SIBO and the Low FODMAP Diet
- 2 hours ago
- 4 min read
Why “Healthy” Foods May Be Triggering Your Symptoms
If you constantly feel bloated after meals, struggle with uncomfortable digestion or find that “healthy eating” often makes you feel worse rather than better, you are not alone.
Many of the clients I work with come to me feeling frustrated and confused.
They are eating salads, smoothies, fruit, hummus and high fibre foods because they are trying to support their health, yet they are dealing with symptoms such as:
• Bloating
• Gas
• Abdominal discomfort
• Reflux
• Constipation or diarrhoea
• Food sensitivities
• Fatigue after eating
• One of the most common underlying issues I see in clinic is SIBO.
What are FODMAPs?
FODMAPs are a group of fermentable carbohydrates and sugars found in certain foods. The term stands for:
• Fermentable
• Oligosaccharides
• Disaccharides
• Monosaccharides
• And Polyols
These carbohydrates are not fully absorbed in the small intestine, so they travel into the digestive tract where they ferment and can trigger symptoms in sensitive individuals.
For some people, this fermentation happens more significantly in the small intestine itself, particularly in cases of SIBO.
What is SIBO?
SIBO stands for Small Intestinal Bacterial Overgrowth.
In simple terms, it means bacteria have overgrown in the small intestine, where they should normally exist in much smaller amounts.
The small intestine is where much of our digestion and nutrient absorption takes place. When excess bacteria are present there, they ferment carbohydrates too early in the digestive process, producing gas and triggering symptoms.
Importantly, SIBO is not always caused by “bad” bacteria. Often, it is bacteria that belong in the large intestine ending up in the wrong place.
Signs your symptoms may be linked to SIBO
One clue I often look for is timing.
If bloating and discomfort begin quite soon after eating, this can sometimes indicate SIBO rather than fermentation happening further down in the large intestine.
Common symptoms can include:
• Bloating
• Gas
• Abdominal pain
• Constipation
• Diarrhoea
• Feeling full quickly
• Food sensitivities
• Fatigue after meals
Many people are told these symptoms are “just IBS”, but there is often more going on underneath the surface.
Why “healthy” foods can make symptoms worse
This is where things become confusing for many people.
Foods such as:
• Watermelon
• Mango
• Garlic and onion
• Hummus and pulses
• Cauliflower
• Wheat based pasta
• Certain fruits and smoothies
can all be very high in FODMAPs and may worsen symptoms in sensitive individuals.
So while these foods may be nutritious in many contexts, they may not feel supportive for someone dealing with SIBO or FODMAP intolerance.
What can cause SIBO?
SIBO rarely appears in isolation.
Underlying contributors can include:
• Low stomach acid
• Poor digestive enzyme production
• Chronic stress
• Sluggish bowel motility
• Frequent antibiotic use
• Parasite or GI infections
• Hypothyroidism
• Frequent use of acid reducing medications such as PPIs
• Crohn’s or Coeliac disease
• Oral contraceptive use
• Moderate to heavy alcohol intake
This is why Functional Medicine focuses on understanding root causes rather than simply removing foods.
Can a low FODMAP diet help?
For many people, yes.
A low FODMAP approach can help reduce symptoms by temporarily removing the fermentable carbohydrates feeding the bacteria and triggering symptoms.
However, this is where many people get it wrong.
The low FODMAP diet is not designed to be a permanent restrictive diet.
The goal is to:
• Calm symptoms
• Identify trigger foods
• Support gut healing
• Gradually reintroduce foods where possible
In many cases, clients only react to certain FODMAP groups rather than all of them.
The reintroduction phase matters
One of the biggest mistakes people make is staying on a strict low FODMAP diet for too long. Once symptoms improve, foods should usually be reintroduced methodically and gradually.
The reintroduction phase helps identify:
• Which FODMAP groups trigger symptoms
• How much your body can tolerate
• Which foods can safely return to the diet
For example:
• Polyols may be tested with avocado or apricots
• Lactose with milk or yoghurt
• Fructose with mango or honey
• Fructans with bread, garlic or onion
• Galacto oligosaccharides with lentils or chickpeas
This should ideally be done with guidance, especially for more complex or long standing digestive issues.
Helpful tools and practical tips
I often recommend the Monash University FODMAP app, which can help people identify:
• Low FODMAP foods
• Portion sizes
• Hidden triggers
• Safer swaps
Simple low FODMAP meal ideas can include:
• Grilled salmon with quinoa and cucumber
• Roast chicken with potatoes and salad
• Rice bowls with allowed vegetables
• Gluten free oats or rice cereals
• Berry platters with strawberries and blueberries
The aim is never fear around food. It is learning what your body tolerates while supporting gut healing.
A note on probiotics and treatment
Many people assume probiotics are always beneficial, but with active SIBO this is not always the case.
Some probiotics may worsen symptoms in certain individuals, particularly during active bacterial overgrowth.
In more stubborn or severe cases, antimicrobial support or antibiotics may sometimes be needed alongside dietary changes and root cause work.
This is why personalised support matters so much.
Final thoughts
Digestive symptoms are common, but they are not something you simply have to live with.
If you feel bloated after meals, react to lots of foods or feel confused about what your gut can tolerate, it may be worth exploring whether SIBO or FODMAP sensitivities are contributing.
The goal is not restriction forever.
The goal is understanding your body, calming symptoms and rebuilding long term gut health in a sustainable way.
If you would like personalised support for IBS, SIBO or digestive symptoms, you can book book a free discovery call with me today or follow @tracytredouxhealth for regular gut health and Functional Medicine insights.
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