MADRID – More than a third of patients with systemic sclerosis and intestinal symptoms have an increase in gastrointestinal tract bacteria, an alteration in the type of gut microbes present, or both, based on data from a French study presented at the annual European Congress of Rheumatology.
Small intestinal bacterial overgrowth (SIBO) was found to affect 14 (38%) of 37 patients included in the study. These patients had been recruited from a larger group of 120 scleroderma patients who complained of gastrointestinal symptoms over a 2-year period.
"SIBO can compromise patients’ quality of life and be responsible for mortality," study investigator Dr. Marie Tauber said. SIBO can cause GI symptoms such as bloating, diarrhea, malabsorption, weight loss, and malnutrition, which may have a significant impact on patients’ overall prognosis, she noted.
Dr. Tauber, a dermatologist who took part in the research as part of an internship within the rheumatology department of the Hôpital Cochin in Paris, explained the three goals of the study. The first was to examine the prevalence of SIBO in patients with systemic sclerosis exhibiting GI symptoms, and the second was to identify subsets of patients who might be at increased risk. A third goal was to observe the impact of optimal SIBO treatment on the patients’ conditions.
The median age of participants was 59 years, and 79% were women. The median disease duration was approximately 10 years, and 49% of patients had diffuse cutaneous disease.
A diagnosis of SIBO was based on positive hydrogen and methane breath tests, and blood assays were used to assess the presence of malabsorption.
The researchers also administered two questionnaires – the generic SF-36 (Short Form 36) Health Survey and the disease-specific UCLA SCTC GIT (University of California, Los Angeles, Scleroderma Clinical Trial Consortium Gastrointestinal Tract Instrument) – to patients at the time of their breath testing visits.
All patients with SIBO were treated with a rotating regimen of amoxicillin, ciprofloxacin, and metronidazole, each given for 1 month at a time. Breath tests, as well as the UCLA SCTC GIT, were repeated. Fewer than 50% of patients had a negative breath test after antibody treatment, which highlighted a need to repeat the test after antibiotic treatment to determine whether a second course is required, Dr. Tauber noted.
Three clinical parameters separated patients with and without SIBO: longer disease duration (11 vs. 7 years; P = .02), lower prevalence of anti-topoisomerase I antibodies (Anti-Scl-70 Ab, 7% vs. 39%; P = .04), and higher prevalence of definite pulmonary arterial hypertension (PAH, 21% vs. 0%; P = .04).
Total UCLA SCTC GIT scores were higher in patients with SIBO than in those without it (0.79 vs. 0.31; P = .03). SIBO-affected patients also were more likely to have weight loss of 5% or more (43% vs. 8%; P = .03).
Given the small number of patients, it is difficult to draw firm conclusions from these data, and larger studies are needed, Dr. Tauber observed. However, the findings suggest that there may be factors associated with SIBO that could be targeted in an intervention program.
Two patients with SIBO died despite antibiotic treatment, which "underscores, unfortunately, the association between SIBO and mortality," Dr. Tauber said.
"To our knowledge, this is the first study using the UCLA SCTC GIT to identify patients at risk of SIBO in systemic sclerosis," and the data support the systematic use of this score, together with regular weight evaluation in these patients, she concluded.
Dr. Tauber had no financial conflicts to disclose.