What is a Probiotic?
A probiotic is a live microorganism that, when consumed in the right amounts, provides a health benefit to the host. These beneficial microbes are often bacteria, though some yeasts can also act as probiotics. They help support gut health by maintaining microbial balance in the digestive tract.
Probiotics are commonly found in fermented foods such as yoghurt, kefir, sauerkraut, kimchi, and some traditional sourdoughs. For a food to be considered probiotic, it must contain specific strains shown to survive digestion and deliver health effects.
Probiotics and Sourdough
Traditional sourdough bread involves a natural fermentation process using wild yeasts and lactic acid bacteria. While most of these microbes do not survive baking, the fermentation process can still support gut health in other ways. For example, it may increase digestibility, reduce gluten sensitivity, and support prebiotic effects that nourish existing gut microbes.
Some sourdough breads made using techniques such as retarded fermentation or added fermented dairy (e.g. in a porridge-style loaf) may retain viable cultures if not baked at high heat. However, sourdough is typically not classified as a probiotic food because the live cultures do not usually survive the baking process.
Why Probiotics are Important
Probiotics help regulate digestion, reduce inflammation, and support the immune system. They can also improve mood and cognitive health through the gut-brain axis.
Studies show that a healthy gut microbiome plays a crucial role in nutrient absorption and overall health. Combining probiotic-rich foods with high-fibre, prebiotic sources creates a more favourable environment for beneficial bacteria. This approach helps improve microbial diversity and resilience in the gut ecosystem. You can try our Big Poops Bread recipe that delivers a phenomenal amount of fibre and flavour in one loaf!

Supporting Probiotic Health with Sourdough
Even though sourdough may not always contain live probiotics, it plays a supportive role. The fermentation process increases bioavailability of nutrients and breaks down antinutrients like phytic acid. This improves conditions for existing probiotics to thrive. We integrate this understanding into our courses and teaching at The Sourdough School, using the BALM Protocol to guide baking for gut and mental health.