebiotic Fiber-Rich Foods
Certain plant foods, like artichokes, leeks, onions, and garlic, are extra packed with prebiotic fibers like inulin, which help fuel your gut bacteria. Adding these to your meals will help your microbiome thrive!
5. Aim for 40g of Fiber Per Day
The average Western diet contains less than half of the recommended 40g of fiber per day, but hitting this target is crucial for gut health.
If you aren’t eating much fibre currently, it’s important to do this gradually to give your gut microbes a chance to adjust.
Foods rich in fibre include legumes, whole grains, nuts, seeds and some fruits and veges.
And don’t forget to drink plenty of water while you’re doing it - this is key to help your bowels process and digest the fibre effectively.
6. Choose Polyphenol-Rich Foods
Polyphenols are antioxidants found in foods like berries, nuts, seeds, olive oil, coffee, and green tea. These compounds act as additional fuel for your gut microbes, supporting a healthy and diverse microbiome.
Have you heard of the phrase “Eat A Rainbow”? This is a great way to boost your polyphenol intake! Aim to eat a diversity of different colored foods in your diet, your gut will thank you for it.
7. Try Time-Restricted Eating
Give your gut and your microbiome some time to rest! Ideally, aim to wait 3-4 hours between meals and allow at least 12 hours overnight without eating.
This not only helps your gut repair itself but also promotes a healthier microbiome. We also dive into safe fasting strategies in our courses.
8. Avoid Artificial Sweeteners and Limit Added Sugar and UPF
Artificial sweeteners like aspartame, sucralose, and saccharin can harm gut diversity by disrupting your microbes' metabolism.
Excess added sugar may also mess with our gut microbiome - keep those sweets as occasional treats, not every day foods!
Likewise, ultra-processed foods (UPF) often encourage the growth of unhealthy bacteria, so it’s best to limit these as much as possible.
9. Limit Red and Processed Meats
Red and processed meats can negatively affect gut health by producing inflammatory postbiotics like TMAO, which can damage the gut lining.
Limit red meat intake to a maximum of 300g of cooked meat per week, and limit processed meats (ie ham, bacon, salami) to a maximum of 100g/week to avoid these issues. Try choose wild or pasture raised meat too, as barn or farm meats often contain antibiotics (80% of antibiotic use worldwide is in animal agriculture!)
Eating more brassicas (like broccoli, cauliflower, and kale) may help reduce TMAO production, so including these in your diet to create balance is a great idea too.
10. Avoid Emulsifiers
Emulsifiers in processed foods can damage the gut lining and disrupt the microbiome. Wherever possible, opt for whole foods and skip the processed stuff!
Emulsifiers are usually clearly labelled on packaged foods - checking the label is a great habit to get into, to help you make healthier choices too.
11. Limit Animal Protein
Excess animal protein in your diet can produce hydrogen sulfide, a postbiotic that can damage DNA and trigger inflammation in the gut.
If you eat animal protein, try pairing it with lots of fiber-rich foods to help suppress hydrogen sulfide production.
While you don’t have to go vegan, the more plant proteins you can include in your diet the better, aiming for at least 80% of your diet to be plant based foods if possible.
Plant proteins are usually found in foods like legumes, beans, nuts, seeds, and whole grains (which as an added bonus are usually rich in fibre too!)
We teach you how to boost your plant protein intake in our Reboot and Nutrition courses (with recipes to make it easy and tasty!)
12. Include Fermented Foods
Fermented foods like kefir, kombucha, miso, kimchi, sauerkraut, and yogurt are rich in probiotics that promote gut health.
Regularly eating these can significantly improve gut microbiome diversity in just a few weeks!
Like with fibre, if you don’t eat many fermented foods currently, introduce them gradually to allow your gut microbiome to adapt (often just a tablespoon each day is enough for some people). Otherwise your gut may not be happy - and will let you know about it 😂
13. Get Regular Exercise
Exercise isn’t just good for your body—it’s great for your gut too!
Physical activity has been shown to improve both gut wall health and the diversity of your microbiome, so getting moving is key for good gut health.
We also explore exercise in our Boost Your Activity and Reboot courses to help you get moving!
14. Manage Stress and Prioritize Sleep
Both stress and lack of sleep can disrupt your gut microbiome, so make sure to prioritize self-care.
In our Stress, Sleep, and Reboot courses, we cover ways to reduce stress and improve your sleep to support your gut health.
15. Use Medications Sparingly
Only use antibiotics and other medications when absolutely necessary, as they can seriously disrupt the gut microbiome - sometimes wiping out whole species of bacteria!
Even common medications like ibuprofen or reflux meds can harm gut health - so try save these for when they’re really needed!
16. Skip the Disinfectants
Overuse of disinfectants and antibacterial products can harm your gut microbiome.
If you can, opt for soap and water when cleaning hands to avoid disrupting the balance of bacteria in your gut.
Anti-bacterial mouthwashes and soaps also impact our skin, oral and gut microbiome - so avoid these if at all possible (unless required based on medical advice)
17. Don’t Rely on Supplements
Supplements—especially probiotics—are often marketed as a quick fix, but there’s little evidence they’re necessary in most people - and in some cases may even harm our gut microbiome.
It’s much better to get your probiotics from fermented foods and focus on feeding your own gut bacteria with fiber-rich foods. Your microbiome thrives on real food!
Probiotics can be useful in specific circumstances, but it’s best to get tailored advice on this from a qualified health professional, rather than just popping them willy nilly 😉
18. Get Outdoors and Connect with Nature
Spending time outdoors, especially in natural environments, can increase microbiome diversity.
Whether it’s gardening, walking in the woods, or spending time around pets, exposure to nature helps nurture a healthy microbiome.
The Bottom Line
While some factors—like the type of birth we had or the use of antibiotics—are beyond our control, we do have the power to make a huge difference in our gut health through our diet and lifestyle. By focusing on fiber and plant foods, we can help recolonize our microbiome and support healing. And it’s never too late to change!
If we had to pick a few golden rules for a healthier gut, they would be:
Aim for 30-40g of fiber per day (apps like Cronometer can help track it!)
Follow the 30+ rule: Include 30 different plant foods in your diet each week.
Focus on whole plant foods and include fermented foods regularly. Aim to make your diet mostly plants, limit red and processed meats, and choose plant proteins over animal proteins for the majority of your protein intake.
Avoid ultra processed foods (which often contain emulsifiers, additives, and artificial sweeteners) as much as possible
Limit antibiotics and exposure to anti-microbial products unless absolutely necessary.
Prioritize sleep, exercise, and stress management.
And most importantly, don’t stress over perfection!
It’s the 80% of things we do consistently that matter most, not the small details.
Food is meant to nourish and be enjoyed—let’s find that balance! ❤️
We cover all of this—and much more—inside our Nutrition Focus module and Reboot Your Health courses. Plus, you'll get access to over 60 original plant-based recipes to make eating more fiber and diversity easy and delicious.
Check them out if you'd like to learn more, and start your gut health journey today!