We will conduct a 2 months clinical intervention in which a 20 g appled derived fibre supplement will be compared with a placebo without fibre. The main outcome will be the reduction in the Gastrointestinal System Rating Scale

Participants with constipation and mild gastrointestinal symptoms will be invited to participate. Those with alarming symptoms such as gastrointestinal bleeding or weight loss, those using laxatives or medications with anticholinergic actions will be excluded from the study At baseline, participants will be weighed and interrogated about Their gastrointestinal symptoms using the "Gastrointestinal symptom rating scale" Their type of stools using the Bristol visual stool scale The number of complete spontaneous bowel movements per week Afterwards, they will be randomized, balancing by age, gender and body mass index to receive in a doubly blind fashion A 20 g/day powder with apple derived fiber A similarly looking placebo powder The intervention will last 8 weeks. Every two weeks, participants will be cited to provide a new supply of the product, retrieve the used vials and be interrogated using the same tools as baseline. At the end of the intervention, participants will be weighed again

Inclusion Criteria:

• presence of constipation or functional gastrointestinal symptoms

Exclusion Criteria:

having serious cardiovascular, kidney or hepatic diseases

• gastrointestinal bleeding weight loss use of laxatives use of medications with anticholinergic actions

All information will be in databases without any identification information of participants

Active product and placebo will have the same appearance. All vials will have an unique numerical code