Bacteria in the gut that form the microbiota affect intelligence
Researchers from the José Mate Institute of Nutrition and Food Technology and the Institute of Neurosciences of the University of Granada, in collaboration with the Helmholtz Center for Environmental Research in Leipzig, have shown that microbiota contributes to the development of cognitive functions (intelligence and memory). ) through probiotic microorganisms and histidine metabolites.
The results of this study open the possibility of developing new innovative treatments to improve children’s neurodevelopment through the use of probiotic compounds or microorganisms.
The research work, coordinated by Antonio Suarez, professor of biochemistry and molecular biology at UGR, was published in the latest issue of the scientific journal. Host cell and microbe.
Over the past decade, the realization that the microbiota regulates the physiology and activity of the central nervous system has revolutionized biomedicine by demonstrating the existence of a bidirectional connection between chemical messengers, neuronal pathways, and the immune system, called the “microbiota-brain axis.” .
Some studies have also shown that its alteration is associated with diseases of the nervous system (autism), neurodegenerative diseases (Parkinson’s disease, Alzheimer’s disease, multiple sclerosis) and behavioral diseases (anxiety, depression, attention deficit hyperactivity disorder). However, to date, the mechanisms linking the microbiota and the development of the nervous system in children are not known.
Probiotics, histidine and cognitive development
Those responsible for the study were able to notice that the composition of the microbiota in 6-month-old infants differed depending on their cognitive response to the Bayley test, which measures motor, cognitive, social-emotional and language development. They also found that the function of the microbiota also varied, with histidynamia lyase or histidase present in the microbiota associated with cognitive performance in infants. This enzyme belongs to histidine metabolism, which has previously been linked to cognitive performance. Support for this association was obtained by observing that histidine metabolite profiles differed as a function of infant cognitive behavior.
To carry out the experimental tests, the researchers transplanted the microbiota of infants into axenic or germ-free mice provided by the Animal Experimentation Unit of the UGR Center for Scientific Instrumentation, the only institution with this type of mice in Spain.
Special experimental model
Germ-free mice are a special experimental model because they are born germ-free and live in a completely sterile, free environment. These mice provide one of the most compelling tests of the relationship between microbiota and the brain, as the absence of microbiota causes changes in neurotransmitters, synaptogenesis and brain volumes, leading to changes in their motor activity, behavior and memory compared to normal mice. provided with their microbiota.
In an object recognition test traditionally used in mouse models, mice fed the microbiota of infants with better cognitive abilities showed greater memory capacity than children with poorer cognitive abilities. Subsequent analyzes showed that bacteria from the genera Phocaeicola, Bacteroides and Bifidobacterium were positively associated with intelligence and memory. Finally, the researchers were also able to verify that the mice had different ratios of urocanate, glutamate and histidine metabolites in the perirhinal cortex, which controls memory, bringing the molecular mechanism full circle.
Following the discovery of the molecular mechanism, these results suggest that probiotic Bifidobacterium and histidine metabolites, independently or in combination, may improve children’s memory and cognition, especially in childhood diseases with cognitive impairment such as autism or hyperactivity disorder.
The importance of microbiota for health
Microbiota is a collection of millions of microorganisms that coexist with us in symbiosis, mainly in our digestive tract. Understanding and maintaining a healthy microbiota balance is essential to human well-being as it plays a critical role in health, influencing processes such as digestion and nutrient absorption, regulation of the immune system, regulation of metabolism, and energy absorption. , synthesis of vitamins and neurotransmitters, barrier function of the intestinal mucosa, protection against pathogens and regulation of the inflammatory response.
Link: Cerdo T., Ruiz-Rodriguez A., Acuña I., Torres-Espinola F.J., Maenchen-Marquez S., Gamis F., Gallo M., Jemlich N., Haange S.B., von Bergen M. , Campoy S., Suarez A. “Infant Gut Microbiota Promotes Cognitive Performance.” performance in mice.” Magazine Host cell Microbe, November 2023 | DOI: 10.1016/zh.chom.2023.11.004.