A recent study, partially led by researchers at Mount Sinai, has unveiled a significant relationship between the composition of the gut microbiome and the risk of cognitive impairment (RCI) in adults. This work highlights the intricate interplay between biological systems and social determinants of health, particularly food insecurity, in shaping brain health outcomes. Importantly, it is the first epidemiologic investigation to examine how food insecurity may alter the connection between gut microbiota composition and cognitive decline.
Published in NPJ Aging, the study examines the role of food insecurity as a modifier of the association between specific microbial groups in the gut and the risk of cognitive impairment. The researchers found that adults with reduced microbial diversity and specific bacterial imbalances were notably more likely to experience cognitive dysfunction. Additionally, food insecurity—defined as limited or uncertain access to nutritionally adequate and safe food—was independently associated with both compromised gut microbiome profiles and diminished cognitive performance, reinforcing its dual role as a social and biological stressor.
Dr Shoshannah Eggers, Assistant Professor of Epidemiology at the University of Iowa College of Public Health and the study’s corresponding author, began this research while serving as a Postdoctoral Fellow at the Icahn School of Medicine at Mount Sinai. “In 2022, over 12 percent of U.S. households—equating to 17 million—experienced food insecurity at some point during the year, an increase from 10.2 percent the previous year,” Dr Eggers noted. “This consistent link between food insecurity and poor health outcomes, including adverse neurological outcomes, demands we examine how physiological systems like the gut microbiome interact with social conditions to influence brain health.”
The research cohort comprised 360 adults from the Survey of the Health of Wisconsin, each providing complete data on food insecurity status, cognitive function assessments, and stool samples for 16S rRNA gene sequencing—an established method for identifying bacterial taxa present in the gut. Using an interpretable machine-learning algorithm, the team was able to detect small networks of co-occurring bacteria, or “microbial cliques,” associated with cognitive impairment. This algorithm not only predicted associations but also provided insight into the underlying structure of those predictions, thereby enhancing interpretability and scientific transparency.
Analyses were stratified by food security status and adjusted for relevant confounders, including age, body mass index (BMI), and smoking status. The researchers identified two microbial cliques whose relationships with cognitive impairment varied depending on participants’ food security levels. For individuals experiencing food insecurity, a microbial group containing Eisenbergiella or Eubacterium exhibited a stronger association with cognitive decline. Conversely, among food-secure individuals, a different clique—comprising Ruminococcus torques, Bacteroides, CAG-352F, and Eubacterium—was more strongly linked to cognitive impairment.
These contrasting microbial signatures between the two groups suggest that the gut-brain axis is modulated not only by microbial composition but also by contextual factors such as nutritional access. According to the study’s senior author, Dr Vishal Midya, Assistant Professor of Environmental Medicine at the Icahn School of Medicine at Mount Sinai, this nuanced interaction implies that future microbiome-based interventions may need to account for food security status. “These findings suggest that food insecurity transcends socioeconomic boundaries and may exert biological effects that influence brain health through the gut microbiome,” Dr Midya stated. “With the prevalence of cognitive impairment rising, especially among older adults, integrating food insecurity into etiological models of cognitive decline is increasingly urgent.”
In light of these findings, the study advocates for more holistic public health strategies that address both dietary accessibility and microbial health. Interventions that pair nutritional support with targeted modulation of the gut microbiome—such as through diet, probiotics, or prebiotics—could potentially mitigate the risk of cognitive decline in populations most vulnerable to both malnutrition and neurological disorders. As our understanding of the gut-brain axis deepens, incorporating social determinants of health into biological research will be vital in developing inclusive and effective public health solutions.
More information: Shoshannah Eggers et al, Food insecurity modifies the association between the gut microbiome and the risk of cognitive impairment in adults, npj Aging. DOI: 10.1038/s41514-025-00241-0
Journal information: npj Aging Provided by The Mount Sinai Hospital / Mount Sinai School of Medicine
