A low-fat, high-fiber diet (LFD) decreased inflammation and improved quality of life measures for patients with ulcerative colitis (UC) in remission, according to results from a parallel-group, cross-over study published in Clinical Gastroenterology and Hepatology.

Researchers monitored 17 patients with UC in remission or with flares in the past 18 months from 2015 to 2018. Patients were randomly assigned to 2 groups: the LFD group had a diet composed of 10% calories from fat while the improved standard American diet (iSAD) group had 35-40% of calories from fat for 4 weeks, a wash out period for 2 weeks, and then switched to LFD for 4 weeks. All meals were catered to the patients’ homes. The researchers collected serum and stool samples at the beginning of the study and after 4 weeks of using each diet. Researchers performed 16s rRNA and metabolomic analyses on the samples. They measured patient quality of life using a questionnaire.

All participants remained in UC remission throughout the study period. Both diets improved quality of life compared with baseline iSAD questionnaire score=4.98, P =.02; LFD =5.55, P =.001).

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Serum amyloid A levels decreased significantly from baseline in the LFD group (7.99 mg/L vs 4.50 mg/L; P =.02), as did the relative abundance of gut microbes in the genus Actinobacteria (13.69 vs 7.82%; P =.017). The relative abundance of gut microbes in the genus Bacteroidetes, fecal levels of acetate, and fecal levels of tryptophan significantly increased from baseline in the LFD group (14.6% vs 24.02%, P =.015; 40.37 vs 42.52, P =.05; 1.33 vs 2.27, P =.04), respectively.

The relative abundance of Faecalibacterium prausnitzii showed a greater increase over time in the LFD group than in the iSAD group (7.20% vs 5.37%; P =.04). Fecal levels of lauric acid had a differential response in both diets. At baseline the fecal lauric acid level was 203.4, but after LFD, it decreased to 29.91 (P =.04) and after the iSAD it increased to 381.4 (LFD vs iSAD, P =.02).

Limitations of this study include the short intervention time, the small sample size, and the fact that no endoscopy was performed.

The researchers state that both diets were well tolerated and increased the patient-reported quality of life. The LFD decreased markers of inflammation and intestinal dysbiosis in fecal samples. The study authors asserted that dietary interventions may offer benefits to patients in remission from UC.

Disclosures: Some authors declared receiving consulting or funding from the pharmaceutical industry. A complete list of disclosures can be found in the original study.


Fritsch J, Garces L, Quintero M A, et al. Low-fat, high-fiber diet reduces markers of inflammation and dysbiosis and improves quality of life in patients with ulcerative colitis. [available online May 14, 2020]. Cin Gatroenterol Hepatol. doi:10.1016/j.cgh.2020.05.026