If you eat junk for too long, the damage to your gut might be permanent—even if you switch to salads later.
March 20, 2026
Original Paper
Diverse high-fat diets drive multi-omic reprogramming that persists after dietary reversal
bioRxiv · 10.64898/2026.03.17.708620
The Takeaway
In a long-term study, researchers found that about half of the changes to gut bacteria caused by a 'junk food' diet never returned to normal after the diet ended. This suggests that poor eating habits can leave a permanent 'scar' on your internal ecosystem that cannot be fully erased by a salad.
From the abstract
Dietary fat composition modulates host physiology and the gut microbiome, but the long-term effects of specific fat sources and the extent to which these changes resolve after dietary reversal remain incompletely defined. Here, we present a longitudinal multi-omic resource of mice maintained for one year on a purified control diet, seven high-fat diets differing in predominant fat source, or reversal regimens in which animals were switched from high-fat to control diet after 4 or 9 months. We fu