A new study tested the effects of a low-calorie, plant-based, fasting diet on the symptoms and pathology of inflammatory bowel disease in mice models.
Inflammatory bowel disease refers to chronic conditions that cause inflammation in some parts of the intestine. There are two main kinds of inflammatory bowel disease: Crohn’s disease and ulcerative colitis. Crohn’s disease can affect any part of the gastrointestinal tract from the mouth to the anus. Ulcerative colitis is usually limited to the intestinal mucosa.
The exact cause of inflammatory bowel disease is unknown
Although the exact cause of inflammatory bowel disease is still unknown, it is believed to be a result of a defective immune system that responds incorrectly to the environmental triggers causing inflammation of the gastrointestinal tract. Genetic predisposition, factors that change gut microbiota, certain types of diets, and stress are the main risk factors associated with inflammatory bowel disease.
Finding the right treatment for inflammatory bowel disease can be challenging
Because the cause of inflammatory bowel disease could be very diverse, varying from an underlying genetic predisposition to microbial infection, the treatment for this disease is difficult. Although there are various medicines available to treat inflammatory bowel disease, it is difficult to reverse the pathology of the disease. Therefore, there has been ongoing research to find therapies for inflammatory bowel disease that can result in long-term remission in patients.
The role of diet in treating inflammatory bowel disease
The scientists agree that patients with inflammatory bowel disease have very different gut microbiota compared to people without the disease. Studies have shown diets that cause these pro-inflammatory changes in the bacterial population of the gut are associated with the development of inflammatory bowel disease pathology.
Although researchers are still working to understand the effect of nutrition on inflammatory bowel disease, many animal studies have shown benefits of periodic fasting and fasting-mimicking diet in improving the healthy lifespan as well as treating a variety of diseases such as multiple sclerosis and diabetes.
New study tested the effect of fasting-mimicking diet on inflammatory bowel disease
The researchers from the University of South California conducted a study in mice to examine the health benefits of periodic cycles of low-calorie, low-protein plant-based fasting-mimicking diet in reversing the pathology of inflammatory bowel disease and the effects of the diet on markers of inflammation in humans. The study was recently published in the journal Cell Reports.
The researchers used dextran sodium sulfate (DSS), a compound that causes inflammation of the gut, to induce the symptoms and pathology of inflammatory bowel disease in mice. The pathological features of inflammatory bowel disease in mice included leaky gut, presence of immune cells in the gut, shortened length of the gut, and blood in stools.
The researchers then gave one group of DSS-treated mice a 4-day fasting-mimicking diet that included human grade vegan-food. The second group of DSS-treated mice received a water-only diet for 48 hours.
The fasting-mimicking diet alleviated some and reversed other inflammatory bowel disease symptoms
Multiple cycles of fasting-mimicking diet followed by normal diet showed reduced inflammation of the gut, increased the number of stem cells, increased the presence of protective gut microbiota, and increased the gut length. The researchers did not observe the same changes for mice on water-only diet. These results suggest that certain nutrients from the fasting diet act as pre-biotic and induce the anti-inflammatory and microbial changes that help reduce the pathophysiology of inflammatory bowel disease
The fasting-mimicking diet may have the potential to mitigate inflammatory bowel disease
The results of this study show that cycles of fasting-mimicking diet followed by normal diet increase beneficial gut microbiota, increase intestinal stem cell, and reduce intestinal inflammation. Multiple cycles of fasting-mimicking diet resulted in activation of stem cells and regeneration of colon. The researchers suggest that fasting primes the body for improvement while re-feeding with normal diet provides the nutrients for rebuilding cells and tissues. This regimen may be helpful in mitigating inflammatory bowel disease.
The researchers also observed that the transplants of Lactobacillus or fecal microbiota resulted in reversing of inflammatory bowel disease symptoms such as shortening of colon, intestinal inflammation, and reduced stems cells in the colon induced by DSS. Thus, the fasting-mimicking diet, in combination with lactobacillus transplant may have the potential to reverse the symptoms and pathology of inflammatory bowel disease.
The effect of fasting on white blood cells and inflammatory markers in humans
Using the results from this and previous studies, the researchers showed that the fasting-mimicking diet helps in reducing the markers of inflammation, such as C-reactive protein (CRP) that is usually elevated in patients with inflammatory bowel disease. The cycles of fasting-mimicking diet also reverse the associated increase in white blood cells.
Clinical trials involving use of fasting-mimicking diet on humans are needed
The present study showed that two cycles of four-day fasting-mimicking diet followed by normal diet proved to be helpful in mitigating some and reversing other symptoms and pathologies of inflammatory bowel disease. The water-only diet, however, did not achieve the same effects.
The authors of the study expressed the need for randomized controlled clinical trials involving humans to test the beneficial effects of a fasting mimicking diet in reversing the pathology of inflammatory bowel disease. Although the results of the study on mice are promising, the safety and efficacy of these dietary treatments need to be established in humans before they can be used for successful treatment of inflammatory bowel disease.
Written by Preeti Paul, MS Biochemistry
Reference: Priya Rangan et al., Fasting-Mimicking Diet Modulates Microbiota and Promotes Intestinal Regeneration to reduce Inflammatory Bowel Disease. Cell reports 26, 2704-2719, March 5, 2019 https://doi.org/10.1016/j.celrep.2019.02.019