Table 2.

Human studies investigating microbiota involvement in the development of NAFLD and NASH.

	Study	Technique	Groups	Samples	Main findings
NAFLD	Michail et al., 2015 [52]	16s rRNA Microarray microbial community profiling	13 obese children with NAFLD 11 obese children without NAFLD 26 healthy children	Stool	Obese children with NAFLD: ↑ Gammaproteobacteria ↑ Epsilonproteobacteria ↑ Prevotella
Spencer et al., 2011 [53]	16s rRNA V1–V2 region sequence analysis	15 individuals: 10 days normal diet (baseline), then 42 days choline-depleted diet. Back to 10 days normal diet	Multiple stool samples from multiple time points	Baseline samples: ↑ Gammaproteobacter at baseline correlates to lower risk of developing fatty liver on low-choline diet. ↑ Erysipelotrichia at baseline correlates to higher risk of developing fatty liver on low-choline diet.
Raman et al., 2013 [55]	16s rRNA V1–V2 region sequence analysis	30 obese NAFLD patients 30 healthy controls	stool	Obese NAFLD versus healthy controls: ↑ Lactobacillus ↓ Firmicutes ↓ Oscillibacteria
NASH	Zhu et al., 2013 [56]	16s rRNA V4–V5 region sequence analysis	22 NASH children 25 obese children 16 healthy controls	stool	Obese and NASH versus Healthy controls: ↑ Bacteroidetes ↑ Prevotella NASH versus obese and healthy controls ↑ Proteobacter ↑ Enterobacteriaceae ↑ Escherichia
Wong et al., 2013 [136]	16s rRNA V1–V2 region sequence analysis	16 NASH patients 22 Healthy controls	stool	NASH versus healthy controls: ↓ Firmicutes No Change – Bacteroidetes ↑ Parabacteroides ↑ Allisonella ↓ Faecalibacterium ↓ Anaerosporobacter
Boursier et al., 2016 [59]	16s rRNA V4 region sequence analysis	22 NAFLD patients 35 NASH patients	stool	NASH versus NAFLD: ↑ Bacteroidetes