Gut Microbiota and Psychological Distress in Fibromyalgia: A Systematic Review.

OBJECTIVEThis systematic review aimed to summarize the recent evidence of the relationship between gut microbiota and psychological distress in patients with fibromyalgia (FM).

METHODSAccording to PRISMA guidelines, we conducted a systematic search of the literature on PubMed, Scopus, EBSCO, Web of Science, and Cochrane. The records were selected using multiple combinations of relevant search terms involving microbiota, psychological distress, and FM. Articles in English with human participants were reviewed.

RESULTSThe initial search identified 135 records, excluding duplicates, of which 10 research reports met the predefined inclusion criteria and were analyzed. Most studies ( n = 7) were case-control, 2 were randomized controlled trials, and 1 was observational. Most studies found an imbalance in the gut microbial communities of FM patients and a significant difference between FM patients and HC in microbiome composition/diversity or gut permeability. Intestinal dysbiosis and gut permeability were also associated with high psychological distress (emotional, cognitive, and somatic symptoms).

CONCLUSIONSAlterations in the gut microbiota of FM patients seem to support the hypothesis that gut-brain axis regulation is impaired in stress-related pain conditions. Although the results are promising, further studies are needed to clarify the role of the microbiota-gut-brain axis in the pathophysiological mechanisms underlying FM.