The Relationship Between Microbiota, Nutrition, and Gastrointestinal Tract Symptoms in Patients with Systemic Sclerosis: A Systematic Review of the Literature.

Gastrointestinal (GI) involvement is frequent in systemic sclerosis (SSc). Recent studies have highlighted a possible association between GI symptoms, gut microbiota (GM), and nutrition. In this systematic review, the evidence supporting these relationships was evaluated. Articles selected from the MEDLINE database and published between 2010 and 2025 were included. Keywords used in the sources included "systemic sclerosis", "gut microbiota", "malnutrition", and "gastrointestinal symptoms". Forty-nine articles were selected, for a total of 6270 SSc patients. The evidence suggests a complex relationship between SSc, GI symptoms, and GM dysbiosis. Both are manifestations of the disease, and in turn they influence its severity. Digestive tract fibrosis and dysbiosis alter nutrient absorption, which can lead to malnutrition. However, data considering these complex relationships between the GI tract, microbiome, and nutritional status are few and very heterogeneous. Further studies are needed to investigate these complex interwinings and identify nutritional interventions able to reduce GI dysfunction and simultaneously counteract malnutrition.