Britain's newfound obsession with digestive health is booming — along with some healthy scepticism.

A Bowel Movement

Trend-chasing obscures the unglamorous truth about feeding your microbiome.

An old obsession, revived

In 2025, one can hardly turn a corner in Britain without bumping into the country's new fixation: gut health. Supermarket aisles now feature "gut-friendly" sections hawking kefir smoothies and sauerkraut, while cafés blend probiotic yogurt into smoothies. At dinner parties, hosts extol the virtues of kimchi and kombucha. Never before have bowels been discussed so politely over pudding. It's an unlikely wellness craze, albeit one with deep historical roots. More than a century ago, the eccentric Dr. John Harvey Kellogg believed "virtually all illnesses originated in the bowels". Around the same time in 1904, Nobel-winning scientist Élie Metchnikoff caused a Parisian yogurt mania by claiming that fermented milk could cultivate longevity-promoting microbes. In short, the idea that our guts hold the key to health is not new; it has merely fermented over time.

For much of the late 20th century, gut health was a backwater topic associated with prunes, fibre cereals and little pots of live-culture yogurt. That began to change in the 2010s as modern microbiome science emerged. Genetic sequencing revealed that the human gut contains trillions of bacteria intricately linked to digestion, immunity, and even brain chemistry. The microbiome became a scientific buzzword and a marketing boon. By 2024, searches for terms like "gut health" had surged 35% online, and the global market for digestive health products swelled to around $117 billion. Once a vaguely embarrassing subject, the gut turned positively trendy.

The science of the gut (with a pinch of salt)

Enthusiasts portray the gut as a magic portal to well-being, blaming unbalanced microbiomes for ailments ranging from acne to anxiety. Serious scientists are indeed uncovering remarkable links: disturbed gut bacteria have been correlated with depression, and certain microbial strains show promise in treating obesity and inflammatory disease. This year, researchers even identified dozens of "gut-brain" molecules produced by intestinal microbes that might influence mood and cognition. Other studies are probing whether fecal microbiota transplants – the somewhat medieval-sounding transfer of stool from a healthy donor – could help conditions beyond the gut, from metabolic illness to endometriosis. Such findings stoke excitement that a balanced gut could become a panacea.

Yet for all the intriguing papers, the scientific community remains cautious. Notably, there isn't even a universally agreed definition of "gut health" in clinical terms. Many effects of the microbiome are correlational or complex, making it hard to separate hype from actionable advice. Regulators certainly aren't as excited as consumers. In the EU (and by extension until recently the UK), probiotic foods are forbidden from making any explicit health claims on labels; only certain fibre-based prebiotics are allowed to claim digestive benefits, such as inulin for "normal bowel function". In other words, European authorities demand more than just friendly bacteria mascots to prove a product truly "supports gut health." As a result, probiotic yoghurt drinks in Britain tiptoe around promises, sticking to bland statements about "live cultures" rather than miracle cures. This institutional scepticism hints that the science, while promising, is still catching up to the craze.

Even some of the latest research offers a reality check. In January 2025, Cambridge scientists reported that eating more fibre – found in vegetables, beans and whole grains – helps "support the growth of good bacteria" in the gut and crowd out harmful bugs, reducing infection risks. Popping probiotic pills, by contrast, did little to change gut conditions in their experiments. The lesson sounds almost heretical to the wellness industry: an apple or bowl of porridge might do more for your microbiome than a pricey capsule of Lactobacillus. Similarly, multiple trials confirm that boosting dietary fibre reliably increases beneficial gut bacteria diversity, whereas many over-the-counter probiotics don't even colonize the gut for long. "Trust your gut" may be good intuition, but when it comes to products, trusting the evidence is wiser. As one nutrition professor dryly noted, the benefits of personalised microbiome diets so far seem "marginal" compared to plain healthy eating.

Trends: fermented foods, tests and taboos

Hard science notwithstanding, the commercial and cultural momentum around gut health is immense. Nothing illustrates this better than Britain's fondness for fermented foods. The so-called "four K's" of gut health – kimchi, kefir, kombucha and kraut (sauerkraut) – have graduated to supermarket staples. Sales of kombucha, a fizzy fermented tea, are climbing fast (global demand is rising in double digits), and fizzy "probiotic sodas" are bubbling up in trendy bars as alternatives to beer. Kefir, a tangy cultured milk, now comes in flavours like mango or cacao to court the modern palate; its leading British brand, Biotiful, has grown from a 2012 niche startup to a range of gut-friendly yoghurts, oats and snacks riding the fermentation wave. Even dark chocolate has been reimagined as a gut health product, after studies noted that cocoa's polyphenols can feed beneficial microbes. British consumers can now buy prebiotic chocolate bars or "gut-loving" gummy bears laden with fibre – a supreme irony, perhaps, that confectionery is being marketed as a digestive aid. (One wonders what Charlie and the Chocolate Factory would have been like if Willy Wonka had added inulin to his recipes.)

Another booming business is gut microbiome testing. Rather than relying on generic advice, some consumers are mailing off stool samples to companies that promise personalised diet plans based on one's unique gut flora. The UK's star in this arena is Zoe, a nutrition-tech startup co-founded by a prominent epidemiologist. Launched in 2022, Zoe attracted 130,000 subscribers within two years and at one point had a quarter-million people on its waiting list, all eager to have their innards analysed for insights. The appeal is obvious: who wouldn't want a bespoke eating plan vetted by "your own microbes"? Zoe's popularity (it earned £66 million in revenue in 2024) reflects how mainstream the microbiome craze has become. It also reflects a willingness of Britons to undergo a regime that includes wearing a glucose monitor and, yes, fishing out a sample of one's stool for science. That's commitment to the cause.

Still, personalised nutrition remains an emerging science, and some experts caution that such apps may be "personalising stuff that doesn't matter," dressing up common healthy-eating advice with high-tech gimmickry. The UK's Food Standards Agency pointedly noted that while microbiome testing is intriguing, its practical benefits are so far modest. That hasn't stopped thousands from trying it, but it suggests the average British gut might thrive just as well with broad dietary improvements (more plants and fibre, less processed junk) as with a pricey personalised program.

Consuming culture: a fibre paradox

The year 2025's gut-health craze isn't all kombucha and kumbaya. There are striking paradoxes in how people approach their insides. On one hand, Britons are guzzling probiotic drinks like never before – one survey found a quarter of UK adults now regularly consume fermented drinks such as Yakult or Actimel, and among the over-55s the share is nearly 40%. The same poll shows that overall, 39% of Britons drink some kind of "functional beverage" (be it energy drink, protein shake or probiotic potion) in a given week, all part of the wellness trend. And new gut-focused products keep arriving: high-fibre cereals, "live culture" pickles, even digestive health supplements for pets. In the United States, a Danone survey reported an astonishing 84% of consumers have become more interested in gut-health products than in previous years – a figure that underscores a global phenomenon, not just a British quirk. Gut health has gone mainstream, arguably to a degree not seen with any wellness trend since perhaps yoga or low-carb diets.

Yet, despite the proliferation of gut-friendly products, most people are neglecting a basic pillar of digestive health: fibre. The recommended fibre intake in Britain is 30 grams per day (roughly equivalent to five portions of veg and two Weetabix), but the reality is alarmingly far off. 96% of UK adults do not meet the target, and average consumption hovers around a measly 20 grams. New national diet data shows only 4% of adults achieve the fibre recommendation – in effect, almost everyone is running a fibre deficit. Shockingly, many Britons don't even realise the gap: when polled, the average person believed just ~12 grams a day was sufficient fibre, less than half the actual guideline (a likely legacy of starchy, beige diets). This "fibre paradox" sits at the heart of the gut health trend. People will merrily spend on probiotic gummies or fancy yogurts, yet few eat enough whole grains, fruits and legumes to nourish the very microbes they're trying to boost. As nutritionists like to remind us, probiotics are only houseguests in your gut – prebiotic fibre is the feast that keeps your resident bacteria happy.

There are other contradictions, too. Fad diets pulling in opposite directions have sprouted from the gut obsession. On social media, one faction of wellness influencers advocates "fiber-maxxing," loading 50+ grams of fibre daily via chia smoothies and bean-rich meals (inevitably leading to rather windy side effects). At the same time, a rival camp touts all-meat carnivore diets, claiming that cutting out fibrous plants entirely is the cure for bloating and inflammation. Both extremes cite "gut health" as justification, and both can produce evangelists swearing by their intestines' improved state. It would be amusing if it weren't so confusing for the average person. The upshot: while gut health awareness has skyrocketed, clarity has not. Nearly half of people admit they struggle to identify which foods or habits actually benefit their gut, a confusion worsened by the plethora of contradictory online advice.

Britain's gut check

Is Britain's gut-health craze actually doing anyone good? The answer is a qualified yes – with caveats. On the positive side, awareness of the microbiome has spurred many to eat more fermented foods and try novel fibres. Supermarkets report increased sales of high-fibre breads and yogurts with "live cultures." The Food & Drink Federation has even partnered with companies on an "Action on Fibre" initiative, aiming to bridge the nation's fibre gap by making high-fibre foods more appealing (one approach: promoting a cheeky "Fibre February" campaign each year to celebrate wholegrain breads and beans). Public discourse about digestive well-being, once awkward, is now commonplace – potentially eroding stigma around digestive disorders. And some early adopters of gut-friendly diets do report improvements in issues like irritable bowel syndrome or simply feeling more energetic, though anecdotes are not data.

However, Britain's experience also shows the limits of a trend built on equal parts science and marketing. The market is booming, but measurable public health progress (like higher fibre intakes or lower digestive illness rates) remains elusive so far. For all the kombucha and kefir being consumed, the average Brit's diet is still low in fibre and high in ultra-processed food. Probiotic popcorn and "healthy" crisps fortified with chicory root won't offset the effects of a chronically fibre-poor diet. Policymakers have begun to worry that crucial messages about eating vegetables are getting lost amid the probiotic hype. If 2025 is the peak of gut-health consumerism, one hopes 2026 will be the year of practical implementation – perhaps Brits swapping some of those fancy supplements for a humble bowl of porridge and a side of greens.

As ever, a dose of British scepticism may be the best medicine. The Gut Tailor advises its readers to take trends "with a pinch of salt"; in this case, perhaps a pinch of salt and a serving of sauerkraut. Gut health in 2025 is both promising and peculiar: a field where serious breakthroughs (like bespoke probiotics to target disease) co-exist with dubious claims and sugary "gut-friendly" sweets. The task for consumers is to discern which is which. In the meantime, the nation's newfound fascination with the microbial world inside us is certainly an improvement over total neglect. If nothing else, it has got people talking about bowel movements in polite society – a public health victory in itself, some might say. The challenge ahead will be to translate all this awareness into habits that truly nourish our inner ecosystems, rather than just feeding the fad. In other words: by all means love your gut, but remember to feed it some broccoli.

At The Gut Tailor, we focus on fibre. We serve fibre in two ways - either as a supplement or inside porridge. Check out The Fibre Plan supplement or our porridge range to find out more.