GAPS and FODMAP diets for curing IBS, SIBO and digestive problems

Aubre Weber, DO, DipABLM
September 17, 2017

Have you ever heard the expression “I have a gut feeling” or do you get butterflies in your stomach thinking of the morning meeting with your boss?

New discoveries have proven links between your big brain (central nervous system) and your gut/enteric brain (called the enteric nervous system). This is commonly referred to as the CNS-ENS connection.

This new understanding has helped us see how healing the gut is not just important to your digestion, it is critical for thinking, memory and psychological health.

And yet 40 million people have Irritable Bowel Syndrome (IBS), a condition characterized by gas , bloating , diarrhea, cramping and constipation and even more have regular digestive distress. It seems that many people have very unhappy guts. And we know that if the gut is unhappy, thanks to the CNS-ENS connection, the rest of the body and the mind is unhappy, too.

Thankfully we can often heal digestive issues with dietary changes – and by healing our guts we can start the process of healing the rest of the body – including the mind.

At Parsley Health, a doctor and health coach work with you – and use cutting-edge diagnostic testing – to assess which diet may specifically help your symptoms. Generally speaking healing starts with diet, and lifestyle change. Supplements play an important role as well.

When it comes to diets and unhappy digestion, there are a few that many of our members with digestive issues ask us about on day one.

Here we explain two of the most common diets – FODMAPs and GAPS – so that you can decide if trying one is right for you.

What is the FODMAPs Diet?

The FODMAPs diet was initially developed by Monash University out of Melbourne, Australia. It is extensively studied and cited as a diet used throughout the world for irritable bowel syndrome and other GI disorders (1). FODMAP stands for Fermented Oligosaccharides, Dissaccarides, Monosaccharides and Polyols. What is this you may ask. This is a group of small and medium-chain carbohydrates and sugar alcohols found either naturally or artificially.

Examples of each are wheat (oligosaccharide), dairy (dissaccharide), high fructose corn syrup (monosaccharide) and sorbitol (polyol). For a complete list, please take a look at this FODMAP guide .

FODMAPs can ferment in the gut which produce gas, bloating and distention. Additionally, they are highly osmotic and pull water into your digestive tract changing the way your gut moves. To initiate the diet, you remove all FODMAPs for a short period of time as determined between you and your physician. Eventually, a re-introduction of FODMAPs foods is done at a slow pace keeping up with GI symptoms as you go.

What is the GAPS diet?

GAPS stands for Gut and Psychology Syndrome, was initially coined by Dr. Natasha Campbell-McBride, MD, a prominent neurologist in England, in 2004. She used a well-known diet, the Specific Carbohydrate Diet (SCD) created by Dr. Sidney Valentine Haas, and altered it to form the GAPS diet – a nutrient dense protocol delivering fresh, whole foods . GAPS was developed solely of Dr. Campbell-McBride’s patient data and her own scientific literature search discovering articles written on neuropsychiatric symptoms coexisting with gut dysfunction (2).

The GAPS diet is made up of 6 introductory stages, progressing to a maintenance phase. The stages start with elimination of all grains, starchy vegetables, sugar, beans and legumes which remains standard throughout all stages and the maintenance phase. The diet revolves around homemade meat stocks, soups, stews, cooked vegetables and natural fats. Common allergens such as dairy and egg are introduced, but not until the second and third introductory phases.

Each phase is typically a few days long progressing as long as digestive issues are not worsening. These stages are utilized to heal the gut while starving out bad bacterial colonies and overgrowth. In addition, each stage introduces different methods of cooking meats, vegetables as well as the process of fermentation. Essentially, the diet starts out very bland and cooked and progresses into various degrees of spice and rawness. This is done in an effort to allow the gut to heal, repopulate with healthy bacteria that have the ability to tolerate allowed foods in a variety of culinary forms.

Wait, which one do I use!?

They each are known for their gut-healing benefits with FODMAPs being more geared towards IBS and bloating (3) and GAPS geared towards neuropsychiatric symptom improvement. In truth, both diets can be helpful for both types of symptoms. We find that many patients who have searched for an IBS remedy found GAPS to be an incredible help, and those who needed relief from ongoing anxiety and depression found comfort in FODMAPs. Diets are words printed on paper until you see a patient come in with true problems and walk away with none after a gut-healing diet.

Recently one of our members at Parsley came in came in with a stack of medical records and a list of complaints a mile high. His parents both had autoimmune disease , and the patient, himself, had active and worsening rheumatoid arthritis. His blood tests were chalk full of alerts telling anyone who looked that inflammation was a big problem and it was causing a domino effect on everything else. His other concerns included stomach bloating, and joint pain, not to mention he was terribly depressed. He had many intolerances to food including one to dairy which made his arthritis flare and soy which caused eczema to come on with a vengeance. He couldn’t figure out why his situation wasn’t getting better. He was on the medications the doctors gave him, but it didn’t seem to fix his ailing stomach and worsening blues.

In his case I recommended the GAPS diet to the rescue – along with the Parsley Health gut healing supplement protocol, which includes supplements that soothe a very inflamed and malabsorbing gut.

It was a hard few weeks because he wasn’t initially used to eating this way or taking supplements but he was committed. He worked with his health coach, and when I saw him on follow up the change was startling.

The most significant thing about him on his return into the office was the brightness in his mood. Things had certainly changed and it was only the beginning. Six months into GAPS he was a different person. His lab work showed it, too. All his inflammatory markers were much lower if not completely normalized. His abdominal pain and bloating were entirely gone. His rheumatoid arthritis had not flared in over 3 months and he was discussing coming off his medication with his rheumatologist. Do I need to say more?

Patient stories are a true testimonial to using food as medicine. GAPS was a significant impact for this patient and we have seen similar stories when it comes to the FODMAPs diet in the treatment of SIBO . Here at Parsley, we advise a discussion of pros and cons with your doctor and coach before implementation of any one diet.

How to get started

We recommend blood work and occasionally further tests such as stool studies that can reveal parasites, yeast, dysbiosis (an imbalance in lower intestinal gut bacteria) or small intestinal bacterial overgrowth (SIBO).

SIBO in particular can be the root cause of IBS and other mental health complaints which can include abdominal pain, bloating, gas, nausea, change in bowel pattern as well as fatigue , brain fog , anxiety and even depression.

Your doctor will evaluate your testing along with your reported symptoms and develop a nutritional plan. This should include beginning goals, check-ins and eventual reintroduction of previously restricted foods. Further lab testing including blood and stool tests may be performed to assess improvement and certainly if there is any worsening in symptoms.


As with any diet, there are some risks and pitfalls to watch out for and here are a few in a nutshell.

First, diets can be restrictive and difficult to stick to without support. Find a buddy or significant other to do it with you. If you’re a Parsley Health member work with your coach for support – people who work with a health coach are twice as likely to succeed in achieving their goals!

Second, keep hydrated, and know your hunger signs – no one likes to be ‘hangry’.

Third, be mindful of your social obligations especially when it comes to birthdays, weddings and other social events that have the tempting food tray or the social pressure to eat whatever is on hand. In the beginning, it may be difficult to be out socially until you feel comfortable knowing your diet and understanding what you can and cannot eat. The key is to plan ahead and be committed – those cookies and crackers aren’t going anywhere and will be waiting for you when you are ready to reintroduce them.

How do you know if the diet worked?

We have this question time and time again on how to determine if the diet worked. Our question to you is how do you feel?

The best advice is to listen to your body. If you are feeling better then chances are the diet is doing what it set out to do – healing and sealing your gut. We recommend tracking symptoms like gas and bloating and noting if when you reintroduce foods on the FODMAPS or GAPS list that you removed, the symptoms come back.

The goal of the diet is to shift the ecosystem of bacteria in the gut to one that is more tolerant of the fibers that you removed on the GAPS or FODDMAPs diet. Most people are able to reintroduce them, or at least to follow the 80/20 rule – avoiding the foods 80% of the time but tolerating them well the other 20%.

Reference list:

  1. Halmos, EP, Power VA, Shepherd SJ, et al. A Diet Low in FODMAPs Reduces Symptoms of Irritable Bowel Syndrome. Gastroenterology 2014;146(1)67-75.
  2. Cade R et al. Autism and schizophrenia: intestinal disorders. Nutritional Neuroscience, March 2000.
  3. Staudacher HM, Irving PM, Lomer MC, Whelan K. Mechanisms and efficacy of dietary FODMAP restriction in IBS. Nat Rev Gastroenterol Hepatol. 2014 Apr;11(4):256-66.
Aubre Weber, DO, DipABLM

Credentials: Board-certified Physician in 3 medical specialties: Internal Medicine, Obesity/Metabolic Medicine & Lifestyle Medicine. Completed functional medicine training.

Training Institutions: Medical school – Philadelphia College of Osteopathic Medicine * Residency – Christiana Care Health System * Post-graduate training – Columbia University’s Institute of Human Nutrition, Obesity Medicine Association, American College of Lifestyle Medicine & American College of Preventative Medicine.

Clinical Interests: Weight Maintenance • Lifestyle Medicine * Epigenetics & Nutrigenomics • Food Allergies & The Allergic March • SIBO & Gastrointestinal Health • Autoimmunity & Systemic Inflammation • Mitochondrial Dysfunction • Hormones • Biology of Aging • Detoxification & complementary oncology strategies * Complementary neurodevelopmental treatment strategies for ASD, ADD/ADHD * Clinical teaching and advisement of other physicians

What I’m most excited to bring to Parsley Health members: As a mother of two daughters with special needs and walking beside my beloved mother-in-law undergoing treatment for a rare stage IV cancer, I am a firsthand eyewitness to what is lacking in current mainstream medicine. My excitement and passion in developing a deeper understanding of complex disease, the discovery and detective process as to why disease happens, and how to address the root cause have come from my very own personal experiences and struggles with my family’s medical journey. From this, I have become known as a proclaimed “digger”, a staunch advocate who will not give up, who firmly believes there is great importance in not just knowing a diagnosis but understanding the why behind it. In using a shared lens for both traditional and non-traditional medicine, I am excited at Parsley Health to capture and create meaningful, personalized and precise health solutions for my patients.

Ask me about: about my family and how this has changed my life towards healthier living and thrust me into a world of cutting-edge therapeutics in order to promote healthy genetic expression and reverse dysfunctional phenotypes in known disease states.

Most likely to find me: At home in Connecticut spending time with my quirky bunch which includes a husband that can really rock the guitar, my two wonderful girls, a grumpy french bulldog and me.

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