Fasting-Mimicking Diet Reduces Inflammation in Crohn’s Disease

A clinical trial led by Stanford Medicine has found that a fasting-mimicking diet (FMD) can induce clinical response and remission in adults with mild-to-moderate Crohn’s disease. The findings, published in Nature Medicine, suggest that a specific dietary intervention may provide relief for a condition that has historically lacked clear dietary guidance.

The study, an open-label, randomized, controlled trial, involved 97 participants. Those in the FMD group followed a regimen consisting of very low-calorie, plant-based meals for five consecutive days per month. This cycle was repeated for three consecutive months, with participants returning to their regular baseline diets on all non-FMD days. The control group continued their baseline diets throughout the duration of the study.

Clinical Response and Remission Rates

Researchers measured the primary outcome of clinical response based on the Crohn’s Disease Activity Index (CDAI). A clinical response was defined as a reduction in the CDAI of at least 70 points or a CDAI score of 150 or less after the completion of the third five-day diet cycle.

The results showed that 45 patients in the FMD group, representing 69.2% of the group, met the primary outcome of clinical response. In comparison, only 14 patients, or 43.8%, in the control group achieved the same result (P = 0.03).

The study also tracked clinical remission as a secondary outcome. Forty-two patients in the FMD group (64.6%) achieved clinical remission, while 12 patients (37.5%) in the control group did so (P = 0.02).

Biochemical and Inflammatory Markers

Beyond patient-reported symptoms, the trial measured biological markers of inflammation to determine if the diet produced physical changes in the body. Specifically, the researchers tracked fecal calprotectin, a known inflammatory marker.

The FMD group experienced a 22.0% decline in fecal calprotectin from baseline. Conversely, the control group saw an 8.0% increase in the marker (P = 0.03).

Exploratory analyses further examined peripheral blood mononuclear cell gene expression and plasma metabolites. These analyses revealed that the fasting-mimicking diet led to decreases in immune-effector transcripts and key inflammatory lipid mediators, which the researchers noted were concordant with the reduced activity of the Crohn’s disease.

Dietary Guidance in Inflammatory Bowel Disease

The trial addresses a significant gap in the management of inflammatory bowel disease (IBD), which includes both ulcerative colitis and Crohn’s disease. According to Stanford Medicine, the question What should I eat? is one of the most common queries patients with IBD pose to their physicians, yet it remains one of the most difficult to answer due to a lack of extensive, well-controlled studies on dietary changes.

Researchers noted that studying diet is inherently challenging because participants may not always accurately report their food intake. Placebo effects are difficult to avoid in dietary trials since participants are aware of the diet they are following.

Despite these challenges, the trial results demonstrate that the FMD is superior to a baseline diet for inducing clinical response, clinical remission, and biochemical improvement in patients with mild-to-moderate Crohn’s disease.

The researchers concluded that these findings support the further investigation of fasting-mimicking diets as an adjunctive therapy for chronic inflammatory diseases. The trial was registered under the ClinicalTrials.gov identifier NCT04147585.