Prebiotics and probiotics - do we really need them?

Since when did bacteria become 'friendly'? Surely bacteria are germs, which is why we all need antibiotics at some time? In fact, we need bacteria for our very survival. Our guts are stuffed full of bacteria which not only don't hurt us, but do an essential job helping us to digest our food and reduce levels of harmful germs. Unfortunately, there's a constant battle between 'good' and 'bad' bacteria, and sometimes the unhealthy bacteria get the upper hand. That's where probiotics and prebiotics come in.

Probiotics and prebiotics - what are they?

Probiotics are products which contain bacteria which help our guts to function effectively. The most common ones are Bifidobacterium and Lactobacillus, which changes the acidity in our guts and may stop growth of other germs.

Prebiotics are fermented foods which change the normal gut bacteria, called the 'microbiome', to a more favourable profile. There has been an explosion of interest in the gut microbiome in recent years, suggesting our diet and the bacteria in our gut can play a role in everything from obesity to type 2 diabetes and cancer. Most prebiotics are forms of fibre, which aren't digested in the stomach and aren't altered during the digestive process in the early stages of the gut. Once they reach the large bowel, they provide a perfect food source for friendly bacteria, allowing them to flourish.

The problem is working out which probiotic products have enough 'friendly bacteria' to get through the rest of our digestive system to reach the last part of our guts, where they do their good work. Some studies suggest that liquid forms of probiotic are more likely to 'survive and thrive' than tablets or capsules. There isn't the same issue with prebiotics, which survive the digestive process unscathed.

Can I get them in my diet?

Dairy products including live natural yoghurt (and some non-dairy foods including sauerkraut!) have lots of lactobacillus. However, it's not clear if enough of them survive the acid in our stomachs to have a major benefit.

Good sources of prebiotics in your diet include onions, leeks, asparagus, bananas, garlic and tomatoes

Does everyone need probiotics?

The very short answer is no. If you're completely healthy, aren't going into hospital and aren't planning a holiday abroad, you probably don't need them. There are dozens of studies going on to look at a possible role for probiotics in everything from bacterial vaginosis, thrush, recurrent urine infections and even fibromyalgia. The theory is that probiotics can help strengthen your immune system, but so far we don't have enough positive results to recommend them routinely. However, there are lots of times when they can be useful.

Irritable bowel syndrome (IBS)

One in five of us know the misery of IBS - its symptoms include wind, bloating and diarrhoea or constipation (or sometimes both!). The National Institute for Health and Clinical Excellence recommends that if you have IBS and try probiotics, you should carry on taking them for at least four weeks to get the best chance of benefit.

Preventing diarrhoea

Let's face it, diarrhoea is never fun. But in older people, it can cause serious complications like dehydration and kidney damage. While probiotics and prebiotics don't stop this altogether, they may cut the risk of getting diarrhoea, if you're taking a course of antibiotics. There is also some evidence that they may protect against traveller's diarrhoea.

Two long term gut conditions called Crohn's disease and ulcerative colitis also cause frequent bouts of diarrhoea, among other symptoms. Unfortunately thus far, probiotics have shown little benefit for people with Crohn's disease. Research into the use of probiotics for Ulcerative Colitis have been a bit more promising, but some of the evidence is conflicting. That means it may be worth a try - as with IBS, probably for at least four weeks to see if they make a difference - but they aren't routinely recommended.

Serious gut infections in hospital

A particularly nasty germ called Clostridium difficile can cause severe diarrhoea, especially in older people in hospital who need antibiotics. Strange as it may seem, the main cause of C Diff is taking antibiotics. That's because antibiotics may kill many of the harmless or positively helpful bacteria in your gut, but not C Diff. Without competition for food from other bacteria, C Diff can flourish. Taking a probiotic containing lactobacillus has been shown in a hospital study to cut this risk very effectively. Lactobacillus may not be on the hospital canteen menu, but it may be worth taking a regular supply to your loved one while they're in hospital.

Supplements - all good or all hype?

Fact - we don't all need vitamin supplements if we have a healthy diet. However, at some points in your life they can be invaluable:

  • Early pregnancy. Take folic acid supplements (400 micrograms a day) from before you get pregnant until three months in.
  • Vitamin D. Lots of us - especially older people and those who don't get out in the sunshine - are short of this bone-builder. In fact, recent national UK guidance recommends that everyone should take a 10 microgram supplement every day from October-April. If you're pregnant or breastfeeding, cover up for religious reasons, are over 65 or housebound, you should take the same dose all year round. People with darker skins may be more prone to vitamin D deficiency because they don't make it as easily in their skin when they're exposed to sunshine. Pale English Roses who avoid the sun like the plague to cut their risk of skin cancer may also be at risk. 1-4 year olds should have 10micrograms daily, and under 1s should have 8.5 micrograms a day unless they're getting at least 500 ml of formula milk.
  • Calcium. Good food sources include dairy products and fish with bones. You need 750 mg a day.
  • Not eating well because of illness? Older people are at surprisingly high risk of malnutrition, even if they're not underweight. Drink supplements on prescription may be needed for vitamins, minerals and energy after an assessment from a dietician.

Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. Patient Platform Limited has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.


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