Diet influences almost every aspect of our health—from digestion and mood to energy levels and chronic disease risk. Yet accurately tracking what we eat has always been tricky. Self-report methods, like food diaries and questionnaires, often fall short: Who remembers exactly what they ate two days ago? Was it one glass of orange juice or two?
But what if the answer to tracking your diet - and, by extension, better managing Irritable Bowel Syndrome (IBS) - was as simple as a smart toilet analyzing your stool?
In a new study published in Nature Metabolism, researchers from the Institute for Systems Biology introduce Metagenomic Estimation of Dietary Intake (MEDI) — a novel approach to dietary analysis that relies on the genetic material found directly in human stool. By analyzing food-derived DNA present in fecal samples, MEDI precisely identifies and quantifies dietary components without the inaccuracies of self-reporting. Rather than relying on memory or written logs, MEDI tracks dietary intake by detecting and measuring tiny fragments of food-derived DNA in stool samples.
The research team first created a vast database containing genetic fingerprints of over 400 edible plants and animals. They then developed a specialized algorithm capable of spotting traces of this DNA within the complex mixture of human and microbial genetic material found in stool samples.
Although food DNA makes up only about 0.001% of the total DNA in stool, MEDI accurately identifies these dietary traces. In controlled feeding studies, MEDI’s accuracy rivaled detailed daily food diaries, correctly estimating calorie, protein, carbohydrate, potassium, cholesterol, and vitamin B12 intake.
This precision can offer invaluable insights to IBS sufferers, who often struggle to pinpoint specific dietary triggers behind their symptoms.
MEDI accurately identified when babies transitioned from milk to solid food, beginning around 160 days of age. MEDI’s dietary estimates closely matched results from traditional food frequency questionnaires, validating its real-world effectiveness. MEDI even identified specific dietary patterns linked to metabolic syndrome—highlighting higher animal-food intake and lower plant-based consumption, along with increased lactose, cholesterol, and certain fats. These findings reinforce well-known dietary patterns linked to inflammation and chronic gastrointestinal discomfort, common in IBS.
MEDI’s potential to objectively track diet offers hope for IBS patients, potentially revealing personalized dietary interventions without tedious logging. As research evolves, IBS patients should keep a close eye on stool analysis approaches —it just might hold the key to better dietary management and improved quality of life.
Diet is the most important piece of the puzzle in IBS. Recent advances in treatments provide more drug-based solutions. In addition to currently available treatments, such as laxatives, antidiarrheals, analgesics, and antispasmodics, targeting the underlying stress with opioid delta-receptor agonists (DOP agonists) may offer a quicker solution with minimal adverse effects. Animal studies showed these compounds reduced abdominal pain and improved bowel regularity through their influence on the brain’s insular cortex, potentially relieving both physical and emotional symptoms. Other promising solutions are psychotherapy, including cognitive-behavioral therapy (CBT) and psychodynamic therapy, Ibodulant, targeting gut neurokinin receptors, significantly reducing abdominal pain and diarrhea symptoms in early studies; GaRP (Gastrointestinal Reprogramming) aiming to reset gut functions, and Blautix, a live probiotic therapy designed to restore gut microbiome balance.
REFERENCES
Diener C, Holscher HD, Filek K, Corbin KD, Moissl-Eichinger C, Gibbons SM. Metagenomic estimation of dietary intake from human stool. Nat Metab. 2025 Feb 18. doi: 10.1038/s42255-025-01220-1. Online ahead of print. PMID: 39966520 (preprint: bioRxiv 2024 Feb 6:2024.02.02.578701. doi: 10.1101/2024.02.02.578701.
Yoshioka, T., et al. (2024). Agonists of the opioid δ-receptor improve irritable bowel syndrome-like symptoms via the central nervous system. British Journal of Pharmacology. doi.org/10.1111/bph.17428.
Mozaffari S, Nikfar S, Abdollahi M. Drugs of the future for diarrhea-predominant irritable bowel syndrome: an overview of current investigational drugs. Expert Opinion on Investigational Drugs. 2024 Mar 3;33(3):219-28.
Pitashny M, Kesten I, Shlon D, Hur DB, Bar-Yoseph H. The Future of Microbiome Therapeutics. Drugs. 2025 Jan 23:1-9.
Brian Doctrow, Tracking diet from stool samples. https://www.nih.gov/news-events/nih-research-matters/tracking-diet-stool-samples
