There is a plethora of information about probiotics and we are constantly bombarded with advertisements promoting their use, for gut health, so what should we believe? Probiotics are products or food that contain bacteria, in large enough amounts to alter the number and/or type of bacteria that live in the large intestine (see diagram at the bottom of the page.) Everyone has populations of bacteria in their gut and we know that changes to these natural populations can occur in food poisoning or with any illness that occurs within the digestive tract. This could be irritable bowel syndrome, crohns or ulcerative colitits for example, but other disorders can affect the populations of bacteria. We are only just beginning to understand how these bacteria affect our health; they produce substances called short chain fatty acids from starchy foods, which help feed the digestive tract, keeping it healthy, a real benefit. They also help to produce vitamin K, a vital nutrient that helps our blood to clot and our bones keep healthy. So the relationship with our bacteria is beneficial for both the bacteria and us. These ‘good bacteria‘ also help to prevent some of the more harmful bacteria from developing and causing illness. Our bowels contain huge numbers of bacteria; our bodies contain about ten times more bacteria cells than the cells that make up our body, a good proportion of these are in our gut, an astounding fact.
What are often called ‘good bacteria’ are various types of bacteria commonly found in our bowel, and it is felt that if this natural ecosystem is damaged by illness, then replacing those bacteria helps to reduce symptoms such as diarrhoea, bloating and pain, which often accompany some digestive diseases. The theory is that taking these bacteria in food or drink will replace the bacteria that are missing; however in reality the effects are variable.
These bacteria are produced from dairy foods, such as Lactobacillus, Bifidobacterium and Lactobacillus acidophilus – long names for such cool microorganisms. We have good evidence that taking bacteria at the start of a course of antibiotics can prevent the diarrhoea that can accompany these medicines – antibiotics can reduce the natural populations of good bacteria in our bowel, which slightly alters digestion of starchy foods, resulting in diarrhoea. The case for probiotic effectiveness in reducing episodes of ulcerative colitis is controversial, but probiotics can be effective in reducing occurrence of infections that occur in people who have had reconstructive small bowel surgery (called pouches,) and can prevent diarrhoea that occurs when travelling abroad. For illnesses such as food poisoning, they may reduce the amount of days you are ill and reduce the number of times you need to visit the loo -which is always a benefit!
The products that are available also have varying effects in people with irritable bowel syndrome (IBS,) and the evidence for their usefulness for preventing further attacks of crohns disease is still uncertain. As these products are generally not harmful in most individuals, if you have irritable bowel syndrome UK health professionals advise that you could try them and see if they work for you. If you have crohns disease or colitis, it is probably better to discuss this with your gastroenterologist before you try them out. Try them for at least a month if you wish and follow the manufacturers instructions, you may need to continue taking them if you find them beneficial, as their effect can be temporary. It is also advisable to store these products as the manufacturer recommends and use them within the date advised, to ensure that the products are effective as they can be.
Some people may be better to avoid taking these bacteria, for example if you have a severe intolerance to lactose (a natural sugar found in dairy foods,) most of the manufacturers products are based on milk, therefore they may give symptoms, as they may contain varying amounts of lactose, depending on the product. However the bacteria will have reduced the amount of lactose naturally found in these foods, so caution is advisable if you wish to try them. Also if your doctor has told you that you have a weak immune system then you should not take these products.
Again we do not have evidence that probiotics can be helpful in preventing allergies or stopping infections of the bladder in adults, so don’t waste your money! Although I was informed by blogger yesnobananas that there is some evidence for a strain of lactobacillus Ramnosus in protection from developing atopic eczema, which is hard to find, but see her blog for further information
But where we know they are effective, or the products are recommended by your registered health professional, they are certainly worth considering. If you wish to try them and are not too sure about your situation, you could always discuss their use with your healthcare provider.
Health professionals can check the links below for evidence base references: