Probiotics is the name given to living micro-organisms - often referred to as “friendly” bacteria - that may have health benefits in the body. Many probiotic bacteria are similar to those found naturally found in the body, especially in the digestive tract. The exception to this is Saccharomyces boulardii, a probiotic yeast that is not naturally found in the body but acts as a probiotic when taken in supplement form.
Probiotics have become popular in supplements and as food ingredients with perceived benefits, most often used to promote healthy digestion. They are found naturally in fermented foods (such as saurkraut), yoghurt and kefir, fermented soy products, and in probiotic ‘shot’ drinks where their numbers are far, far higher than the levels found in fermented foods. In addition they are available as freeze-dried powders, capsules, and tablets. All probiotics must contain viable bacteria that are ‘alive’ when consumed. Previous research on ‘over the counter’ probiotic supplements has found some supplements to lack living bacteria, or to contain bacterial strains that are not probiotic. Some research has shown health risks with probiotic use, such as a higher mortality in hospital patients with pancreatitis prescribed specific probiotic supplements.
What can probiotics do for us?
Probiotics work in a variety of ways along our digestive tract. Most of us know that they can help balance the levels of micro-organisms in the intestines and drive down numbers of harmful bacteria.
Some probiotics attach themselves to the surface of our bowels, where they establish cell-to-cell contact and can ‘talk’ to our bowel cells, exchanging information which helps maintain vigilance of our gut immune function and help defend us against gastroenteritis. Once attached, they help prevent other, less friendly bacteria such as Staphylococcus aureus, from gaining a foothold and causing us to become ill.
Some probiotics sweep straight down the digestive tract, helping maintain a healthy bowel by suppressing unfriendly bacterial growth, and by preventing constipation. Probiotic bacteria such as the Bifidobacteria group ferment dietary fibres and other substances as they pass along, forming tiny fats (called short chain fatty acids, or SCFA). These tiny fats eventually become fuel for our large bowel ( colon) cells, keeping our colon cells healthy.
Short-chain fatty acids are slightly acidic in nature, so as they travel along our bowel towards the colon they acidify bowel contents. This acid environment helps acid-loving bacteria, such as probiotic Lactobacilli to flourish and grow, again helping to prevent the growth of pathogenic (disease causing) bacteria such as C Difficile and salmonella.
Probiotic and other healthy bacteria supplement our dietary vitamin intake by making their own micronutrients that our body can also use. Vitamin B12, biotin and vitamin K made by bowel bacteria can be used by us to help maintain our health.