Bacteria-derived membrane vesicles in urine: a marker for autism

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Analyzing the vesicles produced by commensal bacteria and excreted in the urine provides valid information on the composition of the intestinal microbiota in people with autism.

 

People with autism present with intestinal dysbiosis, which is thought to influence the severity of symptoms via the gut-brain axis. Korean researchers focused on the extracellular vesicles produced by commensal bacteria, which can be found throughout the body, particularly in urine. These vesicles contain bacterial DNA and therefore provide information about which strains are present as well as active in the intestine, since they produce vesicles.

To test this hypothesis, the authors included in their study  20 people with autism with an average age of 22 and 28 age-matched healthy volunteer control subjects. They collected their urine and analyzed the extracellular vesicles. The results showed differences in the microbiota between the two groups. The authors catalogued the results by phyla, class, order, family, and genus. As a result, compared to healthy subjects, they observed that patients with autism had declines in the genera Pseudomonas, Sphingomonas, Agrobacterium, Achromobacter and Roseateles, and conversely, increases in the genera Streptococcus, Akkermansia, Rhodococcus, and Halomonas. The analysis of the dysbioses observed from the bacterial vesicles present in the urine of people with autism was consistent with that conducted in previous studies from patients’ fecal samples.

This information confirms the usefulness of extracellular vesicles, which are very easily accessible in urine, as a means of conducting regular monitoring of the microbiota for patients with autism. These results still need to be confirmed in children. These extracellular vesicles may contribute to early detection of the disease (between 1.5 and 3 years).

 

Sources:

Lee Y ert al.  Rapid Assessment of Microbiota Changes in Individuals with Autism Spectrum Disorder Using Bacteria-derived Membrane Vesicles in Urine. Exp Neurobiol. 2017 Oct;26(5):307-317