Distinct plasma vs gut microbiome seen in SLE patients, healthy individuals

A distinct community and greater heterogeneity have been observed in the plasma microbiome compared to the gut in both patients with systemic lupus erythematosus (SLE) and healthy individuals, reports a recent study. This suggests that the predominant circulating microbiome may originate from sites other than the gastrointestinal tract.

“Blood microbiome has been analysed in cancer patients using machine learning,” according to the authors, who sought to determine whether the plasma microbiome represents the microbial community in the gut among patients with SLE and healthy controls (HCs).

Using a microbial 165 ribosomal RNA sequencing, paired plasma and stool samples from female patients with SLE and female HCs were analysed to reveal the microbiome composition.

The authors observed decreased microbial alpha diversity in stool compared to plasma as well as distinct plasma and gut beta diversity in both SLE patients and HCs. Gut microbial diversity did not differ between the two cohorts, but plasma alpha diversity was reduced in patients with SLE compared to HCs.

Of note, the predominant bacteria were different between plasma and stool in both groups. While the predominant plasma and stool genus bacteria were similar between SLE patients and HCs, some evidently differed.

“The decreased plasma but not gut alpha diversity in patients with SLE compared to HCs implies an altered plasma microbiome in SLE, which may be important for systemic immune perturbations and SLE disease pathogenesis,” the authors said.