Diet for SIBO (Phase 1 & Phase 2)
by Sue Kira, Naturopath & Clinical Nutritionist
- It’s all about the type of bacteria in our small intestines
- What causes SIBO?
- Symptoms of SIBO
- Weight loss and the SIBO diets
- The Phase 1 diet includes
- Vegan and vegetarian options with the SIBO Phase 1 diet
- The Phase 2 diet includes
- What’s next after phase 2?
Links to two SIBO Case Studies
Introduction to SIBO
The health of our gut is the foundation of the health of our entire body.
The gut is not just an organ that we push food in and waste come out the other end. In fact, our intestines have an amazing number of jobs to do. It certainly breaks down and digests our food so that we can get the nutrients needed to stay healthy “but wait there’s more”. Our intestines host innumerable amounts of bacteria both good and bad.
It’s all about the type of bacteria in our small intestines
Apparently, we have more bacterial DNA in our body than human DNA in our body. Most of these bacteria work in harmony with our cells. The cells and the bacteria work together symbiotically to create many necessary changes needed to run this machine of ours. There’s a type of ‘pay off’ system, whereby the bacteria, in the process of breaking down food (along with digestive enzymes etc) to get what they need to survive, give us what we need to survive and thrive. In other words, we look after each other.
We see this type of symbiotic relationship in the plant and animal kingdom when something is unwell or weak, and then another animal, plant or insect will kill and break it down so that the cycle continues with birth, death and recycling and feeding off each other. Now we really don’t want something in our body breaking us down, so it’s imperative that we maintain a healthy body.
Digestion starts when we chew food which then travels to the stomach. The chewing action stimulates the release of hydrochloric acid into the stomach which continues to break down the food.
After about three hours (depending on the type of food), the mixture passes into the small intestine which should be an alkaline environment that is aerobic (with oxygen). Then later, the mixture moves into the large intestine, an acidic anaerobic environment (without oxygen) where the bacteria is there to finish off and fully break down any scraps.
However, the acid in the stomach is supposed to be very acidic, and if not acidic enough, then it won’t break down the food properly before it is passed down to the small intestine where alkaline pancreatic acids are secreted.
And in reverse, should the bacteria in the large intestine (the acidic environment) get into the small intestine, they change the environment in the small intestine to one that is acidic and anaerobic. As a result, the large intestine bacteria kill off the friendly bacteria in the small intestine that need oxygen and an alkaline environment to thrive.
This environment makes the small intestine acidic and putrid with the right conditions for the acidic bacteria to grow and breed in the small intestine, hence Small Intestine Bacterial Overgrowth (SIBO).
As this acidic large intestine bacteria erodes or chews down the microvilli of the small intestine, this really upsets the apple cart as then we can’t absorb our nutrients properly anymore. If you don’t get the nutrients that would normally be absorbed from normal healthy digestion then you are likely to be deficient in vitamins, minerals and amino acids needed to balance hormones, neurotransmitters, build muscles, repair tissues and cells and give you the energy you need.
In this environment, food rots (ferments) rather than digest in our hot little bodies, giving off poisonous noxious smelling gasses (farts) such as methane and/or hydrogen causing bloating, wind, cramping, diarrhoea, burping, constipation and many more symptoms.
It is also thought that this gas can cause ‘leaky gut syndrome’, where the cell wall of the gut becomes permeable (leaky) which allows food particles into the blood stream instead of broken down nutrients and molecules. In turn, this creates an immune response because the immune system sees these particles as foreign, leading to food intolerance or even allergy if it continues. It is postulated in some cases to contribute to the creation of auto-immune diseases.
This is why a fully functioning digestive system is so important for us, where the payoff is the removal of waste without it rotting inside us and poisoning our body. The payoff for the bacteria is their survival.
What causes SIBO?
SIBO can be triggered in different ways, including the overconsumption of simple carbs and sugar, poor digestion from low stomach acid, candida overgrowth, an ileocecal valve problem, stress, underactive thyroid, the pill, antibiotic use, constipation, parasitic infections, bacterial overgrowth and various other causes.
Foods containing fermentable fibre, starch, lactose and fructose can create and/or aggravate SIBO, so part of the solution is to avoid these fermentable foods and allow the intestines to repair before consuming them again.
Given the right conditions the gut is very capable of repairing itself, but usually additional support with herbal antimicrobials, antibiotics (or both) is needed to kill off some of the bad bacteria, fungi and parasites. Be sure to get advice from your health care provider. There are stool tests and breath tests readily available to determine the level of SIBO, how bad it is and the type (Hydrogen or Methane dominant).
Symptoms of SIBO
- Bloating
- Cramping
- Wind/flatulence or burping
- Constipation &/or diarrhoea
- Food sensitivities
- Skin rashes and other skin conditions
- Recurrent iron and/or B12 deficiency
- Recurrent headaches
- Restless legs syndrome
- Inability to lose weight or maintain weight in some cases
About the SIBO Diets
Note 1: Before you commence this diet, see your medical or health care professional for qualified guidance. While on this diet, do not stop any medications or supplements previously prescribed unless advised otherwise by your medical or health care professional, who may even prescribe extra supplementation.
Note 2: During the early stages of your new diet, you may experience symptoms such as fatigue, headaches or body aches, which may occur because your body is detoxifying. However, if you are unsure about a symptom at any time, check immediately with your medical or health care professional.
The SIBO diet is in two parts, the first part (Phase 1) being rather strict and limiting in the foods allowed and it can be hard to stick to (some of my clients have said it is the hardest thing they have ever done but so worth it), depending on what you are used to eating. It is important to follow Phase 1 at least until your symptoms have settled or around six weeks. If you still have symptoms after 6 weeks you will need to speak with your practitioner about further testing.
Then under the guidance of your practitioner you may be able to go to Phase 2 foods which allows more flexibility, but be careful with sweeteners and feel when your body tells you that a food doesn’t suit you or causes bloating or any other symptoms.
After Phase 2, again for around six weeks, you can try adding some of your normal foods, but be vigilant of any returning symptoms. Be mindful of any constipation or diarrhoea, as both can re-ignite SIBO. You will also, under the care of your health provider, need some good strength multi-strain probiotics prescribed – and not just any old ones from the shops as many contain strains that may make matters worse for you. Commonly acidophilus types are not suitable at this stage.
If Phase 2 foods re-ignite the SIBO symptoms again, you can always go back to Phase 1 foods for a while. Usually this means that you need more anti-microbials, but if your body has become sensitive to antimicrobials or antibiotics, then the diet will play a big role in your recovery.
Weight loss and the SIBO diets
Some of my clients have lost a lot of weight, particularly with the Phase 1 SIBO diet. For some this is a blessing, but for the slimmer ones, not so welcome.
If the weight loss becomes a problem for you, include more fats and oils to help keep the calories up. Every gram of carbohydrate (vegies included) has 4 calories and every gram of fat has 9 calories, so you can see that fat is a much more calorie dense food. If you want to increase your calories, try eating coconut oil, or the skin and fat from organic roasted chicken, or by not straining the fat when making bone broths. Your weight will adjust as you bring in more foods in the Phase 2 SIBO diet and beyond.
The SIBO – Phase 1 diet
The Phase 1 diet includes an unlimited quantity (but don’t go overboard) of:
- Meat
- Fish
- Poultry
- Eggs
- Bone broth from beef or lamb bones
- Chicken meat broth (no bones or cartilage)
- Bok Choy
- Carrots
- Kale
- Lettuce
- Olives (in olive oil or brine but not vinegar)
- Capsicum/bell peppers
- Radish
- Rocket
- Tomatoes
- Sunflower sprouts
- Lemons
- Limes
- Unlimited amounts of water, herbal teas or Rooibos tea in warm/hot water
Plus: only one of the following per meal if desired*
- Fresh Beetroot/Beets, 2 slices (not in vinegar) can be shredded (cooked or raw)
- Broccoli – ½ cup
- Celery – 1 stick
- Fennel bulb – ½ cup
- Green beans – 10 beans
- Peas – ¼ cup
- Snow peas – 5 pods
- Zucchini – ¾ cup
- Pumpkin – ¼ cup
- Almonds – 10
- Macadamias – 20
- Pumpkin seeds – 1Tbs
- Sunflower seeds – 2Tbs
- Pecans – 10
- Hazelnuts – 10
You can also mix up things and have less of one item and add a portion of another e.g. 5 green beans plus 5 chopped almonds sprinkled on top of the other vegetables
* Two extras per meal for vegans (see also notes below)
Plus some:
- Fats and oils: olive, coconut, grape seed oils; coconut cream – ¼ cup max per day
- Salt and pepper; all fresh and dried herbs and spices – but not the blends as they often have additives – if additive free then that’s fine
Vegan and Vegetarian options with the SIBO Phase 1 Diet
If you are vegan or vegetarian it is certainly a lot harder to follow a SIBO diet because of the limited foods available. It is much more restrictive than the meat eater’s option as legumes and pulses are temporarily off the list which really restricts the food choices. But generally, vegans and vegetarians respond quicker to the diet and can often transit to the Phase 2 diet faster and then have more variety of foods to choose from.
Vegetarians have the option of using eggs as their main protein source along with the vegetables, nuts and seeds.
Vegans need to have plenty of the allowed vegetables and two lots from the Additional Foods section. For example, plenty of bok choy, carrots, kale, lettuce, olives, capsicum/bell peppers, radish, rocket, tomatoes, sunflower sprouts plus ½ cup fennel plus 10 macadamia nuts and 1 tablespoon of sunflower seeds.
Or as another example, bok choy, carrots, kale, lettuce, olives (in olive oil not vinegar), capsicum/bell peppers, radish, rocket, tomatoes, sunflower sprouts plus 5 macadamias, 1 tablespoon of sunflower seeds and 1 tablespoon of pumpkin seeds. You can mix and match to get your protein and variety.
If your symptoms don’t improve or get worse during the Phase 1 treatment, then you may have histamine sensitivity. Some bacteria actually secrete histamine, and if this is the case, then you will need to include a low histamine diet with the SIBO Phase 1 diet to reduce the inflammation that this extra histamine causes. Any added histamine from food can further drive inflammation and make it hard for your body to heal. Speak with your practitioner before changing or adding diets. With elevated histamine you may need additional antimicrobials and specific enzyme treatment.
The SIBO – Phase 2 Diet
If your practitioner has advised you to go straight to the SIBO – Phase 2 Diet, it’s best to read all of the above information as much of it is not repeated in this Phase 2 section.
Phase 2 brings much more variety to your meals and is a welcome change from the Phase 1 diet.
If you have been on the SIBO – Phase 1 diet, then in Phase 2 you can slowly introduce more of the foods you love, but be aware that if any symptoms return, then go back to Phase 1 and after a couple of weeks, reconsider what foods you gradually reintroduce. Speak to your practitioner about any symptoms you are unsure of or if any new symptoms arise.
The Phase 2 diet includes
The foods in phase 2 are either the same as phase 1 but you can now have a greater quantity of them, or there may be new foods (and old favourites) that you may wish to introduce now.
An unlimited quantity (but don’t go overboard) of:
- Meat
- Fish
- Poultry
- Eggs
- Bone broth from beef or lamb bones
- Chicken meat broth (no bones or cartilage)
- Bok Choy
- Carrots
- Kale
- Lettuce
- Olives (in olive oil or brine but not vinegar)
- Capsicum/bell peppers
- Radish
- Rocket
- Tomatoes
- Sunflower sprouts
- Lemons
- Limes
- Unlimited amounts of water, herbal teas or Rooibos tea in warm/hot water
- Black coffee, black tea (limit the caffeine varieties)
Additional Foods: only one of the following per meal if desired
Note: just have one of these foods below per meal in addition to your core diet above. You will slowly be able to introduce more of these as you progress, provided you don’t have any recurring symptoms. Be guided by your health practitioner.
- Fresh Beetroot/Beets, 2 slices (not in vinegar) can be shredded (cooked or raw)
- Broccoli – ½ cup
- Celery – 1 stick
- Fennel bulb – ½ cup
- Green beans – 10 beans
- Peas – ¼ cup
- Snow peas – 5 pods
- Zucchini – 1 cup
- Pumpkin – ½ cup
- Almonds – 10
- Macadamias – 20
- Pumpkin seeds – 1Tbs
- Sunflower seeds – 2Tbs
- Pecans – 10
- Hazelnuts – 10
- Spring onion – one shoot
- Parsnip – 1 small one
- Asparagus – 3 spears
- Brussels sprouts – ½ cup
- Leek – ½
- Spinach – 5 leaves/150g
- Banana – ½
- Berries (all varieties) – ½ cup
- Citrus – 1 piece
- Kiwifruit – 1 piece
- Rockmelon, honeydew, paw paw, papaya, pineapple – ¼ cup
- Passionfruit – 1 piece
- Rhubarb – 1 stalk
- Avocado – ¼
- Cherries – 3
- Grapes – 10
- Lychee – 5
- Pomegranate – ½ small or ¼ cup of seeds
- White Rice: Basmati or Jasmine – ½ cup per serve
- Organic Honey (clear)– no more than 2 tbsp per day (preferably none)
- Unsweetened Almond Milk – 1cup
- Hazelnuts – 20
- Pecans – 40
- Walnuts – 100g
- Apple cider vinegar (only this type of vinegar) 1tsp per day
- Sugarless Mayonnaise, Tabasco, Wasabi, Mustard (without garlic at this stage)
You can also mix up things and have less of one item and add a portion of another e.g. 5 grapes plus 20 pecans
Plus some:
- Fats and oils: olive, coconut, grape seed, pumpkin seed, sesame oils; infused oils e.g. garlic, basil, chilli; coconut cream – ¼ cup max per day
- Salt and pepper; all fresh and dried herbs and spices – but not the blends as they often have additives – if additive free then that’s fine
What’s next after Phase 2?
After you have completed three to six weeks on Phase 2 (the time will depend on symptoms – check with your practitioner), then you may slowly re-introduce some of your other favourite foods and keep your sugars and heavy starches (grains) low so that you don’t re-create the SIBO again.
Be ever watchful and observe what your body tells you if you eat something that creates symptoms.
Links to two SIBO Case Studies
Following are links to two SIBO Case Studies involving my clients:
Symptoms settled after two weeks on SIBO diet