7 hours agoShareSaveHugh PymHealth editorShareSaveBBCGuts have become a source of immense fascination. Social media influencers promote unproven supplements said to boost gut health, whilst milk and kombucha brands promise to nourish them with “good bacteria”.Some have dismissed the gut-obsession as a passing fad – however many doctors think that our gut microbiome might affect a whole spectrum of things, from mental health to the likelihood of getting certain cancers.But there’s another medical possibility that I’m particularly interested in: how our gut impacts how well (or badly) we age.Which is why, a few months ago, I found myself at St Mary’s Hospital in London, famous for the discovery of penicillin, preparing to receive a nerve-wracking insight into my own gut health.I was there to meet Dr James Kinross. He’s a professor in surgery at Imperial College London and a practising colorectal surgeon – but perhaps the most colourful part of his job is that he analyses people’s poo.Weeks earlier, I’d sent my own stool sample to a laboratory. Tests like these can provide insights into our gut microbiome – the trillions of microbes that live inside our stomach (including mostly bacteria, but also viruses and funghi).”I’m a microbiome evangelist,” he says. “[It’s] is so deeply ingrained in all aspects of our health.”He believes the gut may play a crucial role in the ageing process – with consequences for how long we live, and how physically strong we remain in our elderly years.Some experts think that the importance of the gut microbiome in the ageing process has been overhyped, and everyone I speak to thinks that more research is needed.Now that I am in my 60s and recently became a grandparent, it seems a good time to find out what my own gut tells me about how I will fare in coming decades.And the answer to the bigger question: if gut health really can affect ageing, what, if anything, can we do to improve it?The 117-year-old woman and her daily yoghurtMaria Branyas Morera was the world’s oldest person. After she died in 2024 in northern Spain, aged 117, scientists took samples from her stool, blood, saliva, and urine and compared them with 75 other women from the Iberian peninsula.They said that she enjoyed a broadly healthy lifestyle: she lived in the countryside, walked one hour a day, and ate an oil-rich Mediterranean diet. But what really set her apart was the fact that each day she ate three servings of yoghurt.Dr Manel Esteller, a geneticist at the University of Barcelona who co-wrote the study, thinks that Morera’s yoghurt habit may have given her a high level of helpful bacteria that can reduce inflammation.”She had cells that seemed younger than her age,” Esteller says.There have been other studies of centenarians – the superheroes of the longevity world. ShutterstockAgain and again, scientists have looked inside the guts of this blessed population of over-100s and found an impressive array of bacteria.In another study, published in 2022 in a journal, Nature, researchers in Jiaoling County, southeastern China, took stool samples from 18 centenarians – and found a high diversity of bacteria when compared to younger adults.Guts should be ‘diverse like a garden’This makes sense to Dr Mary Ni Lochlainn, a clinical lecturer in geriatric medicine at King’s College London. She says it’s helpful to think of our gut microbiome like a garden: we want it to be as diverse as possible.”If you go into a garden where there’s no plants and it just looks barren, that’s a low-diversity garden,” she explains. “What you want is lots of flowers, colour, seeds.”The trouble is, as we get older the diversity of our microbiome drops significantly. Some of the helpful bacteria disappear from our guts. But elderly people who buck this trend – and who hold on to their good bacteria well through their eighties and nineties – have been shown to live longer, healthier lives.For Ni Lochlainn, those studies are proof of a link between our gut and ageing. “We know that centenarians… have more diverse microbiome.”Getty Images”There’s something about those people who are kind of superior beings, in a way. They’ve managed to keep their diversity.”And it’s not just about how long someone lives – it’s also about how well they live during their later years. Kinross says there is a link between gut bacteria and frailty, or an elderly person’s ability to bounce back from an illness or injury.My real age vs my gut’s ageBack in the lab at St Mary’s Hospital, Kinross announces his verdict: I have good “gut diversity in the microbiome”. It is “broadly healthy” which is good news. But from his tone I detect some caveats.Duly they come. First, he explains there are a couple of “players in the gut” which might increase the risk of cardiovascular disease. Rather alarmingly, some nasty bugs are found too. E.coli and C-Difficile are present, which is not unusual. (Antibiotic use or a previous bout of gastroenteritis might have caused that.)But then we get to the age question.Ki …
