Synbiotics for nonalcoholic fatty liver disease Original paper

In this randomized controlled trial in participants with nonalcoholic fatty liver disease, taking synbiotics decreased liver fat compared to a placebo.

The effects of supplementing with synbiotics in participants with nonalcoholic fatty liver disease (NAFLD).

The primary outcome was the change in liver fat, measured using ultrasound. The secondary outcomes assessed were liver stiffness, HbA1c, total cholesterol, triglycerides, estimated glomerular filtration rate, interleukin 6, high-sensitivity C-reactive protein (hsCRP), gut transit time, and measures of gut microbial richness (alpha-diversity and beta-diversity).

84 participants (average age of 69) with NAFLD, including 24 participants with nonalcoholic steatohepatitis.

In this 12-week randomized controlled trial, the participants took either a synbiotic supplement or a placebo daily. The synbiotic supplement provided 6.4 grams of inulin and 64x10⁹ colony-forming units from a combination of Lactobacillus acidophilus CBT LA1, Lactobacillus casei CBT LC5, and Bifidobacterium lactis CBT BL3.

All of the participants were prescribed an individualized diet based on the Mediterranean diet by a registered dietitian. The diet was started 2 weeks before the start of the study and maintained throughout the intervention. The participants were also advised to walk at least 8,000 steps per day.

Changes in gut microbial richness were assessed using stool samples and gut transit time was evaluated using the “blue stool challenge”.^[1]

Compared to the placebo group, liver fat decreased in the synbiotics group.

For secondary outcomes, compared to the placebo group, hsCRP and gut transit time decreased and alpha-diversity increased in the synbiotics group.

The researchers did not adjust for multiple comparisons, which increases the risk of false-positive results. As such, the results for the secondary outcomes, in particular, should be interpreted with caution.