IBS-SIBO Relief: A Comprehensive Guide to The Low Fermentation Diet

BloatingIBSAdvice
Written By Marilia Chamon

Irritable Bowel Syndrome (IBS) is a common gastrointestinal disorder that affects millions of people worldwide. It is characterised by abdominal pain, bloating, and altered bowel habits, which can significantly impact the quality of life. While various strategies exist, no one-size-fits-all solution has been found. However, emerging research points to the potential benefits of a low fermentation diet in managing IBS-SIBO symptoms. In this blog post, I’ll dive into the principles of this diet and how it may help alleviate IBS-related discomfort.

What is the Low Fermentation Diet?

The low fermentation diet is a relatively new dietary approach that aims to reduce the production of gas and other byproducts from the fermentation of undigested carbohydrates in the gut. These byproducts, such as hydrogen, methane, and hydrogen sulfide, are thought to contribute to the bloating, pain, and altered bowel habits experienced by IBS sufferers. By minimising the fermentation process, the low fermentation diet may help alleviate these symptoms.

Dr. Mark Pimentel, a gastroenterologist and the Executive Director of the Medically Associated Science and Technology (MAST) Program at Cedars-Sinai Medical Center in Los Angeles, has played a significant role in the development of the low fermentation diet. Dr. Pimentel is a leading expert in IBS and small intestinal bacterial overgrowth (SIBO), and his research has contributed to the understanding of the role of gut bacteria and fermentation in IBS symptoms.

Dr. Pimentel and his team have developed the low fermentation diet as a dietary approach specifically targeting IBS and SIBO symptoms by reducing the fermentation of carbohydrates in the gut. The diet is based on the principle of limiting the production of gas and other byproducts of fermentation to help alleviate bloating, abdominal pain, and other IBS-related discomforts.

Key Principles of the Low Fermentation Diet for IBS

Low fermentation eating has two essential rules:

  • Limit the intake of foods that contain high levels of carbohydrates or ingredients in food that humans can’t digest, and therefore are digested by gut bacteria

  • Space meal out four to five hours apart

Foods allowed in the Low Fermentation Diet

Here's a list of low fermentation foods that are typically well-tolerated in a low fermentation diet. Remember, individual tolerances may vary, so it's essential to tailor your diet to your specific needs.

Vegetables:

  • Carrots

  • Cucumbers

  • Bell peppers

  • Aubergine

  • Courgette

  • Tomatoes

  • Green beans

  • Lettuce

  • Spinach

  • Kale

  • Chard

  • Rocket

  • Parsnip

  • Potato

Fruits:

  • Avocado

  • Oranges

  • Grapes

  • Blueberries

  • Strawberries

  • Raspberries

  • Pineapple

  • Kiwi

  • Cantaloupe

  • Honeydew melon

Grains:

  • White rice

  • Gluten free pasta made from white rice or corn

  • Sourdough bread

Proteins:

  • Chicken

  • Turkey

  • Lean cuts of beef

  • Pork

  • Fish (salmon, tuna, cod, etc.)

  • Seafood (shrimp, scallops, etc.)

  • Eggs

Nuts & seeds:

  • Almonds

  • Chestnuts

  • Hazeznuts

  • Walnuts

  • Pecans

  • Macadamia

  • Brazil nuts

  • Sunflower seeds

  • Pumpkin seeds

Dairy & Alternatives:

  • Yellow cheeses (parmesan, cheddar, manchego, gruyere)

  • Lactose-free milk

  • Almond milk

  • Coconut milk

  • Rice milk

  • Oat milk

Herbs & spices:

  • Basil

  • Oregano

  • Thyme

  • Rosemary

  • Parsley

  • Chives

  • Cilantro

  • Ginger

  • Peppermint

  • Cinnamon

Oils & fats:

  • Olive oil

  • Coconut oil

  • Avocado oil

  • Butter (in moderation)

Beverages:

  • Water

  • Herbal tea

  • Green tea

  • Black tea

  • Coffee

Sweeteners:

  • Honey (small amounts)

  • Maple syrup

Foods to limit in the Low Fermentation Diet

Here's a list of foods that are typically avoided or limited in the low fermentation diet due to their high-FODMAP content or potential to promote fermentation. Keep in mind that individual tolerances may vary, and it's essential to tailor your diet to your specific needs.

Vegetables:

  • Garlic

  • Onions

  • Leeks

  • Asparagus

  • Artichokes

  • Brussels sprouts

  • Cauliflower

  • Broccoli

  • Cabbage

  • Beans and lentils

  • Peas

Fruits:

  • Apples

  • Pears

  • Banana

  • Prune

  • Fig

  • Date

  • Dried fruits

  • Fruit juice concentrates

Grains:

  • Brown rice

  • Oats

  • Whole wheat pasta, breads and cereals

Dairy & Alternatives:

  • Cow's milk

  • Soft cheeses (e.g., ricotta, cottage cheese, cream cheese)

  • Yoghurt

  • Soya milk

Sweeteners:

  • Sucralose

  • Inulin

  • Agave syrup

  • High-fructose corn syrup

  • Sorbitol, mannitol, xylitol, and other sugar alcohols

The Importance of Meal Spacing in the Low Fermentation Diet for IBS Relief

Spacing meals out is an essential rule of the low fermentation diet because it allows the digestive system to efficiently process and absorb nutrients while minimizing the potential for fermentation. When meals are spaced out, it gives the gastrointestinal (GI) tract time to clear out food from one meal before introducing the next. This can help prevent an overload of fermentable substances in the gut, which could otherwise lead to increased gas production, bloating, and abdominal pain.

The migrating motor complex (MMC) is another crucial factor in understanding the importance of spacing meals. The MMC is a series of coordinated contractions that occur in the stomach and small intestine during fasting periods. These contractions help clear undigested food particles, bacteria, and other substances from the GI tract. By allowing adequate time between meals, the MMC can function optimally and reduce the likelihood of bacterial overgrowth and fermentation.

Spacing meals can also help regulate the amount of food consumed at each meal, preventing overeating and reducing the strain on the digestive system. This can further aid in minimising fermentation, as the body is better equipped to break down and absorb smaller portions of food.

In summary, spacing meals out is essential in the low fermentation diet because it:

  • Allows the digestive system to efficiently process and absorb nutrients

  • Minimises the potential for fermentation

  • Supports the optimal functioning of the migrating motor complex

  • Helps regulate portion sizes and prevent overeating

The Low Fermentation Diet x The Low FODMAP Diet

A low fermentation diet and a low FODMAP diet share some similarities, but are slightly different. Here's a brief comparison of the two diets:

  • Low Fermentation Diet: The primary goal of a low fermentation diet is to reduce the production of gas in the gut by limiting the intake of foods that feed gut bacteria. A low fermentation diet emphasises consuming easily digestible carbohydrates and proteins, and avoiding foods that are high in resistant starches, fibers, and other hard-to-digest carbohydrates. This diet may include some food restrictions similar to the low FODMAP diet, but the focus is specifically on limiting the intake of foods that feed gut bacteria.

  • Low FODMAP Diet: The low FODMAP diet aims to alleviate symptoms in individuals with IBS and other gastrointestinal issues by reducing the intake of specific types of carbohydrates known as FODMAPs (Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols). These carbohydrates are poorly absorbed in the small intestine, leading to fermentation in the large intestine, and resulting in symptoms like bloating, gas, abdominal pain, and diarrhoea. The low FODMAP diet involves eliminating or reducing high-FODMAP foods, such as certain fruits, vegetables, dairy products, legumes, and sweeteners, and replacing them with low-FODMAP alternatives. It is often implemented in three phases: elimination, reintroduction, and personalization, allowing individuals to identify and manage their specific food triggers.

In summary, while both diets aim to alleviate gastrointestinal symptoms by limiting the intake of fermentable carbohydrates, the low fermentation diet focuses on reducing foods that feed gut bacteria, while the low FODMAP diet specifically targets FODMAPs as the primary source of concern.

Conclusion

The low fermentation diet offers a promising new avenue for managing IBS symptoms. By focusing on reducing the fermentation process in the gut, this dietary approach may help alleviate bloating, abdominal pain, and other discomforts associated with IBS. However, it is important to remember that individual responses will vary, and personalising your diet based on your specific needs is essential for success. Always consult a healthcare professional before making significant changes to your diet, especially if you have IBS or other gastrointestinal disorders.

Written by Marilia Chamon

Registered Nutritional Therapist, Gut Health, IBS & SIBO Expert

Founder of Gutfulness Nutrition 

Instagram @gutfulnessnutrition

Marilia Chamon
Previous

Best Foods For Gut Health: Boost Your Digestion with These Nutritional Powerhouses
Next

Gut-Skin Connection: How Gut Health Influences Skin Appearance