Recent studies have highlighted the ways that a Western diet -- one that contains large amounts of fats and sugars -- can negatively impact consumers’ health. Now, experts from Washington University School of Medicine have explored the ways that this type of diet can negatively affect gut inflammation.
“Inflammatory bowel disease has historically been a problem primarily in Western countries such as the U.S., but it’s becoming more common globally as more and more people adopt Western lifestyles,” said researcher Dr. Ta-Chiant Lu. “Our research showed that long-term consumption of a Western-style diet high in fat and sugar impairs the function of immune cells in the gut in ways that could promote inflammatory bowel disease or increase the risk of intestinal infections.”
Diet and its impact on gut health
The researchers conducted two studies -- one on humans and one on mice -- to determine what impact diet had on overall gut health. In both instances, the team analyzed Paneth cells, which are immune cells that regulate gut inflammation. Abnormalities in these cells typically indicate inflammatory bowel disease.
The team enrolled 400 people in one part of the study, some of whom had gut health issues and others who did not. The study revealed that participants with high body mass indices (BMIs), which the researchers attributed to diets high in sugars and fats, were more likely to have markers of inflammatory bowel disease, including unhealthy Paneth cells.
However, the researchers also analyzed mice and learned that it wasn’t just obesity that contributed to issues with gut health -- it also had to do with what was specifically being eaten. The team analyzed Paneth cells from mice prone to obesity, and the reports came back healthy. It wasn’t until the researchers gave the mice a traditional Western diet that their Paneth cells changed and revealed gut abnormalities.
After four weeks on this diet, the mice were more prone to intestinal infections and inflammatory bowel disease. Following that experiment, the researchers switched the mice back to a healthier diet and the results changed. Eating less sugary and fat-dense foods improved the mice’s gut health.
“Obesity wasn’t the problem, per se,” said Dr. Liu. “Eating too much of a healthy diet didn’t affect the Paneth cells. It was the high-fat, high-sugar diet that was the problem.”
More research needed
The researchers say there are still questions about whether humans can change the course of their gut health by changing their diets. While adopting a healthier lifestyle certainly comes with benefits, more work needs to be done to determine the impact a change in diet can have on overall gut health.
“This was a short-term experiment, just eight weeks,” said Dr. Liu. “In people, obesity doesn’t occur overnight or even in eight weeks. People have a suboptimal lifestyle for 20, 30 years before they become obese. It’s possible that if you have a Western diet for so long, you cross a point of no return and your Paneth cells don’t recover even if you change your diet. We’d need to do more research before we can say whether this process is reversible in people.”