Recent evidence has suggested that alteration of intestinal microbiota may play a crucial role in the health of the gut–liver axis.
Indeed, a new review published in the Journal of Functional Foods, suggests that the use of probiotics could offer a potential route to the prevention and treatment of NAFLD and other hepatic complications thanks to their ability to enhance intestinal barrier function, prevent production of lipopolysaccharides (LPS) and modulate the immune system.
“It has been reported that alteration and equilibrium disruption of intestinal microbiota play a critical role in the induction and progression of liver disease,” explained the review authors – led by Shayan Mohammadmoradi from Omega Research Team (ORT), USA. “In other words, an impaired gut barrier may result in negative impacts of gut-derived toxins.”
“Hence, modulating the aforementioned alteration and favourably affecting the functions of GIT microbiota may be a key factor in the treatment/prevention of hepatic diseases.”
The reviewers noted that probiotics, as safe and effective compounds that are found in foods and supplements, have the potential to influence gut barrier functions and immune cell regulations resulting in liver health improvements.
Probiotic potential
Mohammadmoradi and colleagues noted that some studies have indicated that probiotics may have the potential to improve GIT inflammatory conditions by altering the intestinal barrier function or permeability, and potentially regulating the immune system.
“It has been documented that probiotics may prevent BT [bacterial translocation] … via adhering to the GIT mucosa,” said the team. “Also, by acidifying the gut lumen, producing antimicrobial substances and consuming nutrients, probiotics may have the potential to inhibit the growth of pathogenic bacteria.”
They cited several studies on the VSL#3 mixture, which have shown promise in the prevention and/or treatment of liver conditions through microbial modification.
The VSL#3 multi-strain mixture is consisted of Bifidobacterium longum, Bifidobacterium breve, Bifidobacterium infants, Lactobacillus casei, Lactobacillus plantarum, Lactobacillus acidophilus, Lactobacillus delbrueckii subsp bulgaricus, and Streptococcus thermophiles.
This mixture has been shown to reduce pro-inflammatory signals in mice and modulate other immune pathways, in addition to reducing the incidence of insulin-resistance and hepatic steatosis in mice, said Mohammadmoradi and colleagues.
“A total of 22 NAFLD and 20 alcoholic liver cirrhosis patients participated in the study compared with 36 HCV-positive patients with chronic hepatitis with or without liver cirrhosis. It was documented that VSL#3 treatment resulted in a significantly improved plasma level of 4-hydroxynonenal (4-HNE), interleukin (IL)-6 and -10 and TNF-alpha in NAFLD patients,” they noted.
The authors suggested that future research focusing on liver conditions should tackle the challenges involved in the accurate selection of probiotic strains and doses, while adding that the lack of enough large scale and well-designed RCTs “does not let us draw a concise conclusion regarding the effectiveness of probiotics in the treatment of NAFLD and other liver diseases.”
“Also, studies should focus on the determination of responsible gut bacteria for hepatic damage and specific immune reactions underlying the gut microbiota-related liver disease,” they said.
Source: Journal of Functional Foods
Volume 11, November 2014, Pages 30–35, doi: 10.1016/j.jff.2014.08.022
“Boom of probiotics: This time non-alcoholic fatty liver disease – A mini review”
Authors: Shayan Mohammadmoradi, Aida Javidan, Javad Kordi