Gene expression is regulated by epigenetic modifications such
as DNA methylation, histone modifications, and binding of
non-coding RNAs [1,2]. Gut microbiota can affect epigenetic
processes of the host, consequently causing diseases such as
allergy, Inflammatory Bowel Disease (IBD), autoimmune disease,
metabolic syndrome, colorectal cancer, stress-related disorders,
and neurodevelopmental disorders [3-9]. This possibly results
from dysbiosis, a negative alteration of the gut microbiota, as
well as changes in microbial metabolites, which are triggered
by environmental factors such as diet, age, toxic chemicals, and
pharmacological factors [10,11]. In fact, a pilot study reported
a significant relationship between the predominant bacterial
phyla and methylation patterns of the host in the human gut
Dysbiosis can be
induced by various environmental factors such as diet, stress,
and exposure to antibiotics, stress, toxins, drugs, and pathogens
[22,24-26]. Accumulated evidence regarding clinical implications
of dysbiosis via direct or indirect influences on related diseases,
including immune disease and others, are reviewed below
The human epigenome can be affected by various environmental
factors, particularly those that affect the gut microbiota and
their metabolites. The effects of the gut microbiome on host
epigenetic regulation with respect to various diseases have been
reviewed. Moreover, the link between the gut microbiome and
the epigenome can be used as effective targets for the diagnosis
and treatment of diseases. The recent developments in highthroughput technologies have broadened our understanding of
gut microbiota and epigenomes, and it would serve as a key tool
in identifying targets for diagnosis and treatment.