Detection of FODMAP Intolerances and Symptom Improvement Following Dietary Intervention in Patients from Northwestern Mexico

Introduction: Fermentable oligo-, di-, monosaccharides, and polyols (FODMAP) are associated with gastrointestinal symptoms in patients with gut-brain interaction disorders, negatively impacting quality of life if left untreated. Objectives: To identify FODMAP intolerances in patients from Northwestern Mexico referred by gastroenterologists and to design low-FODMAP diets to alleviate their symptoms. Methods: A single-group quasi-experimental study was conducted, including breath hydrogen tests to detect small intestinal bacterial overgrowth and intolerances to lactose, fructose, sorbitol, and fructans. Personalized low-FODMAP diets were designed to manage symptoms. Symptoms were assessed at baseline and post-intervention using a 100-mm visual analog scale, and 24-hour dietary recalls were applied. Results: Of the 36 patients recruited, 21 (mean age: 35.9 years) completed the study, with 42% diagnosed with irritable bowel syndrome (IBS). At baseline, 92% reported abdominal bloating (mean severity: 6.5 ± 2.4) and flatulence (5.6 ± 2.8). Other reported symptoms included nausea (31%), reflux (28%), anxiety or stress (22%), and insomnia or irritability (17%). Intolerances were observed in 39% for lactose, 33% for fructose, 56% for sorbitol, and 61% for fructans. Following the dietary intervention, severity of abdominal bloating, abdominal pain, borborygmi, diarrhea, constipation, and flatulence decreased significantly (p ≤ 0.05). Energy and macronutrient intake remained stable throughout the study, whereas FODMAP intake decreased markedly. Conclusion: A low-FODMAP dietary intervention tailored to pre-identified specific intolerances effectively reduced patients’ gastrointestinal symptoms.