Understanding the human gut microbiome requires comprehensive genomic catalogues, yet many lack geographic diversity and contain medium-quality metagenome-assembled genomes (MAGs) missing up to 50% of genomic regions, potentially distorting functional insights. Here we describe an enhanced Human Reference Gut Microbiome (HRGM2) resource, a catalogue of near-complete MAGs (>= 90% completeness, <= 5% contamination) and isolate genomes. HRGM2 comprises 155,211 non-redundant near-complete genomes from 4,824 prokaryotic species across 41 countries, representing a 66% increase in genome count and a 50% boost in species diversity compared to the Unified Human Gastrointestinal Genome catalogue. It enabled improved DNA-based species profiling, resolution of strain heterogeneity and survey of the human gut resistome. The exclusive use of these genomes improved metabolic capacity assessment, enabling high-confidence, automated genome-scale metabolic models of the entire microbiota and revealing disease-associated microbial metabolic interactions. This resource will facilitate reliable functional insights into gut microbiomes.