Table 4:

Comparison of adult ankylosing spondylitis microbiome studies

AS Microbiome Study # samples Tissue (country)	Lower abundance in AS patients	Increased abundance in AS
AS (n=9)	Veillonellaceae	Lachnospiraceae
HC (n=9)	Prevotellaceae	Porphyromonadaceae
Terminal ileum		Ruminococcaceae
Biopsy specimen[33]		Bacteroidaceae
		Rikenellaceae
SpA (n=87)	Prevotellaceae	Ruminococcus gnavus
RA (n=28)
HC (n=69)
Fecal (France)[4]
AS (n=73) HC (n=83) Fecal (China)[34]	Bacteroides spp.	Prevotella melaninogenica, Prevotella copri, Prevotella sp.
AS (n=41) HC (n=21) Fecal (China)[35]	Eubacterium ruminantium, Ruminococcus gnavus, Lachnospira, Bacteroides	Prevotella 9, Dialister, Comamonas, Collinsella, Streptococcus, Alloprevotella, Prevotella 2
AS (n=150) HC (n=17) Fecal (Sweden)[36]	Bacteroides, Lachnospiraceae	Proteobacteria, Enterobacteriaceae, Bacilli, Streptococcus species, Actinobacteria
AS (n=85) HC (n=62) Fecal (China)[37]		Bacteroides coprophilus, Parabacteroides distasonis, Eubacterium siraeum, Acidaminococcus fermentans, Prevotella copri

As: Ankylosing spondylitis, HC: Healthy control, SpA: Spondyloarthropathy, RA: Rheumatoid arthritis