2020 – A mouse fecal‑transplant experiment demonstrates that transferring gut microbes from young to old mice can extend lifespan, suggesting a causal link between microbiome composition and ageing[1].

2020s – A northern‑Italy cohort study of adults aged 22‑ to 109 years provides reference data for “gut age” comparisons, forming the basis for Dr Kinross’s assessment of gut ageing in the journalist’s test[1].

Jan 8, 2026 – Researchers analysing the Chinese Longitudinal Healthy Longevity Survey find that vegetarians, especially vegans, have lower odds of becoming centenarians (OR 0.71) and that underweight vegetarians are particularly disadvantaged, prompting a call for balanced diets that include animal protein for the oldest old[3].

Jan 13, 2026 – Journalist Hugh Pym submits a stool sample at St Mary’s Hospital and meets Professor James Kinross, who explains that gut diversity “may influence ageing” but notes the field remains in early stages[1].

Jan 13, 2026 – Kinross compares Pym’s gut profile to that of a northern‑Italian man five years older, cautioning that the apparent “five‑year gut age gap” could reflect diet and environment rather than inevitable decline[1].

Jan 13, 2026 – Dietitian Raquel Britzke designs a high‑diversity plan featuring flax and chia seeds, kefir, berries, leafy greens, beans, broccoli, salmon and brown rice, plus probiotics, omega‑3 and vitamin D3, stressing that “meaningful change requires significant, consistent dietary adjustments”[1].

Jan 13, 2026 – Kinross predicts that strict adherence to the prescribed regimen could shift the gut microbiome within weeks, warning that modest or inconsistent changes “are unlikely to produce meaningful benefits for ageing”[1].

Feb 17, 2026 – An analysis of more than 100,000 UK Biobank participants shows that close adherence to any of five recognized eating patterns—Mediterranean, Diabetes‑Risk‑Reduction, DASH, plant‑based, or AHEI—correlates with increased longevity[2].

Feb 17, 2026 – Researchers control for 19 longevity‑related genetic markers and confirm that the lifespan benefits of these diets persist independent of inherited risk, indicating diet can offset genetic predisposition[2].

Feb 17, 2026 – The study estimates that a typical 45‑year‑old man gains two to three extra years of life, while women gain one to two years; men benefit most from the Diabetes‑Risk‑Reduction diet and women from the Mediterranean pattern[2].

Feb 17, 2026 – Harriet Moore remarks that “all five diets are rich in diverse fibers and phytonutrients that support gut microbes and anti‑inflammatory pathways,” highlighting the biological basis for the observed longevity gains[2].

Feb 17, 2026 – Nutritionist Kristy Thomas urges people to “increase vegetables, fruits, whole grains, legumes, nuts and seeds, choose healthy fats and fish, and cut added sugars and ultra‑processed foods” to improve health outcomes[2].

Feb 17, 2026 – The analysis confirms that whole grains, fruits and vegetables are the most protective foods across all five diets, reinforcing their central role in longevity‑focused nutrition[2].