Research Trends in Glutamine Supplementation in Nutrition, Health and Disease: A Bibliometric Analysis (1943–2025)

Background/Objectives: Glutamine supplementation has been investigated across nutritional, clinical and preclinical settings, but the development and thematic structure of this literature have not been comprehensively mapped. This bibliometric study examined publication trends, leading contributors, citation patterns, international collaboration and thematic evolution. Methods: The Web of Science Core Collection was searched on 20 August 2026 using a title-based strategy targeting intervention-oriented glutamine research. The corpus comprised 1321 articles and reviews published during 1943–2025. Analyses were conducted in Python, including country co-authorship networks and author–keyword mapping. Co-occurrence and temporal analyses used author keywords from 925 publications (70.0%), with a 15-occurrence threshold for co-occurrence mapping and six thematic domains examined across four periods (1991–2025). Results: Publication output increased from the 1990s and peaked in 2014. The corpus spanned 512 sources and accumulated 42,356 citations (h-index 87). The United States, China and Brazil contributed the most publications, while the University of São Paulo was the leading institution. Clinical nutrition and critical illness, amino-acid metabolism, oxidative and inflammatory responses, intestinal function, exercise and oncology-related applications were represented. Clinical nutrition and critical illness decreased from 34.0% to 10.6% of keyword-bearing publications between the earliest and latest periods, while oxidative, inflammatory and immune responses increased from 16.0% to 21.1%. International co-authorship occurred in 17.3% of publications. Conclusions: The results demonstrate changing thematic representation and identify major contributors and collaboration patterns within intervention-oriented glutamine research. These descriptive findings do not establish clinical efficacy or the presence of substantive evidence gaps.