What is the Microbiome Diet? Eat these 10 foods for gut health

Can a microbiome diet help you improve your gut health? As a registered dietitian, I’m well acquainted with the facts that the food we choose to eat influences our gut bacteria, which influences our gut health. The microbiome is so important to our health: what we eat can keep our microbiome healthy so in this blog post, I’ve included ways to discover the best foods for optimal gut health nutrition.

You are what you eat. You are also what your gut bacteria eat. Seem impossible? We are learning more everyday about just how important our gut bacteria – or microbiota – are to our overall health. (I mean, with so much new research out, I had enough info to fill an entire cookbook called Good For Your Gut!)

And did you know that our gut microbiota have been connected to almost every facet of our bodies? This includes:

• our gut health
• our nervous system and mental health
• our immune system and inflammation
• our appetite and weight
• our blood sugar balance and cardiovascular risk

We have so much more to learn about how we can best care for our tiny residents, and our own individual responses to certain dietary strategies. However, the early research is enough to give us a solid head start on crafting a microbiome dietary approach – especially because they are 100% in line with time-tested nutritional advice, such as consuming more foods rich in fibre. Let’s start with the basics.

Microbiome definition

People tend to use the terms microbiome and microbiota interchangeably – but there is a distinct difference between the two. Microbiota (micro = tiny, biota = life) refers to the actual bacteria and other living microbes (yeasts, fungi, archaea) living in the gut (and other places on the body). 

Microbiome, on the other hand, refers to the entire community or ecosystem of these microbes along with (as been suggested) their ‘theatre of activity’ AKA their genetic material, the environment they interact with (us!) and their physiological impact on their environment (us!).

How does diet affect the microbiome?

We digest and absorb 80-95% of everything we eat and drink, but what’s left travels through the large intestine where it interacts with the trillions of bacteria and other microbes that live there. So in thinking about nutrition, we have to think not only about how what we eat affects our bodies but also how it shapes the community of bacteria living within us. 

The research has shown a number of observations on how human diet affects the gut microbiome:

• High saturated fat, high added sugar diets tend to create negative changes, favouring species such as Bacteroides
• High fibre diets tend to increase favourable species such as Lactobacillus and Bifidobacteriumand hinder the growth of less favourable species such as Clostridium
• Eating a diversity of plant foods is associated with improved diversity and resilience in the microbiome. According to findings from the American Gut Project, people more than 30 different plant foods a week is optimal.
• The gut microbiome can begin to change in as little as 24 hours in response to a major dietary shift
• Low FODMAP diets can reduce the overall size and diversity of the gut microbiota, which probably contributes to the effects of the diet and suggests that they not be long term

10 of the best foods for gut health…and recipes to help you eat more of them!

If you want to build a healthier gut, it’s time to eat more plants! Whole plant foods offer an abundance of fibre, beneficial phytochemicals like polyphenols as well as a lower intake of added sugars and saturated fats. Moving towards a more anti-inflammatory, plant-rich diet will support your overall health and the health of your microbiome, as the research currently stands. 

There is no need to be rigid in your eating habits: remember, it is what you do day in and day out that will determine your health more than what you put on a single plate. So have some ice cream once in a while, or a few fries. 

And, if you’re looking to supercharge your gut health, there are some foods that standout as anchors of a microbiome-friendly diet.

• Oatmeal + Barley
  Oatmeal and barley are whole grains rich in soluble beta-glucan fibre. Beta-glucans have been shown to improve the growth of Lactobacillus and Bifidobacterium, two beneficial types of bacteria in the gut – along with improving the levels of short-chain fatty acids in the gut. Soluble fibre is also a great regulator of, ahem, elimination. Enjoy this yummy Pumpkin Spice Oats recipe.

• Berries
  Berries such as raspberries and blackberries are super high in fibre, with raspberries containing 8g of fibre per cup. Blueberries and strawberries have slightly less (blueberries have 4g fibre per cup…still good!) but ALL berries are rich in polyphenols, a type of anti-inflammatory phytochemical that helps to boost beneficial bacteria and short-chain fatty acids in the large intestine. Try this Low FODMAP Strawberry Probiotic Smoothie.

• Turmeric
  Turmeric is one of my favourite anti-inflammatory foods – it is polyphenol-rich and shown to improve markers of inflammation and even arthritis pain in early human trials. In lab and animal based trials, curcumin – the active component in turmeric – has been suggested to improve growth of beneficial gut bacteria and improve the barrier function of the gut. However, because human trials have yet to convincingly confirm lab results I recommend that people eat turmeric containing foods rather than supplements in most cases. Try this Turmeric Ginger Smoothie with Greens.

• Sunchokes (Jerusalem Artichokes)
  Sunchokes – also known as fart-ichokes – are one of the highest sources of prebiotic inulin in the food supply. Prebiotics are substances known to improve the growth of beneficial bacteria in the gut. If you’re new to prebiotics, start with a small amount to avoid tummy trouble. There is a wonderful roasted sunchoke salad in Eat More Plants cookbook or try this Mushroom and Sunchoke Pasta.

• Sauerkraut + kimchi
  Sauerkraut and kimchi are fermented foods that are typically made from a base of cabbage and other vegetables, along with salt to create a protective brine for fermentation. Lacto-fermented foods are rich in lactobacilli bacteria, making them a healthy addition to any digestive health eating plan – although they are not as potent as a clinical strength probiotic. I also like cabbage-based ferments as they are rich in l-glutamine, an amino acid that supports the health of the gut. Try this simple coriander jalepeno sauerkraut recipe.

• Lentils + other legumes
  Legumes are high fibre and high in prebiotic/FODMAP carbohydrates that feed beneficial bacteria in the gut. Eating legumes is associated with lowered risk of chronic diseases such as colorectal cancer. For those on a low FODMAP diet, you can still enjoy the benefits of small servings of lentils or chickpeas without triggering symptoms. This chickpea scramble is one of my favourite breakfasts ever.

• Apples
  Apples are one of the higher fibre fruits, while also having more soluble fibre (pectin) and prebiotic/FODMAP carbohydrates. They’re affordable and available year round, so it’s a great everyday gut health food. Try my Apple Hazelnut Slaw. 

• Ginger
  This spicy cousin of turmeric is another one of my fave gut health foods. It is pro-kinetic, meaning it helps to improve stomach emptying and is often used for nausea in pregnancy. The creamy Ginger-Cashew Dressing in my Snap Pea Salad is SO good.

• Leafy greens
  Greens such as kale, spinach, chard and parsley are rich in fibre and anti-inflammatory polyphenols, both of which are fantastic for the gut. However, recently, it was also discovered that green leafy veggies contain a special sulfur-containing sugar called sulfoquinovose that drives the growth of beneficial E.coli in the gut (yes, some E.coli are good!). Try my delish Kale Gratin, it will convince even the kale averse!

• Garlic and Onions
  Garlic and onions are rich in FODMAPs to feed beneficial bacteria in the gut – while garlic is also known to have antimicrobial properties that may support a healthy microbial balance. Interestingly, garlic and onions contain special sulfur-based phytochemicals such called glucosinolates which are thought to be anti-inflammatory when converted to isothiocyanate and early research is suggesting your gut bacteria may be capable of increasing the conversion. These Roasted Garlic and Tomato Tartines are a lovely light meal.

Looking for more articles and recipes to help you boost gut health?

• Smashed White Bean and Kale Sandwiches
• White Bean, Sweet Potato Gratin
• Plant-based Diet and Bloating
• How I manage my IBS