The impact of diet on the gut microbiome has been highlighted in a recent study by researchers at the University of Chicago, published in Nature. The study focused on how different diets affect the ability to restore a healthy gut microbiome after antibiotic treatment in mice.
Mice fed a Western-style diet, characterized by high levels of processed foods, red meat, dairy products, and sugar, struggled to rebuild a diverse gut microbiome following antibiotic use. These mice also showed increased susceptibility to infections from pathogens like Salmonella. In contrast, mice given a diet similar to the Mediterranean diet—rich in plant-based fiber from fruits, vegetables, and whole grains—were able to quickly recover their gut microbiome post-antibiotics.
Lead author Megan Kennedy expressed surprise at "how dramatically different the recovery process is" between mice on these two diets. Antibiotics can devastate the gut microbiome by indiscriminately killing both harmful and beneficial bacteria. Eugene B. Chang compared this effect to a forest fire that requires specific ecological processes for recovery.
Chang explained that when consuming a Western diet, necessary nutrients for microbial recovery are lacking. This results in certain species monopolizing resources without setting up conditions for other organisms needed for full recovery.
Kennedy and Chang's research also examined fecal microbial transplants as a method to restore healthy gut bacteria. However, they found that these transplants had minimal impact on mice fed with Western diets post-antibiotics. "It doesn’t seem to matter what microbes you’re putting into the community through a fecal microbial transplant," said Kennedy if the underlying diet does not support microbial diversity and recovery.
The findings suggest dietary interventions could be used clinically to treat infections following cancer treatments or organ transplants where patients often receive strong antibiotics and immunosuppressants leading to multidrug-resistant bacterial infections.
Chang proposed using dietary changes instead of additional antibiotics: “Maybe we can [instead] use diet to rebuild the commensal microbes that have been suppressed under these therapies." He believes food can act medicinally by affecting specific populations within the gut microbiome.
Joy Bergelson co-authored this paper along with Christopher Henry who provided computational analysis showing how plant-fiber-rich diets promote networks of metabolites essential for rebuilding healthy ecosystems within guts after disruption.
This study was funded by several organizations including National Institutes of Health; Gastrointestinal Research Foundation; Simons Foundation; U.S Department Energy among others while collaborators at Chinese University Hong Kong received funding from Innovation Technology Council Hong Kong