Why Does Bread Make Me Bloated?

It's probably not gluten

When bread leaves you feeling puffy and uncomfortable, the instinct is to blame gluten. But research tells a different story. A 2018 study published in Gastroenterology found that among people who believed they were gluten-sensitive, the majority actually reacted to fructans — a type of fermentable carbohydrate found in wheat — rather than gluten itself.

Fructans are part of a group of short-chain carbohydrates called FODMAPs (Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols). Your small intestine doesn't fully absorb them, so they travel to the large intestine where gut bacteria ferment them. The byproduct? Gas. And gas means bloating.

This doesn't mean coeliac disease isn't real — it absolutely is, and affects around 1 in 100 people in the UK. But if bloating after bread is your main symptom, fructan sensitivity is statistically far more likely.

The most common causes of bread bloating

1. Fructan fermentation

Wheat is one of the highest dietary sources of fructans. Modern commercial bread uses fast-acting yeast and short proving times, which means the fructans don't get broken down before you eat them. Your gut bacteria then do the job instead, producing carbon dioxide and hydrogen gas in the process.

2. Eating speed

Bread is easy to eat quickly — a sandwich at your desk, toast on the way out the door. Eating fast means swallowing more air (aerophagia), which adds to the bloated feeling. It also means less chewing, which puts more work on your digestive system.

3. Portion size

Two slices of toast for breakfast, a sandwich for lunch, garlic bread with dinner. The fructan load adds up over the day. Many people who "can't tolerate bread" actually tolerate small amounts fine — it's the cumulative dose that triggers symptoms.

4. The type of bread matters

Not all bread is created equal when it comes to bloating. The fermentation process, ingredients, and proving time all make a significant difference.

Why sourdough is different

Genuine sourdough bread undergoes a long fermentation — typically 12-24 hours — using wild yeast and lactobacillus bacteria. Research from Monash University (the institution behind the low-FODMAP diet) has shown this process breaks down a large proportion of the fructans in wheat flour.

The key word is "genuine." Many supermarket breads labelled as sourdough are made with standard yeast plus sourdough flavouring or a small amount of sourdough starter, with a standard short proving time. These won't give you the same benefit.

When it might be something more

For most people, bread bloating is uncomfortable but harmless. However, certain symptoms alongside bloating warrant a GP visit.

Coeliac disease vs fructan sensitivity vs wheat allergy

Practical steps to reduce bread bloating

1. Try genuine sourdough first. Swap your regular bread for bakery-made sourdough and see if symptoms improve over a week.
2. Watch your portions. Try one slice instead of two. Fructan sensitivity is dose-dependent — you may tolerate a smaller amount perfectly well.
3. Eat slower. Chew each bite thoroughly. Put your sandwich down between bites. This reduces swallowed air and helps digestion.
4. Track what you eat and how you feel. A food and symptom diary helps you spot patterns. Was it the bread itself, or the cheese and pickle with it?
5. Space out wheat intake. Rather than wheat at every meal, spread it across the day with non-wheat alternatives in between.
6. Consider a low-FODMAP trial. If sourdough alone doesn't help, a structured low-FODMAP approach under guidance can identify your specific triggers. Monash University's app can help.
7. Don't self-diagnose coeliac disease. If you suspect it, get tested first. Cutting out gluten before testing makes diagnosis harder.

What about gluten-free bread?

Gluten-free bread removes wheat entirely, which eliminates fructans from wheat. However, it's not automatically bloat-proof. Many gluten-free breads contain inulin, chicory root fibre, or other ingredients that are themselves FODMAPs and can cause the same fermentation and gas.

If you find sourdough still causes problems and want to try gluten-free, check the ingredients for these common FODMAP culprits. And again — if you're considering coeliac disease, get tested before making any dietary changes.

Frequently asked questions

Why does bread make me bloated but pasta doesn't?

Bread and pasta contain different amounts of fructans. Bread — particularly commercial white bread made with quick-rise yeast — retains more fructans than pasta, which is made from durum wheat semolina and cooked in boiling water (which leaches out some fructans). The long cooking time for pasta also helps break down fermentable compounds.

Is bread bloating a sign of coeliac disease?

It can be, but it's far more commonly caused by fructan sensitivity. Coeliac disease affects about 1 in 100 people in the UK and usually involves additional symptoms like persistent diarrhoea, weight loss, and fatigue. If you're concerned, see your GP for a blood test — but keep eating gluten-containing foods beforehand.

Does sourdough bread cause less bloating?

Research from Monash University suggests genuine sourdough fermentation breaks down a significant proportion of fructans in wheat. Many people who bloat after regular bread find sourdough more comfortable. Look for sourdough with a short ingredient list and no added yeast.

How long does bread bloating last?

Typically 2-4 hours to peak, resolving within 6-12 hours. If bloating persists beyond 24 hours or comes with severe pain, speak to your GP.

Which bread is least likely to cause bloating?

Genuine sourdough bread made with a long fermentation (12-24 hours) tends to cause the least bloating. Spelt sourdough is another option. Gluten-free breads avoid wheat but may contain other fermentable ingredients — check the label.

Related articles

• How to Track Food Intolerances: Find Your Trigger Foods
• Bloating Food Diary App UK
• FODMAP Tracker UK
• IBS Food Diary UK
• Gut Health Tracker UK
• Best Food Allergy Tracker Apps UK

Last reviewed and updated: 5 February 2026