But blame could lay with the duration of disease or the donated poo, experts say.
Faecal microbiota transplants do not appear to reduce lower gastrointestinal tract symptoms in people with systemic sclerosis overall, according to new research.
But patients who had the disease for less time were more likely to benefit from the intervention, rheumatologist Professor Anna-Maria Hoffmann-Vold and colleagues wrote in The Lancet.
Authors of the phase 2 trial of 67 patients with moderate to severe bloating or diarrhoea randomly assigned participants to receive either anaerobic cultivated human intestinal microbiome (ACHIM) or placebo. Most had had limited cutaneous systemic sclerosis for 10 years.
After 12 weeks of treatment, there were no differences between the groups in adverse events or lower gastrointestinal tract symptoms such as bloating or diarrhoea, according to the patients’ self-reported symptoms.
Nevertheless, the cohort was mainly women with long-standing disease and positive anti-centromere antibodies, and many were not on immunosuppressive therapy.
“It is plausible that the pathological changes in long-standing systemic sclerosis, affecting both the enteric nervous system and the structural components of the intestinal wall, might reduce the potential for gut microbiota to influence lower gastrointestinal tract symptoms,”
“On this basis, the fact that the results of this study showed some numerical improvement, albeit not statistically significant, in the few participants with shorter disease duration in the ACHIM group is of clinical relevance.”
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This suggests patients with short-term disease or milder intestinal symptoms could be the preferred target group in future trials, they said.
Another potential impediment was that around one in three patients took antibiotics during the trial and these, along with gastrointestinal and immunosuppressive medications, would have affected the gut microbiota and possibly contributed to the negative results, said Dr Andrea Low, head of the department of rheumatology and immunology at Singapore General Hospital.
The effectiveness of faecal microbiota transplantation also depends on the composition of the donor microbiota, Dr Low and her gastroenterologist colleague wrote in an accompanying editorial.
“The absence of significant change in microbial diversity in the current study raises the question as to whether an alternative faecal microbiota transplantation preparation might yield better results.”
Another trial of patients with ulcerative colitis showed that a greater proportion reached remission with faecal microbiota transplantation if they had early rather than late ulcerative colitis, they said.
“It is tempting to postulate that microbiota-modulating therapies could benefit patients with early systemic sclerosis-associated gastrointestinal tract disease, possibly in the immunoinflammatory phase, rather than those with late stage with established structural changes.”
“Faecal microbiota transplantation is not quite ready for prime time but holds promise for the future with refinement of trial design.”
