Benefits of Sourdough Bread for Gut Health

Bread can be a real problem for those of us with a sensitive gut. In fact, according to the NHS, around one in a hundred people in the UK are diagnosed with coeliac disease, while as much as 10% of the population report symptoms of gluten intolerance^[i]. Additionally, many people report that wheat-based products can trigger IBS or IBS-like symptoms.

With so many bothered by bread it’s not surprising that gluten-free products are becoming so popular. Indeed, British consumption of the classic sliced loaf has fallen by 15% in the past five years, with younger people least likely to purchase pre-packaged bread^[ii].

But while we may no longer think sliced bread is the best thing since...well, never mind...we still can’t resist a slice of sourdough. So why, in an anti-wheat era, is sourdough still able to capture our hearts and our guts?

Why Are Fermented Foods So Good for Gut Health?

Fermented foods are really having a moment. It’s not just a fad; kimchi, kefir, yoghurt and sourdough really do come with a ton of benefits...

How fermentation works in sourdough bread

If you’ve ever baked sourdough, you’ll know that the baking process and ingredients are very different to that of ‘normal’ bread. Sourdough requires the addition of what’s usually referred to as a starter. It’s this gloopy gunk which is key to sourdough’s health benefits.

Made with just flour and water and left to naturally bubble, a sourdough starter contains natural wild yeasts and lactic acid bacteria, both of which are present in the environment around us as well as in flour. Fermentation is essentially the digestion process of these microorganisms as they feed off the sugars created by your water-flour mixture^[iii].

Sourdough starters aren’t single use products. They’re intended to be maintained and used repeatedly, their thriving good bacteria giving loaf after loaf the health benefits sourdough is famed for.

Good bacteria v bad bacteria: what’s the difference?

Bacteria can cause us to become ill, sometimes with deadly results. So just how is it that the presence of bacteria is also so vital for our health?

When it comes to the gut, both good and bad bacteria are present.

Bad, or pathogenic, bacteria:

Can have a negative effect on your health, causing digestive issues or immune problems^[iv]
Thrive when you’re under the weather^[v]
Are found in far, far fewer numbers than good bacteria within the gut^[vi]

Meanwhile, ‘good’ bacteria:

Make up as much as 99% of the bacteria in your gut^[vii]
Maintains gut balance by keeping pathogenic bacteria in check^[viii]
Support your wellbeing, including gut health, mental health^[ix] and immunity^[x]

The health benefits of sourdough and other fermented foods

In addition to promoting gut health (and, in turn, supporting mood and immunity), fermented foods like sourdough bread can benefit our health in various ways:

Fermented foods are easy to digest due to the natural breakdown of sugars and starches^[xi]
Containing beneficial bacteria, fermented foods offer a potential probiotic effect^[xii]
Ferments improve the availability of certain nutrients^[xiii] while also reducing the number of so-called anti-nutrients^[xiv]
Research suggests that fermented foods could aid weight loss^[xv]
Fermented food seems to offer some benefits for blood pressure^[xvi] and cholesterol balance^[xvii]

Sourdough and Gut Health: True or False

What’s fact and what’s fiction when it comes to sourdough bread and its health benefits?

Sourdough Bread Can Be Good for People with IBS: True

Many people who experience IBS report being able to eat sourdough without the symptoms that they’d expect following consumption of other types of bread. Scientific research appears to back this up, and it's all down to FODMAPs^[xviii].

Fermentable oligo-, di- and monosaccharides and polyols, or FODMAPs, are common short-chain carbohydrates that are often the cause of gut issues^[xix]. The lengthy fermentation period required to create true sourdough bread reduces the presence of FODMAPs by a massive 90%^[xx].

Sourdough Bread Reduces Bloating: True...Probably

Anecdotal evidence from those who experience bloating after eating suggests that sourdough is far less likely to cause the digestive discomfort that has you reaching for your stretchiest pants.

Though there’s no definitive proof of the link between sourdough and reduced bloating, it seems that FODMAPs are strongly associated with bloating^[xxi], in addition to other gut symptoms. Interestingly, as well as boasting low FODMAP levels, a slow-fermented sourdough produces significantly less gas than comparable non-sourdough breads^[xxii].

Sourdough Bread Supports the Microbiome: True

Research proves that sourdough bread that’s been fermented for a minimum of eight hours is better for your gut’s fragile microbiome than other breads^[xxiii]. Specifically, trials show that sourdough delivers higher levels of Bifidobacterium^[xxiv], a bacterial strain often lacking in individuals with IBS/gut dysbiosis^[xxv].

Sourdough’s fermentation period is also associated with the bioavailability of vital gut-friendly nutrients, including polyphenols^[xxvi], phenolic acid^[xxvii] and fibre^[xxviii].

Sourdough and Your Health: The Big Questions

Sold on sourdough? There’re a few more quick questions you might want to ask yourself...

Can everyone eat sourdough and fermented foods?

While many of us who can’t eat the majority of wheat-based products due to IBS or intolerance are able to tolerate sourdough bread well, that’s not the case for everybody. You should continue to avoid sourdough if you have:

Coeliac disease: though the levels of gluten in sourdough are much lower than in other breads^[xxix] it still contains some gluten, meaning those with severe allergy or intolerance should avoid it
Histamine intolerance: the microorganisms involved in sourdough’s fermentation produce enzymes that, in turn, create histamine. This can lead to allergy-like symptoms in people with histamine sensitivity
Yeast allergy/intolerance: although sourdough relies on a different type of yeast to everyday bread, it’s still a risk for anyone who can’t tolerate yeast
Hashimoto’s disease: like coeliacs, those with Hashimoto’s must avoid gluten. This makes sourdough a no-go despite its lower gluten levels

Is store-bought sourdough as good for my health as homemade?

Mass-produced sourdough bread is usually less beneficial to your health than its homemade counterpart. This is because factories will often rely on shortcuts to produce sourdough, using baker’s yeast to speed up proving, preservatives to improve shelf life and often adding excess salt for flavour^[xxx].

As outlined above, many of sourdough’s health claims rely on long fermentation periods. Large baking companies are unlikely to strive for these beneficial fermenting times, meaning their breads simply aren’t as gut-friendly.

Is sourdough bread easy to make at home?

Baking your own sourdough bread doesn’t have to be difficult. The ingredients and tools needed are minimal and inexpensive. And while a sourdough starter does require maintenance, the hands-on time is surprisingly low – it’s even possible to put your bubbling buddy into dormancy while you hop off on holiday.

That said, baking sourdough is an obsession for some. So if the bug bites, the opportunities to grow your skills and your baking kit are limitless.

Summary

Sourdough bread is a delicious alternative to other bread types, offering potential support for your gut. Key to sourdough’s health claims is fermentation. This seems to reduce FODMAPs as well as gluten levels, while also ensuring high levels of good bacteria, including essential IBS-busting Bifidobacterium. However, though sourdough could offer many great benefits, it’s not suitable for all.

While store-bought sourdough might be more convenient than making your own bread, it’s likely that the potential health benefits will be lost during industrial baking processes. Therefore, the ideal sourdough for your gut’s wellbeing is home baked.

Sources:

[i] https://www.nhs.uk/conditions/coeliac-disease/

[ii] https://www.theguardian.com/business/2025/may/09/crumbs-how-britain-fell-out-of-love-with-the-sliced-loaf

[iii] https://www.sciencedirect.com/science/article/pii/S0924224420307202

[iv] https://pmc.ncbi.nlm.nih.gov/articles/PMC4425030/

[v] https://www.ncbi.nlm.nih.gov/books/NBK209710/

[vi] https://pmc.ncbi.nlm.nih.gov/articles/PMC4528021/

[vii] https://pmc.ncbi.nlm.nih.gov/articles/PMC4528021/

[viii] https://pmc.ncbi.nlm.nih.gov/articles/PMC4421088/

[ix] https://pmc.ncbi.nlm.nih.gov/articles/PMC6469458/

[x] https://pmc.ncbi.nlm.nih.gov/articles/PMC8001875/

[xi] https://pubmed.ncbi.nlm.nih.gov/12728216/