Table 1. Databases used for collecting articles (along with search strategies and appropriate filters).

Type of database	Keywords	Search strategy	Filters used	Number of records identified
PubMed	Hepatic cancer, hepatocellular carcinoma, hepatic neoplasm, liver cancer, hepatocellular cancer, gastrointestinal microbiome	hepatic neoplasm OR hepatic cancer OR hepatocellular cancer OR liver neoplasm OR liver cancer OR (“Liver Neoplasms/diet therapy”[Majr] OR “Liver Neoplasms/etiology”[Majr] OR “Liver Neoplasms/genetics”[Majr] OR “Liver Neoplasms/immunology”[Majr] OR “Liver Neoplasms/metabolism”[Majr] OR “Liver Neoplasms/microbiology”[Majr] OR “Liver Neoplasms/pathology”[Majr] OR “Liver Neoplasms/physiopathology”[Majr] OR “Liver Neoplasms/prevention and control”[Majr] ) AND “Gastrointestinal Microbiome”[Majr]	Free full text, last 10 years, English	327
Cochrane Library	Gut microbiome, liver cancer	Gut microbiome AND liver cancer	Published between 2013 and2023	21
Google Scholar	Gut microbiome, hepatocellular carcinoma, liver cancer	Gut microbiome AND hepatocellular carcinoma OR liver cancer	Published between 2013 and 2023	65
ScienceDirect	Gut microbiome, liver cancer	Gut microbiome AND liver cancer	Published between 2013 and 2023, open access and open archive	2,556