Intestinal Bacteria Produce Neurotransmitter, Could Play Role In Inflammation

[Guest guest]

Intestinal Bacteria Produce Neurotransmitter, Could Play Role In

Inflammation

Monday, June 18, 2012

Source : American Society for Microbiology

Researchers at Baylor College of Medicine and Texas Children's Hospital

have

identified commensal bacteria in the human intestine that produce a

neurotransmitter

that may play a role in preventing or treating inflammatory bowel

diseases such as

Crohn's disease.

" We identified, to our knowledge, the first bifidobacterial strain,

Bifidobacterium

dentium, that is capable of secreting large amounts of

gamma-aminobutyric acid

(GABA). This molecule is a major inhibitory neurotransmitter in the

central and

enteric nervous systems, " says Karina Pokusaeva, a researcher on the

study and a

member of the laboratory of Versalovic.

GABA is one of the chief inhibitory neurotransmitters in the human

central nervous

system. It plays a role in regulating pain and some pain relieving drugs

currently

on the market act by targeting GABA receptors on neural cells.

Pokusaeva and her colleagues were interested in understanding the role

the human

microbiome might play in pain and scanned the genomes of potentially

beneficial

intestinal microorganisms, identified by the Human Microbiome Project,

for evidence

of a gene that would allow them to create GABA.

" Lab analysis of metagenomic DNA sequencing data allowed us to

demonstrate that

microbial glutamate decarboxylase encoding gene is very abundant in

intestinal

microbiota as compared to other body sites, " says Pokusaeva. One of the

most

prolific producers of GABA was B. dentium, which appears to secrete the

compound to

help it survive the acid environment.

In addition to its pain modulating properties, GABA may also be capable

of

inhibiting inflammation. Recent studies have shown that immune cells

called

macrophages also possess GABA receptors. When these receptors were

activated on the

macrophages there was a decrease in the production of compounds

responsible for

inflammation.

" Our lab was curious to explore if GABA produced by intestinal human

isolate B.

dentium could have an effect on GABA receptors present in immune cells, "

says

Pokusaeva. Together with their collaborators Dr. Yamada and Dr.

Lacorazza they found

that when the cells were exposed to secretions from the bacteria, they

exhibited

increased expression of the GABAA receptor in the immune cells.

While the findings are preliminary, they suggest the possibility that B.

dentium and

the compounds it secretes could play a role in reducing inflammation

associated with

inflammatory bowel diseases.

The next step, says Pokusaeva is to conduct in vitro experiments to

determine if the

increased GABAA expression correlates with a decrease in production of

cytokines

associated with inflammation. GABAA receptor signaling may also

contribute to pain

signaling in the gut and may somehow be involved in abdominal pain

disorders.

" Our preliminary findings suggest that Bifidobacterium dentium could

potentially

have an inhibitory role in inflammation; however more research has to be

performed

to further prove our hypothesis, " says Pokusaeva

[Guest guest]

This is very interesting Natasa, thank you for posting it, i dont suppose there

are any probiotics around that contain Bifidobacterium

dentium, does anyone know, Mandi......?

N x

>

>

> Intestinal Bacteria Produce Neurotransmitter, Could Play Role In

> Inflammation

>

> Monday, June 18, 2012

>

> Source : American Society for Microbiology

>

> Researchers at Baylor College of Medicine and Texas Children's Hospital

> have

> identified commensal bacteria in the human intestine that produce a

> neurotransmitter

> that may play a role in preventing or treating inflammatory bowel

> diseases such as

> Crohn's disease.

>

> " We identified, to our knowledge, the first bifidobacterial strain,

> Bifidobacterium

> dentium, that is capable of secreting large amounts of

> gamma-aminobutyric acid

> (GABA). This molecule is a major inhibitory neurotransmitter in the

> central and

> enteric nervous systems, " says Karina Pokusaeva, a researcher on the

> study and a

> member of the laboratory of Versalovic.

>

> GABA is one of the chief inhibitory neurotransmitters in the human

> central nervous

> system. It plays a role in regulating pain and some pain relieving drugs

> currently

> on the market act by targeting GABA receptors on neural cells.

>

> Pokusaeva and her colleagues were interested in understanding the role

> the human

> microbiome might play in pain and scanned the genomes of potentially

> beneficial

> intestinal microorganisms, identified by the Human Microbiome Project,

> for evidence

> of a gene that would allow them to create GABA.

>

> " Lab analysis of metagenomic DNA sequencing data allowed us to

> demonstrate that

> microbial glutamate decarboxylase encoding gene is very abundant in

> intestinal

> microbiota as compared to other body sites, " says Pokusaeva. One of the

> most

> prolific producers of GABA was B. dentium, which appears to secrete the

> compound to

> help it survive the acid environment.

>

> In addition to its pain modulating properties, GABA may also be capable

> of

> inhibiting inflammation. Recent studies have shown that immune cells

> called

> macrophages also possess GABA receptors. When these receptors were

> activated on the

> macrophages there was a decrease in the production of compounds

> responsible for

> inflammation.

>

> " Our lab was curious to explore if GABA produced by intestinal human

> isolate B.

> dentium could have an effect on GABA receptors present in immune cells, "

> says

> Pokusaeva. Together with their collaborators Dr. Yamada and Dr.

> Lacorazza they found

> that when the cells were exposed to secretions from the bacteria, they

> exhibited

> increased expression of the GABAA receptor in the immune cells.

>

> While the findings are preliminary, they suggest the possibility that B.

> dentium and

> the compounds it secretes could play a role in reducing inflammation

> associated with

> inflammatory bowel diseases.

>

> The next step, says Pokusaeva is to conduct in vitro experiments to

> determine if the

> increased GABAA expression correlates with a decrease in production of

> cytokines

> associated with inflammation. GABAA receptor signaling may also

> contribute to pain

> signaling in the gut and may somehow be involved in abdominal pain

> disorders.

>

> " Our preliminary findings suggest that Bifidobacterium dentium could

> potentially

> have an inhibitory role in inflammation; however more research has to be

> performed

> to further prove our hypothesis, " says Pokusaeva

>