This is a prospective clinical intervention trial where patients with moderately active ulcerative colitis are randomized to either normal healthy diet or a diet with elimination of emulsifying agents within the E 400-group with special respect to carragenan, CMC and polysorbates. At study start and end after one month their diet, clinical characteristics and microbiota will be analysed. The hypotheses are that their disease activity measured with calprotectin and their microbiota will improve after intervention.

Patients with ulcerative colitis attending the out-patient clinic at Skåne university hospital with calprotectin 100-600 will be invited to participate in this diet intervention study. They will be divided into two arms with 35 patients in each, normal diet or E-400 elimination. The diet will be recorded at study start and end with a food diary for four days and a food frequency questionnaire regarding E-400 intake. The patients clinical characteristics (demographics) and disease activity (diarrhoea frequency, blood in stools, abdominal pain, CRP and calprotectin) will be recorded and microbiota collectted. The hypotheses are that the activity measured with clinical characteristics and calprotectin as well as their microboita measured with dysbiosis index and total genom with NGS will improve significantly.

Inclusion Criteria:

• Ulcerative colitis,
• Moderately active
• Stable medication

Exclusion Criteria:

• Severe disease
• Recent surgery
• Proctitis
• Pregancy
• Treatment with antibiotics
• Difficulties in understanding the information about the study
• Multimorbidity that makes it impossible to participate

Will be decided based upon cooperation status

Although the patients know that they will be given dietary advice they will not know what type of intervention the other group will be offered. Since dietary advice must be given by the investigators the study cannot be blinded to them.