Researchers in Canada demonstrated that following an eating program similar to the Mediterranean diet was associated with improved microbiome composition and lower intestinal inflammation.
Crohn’s disease is an inflammatory bowel disease that causes tissue swelling in the digestive tract and often leads to abdominal pain and malnutrition. While its causes are unknown, previous studies suggest that diet is an important contributor to Crohn’s disease risk.
This study suggests that an intervention to prevent disease onset should consider the baseline microbiome, as well as a certain diet, which may only be beneficial depending on the presence of a certain microbiome profile.
Other studies have shown that Crohn’s disease patients also have different microbial compositions from healthy people, which led the researchers to hypothesize that the two are connected.
To test the hypothesis, the researchers collected stool samples from 2,289 healthy first-degree relatives of Crohn’s disease patients and had them fill out validated food frequency questionnaires asking about their diet in the previous year.See Also:Health News
The researchers identified three dietary and microbial composition clusters based on their analysis. One of the clusters resembled the Mediterranean diet, one resembled a Western diet and the final dietary cluster was a hybrid.
The researchers found that the people following a MedDiet-like eating pattern generally had a microbial composition with an abundance of fiber-degrading bacteria – Ruminococcus and Faecalibacterium – and significantly lower levels of gut inflammation.
“This is likely due to the increased amount of fiber associated with higher consumption of leafy greens, cereals and other fiber-rich food items [in the MedDiet],” Williams Turpin, a researcher at Mount Sinai Hospital in Toronto and lead author of the study, told Olive Oil Times.
“In this environment, microbes that are capable of degrading fiber (which are not digested by the host) have an ecological advantage, which may promote their abundance in humans consuming more fiber-rich food,” he added.
There was no evidence to suggest the consumption of a single food item directly led to a more diverse microbiome. However, Turpin said, “olive oil showed a trend toward increased microbiome diversity,” but “a weak association with lower inflammation in the expected direction.”
Despite the murkiness between the links of single foods to gut microbiome diversity and subclinical inflammation, the links with long-term dietary patterns are more evident.
“Our study demonstrated that the lower level of subclinical inflammation might be related to both the dietary pattern and the associated microbiome,” Turpin said. “This conclusion is supported by causal inference analysis demonstrating that 47 percent of the anti-inflammatory properties of the Mediterranean-like diet were driven by the microbiome.”
“This also means that a Mediterranean-like diet has a direct effect on subclinical inflammation (53 percent),” he added. “We believe that a microbiome capable of degrading fiber may produce beneficial short chain fatty acids in vivo, which are known for their anti-inflammatory properties.”
Turpin said the study’s results could help guide future dietary strategies that affect the microbial composition and host gut inflammation to prevent diseases.
“This study suggests that an intervention to prevent disease onset should consider the baseline microbiome, as well as a certain diet, which may only be beneficial depending on the presence of a certain microbiome profile,” he said.
“This is especially true since this study has identified that certain bacteria contribute to the anti-inflammatory potential of a Mediterranean diet,” Turpin added.
The results of this study complement those of a 2020 study that found patients suffering from Crohn’s disease who followed a Mediterranean diet, including olive oil, for six months saw their conditions improve.
Instead of focussing on gut microbiomes, the researchers investigated the relationship between weight and the disease. Obese Crohn’s disease patients following the Mediterranean diet saw their body mass index fall along with the occurrence of their symptoms.