Ingestion of Lactobacillus strain regulates emotional behavior
and central GABA receptor expression in a mouse via the vagus nerve
Proceedings of the National Academy of Sciences of the United
States of America Impact factor: 9.674 Javier A. Bravoa,1,Paul
Forsytheb,c,1,Marianne V. Chewb,Emily Escaravageb,Hlne M.
Savignaca,d,Timothy G. Dinana,e,John Bienenstockb,f,2, andJohn F.
Cryana,d,g,2 PANS9.64707/2011 GABA Abstract There is increasing,
but largely indirect, evidence pointing to an effect of commensal
gut microbiota on the central nervous system (CNS). However, it is
unknown whether lactic acid bacteria such asLactobacillus
rhamnosuscould have a direct effect on neurotransmitter receptors
in the CNS in normal, healthy animals CNS, MGB axis
(microbiotagutbrain axis)
1AMGBCNS;1234AMHY5--HPA6/BMGBMcKernan2010;Wang2010;Clarke2012Adams2011;Theije2011;2012;Wang2012TurnbaughGordon2009;2012;20122013/Bravo2011;Heijtz2011;2013Berer2011;Lee2011
Alterations in central GABA receptor expression are implicated in
the pathogenesis of anxiety and depression, which are highly
comorbid with functional bowel disorders. GABAGABA GABA GABA
GABA-AminoButyricAcidGABAGABAGABA GABA GABA GABA ,,GABA GABA(GABA
receptor)
GABAGABAAGABABGABACGABAAGABAcligand-gated ion
channels(ionotropic)GABABG-protein coupled
receptors(metabotropic)GABAAGABAGABAAGABACl-Cl- GABAAionotropic
receptor barbituratesbenzodiazepinesGABA receptorallosteric
modificationGABAGABA barbituratesbenzodiazepinesbenzodiazepines
GABA receptor GABAA: GABAA:GABAAGABA[1] GABAA: GABAAN-:
GABAACl-GABA1212 GABABmetabotropic receptor Lactobacillus rhamnosus
( JB-1 )
One such organism is Lactobacillus rhamnosus ( JB-1 ), which has
been demonstrated to modulate the immune system because it prevents
the induction of IL-8 by TNF- in human colon epithelial cell lines
(T84 and HT-29) ( 17 ) and modulates inflammation through the
generation of regulatory T cells ( 18 ). Moreover, it inhibits the
cardioautonomic response to colorectal distension (CRD) in rats (
19 ), reduces CRD-induced dorsal root ganglia excitability ( 20 ),
and affects small intestine motility ( 21 ).
JB-1IL-8TNF-T84HT-2917T18 CRD19CRD2021 L.rhamnosus ( JB-1 ) --
Materials and Methods Animals. Adult male BALB/c mice (n = 36) All
of the animals were allowed to acclimate for Z 7 d in the housing
facility before the experiment. Animals were grouphoused (nine
animals per cage) in standard conditions (room temperature of 21 C,
with a 12-h lightdark cycle, lights on at 07:00) with access to
regular chow and water ad libitum. Cages were cleaned once weekly
to avoid excessive handling. Mice were of comparable weight (2530
g) and age (1011 wk) at the moment of sacrifice. BALB / cn = 36 $ 7
grouphoused 9 2112 07:00 25-3010-11 Treatments and Sacrifice
Animals were orally gavaged with broth without bacteria (broth
control group, n = 16) or with L.rhamnosus (JB-1) [109 cfu; L.
rhamnosus (JB-1) group, n = 16]. This procedure was carried out
daily between 8:00 and 9:00 for a period of 28 continuous d. Toward
the end of the treatment, the animals underwent a series of
behavioral testing including SIH, EPM, and fear conditioning. In
addition, on the day samples were collected, half of the animals in
each group were put in the FST [broth, n = 8; L. rhamnosus (JB-1),
n = 8] to evaluate behavior and also to measure stress-induced
levels of corticosterone. All of the animals were killed by
cervical dislocation; the head was rapidly removed, and trunk blood
was collected into EDTA-containing tubes for separating plasma.
Animals that were not used for FST were killed between 8:00 and
9:00, while the FST stressed groups were killed 30 min after the
end of the forced swim session (9:3011:45). For each behavioral
test, the experimenter was blinded to the treatment of each animal.
n = 16L JB-1[109 cfu;JB-1n = 16] 8:00 9 28 SIHEPM FST [n = 8;JB-1n
= 8] ; EDTA FST 8:009:00 FST30 930-1145 Bacterial Preparation
S6JB -1GGAFLP(AFLP )E01 / T11E01 / T13 AFLP DNAA JB- 1 LR JB -1GG
LR GG GeneMapper 4.0 Applera Results rhamnosus ( JB-1 )
Administration
rhamnosus ( JB-1 ) had a larger number of entries to the open arms
than broth-fed animals, suggesting anxiolytic effects (open arm
entry defined as all four paws entering the arms of the EPM
apparatus) ( t = 4.662, df = 34; P < 0.001; Fig. 1 A ). This
effect is also reflected in the percentage of time spent in the
open arms, although this observation did not reach statistical
significance [broth v. L. rhamnosus ( JB-1 ): 6.67% vs 7.99%; t =
1.267, df = 34; P = ]. L.JB-1 SIHEPMGABA2223L.JB-1SIH= 1.567DF
=34P= ;1EPML.JB-1EPM= 4.662= 34 ;P