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Egresi et al. NAFLD and gut dysbiosis

They used 16S ribosomal RNA gene sequencing to significantly decreased fibrosis scores, as determined
determine the microbial flora of biopsy-proven NASH by transient elastography compared with placebo. [18]
patients. Here, we highlight the importance of this In fact, it can improve disease severity. Probiotics are
work, because of its novelty in the demonstration of consumed in various forms, such as fermented foods,
the association between gut dysbiosis and severity of like yogurt, cheese and other fermented milk products.
the disease. Another great advantage of this study is The oral intake of probiotics is recommendable for the
the well phenotyped liver lesions of the studied group prevention and treatment of obesity, insulin resistance,
with diagnostic liver biopsy. In so far, the histological type 2 diabetes and NAFLD. As a co-adjuvant
assessment of liver samples is the gold standard of therapy, probiotic combination with metformin can
chronic liver diseases, which is an invasive intervention. lower liver aminotransferases better than metformin
Not only NAFLD, but NASH can be hardly diagnosed alone in patients with NASH. [19,20] The combination
with clinical, laboratory parameters. For this reason of cholesterol-lowering probiotics and anthraquinone
there is a great claim worldwide for easy, reproducible, increase the therapeutic effect on NAFLD by affecting
cheap, safe, non-invasive scores or imaging modalities the process of fat metabolism in rats (up-regulation of
to identify NAFLD or NASH. [8-11] CYP7A1, LDL-R, FXR mRNA, PPAR-α protein and
down-regulation of HMGCR, PPAR-γ and SREBP-1c). [21]
In particular, the authors reported an increased
abundance of Bacteroides genus was independently These findings confirm that dietary interventions can
associated with NASH and Ruminococcus abundance affect the composition and diversity of gut microbiota.
was independently associated with fibrosis severity
(> F2). Besides, patients with NASH had lower Finally, association of gut dysbiosis with histological
[7]
abundance of Prevotella. The exact mechanism of subtypes of NAFLD may be a prognostic factor of liver-
the liver injury is not yet clear. However, metabolites related morbidity and mortality. Analysis of microbial
of the members of the Bacteroides family directly composition may be a useful predictor of disease
stimulate the farnesoid X receptor (FXR), a ligand- stage. However additional analysis will have to explain
activated transcription factor, which plays an important how metabolic functions of the gut microbiota might
role in the pathogenesis of liver damage. They improve have role in NASH pathogenesis and progression.
the obesity phenotype including body weight gain, Further studies are required to understand the
liver damage, lipid metabolism in a mouse model. [12] precise mechanism of how gut microbiota affect the
Despite the relatively small number of cases (n = 57), pathomechanism of NAFLD/NASH and the role of
these results show that analysis of gut microbiota is a probiotics in the therapy of the disease. Since there
good tool to gain information about NAFLD severity. is no available treatment for NAFLD/NASH yet,
According to this work, dysbiosis may have a significant probiotic therapy, as a safe, inexpensive and non-
role in the pathogenesis of human NAFLD/NASH. invasive strategy, may be a good alternative to reduce
Moreover gut microbiota analysis adds prognostic pathophysiological symptoms and improve different
information to NAFLD severity. [7] types of liver diseases without side effects.

Recent studies show, that probiotic/prebiotic Financial support and sponsorship
supplementation may be useful in both animal and None.
human models. Bifidobacterium and Lactobacillus
strains are the most widely used bacteria. [13] Control Conflicts of interest
of the bacterial flora lowers proinflammatory cytokine There are no conflicts of interest.
production (tumor necrosis factor-α, interleukin-6,
interferon-γ) via down-regulation of the nuclear factor Patient consent
kappa B, and decreases the oxidative stress. Probiotic There is no patient involved.
can reduce the urease activity of bacterial microflora,
decreases fecal pH value and reduces amino-acid Ethics approval
fermentation and ammonia adsorption. They may
reduce aminotransferases (alanine aminotransferase, Ethics approval is waived for this kind of article.
aspartate transaminase), improve the lipid status
(total cholesterol, low-density lipoprotein) in NAFLD REFERENCES
patients. [6,14-17] In fact, probiotic was reported to 1. Filozof C, Goldstein BJ, Williams RN, Sanyal A. Non-alcoholic
improve liver histology, and reduce hepatic total steatohepatitis: limited available treatment options but promising drugs
fatty acid content in an animal model of NAFLD. In in development and recent progress towards a regulatory approval
addition probiotic therapy with lifestyle modification pathway. Drugs 2015;75:1373-92.
Hepatoma Research ¦ Volume 2 ¦ December 13, 2016 329