I’ve never given fibre much thought – I knew it promoted regularity and was generally good for you but that was about it. However in recent years, researchers are finding that fibre is also hugely important for the wellbeing of our gut microbiome and immune systems. I’ve read a lot about it over the past few months and I really think it warrants a lot more press than it is currently getting given the findings. So let’s look at why you should get more fiber into your diet.
Your immune system needs it
Your gut is one of the systems that are the most exposed to external elements (think of all the things we ingest….), which is why most of the body’s immune cells are there. The bacteria in your gut play a very important role in regulating your immune system. How? When you feed them the right types of foods (different bacteria eat different types of fibers), they produce short chain fatty acids, which are chemicals that tell your gut’s immune cells how to behave. For example, they will tell them to behave like T-regulatory cells (the cells that prevent auto-immune disease) or T-killer cells (we always have a few cancer cells in our bodies, T-killer cells are the ones that keep them in check). So you see, it is very important for your gut to get fiber.
You need to feed your good gut bacteria or it will eat your gut lining
Protein, fat and refined carbs get processed in the upper part of the intestine and never make it to the colon, where the good bacteria live. Fiber does. So if you aren’t eating fiber, you aren’t feeding those bacteria. What then happens is that they start feeding on your “mucin”, the mucousy gut barrier that separates immune cells from your gut. Once your mucin starts breaking down, things like leaky gut and auto-immune diseases occur. Immune cells see the bacteria and attack them. And you need to make sure you high fiber is constant, so just adding a small amount is not enough. This study done on mice shows that the ones on a high fiber diet had a digestive lining that was twice as thick as mice on a part time high fiber diet. If you want more information on the studies around this, I suggest you look at the research by the Sonnenberg lab at Stanford University, they seem to have some of the most up to date findings on the topic of the gut.
High fiber diet has a strong correlation to weight loss
Short chain fatty acids produced by fiber have not only been linked to improved immune function and decreased inflammation but also to protection against obesity.
How much fibre are you getting?
Right about now, you might be wondering how much fibre you consume. The typical US diet has around 15g/day. They recommend women to intake about 28g/day. Existing hunter gatherer tribes in some parts of the world consume up to 100g. Where do you stand?
So I wrote down everything I ate on a typical day and calculated the amount of fibre I consume:
Breakfast:
Chlorella/wheatgrass shake (don’t ask why, that deserves its own blog post…)
Full fat yogurt, matcha powder and raspberries
A dozen almonds, a dozen cashews followed by a latte
Lunch:
Big salad bowl (quinoa, feta, baby spinach/kale, cherry tomatoes, cucumber, celery, avocado, olives, flaxseeds, lots of lemon juice and olive oil)
Snack:
Spelt muffin, black coffee
Pre-dinner snack:
Popcorn (on some days this is carrots on others it’s chips, it all depends)
Dinner:
Greek salad
Salmon fillet
Reasonably “healthy” I’d say. Fibre content of the above day = 24g, which is under the recommended amount.
I was sure I was getting double the US diet, I was pretty disappointed. And you know what saved me? Avocado, nuts, seeds and quinoa. Although they did contribute, the chlorella/wheatgrass shake, celery, cucumbers, spinach or kale would not have made me surpass the average 15g. The thing with fruits and vegetables is that they all have fibre, but you need to eat a lot (and a variety) of them because only a handful have loads of it. So you see, you may think you are eating pretty well but if you look at it with fibre glasses on, it might not be well enough.
So how does one feed all those good bacterias?
Prebiotics
Prebiotics are a type of fiber that feeds the bacteria already living in your gut. Good sources include dandelion greens, onion, garlic, leek and chicory. Prebiotics are often part of the oligosaccharide or fructans family, which makes them mostly unfriendly to someone following a low FODMAP diet. If you are a low FODMAP follower – check out this list of “safe” prebiotics.
High fibre foods
- Legumes: lentils, split peas, most beans
- Vegetables: artichokes, broccoli, peas, brussel sprouts
- Fruits: avocados, raspberries, blackberries
- Whole grains (oats, quinoa, brown rice, etc)
- Nuts and seeds (chia, flax, etc)
- Coconut (I might reconsider coconut milk in my coffee after all…)
What about probiotics?
Probiotics are good bacteria that you can supplement your gut with. They are ideal for people who do not have enough strains of good bacteria, which is typical in IBS patients or consumers of antibiotics. You can either take a good quality supplement or eat probiotic foods like fermented vegetables, kimchi, kefir, kombucha, certain yogurts, etc.
Keep in mind however that some short chain fatty acids cannot be produced by taking probiotics. For example, butyrate is an important one that only your body can produce in sufficient amounts by consuming certain types of foods like fiber and butter.
Conclusion
Keep up the guacamole habit, have green smoothies, embrace the quinoa trend, eat beans in general, greens, nuts, seeds and some berries. I suspect it isn’t as simple as that because we are all unique and react differently to these foods. But definitely try to incorporate them into your diet and see how you feel. It goes without saying that vegetables in general have so many benefits other than just fibre so definitely keep eating loads of those too. Also seriously think of incorporating prebiotic and probiotic foods.
