SIBO Diet: How does a SIBO Diet Plan look like?

Content
What is Small Intestinal Bacterial Overgrowth?
The Role of Diet in SIBO
Basic Principles of a SIBO Diet
What SIBO diets are there?
Low FODMAP Diet
Specific Carbohydrate Diet (SCD)
SIBO-Specific Food Guidelines (SSFG)
Bi-phasic Diet
Low Fermentation Diet

What is a Small Intestinal Bacterial Overgrowth?

Small intestinal bacterial overgrowth is a bacterial overgrowth in the small intestine, a section of our digestive tract that usually contains few bacteria. When bacteria manage to settle there, they have ideal growth conditions because the small intestine still contains all the nutrients from our food, which the gut bacteria use as nourishment. Additionally, there are few other bacteria in the small intestine as competition—perfect for SIBO pathogens. The SIBO symptoms are almost identical to those of irritable bowel syndrome, making SIBO one of the most important differential diagnoses in suspected IBS.

The Role of Diet in SIBO

Bacteria must produce energy to survive, and they do this by fermenting fibers and carbohydrates from our food. These components in our food are called FODMAPs (Fermentable Oligo-, Di-, Monosaccharides, and Polyols) and can be found in a variety of foods. This is where dietary changes come into play, alongside the use of antibiotics and plant-based substances for treatment.

Foods like onions, garlic, leeks, mushrooms, cruciferous vegetables, grains, dairy products, fruits, and sweeteners like xylitol are involved. By reducing this group of foods in our diet, the bacteria have less food and, due to the absence of fermentation, produce less gas.

Basic Principles of a SIBO Diet

The different dietary approaches for treating small intestinal bacterial overgrowth specifically target FODMAPs. Depending on the diet, fiber-rich foods are more or less strictly avoided (low-fodmap) for a limited period. This helps quickly reduce gas and toxin production, alleviating symptoms and allowing the intestine to rest. However, the diet itself cannot treat the bacterial overgrowth; it is solely intended to reduce symptoms.

What SIBO diets are there?

Dietary therapies suitable for SIBO include the Low FODMAP Diet, Specific Carbohydrate Diet (SCD), SIBO-Specific Food Guidelines (SSFG), Bi-Phasic Diet, and Low Fermentation Diet.

Low FODMAP Diet

The Low FODMAP Diet focuses on reducing the fermentable oligo-, di-, monosaccharides, and polyols in food. In addition to the foods mentioned above, FODMAPs are also found in high-fructose fruits like pears, apples, and cherries. Low FODMAP options include raspberries, melon, and papaya. Vegetables such as onions, artichokes, cauliflower, beans, and other gas-inducing vegetables are high in FODMAPs. Potatoes, squash, and spinach are typically tolerated and considered low FODMAP. (1)

Specific Carbohydrate Diet (SCD)

The Specific Carbohydrate Diet (SCD) was developed by American physician Dr. Haas. This diet focuses on reducing grains and carbohydrates. On this diet, the consumption of starch, sugar (e.g., fructose and lactose), and any form of grains is prohibited. Allowed foods include fresh vegetables, fresh meat, eggs, tea, honey, and fructose-free fresh fruit. (2)

SIBO-Specific Food Guidelines (SSFG)

The SIBO-Specific Food Guidelines (SSFG) developed by Dr. Allison Siebecker combine the Low FODMAP and SCD diets, making this approach even more restrictive. Dr. Siebecker categorizes foods based on their fermentability into four groups. Groups 1–3 are generally allowed, but the amounts of foods in Groups 2 and 3 are reduced. Group 4 contains highly fermentable foods and is completely excluded. Allowed foods include carrots, cucumbers, tomatoes, grapes, pineapples, almonds, butter, eggs, and tea. (3,4)

Bi-phasic Diet

The Bi-Phasic Diet, developed by Dr. Nirala Jacobi, consists, as the name indicates, of two phases. The first phase is very restrictive, avoiding all fermentable carbohydrates for two to four weeks. In the second phase, restrictions are relaxed to provide a small food source for “good” bacteria. Therapeutic supplements are often introduced during this phase. (5)

Low Fermentation Diet

The Low Fermentation Diet, created by Dr. Mark Pimentel (also known as the Cedars Sinai Diet), allows relatively many foods. The focus here is also on meal timing. A four-hour gap between meals is recommended (meal spacing), and it is advised not to eat right before bed. Allowed foods include simple carbohydrates (e.g., rice, potatoes, white bread, pasta), proteins, and fats. Fermentable carbohydrates, fibers, fructose, and lactose should be avoided. (6,7,8)

Each dietary approach should be followed carefully. These diets are not intended for long-term use and are not a treatment for SIBO itself; they primarily help reduce symptoms and support the regeneration of the gut and therefore gut health. Once symptoms improve, a return to a normal, balanced, and healthy diet should be considered. It is recommended to ask a dietitian for help.

References

1. FODMAP-Tabelle-Blog.jpg (761×1200) (fodmap-info.de); zuletzt geprüft 07.05.2023; modifizierte Tabelle aus „Der Ernährungsratgeber zur FODMAP-Diät“ von Prof. Dr. med. Martin Storr
2. Was ist SCD? | scd-blog.de ; latest check 07.05.2023
3. PowerPoint Presentation (siboinfo.com); latest check 07.05.2023
4. Diet – SIBO – Small Intestinal Bacterial Overgrowth (siboinfo.com); latest check 07.05.2023
5. Small Intestinal Bacterial Overgrowth – Home – The SIBO Doctor; latest check 07.05.2023
6. pdf (siboinfo.com); latest check 17.10.2023
7. Irritable Bowel Syndrome: Mark Pimentel, MD (cedars-sinai.org); latest check 21.10.2023
8. Mark Pimentel und Dr. Ali Rezaie (2024); “The Microbiome Connection: Your Guide to IBS, SIBO, and Low-Fermentation Eating”