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3 tips for a good gut microbiota in TBI

Read to me!

Have you heard about your “second brain”? With a TBI, the brain in our skull can become the focus of all our medical appointments, conversations with others, and thoughts! Life can seem to revolve around this part of the body. But what about the rest? 

The brain isn’t so separate from the rest of your body. In fact, it is very well connected to the health and well-being of other parts. And one connection that’s getting a lot of attention these days is the gut-brain axis.

What is the gut-brain axis?

Imagine an old school phone line running between a receiver in your brain and one in your gut — that’s kinda like what the gut-brain axis is!

There are neurons in your brain, but also lots of neurons that surround your digestive system. This nervous system in your gut doesn’t do math or interpret languages. It’s mostly in charge of digestion. But it can also communicate with your brain and when it does it can influence things like mood (think anxiety & depression), memory, and cognitive function.

Brain, Anatomy, Abstract, Art, Branches, Computation

This phone call isn’t a one-sided conversation either. Your brain also communicates with your gut. The brain can influence how much the digestive system is moving and how much it lets pass the wall of the gut into the body, among other things.

This two-way communication is thought to play an important role in the stress response, which is why it’s extra interesting post traumatic brain injury.

If the gut-brain axis is like a phone call between the gut and the brain, who’s talking?

Imagine in your gut an ecosystem of a variety of different plants and animals. There’s some maple trees, evergreens, birch trees, tall grass, squirrels, bunnies, deer, bugs, moss…you get the point. The more diversity of plants & animals, the more that ecosystem has to offer.

Autumn Colors

Well in your gut you have an ecosystem too! Except instead of plants and animals, it’s bacteria and other microbes. All these together make up the gut microbiota and these microbes contribute a lot to the conversation between your gut and your brain.

What type of gut microbiota is good for brain health?

There’s lots of research that looks at the types of gut microbiota and how these may change with certain illnesses. It does seem possible that the microbes in your digestive system could be affected by your brain injury.

But just like each person is unique and each brain injury is different, so is the gut microbiota from person to person.

Assorted-color Candies

As far as we know, it doesn’t always matter the specific kinds of microbes you have, so much as how DIVERSE & STABLE they are. Because the more types of gut microbes you have, and the more resilient these are, the better your gut will function, and the more it will talk to your brain like a supportive friend 🙂

How do I get a diverse and stable microbiota?

Imagine you hosted weekly dinner parties (and yes, you really do need to use your imagination for this one as many of us can’t gather during these quarantimes!). If every week you offered the exact same meal made of only one or two ingredients, it’s likely you’d have fewer and fewer guests each week.

Lunch table

Your microbiota are kind of like your dinner party guests. You want a diverse and abundant population so you need to offer a variety of foods to meet different tastes! And when you do offer a variety of delicious foods each week, your guests will weather any storm to come to your party 🙂

Put into practical terms, here are 3 things you can do right now for a good gut microbiota:

1) Aim for 30 or more different plant-based foods a week.

This may sound like a lot. And if it is, that’s ok! Write out all the plant-based foods you have available to you and/or all the ones you like. This includes not just veggies & fruits, but things like beans, chickpeas, soy & edamame, grains, nuts, nut butters & seeds.

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Then, check off all the ones you’ve had in the past week, or check them off as you have them in the next 7 days. Tally up and see where you’re at. If you’re no where near the 30 mark, no worries. Simply just increase by one or two foods a week. By the end of the year, your gut will be partying like it’s no longer 2020 😉

2) Try to get more food sources of polyphenols in your daily diet.

Polyphenol is the name given to a group of micronutrients found particularly in a certain fruits, vegetables, coffee, tea, and chocolate 🙂 The dark blues and purples seen in blueberries and eggplant come from a specific type of polyphenol in those foods.

In the gut, polyphenols slow down the growth of unhelpful bacteria (pathogens) and encourage growth of your friendly microbiota! And you know what? This relationship goes both ways 🙂

With the help of your gut microbiota, polyphenols are transformed into new metabolites that can act as neurotransmitters in the brain and protect against inflammation. As a result, they support cognitive function.

Assorted Sliced Fruits in White Ceramic Bowl

So while you’re adding more plant-based foods to your diet, try to find some of these to meet your 30 items per week:

  • blueberries, black berries, cherries, black grapes, black currants, strawberries, kiwis, plums, orange juice, grapefruit juice
  • Aubergine (eggplant), yellow onion, curly kale, rhubarb
  • Soy, beans
  • Black tea, green tea, and my favourite… dark chocolate!

3) Give your gut microbiota some carb!

Plant foods have been the highlight here and the reason really comes down to carbohydrate. Carbohydrates have been given a bad name by many people. However included under the family tree of carbohydrates is your best food friend and mine, FIBRE.

Our bodies alone can’t break down nor absorb fibre. There are however some types of fibre that your gut microbiota can break down and transform into helpful metabolites & nutrients. These types of fibres have been given the name Microbiota Accessible Carbohydrates (or MACs).

Close-Up Photo Of Potatoes On Ceramic Tray

Diets higher in MACs are associated with a much more diverse gut microbiota. Though the typical north american diet tends to be low in these beneficial fibre friends.

So is it time for the return of the MAC?? (Oh come on, that’s a great pun from my generation! LOL).

Here are some ways to get more MACs in your day-to-day diet:

  • When possible chose more whole foods that have been minimally processed
  • Chose whole grains including oats & barley
  • Include sources of resistant starch such as potatoes, pasta, rice, beans, lentils, firm bananas
  • Mix it up with some cruciferous vegetables like broccoli, cauliflower, Brussel sprouts, cabbage
Flat Lay Photography of Two Tray of Foods

The gut-brain axis is such a cool aspect of nutrition and neurological health. There’s lots of hype right now around the gut microbiota, and perhaps pills and products that claim to give you the best bacteria. In the end, the more you can feed your gut microbiota it’s favourite foods, the healthier both you and your bacteria will be 🙂

Best in microbiota & brain health,

Krystal Merrells, RD

** Just a note! This post suggests foods that all around are high in fibre. Believe it or not, there are some conditions and times when high fibre may not be in your best interest. Talk with your health care provider if you have any concerns for increasing fibre in your diet.

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Want to add more of these foods to your diet, but have a low appetite? Check out this post on appetite problems post TBI:


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