The study has been cited nearly 100 times since, and the idea has inspired whole new clinical trials<\/a> investigating how some supplements may protect against dementia.<\/p>\n Later that year, scientists at Wageningen University in the Netherlands launched the PRECODE clinical trial<\/a>, which stands for Gut-brain Health Effects of PREbiotics in Older Adults With Suspected COgnitive DEcline.<\/p>\n It’s the first human study to investigate the combined cognitive and microbial effects of three distinct dietary fibers: chicory inulin, resistant dextrin, and seaweed polysaccharide, compared to a placebo<\/a> (maltodextrin).<\/p>\n For 26 weeks, participants over 60 have consumed these dietary fibers twice a day, mixed into water, tea, or coffee<\/a>, and they have had regular brain scans and cognitive tests to track how they are faring. <\/p>\n We’ll know more in 2027 when the trial finishes.<\/p>\n Inulin, a dietary fiber in the\u00a0fructan<\/a>\u00a0class, is the same dietary supplement that proved so good for the brain in that first 2024 twin study.<\/p>\n Watch the video below for a summary of the 2024 study:<\/p>\n During that double-blinded trial, researchers tested two inexpensive plant-fiber prebiotics that are available over the counter in many countries.<\/p>\n The other,\u00a0fructooligosaccharide<\/a>\u00a0(FOS), is a plant carbohydrate often used as a natural low-calorie sweetener.<\/p>\n To look into how these supplements affected\u00a0the aging brain<\/a>, researchers at King’s College London enrolled 36 pairs of twins, all at least 60 years old.<\/p>\n Each duo was randomly split: one twin received a daily prebiotic mixed into protein powder, while the other received a\u00a0placebo<\/a>\u00a0powder.<\/p>\n The twins who unknowingly took inulin or FOS generally scored higher on a cognitive test three months later.<\/p>\n What’s more, the daily fiber supplements were linked to subtle changes in the gut microbiome between twins.<\/p>\n The beneficial\u00a0Bifidobacterium<\/a>, for instance, was more plentiful in those taking inulin or FOS.<\/p>\n Studies on mice suggest that\u00a0Bifidobacterium\u00a0reduces cognitive deficits<\/a>\u00a0by regulating gut-brain connections.<\/p>\n “We are excited to see these changes in just 12 weeks. This holds huge promise for enhancing brain health and memory in our aging population,”\u00a0said<\/a>\u00a0Mary Ni Lochlainn, a geriatric medicine researcher at King’s College London, when the findings were published in 2024.<\/p>\n “Unlocking the secrets of the gut-brain axis could offer new approaches for living more healthily for longer.”<\/p>\n King’s College London (KCL) is home to the UK’s largest adult twin registry, and\u00a0twin studies are highly valuable<\/a>\u00a0when it comes to differentiating between\u00a0the effects of genetics and the environment<\/a>\u00a0on human health<\/a>.<\/p>\n Past studies on rodents<\/a>\u00a0suggest that high-fiber supplements, such as inulin and FOS, can ‘feed’ the colon’s microbiome, allowing ‘good’ bacteria to thrive.<\/p>\n Some of these bacterial players are\u00a0also linked<\/a>\u00a0to improved cognitive function in both mice and\u00a0humans<\/a>.<\/p>\n Evidence for the close relationship<\/a>\u00a0between the gut<\/a>\u00a0and the brain<\/a>\u00a0is growing<\/a>\u00a0year after year<\/a>. Some experts are now so convinced by the results that they\u00a0refer to the gut<\/a>\u00a0as\u00a0the body’s ‘second brain’<\/a>.<\/p>\n But the way these two nervous systems work together remains a mystery.<\/p>\n The twin study at KCL hints that consuming certain ‘brain foods<\/a>‘ could be a promising way to treat cognitive decline, adding to\u00a0research suggesting key nutrients<\/a>\u00a0may be able to slow its progress<\/a>.<\/p>\n “These plant fibers, which are cheap and available over the counter, could benefit a wide group of people in these cash-strapped times. They are safe and acceptable too,”\u00a0said<\/a>\u00a0geriatrician Claire Steves at KCL.<\/p>\n “Our next task is to see whether these effects are sustained over longer periods and in larger groups of people.”<\/p>\n That’s what the PRECODE trial seeks to address. The trial investigators hope<\/a> this ongoing study into fiber supplements will “provide an in-depth evaluation of the microbiota-gut-brain axis in older adults, at risk of cognitive decline.”<\/p>\n Related:\u00a0117-Year-Old Woman’s Diet Could Help Us All Live Longer<\/a><\/p>\n In 2025, researchers reported<\/a>\u00a0that in humans and mice, a lower Bifidobacterium-to-Akkermansia\u00a0ratio in the gut microbiome is linked to multiple sclerosis, and this imbalance was also associated with more severe disease.<\/p>\n Whether these deficiencies can be remedied with supplements, however, remains unknown.<\/p>\n The\u00a0gut has its fingers in many bodily ‘pies’<\/a>, including the immune system and the central nervous system.\u00a0<\/p>\n Feeding its microbiome<\/a>\u00a0certain\u00a0prebiotics and probiotics<\/a>\u00a0could open the door to treating\u00a0a plethora of illnesses<\/a>\u00a0and diseases<\/a>.<\/p>\n The PRECODE trial could give us a first taste of that possibility.<\/p>\n The twin study was published in\u00a0Nature Communications<\/a>.<\/p>\n This article was fact-checked by Clare Watson<\/a> and edited by Rebecca Dyer<\/a>. While we pride ourselves on our process, we are only human. If you spot a mistake, please let us know<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"Cheap daily supplements are changing how scientists view the gut and its connection to the brain. In 2024,…\n","protected":false},"author":2,"featured_media":529410,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[36],"tags":[103,61,60,2209,446],"class_list":["post-529409","post","type-post","status-publish","format-standard","has-post-thumbnail","category-nutrition","tag-health","tag-ie","tag-ireland","tag-msft-content","tag-nutrition"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/529409","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/comments?post=529409"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/529409\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media\/529410"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media?parent=529409"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/categories?post=529409"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/tags?post=529409"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"Subscribe](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/06\/FOMO-1200x628-_Dont-miss-the-next-breakthrough_-cosmic-colourful-642x336.jpg\")
<\/a><\/p>\n![\"Diagram](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/05\/gut_microbiome_with_inset_642.jpg\")
The microbes in each person’s gut make up their individual microbiome. (Science Photo Library\/Canva)<\/p>\n![\"YouTube](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2025\/11\/1763991672_657_0.jpg\")
frameborder=”0\u2033 allow=”accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share” referrerpolicy=”strict-origin-when-cross-origin” allowfullscreen><\/p>\n