The SIBO diet can help treat Small Intestinal Bacterial Overgrowth by removing foods that feed excess bacteria in the gut.
This guide will talk you through what SIBO foods to avoid and how the right SIBO diet can help you manage your symptoms and prevent relapses.
What is a SIBO diet?
The SIBO diet removes foods from your diet that feed excess bacteria in your small intestine, to identify which foods trigger SIBO.
SIBO (Small Intestinal Bacterial Overgrowth) is a digestive condition caused by an excessive amount of bacteria in the small intestine. Symptoms include tummy pain, diarrhoea, constipation, bloating and nutrient absorption issues.
Treatment frameworks for SIBO commonly use antibiotic therapies, however 43% of patients experience SIBO relapses within 9 months of antibiotic treatment.
Addressing the underlying causes of Small Intestinal Bacterial Overgrowth, which includes diet, can therefore help manage your symptoms and prevent relapses.
How SIBO and diet are linked
SIBO occurs when bacteria that are supposed to stay in the large intestine begin move down the intestinal tract to small intestine, triggering an imbalance in the gut’s microbiome.
As the bacteria overgrow in the small intestine, they feed on any food that is present in the gut. This triggers a fermentation process that leads to an imbalance in the gut’s microbiome, known as dysbiosis.
Certain foods are harder to digest or contain complex sugars, making them easier for bacteria to feed on, grow and multiply.
Therefore, removing these foods from your diet is crucial for a successful SIBO treatment framework.
Your SIBO diet food list: what to eat and what to avoid
When considering a SIBO diet, the key principle is choosing food that is easy to digest high up in the digestive tract, leaving less food for any bacteria to feed on in the small intestine.
SIBO foods to avoid
SIBO dietary triggers tend to be high-FODMAP foods (Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols)
FODMAPs contain short chain carbohydrates are absorbed poorly by the large bowel and allow bacteria ferment easily.
High-FODMAPs foods include:
Dairy products
Vegetables such as cauliflower, brussels sprouts, garlic and onion
Fruits containing high levels of fructose, such as apples and pears
Wheat and rye products, including most bread and pasta
Food and drinks containing sweeteners
Processed food
Foods for a SIBO-friendly diet
Low-FODMAP foods don’t feed bacteria the way carbohydrates do and are crucial for a SIBO-friendly diet.
Low-FODMAP foods include:
Meat, poultry, fish, and eggs
Vegetables such as courgettes, bell peppers & carrots
Lower-sugar fruits, such as blueberries & strawberries
Low lactose or lactose-free dairy products
Types of SIBO diet
There are a number of SIBO diets to choose from. Your doctor or nutritionist will help you identify the diet that is most suitable for you and your lifestyle:
Low-FODMAPs diet
This is the most common SIBO dietary approach, which works in phases:
Restriction phase: all high-FODMAPs foods are removed. This phase typically lasts two to six weeks
Reintroduction phase: individual food groups are tested one at a time over three-day challenges. If symptoms stay under control during the three days, that food is considered tolerated and is added back into your regular diet. If symptoms return on any day, you stop the challenge and mark that food as a SIBO trigger
This SIBO diet approach lets you build a personalised long-term diet rather than staying on a blanket restriction indefinitely.
Low Fermentation Diet
This diet is easier to follow and slightly less restrictive than a full low FODMAP approach. It focuses on reducing fibre, fructose, and lactose while allowing easily digested starches like rice and potatoes.
It is often a good starting point for addressing SIBO through your diet, allowing you to move on to the stricter Low-FODMAP diet if your symptoms don't improve.
The Elemental Diet
For severe cases, or when other SIBO diets haven’t worked, the elemental diet is a more aggressive – but effective – option.
It is a liquid-only formula where all nutrients are pre-broken-down into their simplest forms: amino acids, simple sugars, and fats.
Everything is absorbed in the very first section of the small intestine, which then starves the bacteria further along.
Tips for adopting a SIBO diet
Talk to the experts
It can be helpful to work with a dietitian experienced in gut health who can help to identify a suitable diet, such as a low FODMAPs diet, and help you reintroduce foods.
Don’t be “put off” foods
A SIBO diet isn’t meant to demonise foods higher in FODMAPS. It’s to help rebalance your gut microbiome so you can heal your gut and enjoy these foods once again.
Seek medical advice
It is important to have a diagnosis of SIBO confirmed so that other conditions such as Irritable Bowel Disease (IBS) , coeliac disease and Inflammatory Bowel Disease (IBD) can be ruled out.
If you think you might have SIBO, you can self-refer to The Functional Gut Clinic.
Other ways to treat SIBO
A SIBO diet should be adopted as part of a broader SIBO treatment framework, which can also include:
Antibiotics
The primary treatment frameworks for SIBO is oral antibiotics. However, antibiotics have variable success rates: studies have shown relapse rates after antibiotics are common, with approximately 43% of patients experiencing recurrence of symptoms within 9 months of completing treatment.
Furthermore, antibiotics can have side effects such as bacterial resistance and diarrhea.
As a result, a growing number of patients are interested in using complementary and natural treatments such as natural plant extracts and herbal SIBO supplements for their gastrointestinal health.
Herbs for SIBO:
Herbs with antimicrobial properties and specialised herbal SIBO supplementscan help reduce bacterial overgrowth in the small intestine and help restore the balance, without the side effects often associated with antibiotics.
Probiotics:
Probiotics are used as part of a broader SIBO treatment framework, alongside antibiotics or herbal supplements, to restore balance in the microbiome and alleviate the discomfort caused by harmful gut bacteria.
Lifestyle changes to support intestinal motility:
Consistent eating habits, portion control and hydration will help the small bowel sweep bacteria, undigested material and residual secretions towards the colon (intestinal contraction known as peristalsis).
Discover 3 everyday habits that increase your risk of getting SIBO.
Download SIBO Unlocked: your free guide to SIBO
Our free SIBO Unlocked Guide is full of expert advice from AltruVita, unlocking the truth about SIBO and helping you take the first step to understanding your digestive health