The study used Clasado Biosciences' patented prebiotic product Bimuno galacto-oligosaccharides (BGOS).
Published in Synapse, the study on rats showed that intake of BGOS in the critical period shortly after birth modulated the expression of key molecules in the brain involved in cognition, disease and neuropsychiatric disorders. These changes lasted into early adulthood in the animals.
Central expression of key proteins such as brain-derived-neurotrophic factor (BDNF) and glutamate N-methyl-D-Aspartate receptors (NMDARs) after birth is critical to normal neural connectivity and function.
Previous studies have shown germ-free mice lacking these proteins, and enteric microbiota, had abnormal behaviour. Microbial re-colonisation of the mice normalised their gene expression and behaviour, but this was only effective if this was done in early life, not adulthood.
The scientists in the current study demonstrated a proof of concept that early life manipulation of gut bacteria influenced adult neurobiology. This supports the idea of a window of opportunity for dietary intervention.
Asked about the prebiotics used, author Philip Burnet from the University of Oxford Department of Psychiatry told NutraIngredients: "We and others have found that galacto-oligosaccharides actually proliferate the bifido-bacteria better than other prebiotics like FOS (fructooligosaccharides) which is why we’ve been using that compound as it’s a more potent proliferator of gut bacteria."
48 suckling male and female rat pups were fed either a solution of BGOS (4 g/kg/day) or a control solution, from post-natal days three to 21.
The rats were culled at either day 22 or day 56 and hippocampal protein extracts were analysed.
Compared to the control group, BGOS-fed rats had elevated proteins key to normal neural function - specifically hippocampal N-Methyl-D Aspartate receptor (NMDAR) GluN2A sub-unit and synaptophysin (SYN) and brain-derived-neurotrophic factor (BDNF). The results were independent of gender.
The study showed effects of early life BGOS persisted into young adulthood in rats. The scientists proposed that BGOS induces an elevation of pre-synaptic glutamate release and an increase in post synaptic GluN2A, which may have resulted in the observed elevation of hippocampal BDNF.
Rather than altering the cellular and synaptic ‘architecture’ of the developing brain, early life BGOS seemed to influence neurotransmission and signalling.
However they said the mechanisms needed further exploration.
Commenting on future research plans, Burnet said: "We’ve just got a grant to follow up that study so we are going to feed animals like we did and grow them up to adulthood, and then test electrophysiology but actual brain function and behaviour and also metabolism to see if their metabolism changes.
"We are now hoping to look at the effect of prebiotics in school children, so school children that might be stressed in particular, 20% of schoolchildren are anxious so we want to do a small experiment to see if it changes anything, performance at school or anxiety," he said.
They also hope to look at schizophrenia as a neurodevelopmental disorder.
"The immediate work now is extending what we’ve just reported, looking at the functional - these changes are all very well in proteins, it’s exciting that there are changes and that they’re sustained after the prebiotics are taken away, but do they cause a difference in function? That’s the main goal at the moment," said Burnet.
Published online ahead of print, doi: 10.1002/syn.21880
“Neonatal Prebiotic (BGOS) Supplementation Increases the Levels of
Synaptophysin, GluN2A-Subunits and BDNF Proteins in the Adult Rat Hippocampus”
Authors: S. Williams et al.