Scientists at the Weizmann Institute of Science have discovered that intermittent fasting triggers a profound reorganization of the gut microbiome, shifting its composition toward bacterial species associated with exceptional longevity in centenarian populations.
The study followed 200 participants who adopted a 16:8 intermittent fasting schedule (16 hours of fasting, 8-hour eating window) for six months. Researchers found dramatic increases in bacterial species that produce short-chain fatty acids (SCFAs), particularly butyrate, a compound with powerful anti-inflammatory and gut-healing properties.
"The fasting-induced microbiome changes were remarkably similar to the gut profiles we see in healthy centenarians from Blue Zone regions," said Professor Eran Elinav, who led the research. "This suggests that intermittent fasting may activate some of the same biological pathways that contribute to exceptional longevity."
Beyond microbiome changes, participants showed reduced markers of systemic inflammation, improved insulin sensitivity, and enhanced autophagy — the cellular recycling process that declines with age.
The researchers note that the benefits were most pronounced when the fasting window aligned with natural circadian rhythms, with early time-restricted eating (finishing meals by early afternoon) showing the strongest effects. They recommend consulting with healthcare providers before starting any fasting regimen, particularly for those on medications or with existing health conditions.