Higher Risk of Stroke Is Correlated With Increased Opportunistic Pathogen Load and Reduced Levels of Butyrate-Producing Bacteria in the Gut

Abstract

Objective: Gut microbiota is a newly identified risk factor for stroke, and there are no large prospective studies linking the baseline gut microbiome to long-term risk of stroke. We present here the correlation between the gut microbiota and stroke risk in people with no prior stroke history.Methods: A total of 141 participants aged ≥60 years without prior history of stroke were recruited and divided into low-risk, medium-risk, and high-risk groups based on known risk factors and whether they were suffering from chronic diseases. The composition of their gut microbiomes was compared using 16S rRNA gene amplicon next-generation-sequencing and Quantitative Insights into Microbial Ecology (QIIME) analysis. Levels of fecal short-chain fatty acids were measured using gas chromatography.Results: We found that opportunistic pathogens (e.g., Enterobacteriaceae and Veillonellaceae) and lactate-producing bacteria (e.g., Bifidobacterium and Lactobacillus) were enriched, while butyrate-producing bacteria (e.g., Lachnospiraceae and Ruminococcaceae) were depleted, in the high-risk group compared to the low-risk group. Butyrate concentrations were also lower in the fecal samples obtained from the high-risk group than from the low-risk group. The concentrations of other short-chain fatty acids (e.g., acetate, propionate, isobutyrate, isovalerate, and valerate) in the gut were comparable among the three groups.Conclusion: Participants at high risk of stroke were characterized by the enrichment of opportunistic pathogens, low abundance of butyrate-producing bacteria, and reduced concentrations of fecal butyrate. More researches into the gut microbiota as a risk factor in stroke should be carried out in the near future.

Effects of Short Chain Fatty Acids (SCFAs) Modulation on Potentially Diarrhea Causing Pathogens in Yaks Through Metagenomics Sequencing

“…Butyrate is not only a primary energy source for colonocytes, but also can maintain intestinal homeostasis through anti-in ammatory actions via inhibiting nuclear factor kappa β, and histone deacetylation by promoting epithelial barrier function [16,79]. Previously, lower abundance of butyrate-producing bacteria and fecal butyrate were found in stroke patients as higher risk factors [80]. Bacteroidetes from Firmicutes mainly produce acetate and propionate, while Butyrate is mainly produced by phylum Firmicutes i.e.…”

Experimental Stroke Induces Chronic Gut Dysbiosis and Neuroinflammation in Male Mice

“…Changes in the microbiome may also be a risk factor leading to disease, including stroke and stroke-related comorbidities. A prospective study showed that opportunistic pathogens, including Enterobacteriaceae and Veillonellaceae, and lactateproducing bacteria, including Lactobacillus and Bifidobacterium, were increased in patients who had a high risk of stroke compared to low risk controls [17]. Changes in the microbiome of atrisk or post-stroke patients can also be mimicked in rodent models.…”

Sex Differences in Stroke Outcome Are Associated With Constitutive Gut Dysbiosis and Stroke-induced Gut Permeability

“…The estrobiome is the collective term for gut bacterial genes whose products metabolize estrogens Blaser, 2011, Kwa et al, 2016) Tamboli et al 2004). A recent large human study showed that baseline dysbiosis was corelated with an increased risk of stroke (Zeng et al, 2019). Similarly, recent preclinical studies have also shown that age-related differences in stroke outcomes are linked to a constitutive difference in microbial communities.…”