Scientists are learning more and more about the surprising connection between the human gut and the brain.
A new study now suggests that the bacteria living inside our digestive system may affect memory and thinking skills even more strongly in people who struggle to get enough healthy food.
The research was carried out by scientists from the Icahn School of Medicine at Mount Sinai and the University of Iowa. The findings were published in the scientific journal npj Aging. The study is believed to be the first to closely examine how food insecurity may influence the relationship between gut bacteria and cognitive decline.
Cognitive impairment is becoming a major global health problem as populations continue to age. The condition can involve memory loss, trouble concentrating, slower thinking, confusion, and difficulty making decisions. In severe cases, it may progress into dementia-related diseases such as Alzheimer’s disease.
Researchers have already discovered that the gut and the brain constantly communicate with each other through what is often called the “gut-brain axis.”
The digestive system contains trillions of bacteria and other tiny organisms that help digest food, support the immune system, and produce important chemicals that influence many parts of the body, including the brain.
A healthy gut microbiome usually contains many different kinds of bacteria working together in balance. When this balance is disrupted, health problems may develop.
Earlier studies have linked poor gut health to depression, anxiety, obesity, diabetes, heart disease, and neurological disorders. However, scientists still do not fully understand how social conditions, especially access to healthy food, may affect this connection.
In this new study, researchers examined health information from 360 adults who participated in the Survey of the Health of Wisconsin.
The team collected stool samples from participants and studied their gut bacteria using a method called 16S rRNA sequencing. This technology allows scientists to identify different types of bacteria living inside the digestive system.
The researchers also tested the participants’ cognitive abilities, including memory and thinking performance. In addition, they asked questions about food insecurity.
Food insecurity means not always having reliable access to enough healthy and nutritious food. Some people facing food insecurity may skip meals, buy cheaper unhealthy foods, or experience stress and worry about where their next meal will come from.
The results showed a strong pattern. People with less healthy and less diverse gut bacteria were more likely to show signs of cognitive impairment. But the connection became even stronger among people experiencing food insecurity.
The researchers found that certain groups of bacteria appeared to be linked to cognitive problems differently depending on whether people had reliable food access. For example, bacteria such as Eisenbergiella and Eubacterium were more strongly connected to cognitive decline in people who struggled with food insecurity.
At the same time, another bacterial group that included Ruminococcus torques, Bacteroides, and CAG-352F was more strongly associated with cognitive problems in people who were considered food secure.
These findings suggest that the relationship between gut bacteria and brain health may not depend only on biology. Social conditions and daily living situations may also shape how gut microbes affect the brain.
One of the study’s lead authors, Dr. Shoshannah Eggers, explained that food insecurity should not only be viewed as a social problem. According to the researchers, stress, poor nutrition, and unstable eating habits linked with food insecurity may change the gut microbiome in harmful ways that increase the risk of cognitive decline.
This issue is becoming more important because food insecurity is increasing in many communities. In the United States alone, more than 17 million households reported experiencing food insecurity in 2022. That represented more than 12 percent of households nationwide and was higher than the previous year.
Scientists believe this study may help explain one possible biological pathway linking food insecurity to declining brain health. Poor access to nutritious food may lead to unhealthy changes in gut bacteria, which may then affect brain function over time.
The research team also used machine learning technology to identify groups of bacteria that best predicted cognitive outcomes.
Machine learning allows computers to examine large amounts of information and find patterns that humans may miss. In this study, it helped researchers better understand which bacteria seemed most important in predicting cognitive decline.
According to senior author Dr. Vishal Midya, these findings could eventually change how doctors and public health experts think about dementia prevention. If food insecurity changes the way gut bacteria affect the brain, then improving access to nutritious food could become an important strategy for protecting brain health as people age.
The findings also support the idea that health problems are often connected to both biology and social conditions. Preventing cognitive decline may require a combination of medical care, nutrition support, and public health programs that improve access to healthy food.
Researchers say more studies are still needed to better understand exactly how gut bacteria influence the brain and whether changing the microbiome could help prevent or slow cognitive decline in the future.
Scientists are especially interested in whether diet changes, probiotics, or microbiome-based treatments may one day help protect memory and thinking abilities.
This growing field of research is helping scientists better understand that the human body works as one connected system. Brain health may depend not only on genetics or aging, but also on digestion, nutrition, stress, and social conditions.
As rates of dementia and cognitive decline continue to rise around the world, this study highlights the importance of looking beyond traditional medical risk factors. Supporting healthy diets, improving food access, and protecting gut health may all become important parts of future strategies to protect the aging brain.
If you care about brain health ,please read studies about Vitamin B9 deficiency linked to higher dementia risk, and cranberries could help boost memory.
For more health information, please see recent studies about heartburn drugs that could increase risk of dementia, and results showing this MIND diet may protect your cognitive function, prevent dementia.
The research findings were published in the journal npj Aging.
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