You know that old saying, “You are what you eat”? Well, in many ways it’s true: the food we eat is broken down into its nutritional building blocks, which are then absorbed into our blood stream and reassembled into every cell, enzyme and tissue of our body. But exactly how does that happen? And, what do nutrients really do in our body? In honour of national nutrition month, let’s take a look at the nutrients we need - and the nutrients our microbiome needs - to thrive.

What are nutrients?

Nutrients are substances that are, according to the World Health Organization definition, required for survival, growth and reproduction. We typically talk about the macronutrients – carbohydrates, proteins and fats – and micronutrients, the vitamins and minerals found in food. We need macronutrients in large quantities, hence the name macro-nutrients. All food is made up of varying amounts of carbohydrates, proteins and fats and each one of these macronutrients have different functions.

What do macronutrients do in the body?

Contrary to a lot of what you might see online, we actually need all three macronutrients to thrive. So let’s start with carbohydrates, which are our primary energy source. Our bodies harness the energy in carbohydrates to fuel everything from our brains to our nervous systems to our muscles. Proteins, while they can also be burned for energy, offer amino acid building blocks that have biological value way beyond building muscle. Protein is important for the health of our skin and bones, building enzymes that facilitate important reactions in our cells and even creating a strong immune system. In fact, another important function of carbohydrates is that they are protein-sparing: when we eat enough carbohydrates, it helps ensure that the proteins we eat get used for more important work than energy creation. Finally, fats are both concentrated sources of energy and they have important metabolic functions. They are used to build the linings of each one of our cells, as well as helping you use certain vitamins and phytochemicals that are what we call fat-soluble, such as vitamin A and D.

Why do we need micronutrients?

Vitamins and minerals, the micronutrients, are needed in far smaller amounts than macronutrients. We may count requirements in milligrams or even nanograms but they are no less important to our overall health! Micronutrients may be used to build enzymes or antioxidants, or they may be co-factors in harnessing energy from macronutrients. For example, without iron, which found in legumes, green leafy vegetables and meat, our red blood cells could not deliver oxygen to the rest of the body. Calcium is the most abundant mineral in our body: your bones contain at least a couple of pounds of it, where it contributes to the structure and strength of our bones but it also is a critical mineral for our nervous system function. B vitamins like folate are important for building red blood cells, while others like folate and riboflavin are needed for carbohydrate metabolism. Vitamin C, often thought of as an immune-supporter also helps build collagen structures in the skin.

How does nutrition affect the gut microbiome?

Nutrients, by definition, are substances that OUR bodies need to survive and we absorb 80-95% percent of everything we eat and drink. What’s left? Mostly indigestible carbohydrates like fiber and fructans, but it depends a lot on what we eat as well as our biological ability to digest what we eat. For example, people with lactose intolerance will not absorb all of the lactose they consume, so it passes through the gut where it comes into contact with our gut microbiome.

So, how does what we eat affect our gut bacteria? In order to support a healthy gut microbiome, you need to give them the food they need to thrive. And good bugs want you to eat plants, rich in all of those indigestible (to YOU!) carbohydrates like fermentable pectin fibre in apples, or fructans and arabinoxylans in wheat berries. Bacteria have the enzymes required to process these bacterial nutrients and when they do, they thrive and make short chain fatty acids that nourish your gut cells as well as your immune and nervous systems.

For those of us who eat mostly hyper-processed foods, or a lot of fat or animal proteins, our gut microbiome will reflect that and we may need some support to bring it back into balance. While you’re working on introducing more whole plant foods into your life, consider a little extra boost with a fermented probiotic like Bio-K+. It is thought that fermented foods can help shape the diversity of the gut microbiome, and Bio-K+ offers effective, clinically tested bacteria in a live ferment, which makes an easy addition to a healthy diet.

Pattern Over Plate

Nourishing your body – and your gut bacteria – well will help you to live a healthier, happier life. One of my favourite balanced nutrition tools is the “plate method”: when you prepare a meal, try to fill half your plate with fruits and vegetables, one quarter of your plate with a protein-rich food and the other quarter of your plate with a starchy vegetable or whole grain. Doing this most of the time will help you get a wide variety of plant foods that will keep you well-nourished so there is room for a glass of wine with friends, or an ice cream with your kids. In a healthy life, it is the overall pattern of how you eat that matters more than any single food or meal.