Table 1.

Differences of gut microbiota when comparing AN patients and controls.

Year Of Publication	Results in AN Patients	Reference
2009	-No changes in Bacteroidetes, Firmicutes or Lactobacillus -Increase in Methanobrevibacter smithii	[35]
2013	-Higher levels of Escherichia coli -Lower levels of Lactobacillus reuteri -Increase in Methanobrevibacter smithii	[37]
2015	-Lower alpha diversity -Greater levels of Bacilli and unspecified genera in Coriobacteriales -Reduced levels of Clostridia, Anaerostipes and Faecalibacterium	[30]
	-Lower amounts of total bacteria and decrease in Streptococcus genus, Clostridium coccoides group, Clostridium leptum subgroup, Bacteroides fragilis group, and Lactobacillus plantarum	[15]
2016	-No differences in diversity and richness -Decrease in Bacteroidetes and increase in Firmicutes -Higher levels of mucin-degraders (Verrucomicrobia, Bifidobacteria, Anaerotruncus) and members of Clostridium clusters I, XI and XVIII -Reduced abundance of butyrate-producing bacteria (Roseburia spp. and Gemminger spp.)	[38]
2017	-Lower alpha diversity -Increase in Coriobacteriaceae	[34]
	-Decrease in Firmicutes -Increase of Enterobacteriaceae and Methanobrevibacter smithii -Decrease in Roseburia, Ruminococcus and Clostridium	[36]
2018	-Lower alpha diversity -Decrease in: Eubacterium, Roseburia, Anaerostipes and Peptostreptococcaceae -Increase in: Turicibacter, Anaerotruncus, Salmonella and Klebsiella	[51]