Intestinal dysbiosis is common in systemic sclerosis and associated with gastrointestinal and extraintestinal features of disease
Not surprisingly, commensals found in healthy gut like Bacteroides and Faecalibacterium were reduced in representation in SSc patients, while pathogenic species like Enterobacteriales and Fusobacterium were present in greater abundance. The microbiota signature in SSc overlaps with that of Crohn's patients.
Surprisingly, commensals like Bifidobacterium and Lactobacillus, commonly part of probiotic cultures, were enriched is SSc patients.
What does this all mean? Does the autoimmune disease or its treatment restrict the Microbiome, or are certain microbiotal populations truly pathogenic, interacting with the unique individual immune genotypes to manifest in specific disease phenotypes?
I'm persuaded it's the former, since no specific microbiotal species are universally pathogenic (or probiotically safe) across autoimmune diseases. Instead, the common thread in microbiome research across diseases is the restriction of microbiotal diversity during active disease.