SIBO-Diet: Specific Carbohydrate Diet (SCD)
Content
1. What is SIBO?
1.1 Nutrition for SIBO
2. Specific Carbohydrate Diet (SCD)
2.1 Development of the SCD
2.2 Studies about SCD
2.3 How does the SCD work?
2.4 Implementation of the SCD
1. What is SIBO?
SIBO (Small Intestinal Bacterial Overgrowth) is a condition where there is an excessive growth of bacteria in the small intestine. The small intestine is a part of the digestive tract that normally contains only a small number of bacteria. The symptoms of SIBO are almost identical to those of Irritable Bowel Syndrome (IBS), making it one of the most important differential diagnoses when IBS is suspected. Symptoms include abdominal pain, bloating, digestive issues, diarrhea, constipation, belching, a feeling of fullness, and heartburn.
1.1 Nutrition for SIBO
Bacteria need to produce energy in order to survive. They do this, for example, by fermenting fiber and carbohydrates from the food we eat. These components in our diet are called FODMAPs. FODMAP stands for fermentable carbohydrates and sugar alcohols, and they are found in a wide variety of foods. Changing your diet can therefore be used alongside antibiotics and herbal substances to help treat SIBO.
2. Specific Carbohydrate Diet (SCD)
The Specific Carbohydrate Diet (SCD) was developed by the American doctor Dr. Haas and focuses on reducing grains and carbohydrates. When following the diet, the consumption of starch, sugars (such as fructose and lactose), and all types of grains is prohibited. Allowed foods include fresh vegetables, fresh meat, eggs, tea, honey, and fresh fruit that is low in fructose. (1) (1)
2.1 Development of the SCD
Dr. Haas originally developed the SCD to treat celiac disease (2) and cystic fibrosis (a genetic condition in which thick mucus clogs organs like the lungs and pancreas, leading to breathing problems and digestive issues). The SCD also became known as the “banana diet,” as highlighted in a publication by Dr. Haas in 1924 (3).
2.2 Studies about SCD
After his death, Elaine Gottschall promoted the awareness of the diet (4), after it had also helped her daughter with ulcerative colitis. In 2018, a study by Suskind et al. showed that the SCD has positive effects on patients with chronic inflammatory bowel diseases (IBD) (5). O’Dwyer et al. published a study in 2015 that demonstrated positive effects of the SCD in patients with irritable bowel syndrome (IBS) (6).
Although the research on the effect of the SCD on SIBO is not conclusive, this diet is still used in the symptomatic treatment of SIBO.
The bacteria that are increased in the small intestine in SIBO thrive on carbohydrates. The SCD targets this by limiting fermentable carbohydrates. The goal is to deprive the bacteria in the small intestine of their food source with the SCD.
2.3 How does the SCD work?
The Specific Carbohydrate Diet (SCD) is based on the principle of allowing only carbohydrates that consist of single sugar molecules (monosaccharides), as these can be directly absorbed in the small intestine. More complex carbohydrates, on the other hand, are more poorly digested and serve as food for bacteria in the gut, which can lead to fermentation, bloating, and inflammation. By deliberately excluding these difficult-to-digest sugars, the aim is to reduce bacterial overgrowth in the small intestine, relieve the intestinal lining, and improve quality of life.
The SCD therefore classifies foods as either allowed or not allowed. A complete list of foods, divided into allowed and not-allowed categories, is available here (7).
2.4 Implementation of the SCD
Since the SCD is a very restrictive diet, it is not recommended to follow it independently in the long term. A doctor or nutritionist should supervise the implementation of the diet to avoid deficiencies. Additionally, it is advisable to keep a food diary to identify any individual intolerances in advance. Furthermore, diets are mainly suited for symptom management and are usually not sufficient for a complete therapy. Therefore, a doctor or alternative practitioner should ideally support the treatment process with other approaches.
References
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- Was ist SCD? | scd-blog.de ; last checked 29.04.2025
- Management Of Celiac Disease by Sidney Valentine Haas : Free Download, Borrow, and Streaming : Internet Archive; zuletzt geprüft 29.04.2025
- HAAS SV. THE VALUE OF THE BANANA IN THE TREATMENT OF CELIAC DISEASE. Am J Dis Child. 1924;28(4):421–437. doi:10.1001/archpedi.1924.04120220017004
- Breaking the Vicious Cycle – Specific Carbohydrate Diet; last checked 29.04.2025
- Suskind DL, Cohen SA, Brittnacher MJ, Wahbeh G, Lee D, Shaffer ML, Braly K, Hayden HS, Klein J, Gold B, Giefer M, Stallworth A, Miller SI. Clinical and Fecal Microbial Changes With Diet Therapy in Active Inflammatory Bowel Disease. J Clin Gastroenterol. 2018 Feb;52(2):155-163. doi: 10.1097/MCG.0000000000000772. PMID: 28030510; PMCID: PMC5484760.
- Specific carbohydrate diet: irritable bowel syndrome patient case study; O’Dwyer, Darla D.;Darville, Ray L.Nutrition and food science, 09 Nov 2015, Vol. 45, Issue 6, pages 859 – 872; ISSN: 00346659; DOI: 10.1108/NFS-05-2015-0056; Publisher: Emerald Group
- Breaking the Vicious Cycle – Legal Illegal List; last checked 29.04.2025
