Study explores how gut microbial populations impact cognitive function

A greater abundance of gut bacteria from the phylum Bacteriodetes is associated with better cognitive function in adults, says a new study from researchers at the University of Illinois at Urbana-Champaign.

Women with a greater abundance of Bacteriodetes performed better when faced with greater cognitive demand than women with lower abundance, according to data presented this week at the Experimental Biology 2017 event in Chicago.

“A converging body of literature demonstrates that the gastrointestinal microbiota are implicated in multiple aspects of health including cognitive function and brain health. However, this evidence is largely based on rodent models and there is a paucity of data linking characteristics of the gastrointestinal microbiota profiles and cognitive function in humans,” explained the researchers in their abstract, published in the FASEB Journal.

“These results indicate that women with greater relative abundances of Bacteriodetes exhibited greater ability to maintain cognitive performance when faced with greater task demands. These findings are among the first to relate bacterial phylogenetic characteristics to executive function among adult humans.”

Study details

The U of I researchers analyzed data from 34 women aged between 25 and 45. The cohort included women who were normal weight and also overweight and obese, which is known to affect microbial populations.

Correlation of data from fecal sample analysis and tests of cognitive function revealed that Bacteroidetes and Firmicutes were differentially associated with interference control measures.

Probiotic-bacteria.jpg
The Bacteroidetes to Firmicutes ratio is reportedly a good biomarker for obesity, with data from a 2005 study by Jeffrey Gordon and his group at Washington University in St. Louis indicated that obese mice had lower levels of Bacteroidetes and higher levels of Firmicutes, compared with lean mice. Image © iStock

Accuracy interference (or how accurate people can be with their cognitive tasks when faced with interference, and higher scores are associated with poorer cognitive control) was inversely associated with Bacteroidetes and the ratio of Bacteroidetes to Firmicutes. The researchers also found an inverse association between reaction time interference (how reaction times are impacted when faced with interference) and Bacteroidetes and the ratio of Bacteroidetes to Firmicutes.

“These findings are among the first to relate bacterial phylogenetic characteristics to executive function among adult humans. Further study is required to elucidate a causal relationship between dietary manipulation of microbiota composition and changes in selective aspects of cognitive performance,” wrote the researchers.

Source: FASEB Journal

April 2017, 31:965.34

“Gastrointestinal Microbiota and Cognitive Function in Adult Females”

Authors: A.M. Taylor et al.