“Yoghurt is Good for Your Gut”: Is Your Favourite Good for You?

I’m not a fan of yoghurt.  It seems a terrible thing to say given I understand the benefits of eating the product and encourage others to eat it!  It’s the tangy taste that I don’t like and haven’t for many years.

Recently however I had a planned surgery and there was a risk I may find swallowing difficult for a few days.  I therefore thought about ways to support my health as much as possible with soft foods.  Homemade soup, cottage cheese and yoghurt seemed to be reasonable choices.  As I was going to have general anaesthetic it was likely my gut would be temporarily disrupted (it was) and both cottage cheese and yoghurt are thought to support the gut.  Since I don’t like the taste of yoghurt however I had to think how to use it.  Homemade smoothies were my preferred choice with antioxidant rich berries, nutritious avocado, energy giving banana, and protein and nutrient-rich seeds.  I bought a large tub of an organic, natural, live yoghurt that had a proper lid so it didn’t need to be used in one day.  I was brave too and tried a bit on its own; it didn’t taste too bad after all.  This one seemed to taste milder than other yoghurts I’ve tried.

Enough about me though, what about the benefits of this ancient food?  Do all yoghurts give us those benefits?  After all, we hear so much controversy around the health benefits of dairy, but not yoghurt.  This post investigates.

(At risk of starting a spelling war, I’ve chosen to use the predominantly British English spelling of yoghurt.  Any quotes or article references use the spelling used by their authors/publishers.)

Yoghurt is traditionally a dairy product made by heating milk and combining it with cultures (strains of bacteria).  The bacteria feed on the lactose (milk sugar) and produce lactic acid, which gives yoghurt its taste.  Of course, depending on the type of yoghurt you want, other products are added such as additional sugar, fruit purees, colours and flavourings.

Along with the gut health benefits, yoghurt is believed to be a good source of protein, calcium, B vitamins and other nutrients.

The main benefit is from the cultures that are added.  These bacteria (mainly lactobacillus and bifido bacteria species, and streptococcus thermophilus*) can have a probiotic effect, helping to populate the gut’s microbiome.  The benefits of this are believed to include:

• Digestive support including the potential to reduce symptoms in IBS sufferers, and the alleviation of constipation
• Immune system support – the gut plays a huge role in our immunity
• Nutrient manufacture – while a good diet is important, the gut bacteria can produce small amounts of some vitamins and minerals that may be used in the gut or elsewhere in the body
• The potential to alleviate diarrhoea caused by antibiotics.

A further potential benefit is that some individuals with lactose intolerance may find that they are able to tolerate yoghurt.  This may be due to the bacteria within it that help to breakdown the lactose during the digestive process, and, potentially, the acidity of the food (Savaiano, 2014).  While this is great for yoghurt lovers who find themselves unable to tolerate lactose, I should highlight that this will not be the case for everyone – monitor your own symptoms and reactions to any foods that you eat to help you understand their suitability for you.  The research referenced above (by a member of the Dannon Company and financed by the Danone Institute International) discusses an animal study that first identified the importance of the bacteria, supported by a human study of just 10 people.  While promising, a study of 10 people may not be reliable enough to draw definite conclusions.

*Streptococcus thermophilus is not a harmful strain of bacteria.  While a few streptococcus strains are associated with illnesses such as strep throat, this one is not.

This is one of the differences between the yoghurt types.  While all yoghurts are made using bacterial cultures, many of the yoghurts available today have been pasteurised.  This means that the bacteria have been neutralised and so do not support the microbiome in the same way.  For the bacterial benefits you need to look out for ‘live’ or ‘bio-active’ yoghurts.

One question about bacteria in foods is whether or not those bacteria reach the intestines.  After all the acid in our stomachs provides brilliant defence against consumed pathogens!

Good news! The findings of multiple studies suggest that some of the live bacteria does reach the intestines.  That said, while the bacteria’s presence in the gut is beneficial it may not take up permanent residence (Savaiano, 2014).  Instead, the bacteria from yoghurt may only remain for a few days as the small study by Elli, Callegari, Ferrari, et al, 2006 indicates.  This suggests that it is important to consume probiotic foods on a regular basis to get the most benefit.

For years we have been told to avoid fat, but that is not always the best option.  Choosing a low fat yoghurt is likely to mean you are choosing a yoghurt with extra sugar (and/or sweeteners) to provide taste.  Some low fat yoghurts have extra thickeners and even gelatine added to maintain the thick texture without the fat.  Have you ever read the ingredients on your chosen yoghurt and compared them to the full-fat version?  I know it can be difficult to find full-fat versions of many yoghurts these days, but if they are available take a look next time you shop.

When thinking about fat intake, look at the sources of fat and your overall intake.  How natural are the fats that you are consuming?  How processed are the foods that contain these fats (the more processed, the more likely it is that the fats will not offer health benefits)?  Of course, if you have been advised to manage your fat intake for medical reasons you should follow that advice.

Greek yoghurt is strained to remove the whey.  This gives it a thicker texture and tangier flavour.  You may have noticed a watery layer on top of yoghurts – this is the whey.  Plain versions tend to be higher in protein than other yoghurts.

Greek-style yoghurt may be made by adding in additional milk proteins at the start or end of the standard yoghurt production.

While Greek yoghurt is itself a type of yoghurt, varieties of this are also available.  To decide on the most suitable for you, again read the ingredients lists and the nutritional information, and compare products (never simply go with the front-of-pack ‘information’).  In terms of gut health, look out for live or bioactive Greek yoghurts, and try to avoid high sugar varieties.

It is possible to get the probiotic benefits of yoghurt from dairy-free versions but it important to read the labels.  To produce this effect without lactose, the cultures are provided with other sugars to feed on.  This means that the dairy-free product can still have the yoghurt tang.

As with dairy products, check the description and label to check that the finished product contains ‘live’ bacteria/cultures to get the benefits.

• Lactose digestion from yogurt: mechanism and relevance – Saviano (2014) https://www.sciencedirect.com/science/article/pii/S0002916523050797?via%3Dihub
• Survival of Yogurt Bacteria in the Human Gut – Elli, Callegari, Ferrari, et al (2006) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1489325/