What’s with nutritional yeast?

We’ve had a few owners write in asking whether nutritional yeast is related to the yeast found on dog’s skin, and worried that if they feed it to their dog they could make yeast skin infections worse.

We realise we need to put this worry to bed once and for all!  We got our vet founder Dr Lucy to answer this question to sort out any confusion that has arisen from the fact that both are called yeasts – but in fact, as she’ll explain, they couldn’t be more different!

So, is nutritional yeast the same as yeast found on the skin, and can eating it in the diet predispose to skin infections?

Over to Dr Lucy:

“I can totally see where the worry and confusion comes from, obviously they are both called ‘yeast’ but thankfully they are very different and the answer is very simple: nutritional yeast is completely different from the yeast on the skin, and it does not cause skin infections.”

Not convinced or now just curious for more info? Let’s delve a little deeper 🙂


Nutritional Yeast

Nutritional yeast is an inactivated yeast, not capable of multiplying, with incredible properties that make it a vegan superfood. We use it in our Noochy range for the following reasons:

It is choc-a-bloc full of protein (48g/100g that’s almost double the levels found in the most protein dense meats) plus contains B vitamins, zinc and. Last but not least, the major reason that has made it a world-wide flavour favourite and included in vegan sauces (and dressings, pasta bakes, pizza toppings etc) is that a generous sprinkle of it gives the food it is being added to a delicious, natural cheesy flavour. 

Nutritional yeast is a relatively expensive ingredient. While there are lots of cheaper palatants (like the brewers yeast and meat-based palatants) found in many dog foods, none give the natural cheesy flavour that Nooch does, and as such, I was determined that it would be the star of the show.

So when you combine nutritional yeast and mixed herbs, thyme, basil and marjoram, like in Noochy Poochy Adult – it gives this delicious cheesy-herby taste and smell – some owners who have tried it for themselves have even said it tastes like spaghetti bolognese! 


Malassezia Yeast

The yeast found in the skin including in the ear canals are called Malassezia. Contrary to inactivated nutritional yeast with all its helpful properties of flavour and nutrition, Malassezia yeast are living micro-organisms capable of multiplying quickly if the setting is right (and I’ll explain the most likely settings a little later on!)

Malassezia yeast is part of the normal flora on the skin and in the ear canals in low numbers in dogs and humans, and the same goes for normal bacteria on the skin and in the ear canals in dogs and humans. These yeast & bacteria usually live ‘in harmony’ with dogs, humans and themselves (there’s no lesions, no itchiness, no ‘infection’) and bacteria and yeast help to keep each other in check. As such we call these micro-organisms ‘’commensals’’ – it means they are expected to be there, they’re usually not doing any harm and in fact often they may well be doing us some good.

Problems with Malassezia yeast most often occur when there is a change in the skin (or as we vets like to call it, the ‘skin barrier’ – as that is, essentially what skin is to the rest of the body). If the skin or skin barrier gets damaged e.g. scratched; burned; kept wet for a long time; flares up because the dog comes into contact with something they are allergic to: then the bacteria or Malassezia yeast (often one of them gets the upper-hand but sometimes it is both at the same time!) take the opportunity to multiply… which causes the skin to get warmer and wetter ….which only serves to make the bacteria or Malassezia yeast even more happy… and multiply more… and it’s an ongoing cycle. This is called an infection.

 The dog’s skin becomes irritated and itchy and the dog becomes more unhappy as the infection progresses. Often this means head flapping and ear scratching if this is happening down the ears, and more scratching or licking if it’s a skin infection on the body, paws or legs or tail.

Inactivated nutritional yeast does not cause skin yeast infections. Even if you were to place nutritional yeast directly onto damaged or inflamed dog skin, these inactivated yeast could not multiply – nutritional yeast is simply a good nutrient source when eaten. 

Yeasts in food and the future.

As more and more of us choose a vegan lifestyle and the food manufacturing world looks for ways to produce nutrients for us and our companion animals in environmentally friendly ways – the sustainability and production scalability of nutrient-dense, edible yeasts like nutritional yeast, makes it very likely that we will be seeing the word ‘yeast’ more and more in our foods over the next few years as food technology advances.


I hope that this allays any initial worries you may have had when you saw the word ‘yeast’.

In fact, as a vegan recipe that is also wheat-free, Noochy Poochy naturally omits 6 of the 7 most common canine food allergens, plus it has a more balanced Omega 6:3 ratio than most pet foods on the market … many owners report an improvement in skin health after starting to feed Noochy Poochy.