That daily soda may be doing more than you think, especially to your gut and immune system. New research from the Technion-Israel Institute of Technology finds that soft drinks containing white sugar can alter the behavior of gut bacteria in ways that disrupt immune responses.
The good news? The effects may be reversible.
In a study published in Nature Communications, researchers explored how sugar intake affects the genetic activity of gut microbes, specifically a species called Bacteroides thetaiotaomicron. These microbes play a key role in gut health and immune regulation. In lab models, including mice and humans, researchers found that consuming white sugar changed how these bacteria behaved, triggering shifts in immune markers, gut inflammation and barrier function.
The changes were linked to “DNA inversions,” a rapid adaptation mechanism that lets bacteria flip parts of their genome to respond to environmental factors, like diet. In this case, sugar triggered the flips and altered how the bacteria interacted with the host’s immune system.
Once sugar was removed from the diet, the bacterial behavior and immune signals returned to baseline. According to the researchers, this suggests that everyday food choices can quickly and meaningfully influence gut-immune communication.
The findings add to growing evidence that the impact of sugar goes well beyond blood glucose levels. Frequent consumption of sugar-sweetened beverages may weaken key immune defenses by disrupting microbial balance in the gut.
While more research is needed, the study’s authors suggest that diet-based interventions could eventually support immunity by restoring healthy microbiome activity.
The research was supported by a range of public and private organizations, including the Technion Institute of Technology, the Israeli Science Foundation, the European Research Council, CIFAR and the Seerave Foundation. Additional support came from fellowships and scholarships for early-career scientists.