In people with functional gastrointestinal disorders, the consumption of blueberries helps in improving abdominal symptoms, functioning, and well-being.

A randomized cross-over study aimed to assess the effects of blueberries on functioning, well-being, and abdominal symptoms in individuals diagnosed with functional gastrointestinal disorders (FGID).

In this double-blind study, 43 FGID patients were assigned to get either freeze-dried blueberries (equivalent to 180 g fresh blueberries) or a placebo matched for energy and sugar. The study incorporated fructose breath tests to examine how the enteric microbiotic metabolism of fructose contributes to symptoms in patients with FGID.

The major endpoints included comparing the differences in Gastrointestinal Clinical Rating Scale (GSRS) scores and relief of abdominal symptoms following six weeks of intervention. Secondary endpoints included evaluating fructose breath test results, Bristol stool scales, and quality of life and life functioning ratings (using the OQ45.2 questionnaire).

Blueberry use led to a higher percentage of volunteers experiencing significant relief from abdominal symptoms compared to those who received the placebo (53% vs. 30%). Although there was a slight improvement in total and pain GSRS scores (mean treatment differences: -3.4 and -1.0, respectively), the differences were not significant. In comparison with placebo, OQ45.2 scores showed betterment during blueberry treatment (treatment difference of -3.2). No statistical significance was there in the treatment effect differences for the other measures.

Blueberries demonstrated their effectiveness in alleviating abdominal symptoms and enhancing life functioning, quality of life, and overall well-being in individuals with FGID compared to the placebo. The broad beneficial effects of blueberries, stemming from their polyphenol and fiber components, were independent of the sugars present in both treatments.