Multi-Strain Probiotic Shown to Influence Functional Connectivity in the Brain
The gut–brain axis is the biochemical signaling that takes place between the gastrointestinal tract and the central nervous system. A new study suggests that supplementation with a variety of probiotic strains may have an effect on functional connectivity in the brain. The results indicate an influence of probiotic administration not only on emotional processes, but other cognitive processes as well.
Participants included 45 healthy, right-handed adults. One-third
took a multi-strain probiotic, one-third took a placebo, and one-third took nothing
daily for four weeks. The multi-strain probiotic contained nine bacterial
strains; Lactobacillus casei W56, Lactobacillus acidophilus W22,
Lactobacillus paracasei W20, Bifidobacterium lactis W51, Lactobacillus
salivarius W24, Lactococcus lactis W19, Bifidobacterium lactis W52,
Lactobacillus plantarum W62 and Bifidobacterium bifidum W23.
Participants underwent two brain MRI scans, one at baseline and
one at the end of the study. They also filled out daily diaries regarding their
gastrointestinal symptoms and details about their probiotic or placebo intake.
At the end of the study period, participants in the probiotic
group showed changes in functional connectivity in several networks in the brain,
including the default mode network, the salience network, the visual network,
and the middle and superior frontal gyrus network. No changes in functional connectivity
were seen in the placebo or control group. No structural changes were seen in
any of the groups.
The study was conducted by researchers from the University of
Graz. It was published online ahead of print on May 30, 2019 in the European
Journal of Nutrition.