Introduction

While working at a Microbiology Laboratory, I asked my new trainees, "What is your first impression of bacteria?"
They all gave them a negative feedback. No one came out with something positive about bacteria. This is probably because I asked the question in a place surrounded by samples of patients with infections.

The fact is that without bacteria we will not survive! They are not as deadly as we think after all. It is only a very small percentage of them that cause harm, most of them are innoxious. For instance there are over 2500 strains of Salmonella but only two of them can cause the dreaded symptoms that can terrorise the victim and his/her family. It may sound very frightening to know that in fact Salmonella live in our guts along with E-Coli, yes you are reading right: two bacteria known to cause so much havoc! They live in our digestive system, also known as the gut microflora, and while they share our ambient in return they provide us with important vitamins and nutrients.

However, things may go wrong if they become too comfortable and over populate the microflora. Here is where the bacteria we hear about come to the rescue. These 'good' bacteria help keep the population of the 'harmful' bacteria in place. Overpopulation produces excessive gases (hydrogen sulphide, H₂S) hence bloating, diarrhoea, cramps and other symptoms of great discomfort.

What are Probiotics?

Probiotics are dietary supplements containing potentially beneficial bacteria or yeast, however lactic acid bacteria (LAB) are the most common microbes used.

Currently, there is huge interest in the use of foods which may exert a positive functional effect on our health. Two of these 'functional foods' are known as probiotics and prebiotics, both of which have a favourable effect on the 'good' bacteria that reside in our gut microflora. These 'good' bacteria live naturally in our intestines and are essential to good health having a number of positive effects, primarily helping our digestive systems work efficiently. This concept was first promoted by a Russian scientist in 1907!

The 1908, Nobel Prize-winning scientist Elie Metchnikoff of the Pasteur Institute in Paris provided the first evidence that microorganisms may be responsible for the health-promoting effects of fermented milks. After observing that Bulgarian peasants lived to ripe, old ages, Metchnikoff became convinced that their health and longevity were linked to microbes in the soured milk they copiously drank. He suggested that disease-causing 'bad' bacteria could be eliminated by ingesting large amounts of Bulgarian sour milk, which contained a beneficial 'good' bacterium later identified as Lactobacillus bulgaricus.

Just sprinkle some Probiotics and you have your own healthy meal even healthier.

Probiotics help our digestive system work efficiently, e.g. bifidus, lactobacillus and acidopilus (both lactobacillus and acidophilus are now available from here). Schrezenmeier & De Vrese (Am J Clin Nutr 73 (Suppl) 361s-364s 2001) define a probiotic as: 'A preparation or product containing viable, defined micro-organisms in sufficient numbers, which alter the microflora of the host intestine and, by that, exert beneficial health effects on the host'.

Probiotics may be found in live yoghurts or specially formulated powders, supplement pills or probiotic drinks which contain one or more of the strains of these bacteria. With food processing, pollution and antibiotic therapy, the numbers of bacteria living naturally in our gut are reduced, and research has shown that active consumption of bacteria increases the size of intestinal colonies, thereby improving digestion of food. Moreover, numerous studies have also shown that with optimal numbers of 'good' bacteria, the immune system is improved, increasing our ability to fight disease. Probiotics may also have a role in reducing the severity of food allergies and intolerances, and may help reduce severity of symptoms in both osteo- and rheumatoid arthritis.

Health Benefits of Probiotics

• Managing Lactose Intolerance:

Because LAB convert lactose into lactic acid, their ingestion helps lactose intolerant individuals tolerate more lactose than what they would have otherwise. One company that produces a proven effective Lactose Intolerance product is BioCare and their products including a range of probiotics and digestive enzymes are available from the products page.

• Prevention of Colon Cancer:

In laboratory investigations, LAB have demonstrated anti-mutagenic effects thought to be due to their ability to bind with (and therefore detoxify) carcinogenic substances formed in cooked meat. Lower rates of colon cancer among higher consumers of fermented dairy products have been observed in some population studies.

• Cholesterol Lowering:

Animal studies have demonstrated the efficacy of a range of LAB to be able to lower cholesterol levels, presumably by breaking down bile in the gut, thus inhibiting its re-absorption (which enters the blood as cholesterol).

• Lowering Blood Pressure:

Several small clinical trials have shown that consumption of milk fermented with various strains of LAB can result in modest reductions in blood pressure. It is thought that this is due to the ACE inhibitor like peptides produced during fermentation.

• Improving Immune Function and Preventing Infections:

Probiotics are thought to have several beneficial effects on immune function. They may protect against harmful bacteria overgrowth and there is evidence to suggest that they may improve immune function by encouraging production of cells in our body whose main function is to protect us against infections and cancers. Clinical trials have also demonstrated that probiotics may decrease the incidence of respiratory tract infections and dental caries in children. LAB foods and supplements have been shown to be effective in the treatment and prevention of acute diarrhoea; decreasing the severity and duration of rotavirus infections in children as well as antibiotic associated and travellers diarrhoea in adults.

• Reducing Inflammation:

Probiotic foods and supplements have been found to modulate inflammatory and hypersensitivity responses, an observation thought to be at least in part due to the regulation of cytokine function. Clinical studies suggest that they can prevent reoccurrences of Inflammatory Bowel Disease in adults, as well as improve milk allergies and decrease the risk of atopic eczema in children.

• Improving Mineral Absorption:

It is hypothesized that probiotic lactobacilli may help correct malabsorption of trace minerals, found particularly in those with diets high in phytate content from whole grains, nuts, and legumes.

• Prevents Harmful Bacterial Growth Under Stress:

In a study done to see the effects of stress on intestinal flora, rats that were fed probiotics had no occurrence of harmful bacteria latched onto their intestines compared to rats that were fed sterile water.

What are Prebiotics?

Prebiotics can be defined as nutrients and constituents of food which our gut flora feed upon, thus increasing their numbers. Prebiotics include fructo-oligosaccharides, which are found naturally in many plants including leeks, onions, wheat, garlic, chicory root and artichokes where they function as storage carbohydrates, and some other soluble fibres found in pulses, fruit and some cereal products. Fructo-oligosaccharides are low molecular weight carbohydrates, and since they are not broken down significantly by the digestive processes in the stomach and small intestine, they are classified as dietary fibre. Prebiotics also help digestion and the immune system by increasing microflora levels.

Prebiotics have also been incorporated into supplements and functional foods, in order to exert positive effects on the digestion, the immune system and possibly some degenerative diseases. Simply put, probiotics are foods which provide the actual 'good' bacteria, and prebiotics are those nutrients which the bacteria feed on to increase their numbers. The effect of a probiotic may be enhanced by having a prebiotic as the support medium; for example milk contains nutrients for lactobacillus, and so many probiotic drinks are milk or yoghurt-based.

Probiotics and prebiotic formulas are continue to prove very popular. This is mainly because there is ample of medical evidence they promote good health. Not only do they help us digest our food, but they may also help reduce the severity of food poisoning and reduce effects of food intolerance. Users report that formulas also help improve general well-being and they may help improve performance in sport due to improved digestion of food and therefore increased availability of nutrients. Also improved immunity and reduction in illness means fewer interruptions in training.

James Collier Consultant in Nutrition, United Kingdom concludes in his report about probiotics that unless there is a rare and specific reason as to why an individual should not use probiotic formulas, it is strongly recommended that we all include them in our daily nutrition in order to ameliorate a range of nutritional and health disorders and to merely promote general good health and well being.

Do probiotics really have live bacteria?

In one of its surveys the independent magazine 'Which?' reported  that only 5-15% of bacteria in products tested survived all the way to the consumer! So is this a waste of money and false advertisement?

Luckily it is not an entirely 'yes' answer, because scientists demonstrated that the immune system in subjects given dead 'good' bacteria still responds. In California and Jerusalem irradiated probiotics where given to mice with gut inflammation.

The treatment reduced the inflammation in a similar way to giving "live" bacteria, and the researchers concluded that irradiated probiotics were just as effective.

According to the BBC, Professor Eyal Raz, one of the study authors, said: "Our goal was to address whether the metabolic activity of probiotics was mandatory for their protective effect."

The team believes that part of the body's immune system called the "innate" immune system responded to the bugs, regardless of whether they were dead or alive.

This immune response might be damping down the overactive response within the gut.

However, experts say that the presence of live rather than inactivated bacteria in the gut has several advantages.

Firstly, the simple fact that they are occupying space and attached to the gut wall denies that space to harmful bacteria, particularly if their numbers increase over time.

Make your own Probiotic food

BioCare produce a wide range of probiotics, which are highly recommended by many clinics looking after Irritable Bowel Disease and Inflammatory Bowel Disease. There are also flavoured probiotics for children.

BioCare emphasizes that the bacteria within their range remain live, thanks to the way they package it. They also guarantee the number of bacteria per serving. Amongst the range of probiotics, there are powder ones, which can easily be added to foods before eating, hence enjoying the benefit of having probiotic food with guaranteed live bacteria. Simply put 1/4 of a teaspoon and let 4 billion live bacteria enter your system... and BioCare guarantee this.

More information on the Probiotics products section.