Tolerability and Risk of Adverse Events With a Probiotic Supplement: A Randomised and Placebo Controlled Study in Healthy Individuals

The understanding of the role of the gastrointestinal microbes for human health has gained considerable interest in recent years. The butyrate-producing bacterium Faecalibacterium prausnitzii is a naturally occurring bacterial species in the human gut that can make up to 5% of the gastrointestinal flora in healthy individuals.

Several studies have shown that the presence of butyrate producing bacteria, including F. prausnitzii, is lower in patients with inflammatory bowel disease; Crohn's disease and ulcerative colitis. Furthermore, lower levels of short fatty acids have been found in people with ulcerative colitis as compared to healthy individuals. Similar results have been obtained from studies about Crohn's disease, where people with a low abundance of F. prausnitzii run a higher risk of post-operative recurrence of their disease.

It has become evident that bacteria in the human gastrointestinal tract are symbiotic and dependent on each other's metabolism. Studies conducted by the sponsor (Metabogen AB) have shown that butyrate production from F. prausnitzii increases in the presence of Desulfovibrio piger, a common sulphate-reducing bacterium present in the human intestine. The symbiotic relationship between F. prausnitzii and D. piger can be utilised by combining these bacterial species into a probiotic dietary supplement, thus maintaining butyrate production in the intestine.

In animal models, who received approximately 5,000 times higher doses per kilogram of body weight than the highest dose scheduled in the proposed study, the intake of F. prausnitzii has shown anti-inflammatory effects as well as positive effects on the metabolism.

The present study is a double-blind, placebo-controlled, randomized, study in 48 healthy individuals (men and women) between 20 and 40 years old recruited from the general population. These volunteers will either receive F. prausnitzii and D. piger (in two different doses) or placebo orally once a day for 8 consecutive weeks. The investigators will assess how well treatment with the study product compared to placebo is tolerated (termination due to adverse events within 8 weeks of treatment) and if it can cause gastrointestinal symptoms (measured with The Gastrointestinal Symptom Rating Scale). The investigators will also assess if the intake of the study product can potentially give positive effects in the metabolism (blood glucose, fatty acids, protein ect).