Table 3.

Epigenetic modifications associated with specific profiles of gut microbiota.

Strains	Epigenetic mechanism	Route	Clinical effects
Lactobacilli and Bifidobacteria	Butyrate-associated histone deacetylase (HDAC) inhibition	Nuclear factor-κB, peroxisome proliferator-activatedreceptor-γ, interferon-γ	Reduced intestinal and systemic inflammation (88, 104)
	Deoxyribonucleic acid (DNA) methylation secondary to methyl-donor production	Genes involved in inflammatory pathways	Modulation of intestinal and systemic inflammation (88)
Increased Firmicutes/Bacteroidetes ratio	DNA methylation (CpG)	Toll-like receptor (TLR) 2 and TLR-4	Altered expression of pro-inflammatory genes
			Increased risk of type 2 diabetes mellitus (118)
	DNA methylation	SCD5 gene, encoding for a primate-specific stearoyl- coenzyme A desaturase	Altered catalysis of monounsaturated fatty acids from saturated fatty acids
		USF gene, involved in fatty acid synthase and in lipogenesis	Possibly increased risk of overweight, obesity and lipid metabolism disturbances (119)