Small Intestinal Bacterial Overgrowth (SIBO) is a condition in which there is an excessive amount of bacteria in the small intestine. This overgrowth can lead to a variety of uncomfortable symptoms, including bloating, gas, diarrhea, and abdominal pain. Diet plays a crucial role in managing SIBO, both in alleviating symptoms and preventing recurrence. This article provides a comprehensive overview of the SIBO diet, with a focus on the Siebecker Protocol and other dietary approaches.
Understanding SIBO and Its Symptoms
SIBO occurs when bacteria, which are normally found in the colon, migrate or overgrow in the small intestine. This can be caused by a variety of factors, including:
- Taking proton pump inhibitors or opioids
- Gastric surgery
- Nerve damage to the small intestine
- Failure of the ileocecal valve
The most common symptom of SIBO is bloating, which results from the fermentation of sugars and carbohydrates by bacteria, producing gas. Other symptoms can include excess gas, constipation or diarrhea, heartburn or reflux, abdominal pain, and malnutrition. In rare cases, a serious neurological condition called D-lactic acidosis can occur. It's important to note that SIBO symptoms can mimic other conditions, such as Irritable Bowel Syndrome (IBS), and many people with SIBO also have IBS. As many as 78% of people with SIBO also have IBS.
The Role of Diet in SIBO Management
Dietary changes are a cornerstone of SIBO management, working in conjunction with antibiotics or herbal antimicrobials to reduce symptoms and prevent recurrence. The primary goal of a SIBO diet is to starve the bacteria in the small intestine by limiting the availability of fermentable carbohydrates. However, it's important to remember that there isn't a one-size-fits-all approach, and the best diet for SIBO will depend on individual factors and tolerances.
General Dietary Recommendations for SIBO
After SIBO treatment, there are some general dietary recommendations that can help prevent recurrence. These include:
Read also: The Carnivore Diet for SIBO
- Limiting processed sugars: Avoid or severely limit processed sugars such as cookies, cakes, candy, and soda.
- Limiting Alcohol: Alcohol is also eliminated or drunk in minimal amounts.
- Choosing complex carbohydrates: Complex carbohydrates are preferred over simple carbohydrates.
- Considering carbohydrate intake: The total amount of daily carbohydrate may be decreased compared to before treatment but not as severely as a Paleo or ketogenic diet.
Many 'SIBO diets' you find on the internet don’t mention that they’re only supposed to be temporary: usually for a maximum of six weeks.
Common SIBO Diets and Protocols
Several dietary approaches are commonly used for SIBO management. Here's an overview of some of the most popular options:
1. The Low-FODMAP Diet
The Low-FODMAP diet is one of the most well-known dietary approaches for SIBO. FODMAPs (Fermentable Oligo-, Di-, Mono-saccharides and Polyols) are a group of small chain carbohydrates that are often not well absorbed in the small intestine. These carbohydrates provide an easily fermentable food source that perpetuates the overgrowth of bacteria in the small intestine. FODMAPs are found in a wide variety of foods, including:
- Fructose: Simple sugars commonly found in fruits and some vegetables, honey, and agave nectar
- Lactose: A sugar molecule in dairy products
- Fructans: A sugar compound found in gluten products, fruits, some vegetables, and prebiotics
- Galactans: A compound found in some legumes
- Polyols: Sugar alcohols often used as low-calorie sweeteners
Foods that contain higher amounts of FODMAPs include high-fructose corn syrup, agave nectar, honey, soda and soft drinks, garlic, onions, asparagus, butternut squash, cauliflower, artichokes, beans, apples, dried fruits, sausage, flavored yogurt, ice cream, sweetened cereals, barley, rye, grains, peas, mannitol, and sorbitol.
The Low-FODMAP diet is meant to be short-term, followed by a structured food reintroduction phase. While research mainly focuses on IBS, many experts believe the diet may also help SIBO, as the two conditions often overlap.
Read also: Phase 1 SIBO Diet
2. The Specific Carbohydrate Diet (SCD)
The Specific Carbohydrate Diet (SCD) was created over 100 years ago to treat conditions like ulcerative colitis, Crohn’s disease, and celiac disease. The premise behind the SCD is that certain types of carbohydrates increase inflammation and feed the growth of harmful gut bacteria, which in turn interferes with nutrient absorption. The SCD works by eliminating most carbohydrates, starving the harmful bacteria in the small intestine. Foods like rice, potatoes, quinoa, legumes, processed meats, and added sugars are excluded, while fruits, vegetables, eggs, fermented dairy, and meats are recommended.
In a recent study comparing the Low-FODMAP diet to the SCD for IBS, participants on the Low-FODMAP diet saw greater symptom relief. While the SCD may help some people, it's restrictive, time-consuming, and challenging to follow.
3. The Cedars Sinai Diet / Low Fermentation Diet
The Cedars Sinai Diet, also known as the Low Fermentation Diet, was developed by researcher and SIBO expert Dr. Mark Pimentel at Cedars Sinai. This diet focuses on reducing the intake of easily fermentable carbohydrates to minimize gas production in the small intestine. Timing is also important in the low-fermentation diet. Eating specific meals and limiting snacks are suggested to allow for “cleansing waves” in the digestive system. These are described as “housecleaning” for the gut. In reality, most, if not all of these diets are often used in conjunction with this type of meal spacing> The low-fermentation diet simply emphasizes the importance of meal spacing. It is also the only diet that has been specifically studied as a treatment for SIBO.
4. The SIBO Specific Food Guide Diet (Siebecker Protocol)
The SIBO Specific Food Guide diet was crafted by Dr. Allison Siebecker and combines the low FODMAP and SCD diets. Like a stoplight, green-coded foods are "legal," whereas yellow-coded foods are to be eaten with caution in lower amounts. Red-coded foods are "illegal." The guide gives recommended portion sizes for each food. There are no studies on this diet being used to manage SIBO. It is, however, widely used and anecdotally improves symptoms. It is restrictive and not meant to be followed long term. The SIBO diet is one tough cookie (pun intended). Aside from requiring some new vocabulary (try saying Fermentable Oligo-, Di-, Mono-saccharides and Polyols five times fast), a SIBO diet takes time and dedication to successfully implement. While it’s not intended for long term use, many individuals do end up following the SIBO diet for quite some time while they heal their digestion.The SIBO diet doesn’t have to be impossible. With our tips, you can find clarity and encouragement as you begin your treatment plan. So, how exactly do you keep your sanity while on the SIBO Specific Diet?
5. The Elemental Diet
An elemental diet is a premade liquid drink or powder that is mixed with water. The nutritional components of the formula are broken down already so that your body does not have to do any work. The mixture contains proteins in the form of amino acids and carbohydrates, fat, vitamins, and minerals that are broken down. Some products require you to add MCT oil to the mix. The elemental diet formula is absorbed by the body so quickly that the gut bacteria don’t have time to eat it. Effectively it starves the bacteria to death. Clinical trials show an 80-84% success rate in getting rid of SIBO.
Read also: Elemental Diet Research
With that success rate, which is great, why not do this with everyone? There are a few reasons; an elemental diet is not appropriate for some people nor desirable for most. It is a two-week, liquid-only, no solid food diet. Most people do not want to “drink” their food for two weeks. The only proven diet for SIBO is the all-liquid elemental diet, which should only be embarked upon under a doctor’s supervision.
6. The Paleo Diet
The paleo diet is less well-defined than low-FODMAP or SCD diets. In general, the paleo diet eliminates grains, dairy, and processed foods. It also limits sugars.
7. The Low-Histamine Diet
And while there has not been research investigating the low-histamine diet and SIBO, it is possible that the low histamine diet will help SIBO symptoms. By report, people are using it to do so. This diet may be used in a variety of ways from minimal to extensive restrictions. It is not meant to be used long-term. Histamine overload symptoms often improve after SIBO treatment and the diet can be expanded. Fermented foods have the highest histamine levels, so you’ll need to skip the fermented foods - sauerkraut, kombucha, picked veggies, alcohol, etc. Fresh, unprocessed foods have the lowest histamine levels.
8. The GAPS Diet
GAPS stands for Gut and Psychology Syndrome, a term coined by the diet’s founder Dr. Natasha Campbell-McBride. The GAPS diet is a strict elimination diet aimed at decreasing gut permeability, otherwise known as a leaky gut. It’s promoted as a natural treatment for people with conditions such as autism, ADHD, Dyslexia, and other neurologic or mental health disorders (8). No published research studies are using the GAPs diet for SIBO management.
Implementing the SIBO Diet: Key Considerations
- Work with a healthcare professional: It's crucial to work with a doctor, registered dietitian, or nutritionist who is knowledgeable about SIBO to develop an individualized diet plan.
- Address the underlying cause: It’s often a good idea to start on a low dose, in case you have a reaction to your antimicrobial supplements. However we know that you’re more likely to clear your SIBO if you take the right dose for the right amount of time. If you go in at the deep end you’re more likely to feel unwell and give up the protocol completely.
- Consider individual tolerances: In SIBO, what is and isn't tolerated varies greatly per person. One person’s most aggravating food can be the next person’s best tolerated food.
- Start with a balanced meal equation: When initially following the SIBO Specific Diet, we often encourage patients to start with foods that are both low-FODMAP and SCD “legal”. If you were provided a SIBO specific diet handout, this is often depicted as the “green column”.
- Plan ahead: The key to success with any elimination diet is planning. Spending a few hours over the weekend to plan out meals, grocery shop, and prep a few dishes will save you time, money, and stress during the week.
- Create emergency meals: Even with the best planning, there are often times when we are left unprepared. Keep a few staples in your fridge or freezer that can easily be transformed (or just reheated) for a quick meal or snack.
Beyond Diet: Additional SIBO Treatment Strategies
While diet is a critical component of SIBO management, it's often necessary to combine dietary changes with other treatment strategies, such as:
- Antibiotics: Antibiotics (herbal or traditional) will temporarily help SIBO symptoms and are a cornerstone of treatment. But, SIBO relapse rates with antibiotics alone are high.
- Herbal antimicrobials: There are many antimicrobial herbs that work very well to clear SIBO. That particular study used the SIBO breath test to measure the gas levels of one group of patients after a course of Rifaximin, and another group after a course of a herbal supplement.
- Probiotics: Some studies suggest that probiotics may limit bacterial overgrowth, lower scores on the hydrogen breath test, and reduce abdominal pain with SIBO. However, a 2021 systematic review concluded that large, high-quality studies are needed to understand the effects of probiotics on SIBO. Some experts believe probiotics could make SIBO worse.
- Lifestyle modifications: Optimal stomach pH, bile production and flow, motility, ilealcecal valve function and immunity in the small intestine to prevent (and thus successfully treat) SIBO.