Eat more raw, to get the most from prebiotics and probiotics consider how you prepare your food.
As a fermentation fan and a non-strict vegan, eggs are not normally part of my diet. However a recent scientific study that came out of China got me thinking more generally about food preparation. In the UK eggs have enjoyed a love-hate relationship with food experts and nutritionists. In 1988 Health Minister Edwina Currie announced that UK egg production was badly affected by salmonella. Although she lost her job, uncertainty over the benefit of eating eggs remained. There has also been a long standing disquiet over the suffering experienced by hens in the ‘industrialised’ production of eggs. Scientists still suggest that there may be a correlation between egg consumption and a number of health problems.
Conversely a new large scale study from China has suggested eggs may actually reduce risk of stroke and heart disease. The current advice from the NHS is that the cholesterol found in eggs is less of a health problem than the effect of saturated fat from the cooking process. Indicating that boiled or poached eggs may be significantly better for you than fried. This is not an endorsement of eggs as a health food per se’ but it draws attention to the strong relationship between health and food preparation. So what has this got to do with fermentation, prebiotics and probiotics?
One of the reasons we cook food for a sustained period is to destroy potentially harmful bacteria. It follows then that if food, such as sauerkraut is cooked at a high temperature for a sustained period much of the helpful bacteria will be removed. People starting to think about gut-bacteria from scratch (like us), might be surprised to know that commercially available products thought to be ‘probiotic’ may in fact be pasturised (heat treated) or made from pasturised ingredients.
This is one of the reasons why home fermentation is taking off in such a big way. There are certain challenges to delivering high quality, probiotically rich foods, safely and at a competitive price. So if you are purchasing probiotics check the labels to ensure things are as they appear, in particular watch out for the word ‘pasturised’. This is not so say that you can’t cook ‘live’ yogurt in a curry or sauerkraut in a pork casserole. It’s just you may be loosing a lot of the bacterial benefit.
A quick word about prebiotics. Prebiotic is a blanket term for any food ingredients likely to enhance the growth and development of beneficial bacteria, typically (but not limited to) those found in the large intestine. In order to arrive at the large intestine, food needs to be structurally able to resist breakdown in the stomach. Foodstuffs in this group can (loosely) be thought of as ‘dietary fiber’. If you do a little research in this area you’ll find that many of the most useful prebiotics are in fact raw vegetables. That is because cooking can limit the probiotic benefit effect of certain foods.
There are many valid reasons why people may wish to cook fresh fruit, vegetables and dairy products. The take home point is that if you don’t already, you might wish to take a look at how you prepare your food and the extent to which you are maximizing your support for beneficial gut microorganisms.
We review our first DIY kit on this page, visit these pages for more general information about kefir or links to useful kefir resources
The Mad Millie Kefir Kit from Lakeland was our first experience of DIY kefir. The kit cost £9.99 (at the time of writing) contains everything you need to get started and is a useful first step for beginners.
1 litre glass jar
Stainless steel mixing ball
2 sachets of kefir culture.
On the plus side, instructions are good but simple, the kit contains live cultures that can be used with milk, soy, coconut milk or juice. Everything is pretty good quality and we are still using the equipment even after moving onto kefir grains. The bonus of buying in store at Lakeland is that there’s nearly always someone who can offer some advice or tips. The website also offers a few kefir recipes.
However the cultures can only be reused a couple of times, replacements cultures cost (at the time of writing) £4.99 and produce, this makes the cost of the kefir £1 per litre, not including the cost of the milk or juice. Consider that kefir grains (live cultures) can be purchased for around £5 and have an almost indefinite life.
At the time of writing this product had a 3.5 rating (9 reviews) on the Lakeland website, the replacement cultures were rated as 5/5 (3 reviews). From a beginners perspective this felt like a good purchase, it definitely got us started. The sachets of culture are flexible and don’t have to be used immediately so can be transported or even wrapped up and used as a gift. This flexibility means you pay a premium for the actual product compared to grains.I think this product comes into it’s own as a starter kit and not something for an experienced fermenter. Could be a neat way to get kids involved in taking responsibility of their own healthy diet.
Can fibre reduce your chances of contracting colon cancer?
I have been a fan of Dr Michael Greger for some considerable time. He excels at explaining important and often complex nutrition research in a way that most people can understand. Michael recently wrote about the benefits of fibre to health, its crucial role in feeding the ‘good’ gut bacteria. Put simply out gut bacteria converts fibre into short-chain fatty acids (SCFA). SCFAs deliver a range of benefits and are thought to reduce the chances of contracting colon cancer.
It’s not simply that SCFA promote gut health generally, fibre helps to maintain gut flora. A failure to eat enough fibre can lead to the starvation and decline of healthy bacteria. This typically allows for an imbalance (dysbiosis), where potentially harmful bacteria begin to dominate, perhaps leading to a range of inflammatory diseases and even colon cancer. Further links even suggest a connection to cardiovascular disease, metabolic syndrome and type 2 diabetes.
A relative small amounts of fibre is needed to sustain healthy gut bacteria, in many cases just a handful of chickpeas every day. And yet there is evidence that many people in the USA and UK are failing to include sufficient fibre into their daily diet.
What is fermentation and how is it related to health and well being?
The growing area of study linking human microbiota to health and wellbeing is seeing the development of new learning opportunities. The extent to which microorganisms on our skin and in our bodies meditate our lived experience can be understood through a free Coursera module, Gut check; exploring your microbiome. Maggie and I have completed the first two weeks, I thought potential future students might be interested in hearing more about what this course entails.
This MOOC is produced by the University of Colorado Boulder and the tutors are all linked to the institution; Professor Rob Knight, Dr. Jessica L. Metcalf and Dr. Katherine R. Amato.
As you might expect week one offers an overview of the subject area. Explanations are given for what microbes are in relation to each other (Bacteria, Archaea, Eukaryotes and Viruses) and all living organisms. The role of microbes more generally is explained before looking at how microbes and humans interact. Definitions include the distinction between human microbiota (a community of microbes), and the microbiota (the total genes in the microbiota).
The material highlights a number of interesting microbiome facts including that whilst humans share 99.99% of the same DNA, two humans may only have 10% of their microbiomes in common. This is one of the reasons why gut bacteria is thought to be influential in how we experience life. Although the majority of our microbes live in our gut, there are communities all over us (mouth, skin, vagina). We are born sterile and then communities of microbiota become established at a very early age, changes to these communities happen throughout our lives. The module material clearly illustrates that the microbes we are exposed to have an import role in our lives.
The first week provides a useful introduction to the subject and offers a context for later material. Beyond week 1, the course follows a much stronger academic path. Explaining the science behind the study of microbiota and moving onto subjects such as alpha diversity and ‘fuzzy microbes’. If you’ve tried the MOOC what do you think?
Kefir appears to offer significantly greater benefit than commercially produced probiotic drinks.
Dr Michael Mosley has been helping to run a study for the BBC looking at the relative benefits to gut health from a range of products. Volunteers and scientists collaborated to try to discover which of three probiotics/prebiotics had the biggest positive impact on gut bacteria.
The first product was a commercially available drink, branded as a probiotic and available in major supermarkets. The second item up for comparison was kefir, a traditional milk and yeast fermented substance, a little like yogurt. These first two foods were compared with vegetables high in natural prebiotic fibre called inulin. Inulin is found in range of foods including chicory (chicory root is a rich source) and scallions (onions, leeks and garlic).
The poorest preforming of the three in this trial was the probiotic drink. The participants in this group demonstrated a modest (statistically non significant) change in lachnospiraceae gut bacteria. Conversely significant changes in gut flora were seen in the group consuming prebiotic fibre. The people that consumer kefir enjoyed the most positive increase to gut bacteria.
It should be pointed out that any comparison between prebiotics and probiotics is not a like for like test. Prebiotics deliver the food that supports existing bacteria and create the conditions for further colonization. A probiotic is intended to introduce microorganisms directly into the body.
The BBC study concluded that traditionally produced fermented foods (or even home made versions) may offer the greatest benefits to consumers in terms of increased gut flora. A key problem with mass produced fermented foods and drinks is pasteurisation. Pasturised goods are regarded as safer, which also correlates to a longer shelf life. By comparison traditionally made kefir has to be consumed in a relatively short space of time. This is perhaps the choice we consumers face, if we want maximum health benefits from the food we make or buy we may have to sacrifice some of the convenience of long sell by dates.
Polyphenols found in red wine may support oral bacteria able to inhibit tooth decay and gum disease
Moderate red wine consumption has been associated with a range of health benefits. Many of the claims made historically have not been supported by the latest evidence. In any case, increasing alcohol consumption per se could have a negative health impact that outweighs any positive outcome. However research featured by the BBC this week is linking red wine to improved oral health by acting as a probiotic for mouth bacteria.
Recent research into red wine has highlighted the benefits of polyphenols, these are antioxidant compounds present in red wine, thought to fight harmful free radicals in humans. A recent study from Spain indicates that red wine may be able to exert a beneficial influence over damaging oral bacteria. The effect of polyphenols (caffeic and p-coumaric acids) were tested on the bacteria that can harm teeth and causes gum disease. Caffeic and p-coumaric acids were found to be more successful than grape seed and red wine oenological extracts at limiting the ability of bacteria to stick to cells. But when combined with an oral probiotics (streptococcus dentisani), the polyphenols ability to limit the growth of harmful bacteria (streptococcus mutans) was enhanced.
This is an initial study carried out on cells in a lab, not on actual people, it reflects a simplified or reduced approach. Results will need to be replicated in other studies and ultimately with humans. However the important point to take at this stage is that there is some evidence that wine appears to offer probiotic qualities to both mouth and gut bacteria. This isn’t a charter for people to increase wine consumption, the overall effect of drinking wine hasn’t been clearly established and it is likely to be different for each person. However this study offers yet more evidence of the important role of probiotics in human health.
Polyphenols are abundant micronutrients present in a wide range of foods and drinks, not just red wine. The extent to which any individual substance is able to deliver the health benefits of the polyphenols contained within it is still being researched. The ability of our body to digest and make available the polyphenols we consume is a key issue. Other foodstuffs rich in polyphenols include, blueberries, blackberries, cherries, green tea, black tea and coffee.