What are probiotics?

There are a large variety of bacteria that reside in the human gut. These bacteria can either be beneficial (e.g. Lactobacillus, Bifidobacterium), or can be detrimental (e.g. Shigella, Clostridium). Probiotics are living microorganisms that enter the body through food, drink, or supplements, and have positive health effects on the beneficial bacteria that reside in the gut. Probiotics stimulate the growth of the beneficial bacteria that is already in the gut, which has positive health effects on the host. The main two probiotic bacteria are Bifidobacteria and Lactobacilli.

What are prebiotics?

Prebiotics are certain food ingredients that are non-digestible. Prebiotics are beneficial to the host as they selectively stimulate the growth of only the beneficial bacteria that resides in the gut. This leads to a predominance of the health promoting bacteria such as Bifidobacteria and Lactobacilli, over the detrimental bacteria. Prebiotics are described as non-digestible polysaccharides or oligosaccharides, and are extremely selective as they will only promote the health of one or a limited number of the bacteria in the gut. For a food product to be classified as a prebiotic, it must, be resistant to hydrolysis and digestion and must selectively stimulate growth of one or a limited number of bacteria in the gut.

What is the microbiome?

There microbiome is the bacteria that live either on our body surfaces or in our gut. These bacteria can be either beneficial or detrimental to the health of the host. There are more than 100 trillion microbes in our gut, which is approximately ten times the number of cells in our body, and these can be classified into more than 1000 different species. Not only this, but the gut microbiome contains 600,000 genes. This is approximately 25 times the number of genes in the human genome. Because of this there is great potential for the microbiome to have massive effects on our health. The gut microbiota is able to defend against pathogens in healthy individuals in two ways. They can directly affect pathogens by preventing the pathogens that are competing for space and nutrients, from colonising in the gut, or can indirectly affect them by producing antimicrobial compounds that modify the conditions of the gut and make it more difficult for pathogens to colonise. The gut microbiota regulates biological systems such as energy storage, nutrient supply, and fat accumulation. The microbiome of the gut can be manipulated through the use of prebiotics and probiotics, and this can have positive effects such as improving the integrity of the gut barrier, and reducing low grade, intestinal inflammation, which can promote weight loss.

What is metabolic syndrome?

Metabolic syndrome is a group of risk factors, that appear to promote the development of heart disease, type 2 diabetes, and stroke. Metabolic syndrome consists of hypertension, dyslipidemia, central obesity, and increased glucose levels in the blood. The incidence of metabolic syndrome is increasing due to changes in diet and lifestyle in recent years. One of the main risk factors for metabolic syndrome is insulin resistance. There is currently evidence from human studies showing that modifying the microbiome in the gut can have an effect on different risk factors of metabolic syndrome.

What are the benefits of prebiotics?

The use of prebiotics has been shown to have many positive effects such as decreased insulin resistance, increased satiety, reduced food intake, and therefore a contribution to weight loss. There is a difference in the microbiome of lean people and obese people, so when the microbiome is altered this can have positive effects such as weight loss. This can help to lessen the risk factors of metabolic syndrome, as central obesity and insulin resistance are two of the risk factors. As heart disease, type 2 diabetes, and stroke are all possible outcomes of metabolic syndrome, decreasing the risk factors of metabolic syndrome is important so that the risk of these outcomes can be lessened. Prebiotics are important as they are what fuel the probiotics and allow them to perform all of the functions that they do, without prebiotics there would be a decrease in the number of beneficial bacteria in the gut, as they would not have the fuel to stimulate their growth. Prebiotics can also have other health benefits such as increased magnesium and calcium absorption and decreased cancer risk in the large intestine.

What are the benefits of probiotics?

Probiotics can decrease the amount of abdominal subcutaneous and visceral fat significantly. The reduction in visceral fat is more significant as visceral fat is what is primarily involved in metabolic disorders. There have been studies that show that probiotics can not only cause a reduction in body weight and fat mass gain, but could counteract some of the metabolic diseases that are related to obesity. There are many other benefits of probiotics that include, but are not limited to, immune enhancement and alleviation of lactose intolerance by improving lactose digestion, reducing the risk of rotavirus induced diarrhoea and colon cancer, and may include promoting synthesis of vitamins, preventing infections, and inhibiting cancer progression. Probiotics may also reduce cholesterol levels, which can help control metabolic syndrome, as dyslipidemia is one of the risk factors

How can people increase their intake of prebiotics and probiotics in their diet?

Probiotics are often used in the preparation of fermented dairy products such as yogurt and freeze dried cultures. Yogurt is one of the best ways to include probiotics in your diet as it provides great benefits due to its probiotic content and is an easy and accessible food for most people. Kefir, a fermented milk drink, is another great and easy way of increasing probiotic intake. Some of the most common sources of prebiotics are wheat, garlic, onion, leeks, and banana. Bananas are an easy snack as they require no preparation to eat, so are one of the easiest ways to increase prebiotic intake. Garlic is a great source of prebiotics, and is also an easy way of increasing prebiotic intake, as garlic can be easily included in many meals. Leeks and onions are also great sources of prebiotics, and can be easily included in many meals. Prebiotic and probiotic supplements can also be taken if it is felt like there is not enough prebiotic and probiotic intake through diet.