Dietary 2′-fucosyllactose enhances operant conditioning and long-term potentiation via gut-brain communication through the vagus nerve in rodents

Abstract

2′-fucosyllactose (2′-FL) is an abundant human milk oligosaccharide (HMO) in human milk with diverse biological effects. We recently reported ingested 2′-FL stimulates central nervous system (CNS) function, such as hippocampal long term potentiation (LTP) and learning and memory in rats. Conceivably the effect of 2′-FL on CNS function may be via the gutbrain axis (GBA), specifically the vagus nerve, and L-fucose (Fuc) may play a role. This study had two aims: (1) determine if the effect of ingested 2′-FL on the modulation of CNS function is dependent on the integrity of the molecule; and (2) confirm if oral 2′-FL modified hippocampal LTP and associative learning related skills in rats submitted to bilateral subdiaphragmatic vagotomy. Results showed that 2′-FL but not Fuc enhanced LTP, and vagotomy inhibited the effects of oral 2′-FL on LTP and associative learning related paradigms. Taken together, the data show that dietary 2′-FL but not its Fuc moiety affects cognitive domains and improves learning and memory in rats. This effect is dependent on vagus nerve integrity, suggesting GBA plays a role in 2′-FL-mediated cognitive benefits.