The researchers have previously reported that Bifidobacterium longum 1714 and B. breve 1205 may decrease anxiety in lab mice, and they take that research further in their new study with data showing strain specific effects
“In the present study, we show that certain Bifidobacteria strains and B. longum 1714 in particular, are able to induce some positive effects on cognition in fear-related cognitive tasks, possibly by decreasing anxiety in mice,” they wrote in Behavioural Brain Research.
“To the best of our knowledge, this is one of the first studies showing that commensal bacteria can benefit cognition in healthy animals (i.e. without previous physiological intervention such as gut bacterial infection or stress event).”
Gut-brain axis
Data from animal and human studies have suggested that probiotics may exert anti-anxiety benefits, and a recent review published in the Neuropsychiatric Disease and Treatmentby Linghong Zhou and Jane Foster from McMaster University in Canada Using said that probiotics and prebiotics may alter the gut microbiota and influence the gut-brain axis to possibly open up new ways of influencing neuropsychological conditions.
As reported last week on NutraIngredients-USA, increased intakes of fermented foods were reported to be associated with fewer symptoms of social anxiety, particularly for people at higher genetic risk. That study, which was published in Psychiatry Research, was said to be the first report connecting the consumption of natural fermented foods and anxiety.
Study details
For the new study, scientists from University College Cork and Alimentary Health Ltd. in Cork investigated the potential of B. longum 1714 and B. breve 1205 to change cognitive processes in adult male BALB/c mice.
The lab animals received daily supplements of B. longum 1714, B. breve 1205 or control for 11 weeks. Led by Helene Savignac, the researchers subjected the animals to a series of cognitive tests starting at week 4.
Result showed that the B. longum 1714-fed mice performed significantly better than the others in an object recognition test, while the B. breve 1205-fed mice performed better than the control mice.
The researchers also subjected the mice to the Barnes maze, which measures spatial learning and memory, and found that the B. longum 1714-fed mice made fewer errors than the other animals, “suggesting a better learning”, they said.
Better learning and memory was also displayed by B. longum 1714-fed mice in the fear conditioning test.
'A new role for the enteric microbiota'
“There is thus a strong possibility that B. Longum 1714 positively modulated BALB/c behaviour by decreasing their anxiety,” wrote the researchers. “These data confirm that commensal bacteria effects are highly strain-specific but above all that bacteria and the enteric microbiota can also have an impact on cognition, in an unperturbed healthy mouse.
“These findings show a new role for the enteric microbiota and suggest a potential therapeutic approach for treating cognitive deficits associated with stress-related or neurodegenerative diseases, above all as we found evidences of positive impact from B. Longum 1714 in the hippocampus, one of the first brain regions impacted in Alzheimer's disease.
“Therefore, it will be of high interest in further studies to investigate and characterize the molecular mechanisms behind these commensal bacteria's action on behavior.”
Source: Behavioural Brain Research
1 July 2015, Volume 287, Pages 59–72, doi: 10.1016/j.bbr.2015.02.044
“Bifidobacteria modulate cognitive processes in an anxious mouse strain”
Authors: H.M. Savignac, M. Tramullas, B. Kiely, T.G. Dinan, J.F. Cryan