Navigating the low FODMAP diet can feel like walking through a maze, especially when it comes to common ingredients like mushrooms. If you’re managing IBS or other digestive sensitivities, you know that even small dietary choices can have a big impact. Mushrooms are praised for their flavor and nutritional benefits, but their FODMAP content can be confusing.
This guide will clear up the uncertainty surrounding mushrooms and the low FODMAP diet. We will explore which types of mushrooms you can enjoy, what portion sizes are considered safe, and which varieties you should avoid to keep your symptoms at bay. By the end, you’ll know exactly how to incorporate mushrooms into your meals without triggering discomfort.
Understanding FODMAPs and Mushrooms
Before we get into specifics, let’s quickly recap what FODMAPs are. FODMAP is an acronym for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols. These are short-chain carbohydrates that the small intestine has trouble absorbing. For people with Irritable Bowel Syndrome (IBS), these undigested carbs can ferment in the gut, leading to uncomfortable symptoms like bloating, gas, stomach pain, and altered bowel habits.
Mushrooms contain a type of polyol called mannitol. (Wever & Karlijn, 2024) Polyols are also known as “sugar alcohols,” and they are one of the “P”s in the FODMAP acronym. While not all mushrooms contain the same amount of mannitol, many popular varieties are high in this polyol, which is why they are often flagged as a high-FODMAP food. However, this doesn’t mean you have to eliminate them from your diet entirely.
Low FODMAP Mushroom Varieties
The key to enjoying mushrooms on a low FODMAP diet is knowing which types to choose and, crucially, sticking to appropriate portion sizes. Monash University, the leading authority on the FODMAP diet, has tested various mushrooms and provides specific serving size recommendations. (Monash University FODMAP App, n.d.)
Canned Champignon Mushrooms
If you’re looking for a safe and versatile option, canned champignon mushrooms are your best bet.
- Low FODMAP Serving: A generous serving of ½ cup (75g) is considered low FODMAP. (Monash University FODMAP App, n.d.)
- Why they are safe: The canning process is the secret here. Because mushrooms are canned in brine or water, the water-soluble mannitol leaches out of the mushrooms and into the liquid. (Wever & Karlijn, 2024) As long as you thoroughly rinse the mushrooms before using them, their FODMAP content is significantly reduced. (Wever & Karlijn, 2024)
Oyster Mushrooms
Fresh oyster mushrooms are another excellent choice for those following a low FODMAP diet. They have a delicate flavor and a tender texture that works well in stir-fries, soups, and pasta dishes.
- Low FODMAP Serving: You can safely enjoy up to 1 cup (75g) of fresh oyster mushrooms. (Monash University FODMAP App, n.d.)
- FODMAP Content: This serving size is low in both mannitol and another FODMAP, fructans. Be mindful that larger servings will contain moderate amounts of these FODMAPs.
Black Chanterelle Mushrooms
Dried mushrooms can be a great way to add a concentrated flavor to your cooking. Black chanterelle mushrooms are one of the few dried varieties that have a safe low FODMAP serving. (Wever & Karlijn, 2024)
- Low FODMAP Serving: A small serving of 2 teaspoons (7g) is considered low in FODMAPs.
- How to use: This is a small amount, but their rich, earthy flavor means a little goes a long way. Rehydrate them in hot water and use them to add depth to sauces, broths, and risottos.
Mushrooms to Limit or Avoid
While some mushrooms can be enjoyed freely in the right portions, many common varieties are high in FODMAPs and should be avoided during the elimination phase of the diet.
Button, Cremini, and Portobello Mushrooms
These three popular mushrooms are actually the same species (Agaricus bisporus), just at different stages of maturity. (Types of Gourmet Mushrooms: A Chef’s Guide, 2025) Unfortunately, they are all high in mannitol.
- Button/White Mushrooms: A small serving of just ½ a mushroom (10g) is considered low FODMAP. Anything more than that quickly becomes high in mannitol. (Are mushrooms low FODMAP?, 2024)
- Portobello/Portabella Mushrooms: Similar to button mushrooms, only a tiny serving of 1 tablespoon (10g) is low FODMAP. (Wever & Karlijn, 2024) This is not a practical amount for most recipes.
- Cremini Mushrooms: These are also high in mannitol and should be avoided. (Wever & Karlijn, 2024)
Shiitake Mushrooms
Fresh shiitake mushrooms are a popular ingredient in Asian cuisine, but they are high in mannitol. (Wever & Karlijn, 2024)
- Low FODMAP Serving: There is no safe low FODMAP serving size for fresh shiitake mushrooms listed by Monash University. (Monash University FODMAP App, n.d.)
- Dried Shiitake: A small serving of 2 dried mushrooms (7g) is considered low FODMAP. Larger servings contain high amounts of mannitol. (Monash University FODMAP App, n.d.)
Your Guide to Safely Eating Mushrooms
Managing a low FODMAP diet is all about making informed choices. Here are some actionable tips for enjoying mushrooms without the worry:
- Always Measure Your Portions: Use a kitchen scale to accurately measure your serving of mushrooms. The difference between a low and high FODMAP serving can be very small.
- Rinse Canned Mushrooms Well: If you’re using canned champignon mushrooms, pour them into a colander and rinse them under running water for at least 30 seconds to wash away the mannitol-rich canning liquid.
- Read Ingredient Labels: Be cautious with processed foods like sauces, soups, and vegetarian meat alternatives. These often contain “mushroom powder” or “mushroom extract,” which are typically made from high FODMAP mushrooms and are highly concentrated.
- Reintroduce Carefully: Once you have completed the elimination phase, you can test your personal tolerance to mannitol by reintroducing a high-mannitol mushroom, like button mushrooms, in small, controlled amounts.
Find Your Balance with FODMAPs
Living with digestive sensitivities doesn’t mean you have to eat a bland or restrictive diet forever. The goal of the low FODMAP diet is to identify your specific triggers so you can reintroduce a wider variety of foods back into your life. For many, this means finding a balance with foods like mushrooms.
By sticking to low FODMAP varieties like canned champignons and fresh oyster mushrooms in their recommended serving sizes, you can enjoy their delicious flavor without fear of triggering symptoms. Always listen to your body and work with a registered dietitian or healthcare professional to guide you through the diet and help you find what works best for you.
