All pages on this website are written by myself, (C) Peter Thomson. I am a real person, not AI.

Can inulin and oligofructose in the diet be a common cause of Crohn's disease, irritable bowel syndrome? 

The list of problematic foods, worst effects at the top:

I have struggled with problems with my digestive system since I was a small child.

At first I was told that it wasn't anything to do with what I ate - it was just one of those things.

My abdomen tended to be swollen and I missed a lot of school with digestive problems and headaches.

I did notice that on holiday at a family hotel the problems largely went away, and later I realised that I wasn't eating any bread or cakes.

At university breakfast consisted of bacon and eggs, and an evening meal of meat and vegetables, and again my digestion improved. (no lunch, I couldn't afford it)

In my 20s I started to notice a pattern, bacon and eggs for breakfast and I had a comfortable morning, but a wheat based cereal and toast gave me severe problems.

A sandwich lunch gave me an uncomfortable afternoon.

At the age of 30 I was given my first diagnosis by the medical profession. Possibly coeliac, or Crohn's or irritable bowel syndrome, and a suggestion to try a gluten free diet.

And that led me into my research into what exactly I could eat and cook on a gluten-free diet, and the gluten-free diet cookbook.

However the gluten-free diet didn't solve all my problems and I started to build up a list of other foods that I had to avoid.

Further visits to the medical profession and an internal investigation revealed that something was still badly irritating my digestive system, but there was no agreement as to exactly what it was.

By this time I was tutoring courses on data analysis and decided to investigate more methodically exactly what it was that I could and could not eat.

But even though I ate as varied a diet as I could and kept detailed diaries for a couple of years of what I ate and my symptoms I could not find any obvious patterns.

So I took a different approach. From being as varied as possible I started with a diet that was as simple as possible:

Nothing out of packets or tins! Just chicken potato rice and brassicas, and rapeseed oil. Foods that I was fairly sure didn't give me any problems.

Also note that I was only drinking water. No coffee, no tea and

After two weeks on this plain diet my symptoms faded away altogether, and in my mind confirmed that it was something in my diet causing the problems.

I now started a slow process of testing one natural food each two weeks, slowly increasing the amount each day until I detected any problems (if any) and keeping a detailed diary of any symptoms and mood.

If there were no symptoms I could add it to my safe list and my basic diet. If there were symptoms I stopped eating that food, and then had to wait a week for my digestion to recover before trying the next thing.

For each food that caused symptoms or discomfort I had a record of how long it took, and how much I had eaten before symptoms started, and could start to create a list of foods,in the order of how severe the symptoms were and how quickly they appeared.

Jerusalem artichokes headed that list with a violent response within a few minutes!

Gluten-free oats came quite high on this list, suggesting that gluten wasn't the main problem.

Coffee also came high on this list.

What I can eat on a diet free from inulins:

Rapeseed oil and Olive oil can be used in cooking or dressing

Fresh meat

Fresh fish

eggs

potato

rice, rice flour, sticky rice flour.

Sweet corn, maize, flour made from maize

All brassicas: cabbage, cauliflower , broccoli , swede, turnip

Peas, runner beans, lentils

Carrot

mushroom

tomato

squash ,courgettes, pumpkin

Fresh fruit:

Apple

pear

plum

grapes

melon

orange

mango

pineapple

blueberries

unglazed dried fruit without any oil

dried fruit with cottonseed oil

dates, unglazed

quinoa

chia

tapioca

sago

I can also eat fresh banana - this is an odd one because you will often see it listed as a food that contains inulin. However recent studies have failed to detect inulin in banana flesh. It may be present in the banana skin.

The list of problematic foods, worst effects at the top:

Jerusalem artichokes and any products from the sunflower family Topinambur

Chicory

Inula helenium Elecampane

scorzonera

salsify

Dandelion 28% dry weight https://www.researchgate.net/publication/258519409_HPLC-RID_method_for_determination_of_inulin_and_fructooligosaccharides
Wheat

Barley

Rye

Spelt

Oats

Many chocolate and cocoa products now contain significant amounts of inulin. Some have up to 40% of inulin!  https://www.confectionerynews.com/Article/2014/05/19/Have-you-considered-inulin-in-your-chocolate/

Coffee

Milk and dairy products such as butter, cheese, yogurt

Soybeans, Soy and any soya products

Lettuce

Garlic

Onion

Leeks

Sweet Potato

figs

Parsnip

Buckwheat

Asparagus

great burdock (Arctium lappa L.), wooly burdock(A. tomentosum Mill.), and lesser burdock (A. minus(Mill.) Bernh. https://www.researchgate.net/publication/257859221_A_quantitative_assay_for_total_fructans_in_burdock_Arctium_spp_roots

Cashew

Coconut products can be problematic as some brands of coconut milk and coconut yogurt seem to be adding inulin to improve the texture, but it gets no mention on the product information.

Cocoa may contain inulin, or be adulterated with inulin to reduce the bitterness of pure cocoa

I followed this initial investigation with research of the literature to see what these all had in common. Coffee seemed the odd one out until a paper published in 2024 revealed that coffee contains about 4% inulin!

What all these foods have in common are measurable levels of inulin and similar long chain sugar molecules such as oligofructose and  oligosacharieds.

I was now able to start creating my second list:

One of the biggest problems with inulins is that they get added into many manufactured foods as a processing aid, bulking agent or sweetener, and they don't get declared on the label. They may be included as 'added fibre' but not always.

So I must avoid anything out of a packet, jar, tin etc that is not a pure food ingredient on my safe list.

There are many products produced for a gluten-free diet that I cannot eat because they contain undeclared inulins!.

Honey from my own bees is fine, but when I ran out of my own honey and got a jar from Tesco I immediately detected a problem. Tesco later confirmed that some of the honey they were selling was adulterated, probably with inulin which is very hard to detect, and this has now been confirmed as a big problem with the world honey trade.

Inulin  is often  added to dairy products to  act  as a  source of dietary fiber as well as  to provide technological functionality  (e.g., water-holding  or  fat  replacing  functions).  It  is  water-soluble,  has texture-enhancing  properties,  and  is  often  used  to  fortify  dairy products  with  fiber  as  well  as  to  replace  fat  and  provide  creamy mouthfeel in low-fat dairy products such as milk drinks, yogurts, dips, cream cheese, and process cheese https://pubmed.ncbi.nlm.nih.gov/12088531/

I am not a medical expert, so this is just based on my own experience and some detailed research of the medical and food literature, but if you want to check if any of your medical problems might be the result of inulins in your diet try and stick absolutely to the safe foods list above for a month - and note the no coffee or any other purchased drinks or juices.

The problems caused by inulins in the diet may be diagnosed as inflammatory bowel disease, Crohn's disease, Coeliac, leaky gut syndrome, anaemia, skin rashes, arthritis, general fatigue, depression and even neurologic symptoms such as epilepsy.

I do know that adverse reactions to inulin in the diet are far more common than reported.

A medical study states "Therefore, high-dose inulin-type fructans prebiotics may actually worsen symptoms in active Crohn's disease, perhaps explaining why they also consume lower amounts of naturally occurring fructans and rarely use prebiotic supplements. 23 , 24 "

: Prebiotic inulin-type fructans and galacto-oligosaccharides: definition, specificity, function, and application in gastrointestinal disorders

Available at : https://onlinelibrary.wiley.com/doi/10.1111/jgh.13700

I am suggesting that these inulins and oligosacharides may be the cause of these problems

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