Glutamate interactions with obesity, insulin resistance, cognition and gut microbiota composition

• Published in: Acta diabetologica Vol. 56; no. 5; pp. 569 - 579
• Main Authors: Palomo-Buitrago, María Encarnación, Sabater-Masdeu, Mònica, Moreno-Navarrete, Jose Maria, Caballano-Infantes, Estefanía, Arnoriaga-Rodríguez, María, Coll, Clàudia, Ramió, Lluís, Palomino-Schätzlein, Martina, Gutiérrez-Carcedo, Patricia, Pérez-Brocal, Vicente, Simó, Rafael, Moya, Andrés, Ricart, Wifredo, Herance, José Raúl, Fernández-Real, José Manuel
• Format: Journal Article
• Language: English
• Published: Milan Springer Milan 09-05-2019; Springer Nature B.V
• Subjects: Acetic acid; Cognitive ability; Corynebacteriaceae; Diabetes; Executive function; Feces; Glutamine; Gut Microbiome and Metabolic Disorders; Information processing; Insulin; Insulin resistance; Internal Medicine; Intestinal microflora; Medicine; Medicine & Public Health; Metabolic Diseases; Microbiota; Obesity; Original Article; Plasma; Processing speed; Metabolomics; Microbiota; Cognition; Glutamate; Trail making test
• ISSN: 0940-5429; 1432-5233
• DOI: 10.1007/s00592-019-01313-w

Aims
To investigate the interactions among fecal and plasma glutamate levels, insulin resistance cognition and gut microbiota composition in obese and non-obese subjects.
Methods
Gut microbiota composition (shotgun) and plasma and fecal glutamate, glutamine and acetate (NMR) were analyzed in a pilot study of obese and non-obese subjects (
n
 = 35). Neuropsychological tests [Trail making test A (TMT-A) and Trail making test B (TMT-B)] scores measured cognitive information about processing speed, mental flexibility and executive function.
Results
Trail-making test score was significantly altered in obese compared with non-obese subjects. Fecal glutamate and glutamate/glutamine ratio tended to be lower among obese subjects while fecal glutamate/acetate ratio was negatively associated with BMI and TMT-A scores. Plasma glutamate/acetate ratio was negatively associated with TMT-B. The relative abundance (RA) of some bacterial families influenced glutamate levels, given the positive association of fecal glutamate/glutamine ratio with Corynebacteriaceae, Coriobacteriaceae and Burkholderiaceae RA. In contrast, Streptococaceae RA, that was significantly higher in obese subjects, negatively correlated with fecal glutamate/glutamine ratio. To close the circle, Coriobacteriaceae/Streptococaceae ratio and Corynebacteriaceae/Streptococaceae ratio were associated both with TMT-A scores and fecal glutamate/glutamine ratio.
Conclusions
Gut microbiota composition is associated with processing speed and mental flexibility in part through changes in fecal and plasma glutamate metabolism.