Microbiome alternative treatments for hepatic encephalopathy: Reassessment of the potential use of lactose in lactase non-persistent cirrhotics

Background: Hepatic encephalopathy is secondary to liver failure and is prevalent in 20%–40% of cirrhotics. The cause involves ammonia toxicity, gut–brain interactions, and inflammation usually involving the microbiome. The aim was to review succinct management of microbiome disturbances. The purpose includes an argument for further research into the possible selective benefit of lactose and dairy products in managing chronic hepatic encephalopathy in lactose maldigesters. Methods: Articles from 1970 to June 2025 were sought on PubMed and Google Scholar, as well as individual articles, regarding using altered microbiome and hepatic encephalopathy management. Results: Non-digestible disaccharides and synthetic polymers, often combined with non-absorbable antibiotic rifaximin, have been found to benefit hepatic encephalopathy. It is of note that after a few reports, lactose was abandoned as a potential treatment in lactase non-persistent cirrhotic patients. After abandonment for unclear reasons, colonic adaptation in lactase non-persistent populations was clearly defined to be associated with microbiome changes similar to other non-absorbable disaccharides. Conclusions: While current treatment is acceptable to most patients, the potential role of lactose and dairy products likely deserves further studies in patients with lactase non-persistence. The process of colonic adaptation may favour improvement in hepatic encephalopathy by altering the bacterial milieu. Use of dairy foods could also improve nutrition in cirrhosis. As such, use of lactose or dairy products could have a wide application since cirrhosis is common in parts of the world where lactose maldigestion is also widespread.