Prebiotics, probiotics, let’s feed gut bacteria

There are more than 100 trillion bacteria 1 in our digestive system living with us, and if we take care of them, they will support our health. Let’s have a look at the best way to keep our bacteria happy.

How do bacteria get into our body?

Bacteria settle down in our body as soon as we are born. By age five, they reach a characteristic of the adult person. The environment and diet during the first three years of life are the most critical for building a healthy bacterial flora.1 From that time on, we have to regularly take care of it.


What affects our bacteria?

Our bacteria are very sensitive to changes in our lifestyle. For example, people who consume only plant-based diet have different composition of bacteria than those eating meat 2. Compared to healthy people, the presence of bacteria in obese people is different because they lack some good bacteria 3. Exposure to chronic stress, extreme physical strain like in professional athletes 4, antibiotics, other medications, smoking, excessive sugar, lack of fibre or frequent alcohol consumption 5, it all disturbs the bacterial flora.

Why do we need bacteria?

Good bacteria help us with digestion and produce vitamins B and K. They form an important communication channel between the nervous system and our gut. Also, they significantly contribute to functioning of the immune system. Bacteria make up a so-called ” barrier” – the guard who decides what should go from your gut to the bloodstream. In people with a healthy bacterial flora, only what belongs to blood stream can cross the border.6

Green prebiotics

What happens if we do not care about them?

If we experience the above mentioned negative factors, depending on their combination and duration of action, the population of our good bacteria will be greatly reduced. This means that the number of guardians in the gut is reduced. Thus, the substances get into the blood that in healthy person would be left out. In practice, we are talking about the leaky gut. Your immune system then responds to what has suddenly got into the bloodstream.On the outside, it will manifests itself as an intolerance to certain components in the diet. Later on, it can turn into allergy. At the same time, the number of harmful bacteria increase in the gut. However, they do not fulfil the role of good bacteria and further mess up the whole system.


These processes lead to disruption of digestion, absorption of nutrients and increased inflammatory processes. Furthermore, it leads to disruption of communication between the brain, the gastrointestinal tract, and the hormonal system. Following, this creates the basis for developing various diseases. Currently, we know that there is a link between bacterial flora quality and obesity, diabetes, gastrointestinal cancer 6,7, autism 8, depression and other neurological diseases 9.

gut health

 How to take care of our bacteria

First of all, we should realise that by eating, we also feed our bacteria in the body. These bacteria, however, do not like everything we eat, especially sugar and alcohol harm them the most. We can maintain our bacteria by a balanced diet that includes prebiotics, phytochemicals (plant metabolites) and probiotics. Let’s have a look at these three groups, how they support bacteria and where to find them.



Our bacteria eat fibre – oligosaccharides and polysaccharides that you can find in prebiotics. Prebiotics are literally the foods for gut bacteria, so with prebiotics you nourish your bacteria.

Prebiotics are e.g. milk, cheese, fermented products (sauerkraut, yogurt, kefir and others) but also fruits, vegetables and especially foods with insoluble fibre – cabbage, garlic, green leafy vegetable, leek, onion, foods rich in starch – bananas, potatoes and so on.

The daily intake of fibre should be around 20-25 g, which you can achieve with 3 portions of fruit, a bowl (300g) of legumes / grains (buckwheat), a bowl (300g) of vegetables (a combination of leafy vegetable and other veggies). Get inspiration for delicious salad here

prebiotics and probiotics


When we talk about probiotics, we mean the bacteria and yeasts themselves contained either in a tablet or in a product (probiotic cultures). Milk products, as you can see, belong to prebiotics because they contain oligosaccharides but are also probiotics because they contain live bacteria. Here, however, one thing needs to be clarified.

A regular consumer thinks that eating probiotics such as various fermented products and yogurt enriches the body with live bacteria. But this is not entirely true. Although these products contain live bacteria, not all bacteria species can overcome the changes in pH in different parts of our digestive tract when getting through the stomach, small intestine to the colon. Studies show that most of bacteria arrive in the intestine/colon dead and survive only between 0.01% to 30% 10. Therefore, these products do not contribute a lot to the number of live bacteria. And thus, we should consume dairy products, sauerkraut and other fermented foods not because they add to count of population of bacteria but because they support the growth of bacteria, and are of benefit to gut even when they are dead.

Two exceptions

There are exceptions – Yakult drink and kefir. Yakult contains only the specific type of Lactobacillus Casei Shirota, which is able to survive the pH changes and reach the intestine/colon alive. This product has been tested by many independent institutes 11 and so the information about it is not coming only from commercial sources and paid studies as it is the case of many other products. 

This article has no intention to promote Yakult. It is mentioned solely due to evidence that the specific bacteria in this product survive in the gut. However, before consuming it read the list of ingredients, and think whether it is not better to eat prebiotic foods to improve your gut health as promoted here.

Also, kefir compared to yogurt contains a variety of bacteria and yeasts, many of which are resistant to pH changes in the digestive tract, and so there is a likelihood that most (more than 40%) will arrive in the intestine/colon alive.12

Prebiotics, probiotics and phytochemicals

Thus, in addition to these two exceptions, live bacteria can get into the intestine/colon only in the form of a quality tablet or the faecal transplant, when your cultivated bacteria in the lab are added into your colon through your butt

When do you need probiotics in the tablet?

By consuming a balanced diet and avoiding the above mentioned negative factors, the tablets and faecal transplant are not necessary. In contrast, if you have an acute problem and signs that the bacterial flora is disturbed you will benefit from probiotics. The indications are frequent gasses, constipation, diarrhoea, irregular stools, extreme food reactions, food intolerance, allergies or consumption of antibiotics. In this case, you should consider changes in the diet, and add the group of foods we are discussing here. Secondly, I will advise you on how to choose the best probiotics in the tablet.

How to choose quality probiotics 

1. Tablet must have a good coating that will last up to the colon, where the most bacteria are released. Look for a product that has a special patented technology that delivers slow bacterial release, preferably over 8 hours.

2. Tablet must contain the major strains of Bifidobacterium and Lactobacillus. However, it is unclear what is the best combination of bacterial strains and species, especially because it is unique to each person. But if you have a big problem, your body welcomes these bacteria anyway.

3. Tablet should contain more than 10 billion bacteria, otherwise there is no benefit to the body. If there is less bacteria, it’s the same as trying to fill in a large tank with water drops, which would take you years to complete. 13



This group of substances is significantly underestimated when we talk about our bacteria. It includes various herbal substances that fulfil two functions. They help to destroy harmful bacteria, have anti-inflammatory effects, and promote the growth of good bacteria.14  These phytochemicals include flavonoids, polyphenols, tannins, carotenoids, or organ-sulphur compounds. We can find them in fruit, vegetable and various spices (turmeric, grenadier, black pepper, coriander, marjoram, cloves, cinnamon, cardamom, and many others).

Let’s wrap it up

So, it is perhaps a surprise to you that for healthy bacteria, a rich diet in fibre and phytochemicals is the most important. Probiotics themselves are not necessary if your diet is rich in prebiotics and phytochemicals. As a dietary supplement, probiotics are necessary for smokers, people with digestive problems, intolerances and allergies. They are also important when consuming antibiotics, antidepressants, sleeping pills, and for professional athletes in peak performance season.

Nourish your bacteria, and it will reflect on your health!



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  11. Scientific evidence. Accessed August 2018.
  12. Golowczy MA et al. Characterization of homofermentative lactobacilli isolated from kefir grains: potential use as probiotic. Journal of Dairy Research (2008) 75 211–217.
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