A study of the gut bacterial composition in scleroderma patients identified unique bacterial alterations associated with clinical evidence of gastrointestinal disease.
Many patients with scleroderma, also known as systemic sclerosis (SSc), suffer from gastrointestinal tract symptoms, with almost all of those with longstanding disease having upper gastrointestinal involvement. Focus has recently shifted to early detection and intervention because standard pharmacological treatment has proven to have limited benefit.
It is now widely accepted that the intestinal microbial populations (also known as intestinal microbiota) play important roles in both health and disease.
In the study “Gut microbiota profile in systemic sclerosis patients with and without clinical evidence of gastrointestinal involvement,” published in the journal Scientific Reports, researchers aimed to study the composition of the intestinal microbiota and its relation to SSc.
The study involved nine patients with SSc and gastrointestinal involvement (SSc/GI+), nine patients with SSc and no gastrointestinal involvement (SSc/GI-), and nine healthy controls. Fecal bacterial composition in each of these patients was studied using Illumina sequencing of 16S rRNA gene amplicons, which is a method used to identify and compare bacteria present within a given sample.
Overall, the results indicated that SSc/GI+ patients had higher levels of Lactobacillus, Eubacterium and Acinetobacter, and lower levels of Roseburia, Clostridium, and Ruminococcus, compared to healthy controls.
Other studies had shown that bacteria from the genera Roseburia, Clostridium, and Ruminococcus are involved in enhancing intestinal epithelial barrier function and that some are reduced in inflammatory diseases such as inflammatory bowel disease.
Patients with SSc/GI- had gut microbiota compositions that were more similar to healthy controls than to SSc/GI+, except that Streptococcus salivarius was more abundant in SSc/GI-.
“The results of the present study showed that bacterial diversity in terms of both richness and evenness varied significantly between healthy controls and SSc/GI+ patients, whereas no statistically significant differences were found between patients without gastrointestinal symptoms and healthy individuals” the researchers wrote.
Taken together, the team concluded that their study “reveals microbial signatures of dysbiosis [microbial imbalance] in the gut microbiota of SSc patients that are associated with clinical evidence of gastrointestinal disease. Further studies are needed to elucidate the potential role of these perturbations in the onset and progression of systemic sclerosis, and gastrointestinal involvement in particular.”