Part 2: Probiotics and Prebiotics in Gut Health
For background info, please refer to Gut Health, Part 1: Why we should focus on the health of our gut this January and NOT our weight.
(Essential Jo: Click to See my blog post of 6th Jan 2017)
In the second part of this gut health series, we are going to look at the role of probiotics and prebiotics in gut health – possibly one of the most exciting new topics to emerge in nutrition in the last few years. If you missed Part 1: Why we should focus on the health of our gut do take a look at it first to give you a little more background.
(Essential Jo: Click to See my blog post of 6th Jan 2017)
What are probiotics?
Probiotics are “live micro-organisms, which when consumed in adequate amounts, confer a health effect on the host”. Use of probiotic foods is an ancient tradition – even as far back as the time of Genghis Khan, fermented milk was being drunk as an elixir of strength and health.
Most often, probiotic foods or supplements contain strains of either Lactobacillus or Bifidobacterium bacteria, usually from fermented dairy products. However, before starting to act, they have to survive the hazardous journey to reach our gut:
They need to first get through manufacturing, transportation and storage processes, to reach our shopping bags alive and in good condition.
Then they must make it through the acidic environment of our stomach (designed precisely to kill off any wayward bacteria) and through the swamp of potent digestive juices and enzymes secreted by the gallbladder and pancreas.
Finally, if they succeed in reaching their destination, the large bowel, they then actually need do some good for the host rather than just going along for a free ride, or even possibly doing some untoward harm.
Because of these difficulties with getting the right probiotics to the right place, it is important to point out that the benefits which are seen in clinical trials may not all be possible to achieve with the yoghurts, tablets or other supplements available over-the-counter.
Despite all these challenges, however, good quality strains of probiotics have been associated with beneficial effects in some disease processes. The best evidence base for them so far is with antibiotic-associated diarrhoea, but researchers are examining a huge range of other conditions, from cancer to eczema – even mental health – which may benefit from probiotics (Tuohy et al., 2003) (NHS Choices, 2015).
Limitations
Most of the clinical research that has been carried out on prebiotics has been in unwell populations, and even then they are not yet in widespread use. We do not yet know much about the impact that taking probiotics might have in generally healthy people (Puupponen-Pimia et al., 2002). Anecdotally I have found them to be of tremendous benefit for myself and some of my clients – I am always cautious to recommend any supplements on this sort of platform, but when I do use and prescribe probiotics, I go for the very highest quality.
Probiotics, even as tablets, are also still regarded as foods. Therefore they do not have to undergo the same rigorous testing as medicines do, so it is difficult to know if they actually contain the bacteria they claim, alive, in an adequate dose, and are able to give you a tangible benefit (NHS choices, 2015). The European Food Safety Authority has even gone so far as to ban the probiotic food industry from certain advertising claims, such as that they ‘boost the immune system’, because there is insufficient evidence to back such claims up at the moment. A healthy dose of skepticism is often helpful in nutritional science!
As Dr Alessio Fasano so neatly puts it, we can compare our current knowledge of the microbiota to our knowledge of space. We know the universe exists (our microbiota), and we are getting to grips with the fact the Milky Way is there (the major strains of bacteria), but we are far off knowing where London is! In other words, there is a lot of detail still to understand before we are able to fully utilize probiotics for health. Do take a look at some of Dr Fasano’s YouTube talks if you are interested – he makes the gut a really fascinating and understandable topic!
What about prebiotics – are they the same thing?
No. Prebiotics are a class of nutrients called ‘oligosaccharides’ (a type of fibre) which pass through the upper portion of the gut undigested, to feed and stimulate the growth of microbes further down. I think about it as nectar for gut bugs!
Types of prebiotic that are known to alter the microbiota include (Tuohy et al., 2003);
Inulin & Fructooligosaccharides – found in foods such as Jerusalem artichoke, asparagus, leeks, green bananas, chicory and onions (Sabater-Molina et al., 2009)
Lactulose
Galactooligosaccharides – found naturally in breast milk to help feed the microbiota of new born babies.
In general, a dose of more than 20g a day of all of these combined, may lead to unwanted side effects such as flatulence and bloating (Tuohy et al., 2003). Especially if you suffer from IBS, I would suggest it is a sensible idea to ‘start low and go slow’ on introducing these to your diet.
As an added benefit, when our gut microbes break down these prebiotic fibres, especially inulin, they release a compound called butyric acid (Scott et al., 2013). This is especially important in gut health, as not only is in anti-inflammatory, but it also helps build up the gut defence barrier and decreases oxidative stress. All really useful effects. Plus it might even help to signal to our brain that we are full and satisfied at the end of a meal (Hamer et al., 2007).
My pragmatic approach, if you are generally well, and would like to boost your probiotic and prebiotic intake, is to use functional foods wherever possible.
In Part 3: How to nourish your gut health, we will explore lots of ideas on how to do this.
Images and Article -
Source
Gut Health: Part 1
Part 1: Why we should focus on the health of our gut this January and NOT our weight
Hippocrates supposedly said that ‘all disease starts in the gut’. Clearly this isn’t true all of the time (take genetic disorders, for example), but a significant proportion of chronic diseases are indeed linked to gut health. It has just taken medical science a few thousand years to catch up!
This topic is a real interest of mine. I often see clients who are struggling with all sorts of problems – ranging from skin disorders to obesity – which may stem from poor gut health, yet they usually have no idea that this could be the root cause of their symptoms. Once we have worked together to heal and soothe the gut, often their symptoms significantly improve and any excess weight starts to drop off naturally too.
That is why I start off by encouraging almost all of my clients to stop focusing on their weight as a primary outcome of the changes they are making, but instead to focus on the health of their digestion. I hope that after reading my 3-part guide, you might consider thinking this way too!
What do we mean by the ‘gut’?
The gut is a collection of organs, running from the mouth to the bowels, with help from the stomach, liver, pancreas and gallbladder along the way. All of these structures work together to extract the greatest amount of nutrition from whatever we choose to eat.
But newer research has also discovered the powerful impact of our gut microbiota. This consists of trillions of microbes (bacteria, yeast, funghi and viruses), which live inside our bowels, interacting not only with the food we eat, but also with each other and with us. Each microbiota is unique to each person.
When in harmonious balance, these microbes helpfully aid our digestion, make vitamins and other nutrients, break down dietary toxins, strengthen the body’s internal barrier against the contents of gut, prevent overgrowth of bacteria which can make us unwell, and can even influence our immune system and mood (Butel, 2014). But when out of balance, these microbes can also have the potential to wreck health havoc too.
I therefore now see the ‘gut’ not only as an organ system, but as an ecosystem too.
All sorts of factors will affect the composition and function of our microbiota, and therefore our gut health, including:
What is a ‘healthy’ gut?
There is actually no specific definition of what makes a healthy gut, because that depends so much on the individual. But in general, I would consider a healthy gut to:
- Be free from persistent digestive symptoms (such as bloating, abdominal pain or disrupted bowel habits). We all get the odd symptom from time to time though, which is absolutely normal. If bloating is your main problem, take a look at my post ‘Do you often feel bloated?’ for more information
- Eliminate regular, formed (but easily passed) stools.
- Allow complete digestion and absorption of nutrition. The average time for the entire process of digestion / absorption is 24 hours, although this does vary a lot between individuals.
What is an ‘unhealthy’ gut?
There are certain unhealthy gut symptoms which are known as ‘red flags’. These are important warning signs that should be discussed with a doctor as soon as possible. Although some of them may represent a harmless condition that will settle itself, it is important if you have any of these symptoms to seek a medical opinion promptly.
- A sudden, persistent change your bowel habits
- Any bleeding, or black, tarry stools
- Increasing heartburn, indigestion or stomach pains
- Losing weight unintentionally
- Any difficulty or pain on swallowing
- Within the scope of my nutritional practice, I would also look at all sorts of other symptoms (even if they are not necessarily directly related to the gut), such as skin, mood, energy, weight and much more.
How might gut health affect weight?
We know that our gut needs to function effectively to be able to digest and absorb the nutrition that we are eating. This can lead to both underweight and overweight. Perhaps the most important question to ask is firstly whether there could be an underlying medical problem that is driving poor digestion? The best way to work out if this is a possibility is to speak to your doctor or other healthcare provider. These problems usually lead to an unintended decrease in weight (although not always).
Once this has been ruled out, the next step would be a more comprehensive look at overall digestion, and whether there are any signs and symptoms of maldigestion, gut inflammation or irritation. This is often highly variable between people, so I would suggest that you find a well-qualified Nutritional Therapist or Registered Nutritionist (see FAQs for more info) – ideally with some training on Functional Medicine – to help you, if necessary. I run stool, blood, urine and saliva tests where necessary in my practice to help identify what might be going on for each individual.
There is also a lot of interest in the science world at the moment around the potential role of the gut microbiota in the development of obesity, and obesity-related diseases. Lots of this revolves around how certain microbes alter energy absorption by the body. In simple terms; the composition of our microbiota can cause us to either absorb less, or more, energy from exactly the same plate of food.
I think about it in terms of ‘energy harvesting’ – some microbes help us to do this more efficiently than others. One of the ways that our microbes do this is by producing specialized enzymes that help to break down carbohydrates and proteins that would normally be indigestible (Krajmalnik-Brown et al., 2012). The more energy we harvest, the more we absorb.
Unfortunately, we do not know enough about this topic yet to know which types of microbe would help us to lose weight (or indeed, help us to gain weight). However, there are some promising studies emerging (Kadooka et al., 2010). Watch this space!
Further reading
Part 2 & Part 3 of this gut health series will be launched over the next two weeks, exploring the world of probiotics, prebiotics and lots of advice on how to take the first steps to improving your gut health.
For further reading, Gut by Guilia Enders is a fantastic and easy to understand read for anyone interested in improving their knowledge and gut health.
Source Article with References By Amelia Freer
