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Feeding Your Microbiome: Prebiotics & Ferments

Like every surface of your body, the lining of your gut is covered with microscopic bacteria which make up a micro-ecosystem, called the microbiome.

In a healthy person, there are more than 100-300 trillion probiotic bacteria (and yeast) living there, compared to only 10 trillion human cells. That means bacteria outnumber human cells by more than 10 to 1. In other words, we're more bacteria than we are humans! Even more astonishingly, if the bacteria in our body were laid out end to end, they would encircle the globe 2.5 times. Pretty incredible, right? It certainly makes sense then, that there are 400x more messages going from the gut to the brain than there are going from the brain to the rest of the body. The gut truly is the seat of all health which is why keeping it in good shape is so very important.


The key to a healthy microbiome is nourishing and maintaining a balance among the different species of bacteria. There are two ways to do this:

  1. Helping the microbes already living within you to grow, by feeding them pre-biotics. Prebiotics are non-digestible food fibres that enable good bacteria to flourish and reproduce.

  2. Consuming living microbes (probiotics) directly. This means eating fermented foods and drinks or taking probiotic supplements.


Prebiotics are found in many fruits and vegetables, especially those that contain complex carbohydrates such as fibre and resistant starch. These carbs pass through the digestive tract undigested and become food for bacteria and other microbes. Prebiotics are best known as a type of dietary fibre called oligosaccharides.


The best way to ensure you're getting enough prebiotics is to eat a wholefood diet that grew on planet Earth! Artichoke, asparagus, avocado, under ripe bananas, barley, beetroot, bran, chia seeds, chicory, cacao, dandelion greens, eggplant, flaxseeds, fruit, garlic, green tea, matcha, honey, jerusalem artichokes, jicama. leeks, legumes, lentils, onions, kefir, peas, radish, root vegies (potatoes, yams and sweet potatoes), plantain, rye, sea vegies (like kelp, dulse and nori), soybeans (edamame), herbs, spices and tomatoes.


When we eat fermented foods or drinks, we eat the beneficial bacteria – the probiotics – that the food contains. To name just a few of their functions, probiotics are responsible for promoting regular bowel movements (helping to relieve diarrhea and constipation), improving overall digestion, enhancing immune function, producing antioxidants, normalizing skin conditions, reducing cholesterol, managing blood sugars and producing brain chemicals.

"The gut contains more neurotransmitters than the brain & plays a role in 70-80% of our immune response."

When a food is fermented, it means that it’s left to sit until the sugars and carbohydrates become bacteria-boosting agents. The good bacteria break down lactose and other sugars and starches in the food also, making them easier to digest. This is why pot-set yoghurt is better tolerated by some than cheese or ice cream. The best bit is that once these bacteria reach your gut, they continue to help break down food and keep a balance between any nasty or pathogenic bugs residing there.


If eating fermented food is new to you, you might like to start with ordering a miso soup next time you're at a Japanese restaurant or making sure that the yoghurt you buy is a high-quality pot-set version. When purchasing ferments, it's ideal to ensure they don't contain sugar, preservatives or food dyes, but most importantly that they haven't been pasteurized. Heat destroys all delicate bacteria, so the foods must be raw to be beneficial.

Options: Water or milk kefir made from cow, goat, sheep or coconut. Kvass (a traditional eastern Europen drink), sauerkraut, pickles, olives, natto (a traditional Japanese dish made from fermented soybeans), kimchi, tempeh (similar to tofu but the whole bean is used and fermented), miso or cheeses made specifically from raw milk.

What About Kombucha?

Kombucha is a fermented drink of black tea and sugar, and there's no doubt about it - it's boomed as a health tonic in the past few years, but before you jump on the bandwagon, here's something you need to know. While fermented drinks give you probiotic bacteria, the type of ferment you choose matters.

If someone suffers from digestive complaints, kombucha has the potential to promote yeast production or negative bacterial strains that could add to the digestive imbalance. This is because kombucha is what's known as a wild ferment. Ie. You never quite know what your scoby contains and it can become contaminated if not created properly.

"SCOBY stands for 'Symbiotic Colony of Bacteria and Yeast'. Aka the mother, starter or mushroom - used to start the fermentation process for kombucha."

Wild or spontaneous fermentation is the process by which bacteria already present start and control the fermentation process. In a wild ferment, there's a risk of bad bacteria flourishing just as much as good bacteria.

The safer option is to go with a cultured product. That means choosing specific strains or a probiotic capsule, to begin your fermentation. With a culture, you have peace of mind that you're getting the right strains in the right quantities for your gut.

That said if you're gut is OK and you choose a good sugar free brand then kombucha can offer some beneficial strains of bacteria and yeast, like Lactobacillus and Saccharomyces. Plus, B-vitamins, enzymes, minerals, polyphenols and healthy acids.

If you continue to have digestive symptoms despite a diet rich in pre and probiotics, connect with us for a free 10 minute online call and let us help you get to the bottom of things.


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