Tauroursodeoxycholic acid (TUDCA) increases the influx of primary bile acids into the gut. Results obtained on animal models suggested that Firmicutes and Proteobacteria phyla are more resistant to bile acids in rats. As part of a pilot study investigating the role of probiotics supplementation in elderly people with home enteral nutrition (HEN), a case of a 92-year-old woman with HEN is reported in the present study. She lives in a nursing home and suffers from Alzheimer’s disease (AD); the patient had been prescribed TUDCA for lithiasis cholangitis. The aim of this case report is therefore to investigate whether long-term TUDCA administration may play a role in altering the patient’s gut microbiota (GM) and the impact of an antibiotic therapy on the diversity of microbial species. Using next generation sequencing (NGS) analysis of the bacterial 16S ribosomal RNA (rRNA) gene a dominant shift toward Firmicutes and a remodeling in Proteobacteria abundance was observed in the woman’s gut microbiota. Considering the patient’s age, health status and type of diet, we would have expected to find a GM with a prevalence of Bacteroidetes phylum. This represents the first study investigating the possible TUDCA’s effect on human GM.

Background: Home Enteral Nutrition (HEN) patients, often older adults, are susceptible to gut microbiota dysbiosis and low-grade chronic inflammation (inflammaging), which negatively impacts overall health and intestinal integrity. However, evidence on microbiota-targeted interventions in this population remains limited. The development of targeted nutritional strategies, such as probiotic supplementation, has been proposed to address these age-related changes. Methods: This exploratory randomized, open-label study explored changes in gut microbiota composition following a 30-day probiotic intervention in a cohort of sixteen older HEN patients. Gut microbiota profiles were analyzed at baseline and post-intervention using 16S rRNA gene amplicon sequencing. Results: Significant shifts in the gut microbiota were observed, including a statistically significant increase in alpha diversity after 30 days. At the taxonomic level, the treated group showed an increased relative abundance of Lachnospiraceae and Erysipelotrichaceae, suggesting a modulation of gut microbiota structure following probiotic supplementation. Conclusions: These findings provide preliminary insights into microbiota dynamics in this population and may inform the design of future studies integrating functional and clinical outcomes.