Stroke: Intestinal flora imbalance, or closely related to the rupture of hemangioma

The incidence of unruptured intracranial aneurysms (UIAs) is 3%
.
At the time of rupture, ≈50% of patients will die, and 50% of surviving patients will have serious complications
.
Chronic inflammation plays an important role in the rupture of cerebral aneurysms (CA)
.
Some human CA pathology studies and animal models have demonstrated the presence of inflammatory cells and mediators in the CA wall, and subsequent structural deterioration of the CA wall
.
Chronic inflammation may be caused by a multifactorial process involving environmental and genetic factors
.
Although genetic factors play a moderate role, environmental factors play an important role in the cause of subarachnoid hemorrhage (SAH)
.

The gut microbiota is an environmental factor that contributes to human pathophysiology and is involved in various diseases, in which inflammation plays a key role in determining the course and severity of the disease
.
Intestinal microbial group and cardiac vascular relationship between the diseases (e.
g.
, atherosclerosis) has been confirmed
.

In CAs, an animal model study showed that the consumption of antibiotics on the gut microbiome promotes the pathophysiology of the aneurysm wall through inflammation regulation
.
Hungatella hathewayi microorganisms are also involved in the occurrence of UIA
.
However, the relationship between the gut microbiome and SAH is unclear
.

In this way, Shuhei Kawabata et al.
hypothesized that there are differences in the types of microbiome profiles between stable UIA patients and unstable UIA patients that eventually rupture.
This difference may lead to chronic inflammation and pathophysiological changes in the aneurysm wall, and ultimately lead to aneurysms.
Rupture (RAs)
.

To explore the relationship between RAs and the microbiome, they compared the gut microbiome of UIAs and RAs patients immediately after the onset of the disease, and identified the bacteria that cause RAs
.

From 2019 to 2020, a one-year multi-center, prospective case-control study was conducted
.
Stool samples taken immediately after the onset of stable UIAs and RAs patients
.
Use 16S rRNA sequencing to analyze their gut microbiome
.
Subsequently, a phylogenetic tree was constructed and polymerase chain reaction was performed to determine the specific species
.

A total of 28 RAs and 33 UIAs were included in this study
.
There were no differences in patient characteristics between RAs and UIAs: age, gender, hypertension , dyslipidemia, diabetes status, body mass index, and smoking
.
No difference was observed in alpha diversity; however, there was a clear difference in beta diversity in the unweighted UniFrac distance
.

At the phylum level, the relative abundance of Campylobacter in the RA group was greater than that in the UIA group
.
In addition, the gut microbiome of the RA group and the UIA group showed significantly different classifications
.

However, because Campylobacter is a well-known pathogen among these bacteria, it has been studied intensively
.

Then, a phylogenetic tree of operational taxa related to Campylobacter was constructed, and 4 species were identified
.
By polymerase chain reaction of these species, it was found that the abundance of Campylobacter and Campylobacter uremicus was significantly higher in the RA group
.

The important significance of this study lies in the discovery: the intestinal microbiome profiles of patients with stable UIAs and RAs are significantly different
.
Campylobacter and Urolytic Campylobacter may be related to the rupture of cerebral aneurysm
.

Original source:
  Kawabata S, Takagaki M, Nakamura H, et al.
Dysbiosis of Gut Microbiome Is Associated With Rupture of Cerebral Aneurysms.
Stroke.
Published online November 3, 2021:STROKEAHA.
121.
034792.
doi:10.
1161/STROKEAHA.
121.
034792