In the pursuit of addressing the prevailing obesity crisis, scientists have uncovered a significant finding: intermittent calorie restriction yields notable transformations both within the gastrointestinal tract and the human brain, potentially offering fresh avenues for maintaining a healthy body weight.
A recent study conducted by researchers from China focused on 25 individuals categorized as obese over a span of 62 days. During this period, participants engaged in an intermittent energy restriction (IER) regimen, characterized by meticulous control of calorie consumption and intermittent fasting on select days.
The outcomes revealed not only substantial weight loss among participants – averaging 7.6 kilograms (16.8 pounds) or 7.8 percent of their total body weight – but also discernible alterations in the activity of brain regions associated with obesity and shifts in gut microbiota composition.
“When the results were unveiled in December 2023, health researcher Qiang Zeng from the Second Medical Center and National Clinical Research Center for Geriatric Diseases in China stated, ‘Here we show that an IER diet changes the human brain-gut-microbiome axis. The observed changes in the gut microbiome and in the activity in addiction-related brain regions during and after weight loss are highly dynamic and coupled over time.'”
Although the precise mechanisms underlying these changes remain ambiguous, it is evident that a bidirectional relationship exists between the gut and the brain. Consequently, targeting specific brain regions could potentially serve as a means to regulate food consumption.
Functional magnetic resonance imaging (fMRI) scans unveiled alterations in brain activity within regions crucial for appetite and addiction regulation, such as the inferior frontal orbital gyrus. Furthermore, changes in gut microbiota, assessed through stool samples and blood analysis, exhibited correlations with distinct brain regions.
“For example, the bacteria Coprococcus comes and Eubacterium hallii were negatively associated with activity in the left inferior frontal orbital gyrus, an area involved in executive function, including our willpower when it comes to food intake,” explained medical scientist Xiaoning Wang from the State Clinic Center for Geriatrics in China.
The intricate interplay between the gut microbiome and the brain operates through a complex, bidirectional communication pathway. The microbiome produces neurotransmitters and neurotoxins that access the brain through nerves and the bloodstream, influencing eating behavior, while dietary nutrients shape the composition of the gut microbiome.
Given that over a billion individuals worldwide grapple with obesity, which significantly escalates the risk of various health complications ranging from cancer to cardiovascular diseases, understanding the symbiotic relationship between the brain and the gut holds immense potential in effectively preventing and mitigating obesity.
“The next question to be answered is the precise mechanism by which the gut microbiome and the brain communicate in obese people, including during weight loss,” emphasized biomedical scientist Liming Wang from the Chinese Academy of Sciences. “What specific gut microbiome and brain regions are critical for successful weight loss and maintaining a healthy weight?”
The findings of this study were published in Frontiers in Cellular and Infection Microbiology.