Lactulose reduces bacterial DNA translocation, which worsens neurocognitive shape in cirrhotic patients with minimal hepatic encephalopathy

Abstract

Background & aims: Minimal hepatic encephalopathy is associated with poor prognosis and mortality in patients with cirrhosis. We aimed at investigating whether bacterial-DNA translocation affects hyperammonaemia and neurocognitive scores in patients with mHE according to the use of lactulose.

Methods: Observational study including 72 mHE cirrhotic patients, as defined by a psychometric hepatic encephalopathy score (PHES)<-4 and/or a critical flicker frequency (CFF)<39 Hz. Bacterial-DNA, serum ammonia, pro-inflammatory cytokines and nitric oxide levels were evaluated. A second cohort of 40 lactulose-untreated patients were evaluated before and 6-month after lactulose administration (30-60 mL/d).

Results: In the first cohort, bacterial-DNA rate was significantly higher in patients without lactulose (39% vs 23%, P=.03). Serum ammonia and inflammatory markers were significantly increased in patients with bacterial-DNA, regardless the use of lactulose, and correlated with the amount of amplified bacterial-DNA. Neurocognitive scores were significantly worse in bacterial-DNA positive vs negative patients (PHES -7.6±1.1 vs -5.5±1.0; CFF 32.5±2.6 vs 36.2±2.8, P=.01). Lactulose was associated with improved neurocognitive scores in patients without bacterial-DNA. Serum ammonia levels inversely correlated with neurocognitive scores in patients with bacterial-DNA (PHES r=-.84; CFF r=-.72, P=.001). In the second cohort, lactulose reduced bacterial-DNA translocation (36%-16%, P=.02). Neurocognitive scores were significantly improved in bacterial-DNA positive patients who cleared bacterial-DNA during the period on lactulose. Serum ammonia levels correlated with both neurocognitive scores in patients with bacterial-DNA, either before or after lactulose.

Conclusion: Bacterial-DNA translocation worsens neurocognitive scores in mHE patients and it is reduced by lactulose, enhancing the relevance of controlling bacterial antigen translocation in these patients.

Keywords: ammonia; bacterial translocation; cirrhosis; lactulose; minimal hepatic encephalopathy.