The Effect of Natural Carbonated Mineral Water Consumption on Gastrointestinal Transit and on Gut Microbiota in Subjects With Functional Constipation: A Randomized, Placebo-Controlled Pilot Trial

Functional constipation (FC) is a common condition associated with aging, lower socioeconomic status, low physical activity and also with reduced fibre, water and magnesium intakes. Different studies have reported a positive association between the intake of hyper-mineral water containing a high content of bicarbonate, calcium, or magnesium, and the improve of the gastrointestinal transit. There is evidence that magnesium and sulphate, both individually, have a laxative action. However, the impact of other minerals is scarce. It has been described different mechanisms explaining how gut microbiota influence the gastrointestinal transit. Specifically, in FC patients, it is important to understand the particularities of their gut microbiota and understand whether the intake of hyper-mineral water, a natural source of minerals, can modify positively the gut microbiota. The aim of the present randomized placebo-controlled pilot trial is to evaluate, for the first time, the effect of the carbonated mineral water consumption in the gastrointestinal transit and in the gut microbiota of subjects with FC.


Eligibility Criteria:
Inclusion Criteria:

* Age between 18 to 70
* Having Functional Constipation diagnosis criteria, according to the Rome IV criteria
* Not using any laxative drug for 3 days before screening visit
* Drinking 1.0 ± 0.5 L of water per day
* Accept and sign the consent

Exclusion Criteria:

* Treatment or disease (current or past) likely to interfere with evaluation of the study parameters
* Taking antibiotics in the 3 months preceding the recruitment visit
* Taking supplements and any food enriched or presented containing bacteria or yeasts likely to have an effect on the gastrointestinal tract, particularly on intestinal transit, digestive comfort, gas production, the occurrence of abdominal pain in the 30 days preceding the recruitment visit (these products will also be banned during the study period)
* Subject having an alcohol consumption of more than 3 glasses of wine a day, or 2 glasses of beer a day, or 1 glass of hard liquor a day
* Subject having a coffee consumption greater than 5 cups per day
* Subject with constipation attributable to an organic or anatomical cause (Hirschsprung's disease, hypothyroidism, mental deficiency, psychiatric illness, neurological abnormalities, history of operation of the colon or anus, colorectal cancer, anemia, etc.)
* Subject with a history of current gastrointestinal pathology or disorder such as duodenal ulcer, chronic colitis, or chronic inflammatory disease of the gastrointestinal tract (Crohn's disease, ulcerative colitis), celiac disease or syndrome irritable bowel
* Subject having a history of operation of the digestive tract
* Subject having undergone surgery in the two months preceding the recruitment visit
* Subject having undergone bariatric surgery
* History of renal disease (renal insufficiency etc.) or cardiovascular disease (cardiac insufficiency...), respiratory disease, neural disease
* Having participated in a weight loss program (with a 5-10% weight) loss in the last 3 months prior to the recruitment visit
* Body mass index \> 35 kg/ m2
* Taking supplements of magnesium, vitamins, or other minerals during the study period
* Intake of other carbonated mineral waters beyond the given water, during the study period.
* Pregnancy
* Participation in another clinical trial during the last 30 days prior to the recruitment visit