Introduction:
Blastocystis is a genetically diverse unicellular parasite that
colonizes the intestines of humans and a wide range of animals. The
organism’s basic biology is poorly understood, and controversy surrounds
its taxonomy and pathogenicity. Although just three morphological
forms—vacuolar, granular, and ameboid—have been identified, recent
research has discovered more forms—cyst, avacuolar, and multivacuolar
[1].
The organism is categorized as a stramenopile based on molecular
evidence, similar to diatoms, chrysophytes, water molds, and slime nets
[2].
It is customary to refer to Blastocystis organisms isolated from humans
as B. hominis. However, due to low host specificity and significant
genetic variation, the name Blastocystis species is thought to be more
suitable. The subtype (ST), if genetic typing is performed, should also
be recorded. Among the nine STs identified in humans, the four most
common are ST1, ST2, ST3, and ST4. Several other STs might be connected
to zoonotic transmission [2].
Infections occur worldwide in both immunocompetent and immunodeficient
individuals. Blastocystis may be transmitted through food, water, or
contact with human or animal feces. It is more common among people who
live in or travel to developing countries and those who work with
animals. B. hominis infection typically causes non-specific symptoms
such as watery diarrhea, nausea, abdominal pain, bloating, excessive
gas, loss of appetite, weight loss, anal itching, and fatigue.
Metronidazole is advised as the antibiotic of choice if therapy seems
necessary, despite reports of its inability to completely eradicate the
organism [1].
Case reports have suggested a pathogenic role of B. hominis in causing
intestinal inflammation and linking it to irritable bowel syndrome (IBS)
and inflammatory bowel disease (IBD) [3].
This case report explores the relationship between Blastocystis hominis
and its potential exacerbation of Parkinson’s disease symptoms through
gut microbiota dysbiosis. By examining the case of an elderly male with
Parkinson’s disease who developed severe gastrointestinal symptoms
alongside worsening motor function, we aim to shed light on how
microbial disturbances in the gut may influence neurological conditions,
offering insights into potential therapeutic avenues.