Dawn-to-Dusk Fasting for Four Weeks Calms Gut Inflammation in Adults with Obesity

A month of fasting from dawn until dusk may do more than shrink the waistline. A new prospective cohort study published in BMC Complementary Medicine and Therapies reports that four consecutive weeks of Ramadan-style intermittent fasting were associated with measurable improvements in the molecular markers that reflect the integrity of the intestinal barrier and the intensity of subclinical, low-grade inflammation in adults carrying excess weight. The findings, led by Mohamed I. Madkour of the University of Sharjah in the United Arab Emirates together with colleagues in Jordan and the United States, add a distinctive layer to the fast-growing literature on time-restricted eating by focusing not on weight loss alone but on the gut-centered biology that is thought to connect obesity, metabolic dysfunction, and chronic inflammatory disease.

Inflammatory bowel diseases, which include Crohn’s disease and ulcerative colitis, are among the most prevalent immune-mediated inflammatory conditions in the world, and their prevalence continues to climb at an alarming rate, particularly as populations adopt Westernized diets and sedentary lifestyles. Because pharmacological options for preventing these diseases remain limited, researchers have become increasingly interested in safe, non-pharmacological dietary strategies that might dampen the inflammatory pathways upstream of disease. Intermittent fasting regimens have emerged as one of the most actively studied candidates, and the Ramadan fast — in which healthy adults abstain from all food and drink between dawn and sunset for roughly one lunar month — offers a naturalistic, real-world model of a sustained dawn-to-dusk eating window that millions of people already practice every year.

The study enrolled 46 adults with overweight or obesity, 34 men and 12 women with an average age of 37.9 years and a mean body mass index of 29.9 kilograms per square meter. Importantly, none of the participants had diagnosed inflammatory bowel disease, which allowed the investigators to ask whether fasting changes the subclinical inflammatory background that is common in obesity and considered a risk factor for future gut pathology. The researchers assessed each participant twice: once one week before Ramadan began, and once during the fourth week of the fast. At both time points they collected anthropometric measurements, fasting blood samples for metabolic and inflammatory assays, and dietary intake data, enabling a within-person comparison in which each individual served as their own control.

The inflammatory results were striking. After four weeks of dawn-to-dusk fasting, the participants showed statistically significant reductions in several key pro-inflammatory signals, including interleukin-6, tumor necrosis factor-alpha, nuclear factor kappa B, and serum calprotectin, a protein released by activated neutrophils that is widely used as a marker of intestinal inflammation. At the same time, levels of interleukin-10, an anti-inflammatory cytokine that helps restrain immune overactivity, increased significantly. The research team reported these changes at a significance threshold of p less than 0.01, indicating that the shifts were unlikely to be due to chance, although the cohort design means the associations cannot definitively prove that fasting caused the improvements.

Beyond the classical cytokines, the study also probed the molecular machinery that governs cellular defense against oxidative and inflammatory stress. Levels of nuclear factor erythroid 2-related factor 2, or Nrf2, the master transcriptional regulator of antioxidant responses, rose along with peroxisome proliferator-activated receptor gamma coactivator 1-alpha, or PGC-1alpha, a coactivator central to mitochondrial biogenesis and energy metabolism. Elevations in these markers suggest that the fasting period was accompanied by a strengthening of the body’s intrinsic antioxidant and mitochondrial maintenance programs, changes that previous laboratory work has linked to improved resilience of the intestinal epithelium and to reduced endotoxemic stress, the low-level leakage of bacterial lipopolysaccharide into the circulation that is thought to fuel systemic inflammation in obesity.

The metabolic and anthropometric data reinforced the inflammatory picture. Body weight, body mass index, fat mass, and body fat percentage all declined significantly over the fasting month, as did waist and hip circumferences, indicating a genuine reduction in the visceral and overall adipose tissue mass that acts as a factory for inflammatory signaling in obesity. Meanwhile, high-density lipoprotein cholesterol, the lipoprotein fraction generally considered protective for cardiovascular health, increased significantly at the end of Ramadan compared with pre-fasting levels, also reaching the p less than 0.01 threshold. Taken together, the pattern points toward a coordinated shift in both energy stores and inflammatory tone rather than an isolated laboratory fluctuation.

Dietary analysis helped contextualize these biological changes. During Ramadan, the participants reported significant increases in total sugar intake, polyunsaturated fatty acids, and omega-3 fatty acids compared with their pre-fasting baseline, alongside significant decreases in protein and cholesterol intake. These shifts reflect the distinctive structure of Ramadan eating patterns in many communities, where nighttime meals often feature particular traditional foods, and they raise the possibility that some of the observed anti-inflammatory effects could be partly attributable to changes in nutrient composition rather than to the fasting rhythm alone. The authors note that the omega-3 increase is of particular interest, because these fatty acids are known precursors of specialized pro-resolving lipid mediators that actively terminate inflammatory responses.

The study’s authors conclude that observing four weeks of dawn-to-dusk Ramadan intermittent fasting is associated with significant, favorable changes in circulating and molecular biomarkers linked to gut barrier integrity and systemic inflammation in non-IBD individuals with overweight or obesity. In their interpretation, the data suggest a possible improvement in the subclinical inflammatory profile and in systemic endotoxemic stress, highlighting the potential of time-restricted eating rhythms to support metabolic and intestinal homeostasis. If the improvements in calprotectin and inflammatory cytokines reflect a genuinely strengthened gut barrier, the findings carry promising preventive implications for individuals at elevated risk of developing inflammatory bowel disease, a population in which even modest reductions in baseline inflammation could meaningfully alter long-term disease trajectories.

Several important caveats temper these conclusions. The study was a prospective cohort without a randomized control group, so participants who chose to fast may differ systematically from those who do not, and concurrent changes in sleep, hydration, physical activity, and meal composition during Ramadan could all contribute to the observed biomarker shifts. The modest sample size of 46 participants, and the preponderance of men within it, limits generalizability, particularly to women and to populations with different dietary traditions. The measurement window also captured the fast itself rather than a sustained follow-up, leaving open the question of whether the improvements persist once normal eating resumes. Nonetheless, the work provides an unusually detailed molecular portrait of what a month of time-restricted eating does to the interface between the gut, the immune system, and metabolism, and it sets the stage for controlled intervention trials that could test whether structured dawn-to-dusk fasting regimens can be prescribed as a preventive tool against intestinal inflammation in at-risk populations.

Subject of Research: Effects of Ramadan intermittent fasting on gut barrier integrity and intestinal inflammation biomarkers in adults with overweight and obesity

Article Title: Four consecutive weeks of dawn-to-dusk intermittent fasting are associated with improved markers of gut barrier integrity and attenuated subclinical intestinal inflammation in adults with overweight and obesity: a prospective cohort study

Article References: Four consecutive weeks of dawn-to-dusk intermittent fasting are associated with improved markers of gut barrier integrity and attenuated subclinical intestinal inflammation in adults with overweight and obesity: a prospective cohort study. (n.d.). https://doi.org/10.1186/s12906-026-05641-7

Image Credits: AI Generated

DOI: 10.1186/s12906-026-05641-7

Keywords: intermittent fasting, Ramadan, gut barrier, inflammation, inflammatory bowel disease, obesity, time-restricted eating, calprotectin, interleukin-6, Nrf2, omega-3 fatty acids, metabolic health