[Perdurat (OP)]

Hello, new to this forum...
I've red somewhere that research has shown that people suffering from inflammation of the stommach lining have an increased population density of the Helicobacter pylori bactery (bacteria).
question that pops my mind: is this bactery causing the inflammation or is it a case of opportunism?(while the immune system fights the inflammation, the bactery sees a chance to increases its population)
Recent (?) study has shown that people suffering from depression (lack of serotonine) have a reduced population of a certain bactery, what is the name of this bactery? Is this bactery responsible for the synthese of serotonine?
apology for faulty grammar/spelling

[evan_au]

is this bactery causing the inflammation or is it a case of opportunism?

85% of people with helicobacter pylori have no symptoms.

However, symptoms are much more common with the strain that has a group of genes that generate proteins which cause cell damage and inflammation.
See: https://en.wikipedia.org/wiki/Helicobacter_pylori#Cag_pathogenicity_island

Is this bactery responsible for the synthese of serotonine?

Serotonin is produced by specialised human cells in the gastro-intestinal tract, and a smaller amount in the central nervous system.

Some gut bacteria do produce serotonin, but it acts as a toxin and produces diarrhea.
See: https://en.wikipedia.org/wiki/Serotonin

The relationship between the gut bacteria and human mood is rather complex.
See: https://en.wikipedia.org/wiki/Gut%E2%80%93brain_axis#Anxiety_and_mood_disorders

[Perdurat (OP)]

thanks for reply
"Some gut bacteria do produce serotonin"
that i didn't found in the wiki page for which you provided the link

[evan_au]

Serotonin is used by a variety of single-cell organisms for various purposes... The gastrointestinal parasite Entamoeba histolytica secretes serotonin, causing a sustained secretory diarrhea in some people.Patients infected with E. histolytica have been found to have highly elevated serum serotonin levels, which returned to normal following resolution of the infection. E. histolytica also responds to the presence of serotonin by becoming more virulent

See: https://en.wikipedia.org/wiki/Serotonin#Unicellular_organisms

Increased serotonin triggers diarrhea and vomiting, whether due to bacterial infection or due to other food poisoning. See the same article.

[Perdurat (OP)]

the skillset required to find on the internet what you are looking for, seems to have reached a higher level of  development within you compaired to me, thanks for making that skillset available.