Food insecurity and gut microbiome imbalance linked to reduced brain function

In a recent study, US adults with lower microbial diversity and specific gut bacteria imbalances were significantly more likely to experience cognitive impairment. The authors also found that food insecurity was independently associated with both poorer gut health and reduced cognitive performance. 

The analysis, led by Mount Sinai researchers, is the “first epidemiologic study” to assess how food insecurity impacts the relationship between the gut microbiome and the risk of cognitive impairment. 

“Food insecurity is consistently linked to adverse health outcomes such as poorer overall health and adverse neurological health outcomes. Understanding how gut health and social conditions interact gives us a fuller picture of what puts people at risk for cognitive decline,” says co-author Dr. Shoshannah Eggers, assistant professor of Epidemiology at the University of Iowa College of Public Health, US. 

The researchers used data from 360 adults in the Survey of the Health of Wisconsin on participants’ food insecurity, risk of cognitive impairment, and 16S rRNA sequencing, which is used to determine bacteria in a stool sample. 

Gut microbiome imbalance

For the paper published in NPJ Aging, the researchers identified microbial cliques (small groups of closely connected microbes) associated with the risk of cognitive impairment through a machine-learning-based algorithm. This model makes predictions or decisions and informs researchers how and why it made those predictions. 

The team stratified all analyses by food insecurity level and adjusted them for relevant confounders, such as age, body mass index, and smoking. 

For two of these microbial cliques, the associations with cognitive impairment risk were modified by food security status. 

The researchers identified microbial cliques associated with the risk of cognitive impairment, modified by food security.Food-insecure participants with a clique containing either Eisenbergiella or Eubacterium were more strongly associated with cognitive impairment risk, while in the food-secure group, the researchers found a stronger association in cliques containing Ruminococcus torques, Bacteroides, CAG-352F, and/or Eubacterium. 

New microbial interventions

The study’s authors note their findings may be necessary when developing microbial interventions for cognitive impairment, as they indicate food security status may alter the effectiveness of such interventions. 

The findings are timely as the US Department of Agriculture warned of a rise in food insecurity among US households from 2022 to 2023 of almost 5.5%. In 2023, 13.5% of US households were food insecure “at least sometime during the year.” In addition, researchers suggested that decreasing food insecurity in older US adults may decrease the rate of cognitive decline. 

“These findings suggest that food insecurity is not just a socioeconomic issue — it may be a biological one too, influencing brain health via changes to the gut microbiome,” says senior author Vishal Midya, Ph.D., assistant professor of Environmental Medicine at the Icahn School of Medicine at Mount Sinai. 

“Cognitive impairment, including mild cognitive impairment and dementia, is increasing, particularly among older adults, and is primarily driven by an aging population. Future studies investigating why cognitive problems develop in people should consider food insecurity as one possible contributing factor.”

The authors call for more effective public health interventions to prevent cognitive impairment by addressing nutritional access and gut health. 

The authors call for more effective cognitive public health interventions by addressing nutritional access and gut health.They suggest further investigations focus on mechanisms by which these microbial cliques affect the central nervous system and how food insecurity modifies those pathways. 

Brain health nutrition

Scientific research is exploring links between diet and cognitive impairment. For example, scientists linked higher processed red meat consumption to increased risk of dementia and cognitive decline. At the same time, they suggest that replacing red meat with nuts, fish, or poultry may reduce the risk. 

Moreover, researchers linked ultra-processed foods to early signs of the neurodegenerative disorder Parkinson’s disease, although experts advised caution in interpreting its findings. 

At the same time, scientists have identified a specific nutrient profile based on the Mediterranean diet that may slow brain aging. This nutritional lifestyle rich in fruits, vegetables, whole grains, omega-3 fatty acids, plant protein, and unsaturated fats has previously been linked with healthy brains. 

Specifically, the MIND diet, a combination of the Mediterranean and Dietary Approaches to Stop Hypertension diets, has been linked to reduced risk of cognitive decline.