Mediterranean diet may aid healthy aging by altering microbiomes

Author(s): I. Hoskins, Source: BMJ , Date: 19 February 2020

A multicountry study of elderly people finds that switching to a Mediterranean diet can improve biomarkers of healthy aging in the gut. The study found that consuming the diet for a year, increased populations of bacteria that produce short chain fatty acids and reduced populations of bacteria producing secondary bile acids, p-cresols, ethanol and carbon dioxide compared with controls. The findings suggest that the Mediterranean diet can modulate gut flora in a way that promotes health aging and suggest that direct administration of some bacteria could reduce frailty, say the researchers.

 This study is the latest to come out of a multicountry study of nutrition and aging (Nu-AGE study). Frailty in the elderly is accompanied by inflammation and by alterations in gut microbes and consuming a restricted diet exacerbates these changes, according to the study authors. The Mediterranean diet is rich in vegetables, legumes, fruits, nuts olive oil and fish and low in red meat and saturated fats. Previous work from the NU-AGE project has linked the Mediterranean diet to reduced frailty, including reduced bone loss, improved cognition, lower blood pressure and better immune function (see Further Reading).

The study in 5 European countries profiled gut microbes in elderly people, before and after consuming a Mediterranean diet for a year compared with controls who ate their normal diet. Data were available for 612 people after the study ended.

Sampling gut microbes after a year, the researchers found enrichment of taxa that are positively associated with lower frailty and improved cognition, and negatively associated with inflammation. The researchers inferred that the altered microbiome would produce more short chain fatty acids, which are known to help reduce inflammation.

The results suggest the Mediterranean diet promotes health aging by influencing the gut microbiome.

Some food companies were partners in the project.