This is the third part of the gut microbiome series.

After having established what a healthy gut microbiome does and why we need it, I will now go into how we can keep a healthy gut microbiome. I will also discuss what probiotics and prebiotics are and what they do in our gut microbiome.

What can I do to keep a healthy gut microbiome?

Researchers agree here:

You are what you eat!

As I said in the last article, diversity is key when it comes to our gut microbiome. This means that you want to make sure ALL of your bacteria stay happy within your gut. So, to keep your diverse bacteria with you, it is vital to basically eat everything.

As we learned before, one of the key points is that bacteria produce SCFAs from our food. So we should give them foods that are high in complex sugars, like fibres. Or, as your mummy always said, keep eating your veggis.

Also, some studies suggest that certain food additives have an impact on the microbial profile of our guts. These include for example emulsifiers, which work like soaps and kill certain bacterial cells. Also, stabilisers were shown to induce colitis in animals and artificial sweeteners led to a change in the microbial composition and glucose intolerance in mice.

However, it is not clear yet whether these compounds would have the same effect on the human gut microbiota.

Most importantly, antibiotics have drastic effects on the composition of our gut microbiota. Researchers think this is one of the causes of some of our modern chronic diseases.

What are probiotics?

Probiotics are bacterial strains, like Lactobacilli and Bifidobacteria, that have beneficial effects on our health by helping us digesting our food or protecting us from pathogenic colonisation.

The FAO/WHO considers “live microorganisms which when administered in adequate amounts confer a health benefit on the host” as probiotic. This statement can be translated into the following four criteria:

Probiotic strain is sufficiently characterised

Probiotic strain is safe for human consumption

At least one human clinical trial found this probiotic to be beneficial

Probiotic is alive throughout shelf life

What do probiotics do?

Interestingly, probiotics do not reside in the gut over a long time. This means to have a long lasting effect, you should keep eating them over a long time. These kinds of bacteria were shown to enhance our immune system and to produce substances that are toxic to pathogenic bacteria.

For example, a probiotic strain of Escherichia coli can slow down the growth of a pathogenic Salmonella strain. Escherichia coli has transporters that specifically bind iron and uptake iron into the cell. With this mechanism, the Escherichia strain uses the iron of the environment, so that there is none left for Salmonella. Because Salmonella and all other bacteria need iron for growth, Salmonella has trouble growing and colonising the gut environment.

Foods with probiotics are for example fermented foods like yogurt, kefir, kimchi or fermented vegetables. But beware here, as not all of these food actually contain approved probiotic strains.

“The gut party” by Noemie Matthey

If you want to know more about fermented foods and their effects on our body, I can highly recommend this article by my friend Justine.

What are prebiotics?

Prebiotics are basically the food for our gut microbiome party and are defined as “microbial food supplements that beneficially affect the host by improving its intestinal microbial balance“.

These include food that our body is not able to digest, so the bacteria in our gut take care of them. The bacteria then produce SCFAs, which we know have various health benefits for our body.

Prebiotics also promote the growth of probiotic bacteria in our gut and help our gut cells to take up important minerals which we need for our health.

Mostly, prebiotics are complex sugars that can be found in asparagus, onions or garlic as well as fibres.

And what about synbiotics?

Synbiotics are combinations of probiotic bacterial strains and prebiotics. This basically means that the right bacteria come and bring their own food to your gut party.

A healthy gut microbiome and how to keep it

After having read my little gut microbiome series, I hope you know understand why I always say

Be nice to your bacteria!

So, to be nice to you bacteria, don’t forget these points:

We really need our gut bacteria!

Feed your gut bacteria with what they need

Make sure not to inhibit the growth of the gut bacteria

Okay, I hope this little series could shed a bit of light onto the whole mystery of a healthy gut microbiome, what it is and what it does and how best to support it.

If you have any other questions or want me to explain anything in more detail, please let me know in the comments or on social media.