A new study suggests that fasting “has the potential to beneficially modulate infectious gastrointestinal diseases.”
Fasting before and during exposure to the bacteria Salmonella enterica protects mice from developing full-blown infection, in part because of the changes in the gut microbiome of animalsAccording to new research published in PLOS Pathogens by Bruce Vallance and colleagues at the University of British Columbia, Canada.
When people or animals develop an infection, they often lose their appetite. However, it remains controversial whether fasting protects the host from infection or increases its susceptibility. In the new study, mice were subjected to fast for 48 hours before and during oral infection with the bacteria Salmonella enterica serovar Typhimurium, a common cause of foodborne illness in people.
The fasting reduced signs of bacterial infection compared to fed mice, including almost elimination of all intestinal tissue damage and inflammation.
When the fasted animals were fed again for a day after their fast, there was a dramatic increase in the number of Salmonella and invasion of the intestinal walls, although the associated inflammation remained attenuated compared to normal.
When the fasted animals were fed again for a day after their fast, a a drastic increase in the number of Salmonella and invasion of the intestinal walls, although the associated inflammation remained attenuated compared to normal.
The results were not maintained when mice were exposed to Salmonella intravenously rather than orally, and analyzes of the mouse microbiomes showed significant changes associated with fasting and protection against infection.
In addition, fasting did not fully protect germ-free mice (bred to lack a normal microbiome) against Salmonella, suggesting that some of the protection was due to the effect of fasting on the microbiome. experiments with bacteria Campylobacter jejuni cconfirmed that the effect of fasting was not limited to Salmonella, with similar results.
“These data suggest that the therapeutic fasting or calorie restriction they have the potential to beneficially modulate infectious and potentially non-infectious gastrointestinal diseases,” the researchers conclude.
And they add that the research highlights the important role diet plays in regulating interactions between the host, enteric pathogens and the gut microbiome.
“When food is limited, the microbiome appears to sequester the nutrients that remain, preventing pathogens from acquiring the energy they need to infect the host,” they note. Although more research is needed, fasting or adjusting food intake could be harnessed therapeutically to modulate infectious diseases in the future.”