Probiotics

Introduction

Probiotics are live microorganisms that are intended to have health benefits when consumed, generally by improving or restoring the gut flora. Probiotics are considered generally safe to consume, but may cause bacteria-host interactions and unwanted side effects in rare cases. Probiotics are live bacteria good for digestive system.

Although people often think of bacteria and other microorganisms as harmful “germs,” many microorganisms help our bodies function properly. For example, bacteria that are normally present in our intestines help digest food, destroy disease-causing microorganisms, and produce vitamins. Large numbers of microorganisms live on and in our bodies. Many of the microorganisms in probiotic products are the same as or similar to microorganisms that naturally live in our bodies.

How Does Probiotic Work?

Researchers are trying to figure out exactly how probiotics work. Some of the ways they may keep you healthy:

• When someone loses "good" bacteria in their body, for example after they take antibiotics, probiotics can help replace them.
• Probiotics can help balance "good" and "bad" bacteria to keep body working the way it should.

What Does Probiotic Do?

Among other things, probiotics help send food through gut by affecting nerves that control gut movement. Researchers are still trying to figure out which are best for certain health problems. Some common conditions they treat are:

• Irritable bowel syndrome
• Inflammatory bowel disease (IBD)
• Infectious diarrhea (caused by viruses, bacteria, or parasites)
• Diarrhea caused by antibiotics

There is also some research that shows they're useful for problems in other parts of human body. For example:

• Skin conditions, like eczema
• Urinary and vaginal health
• Preventing allergies and colds

History of Probiotics

Probiotics have received renewed attention in the 21st century from product manufacturers, research studies, and consumers. The history of probiotics can be traced to the first use of cheese and fermented products, that were well known to the Greeks and Romans who recommended their consumption.

Élie Metchnikoff first suggested the possibility of colonizing the gut with beneficial bacteria in the early 20th century.

The original modern hypothesis of the positive role played by certain bacteria was first introduced by Russian scientist and Nobel laureate Élie Metchnikoff, who in 1907 suggested that it would be possible to modify the gut microbiota and to replace harmful microbes with useful microbes. Bifidobacteria were first isolated from a breast-fed infant by Henry Tissier, who also worked at the Pasteur Institute. The isolated bacterium named Bacillus bifidus communis was later renamed to the genus Bifidobacterium. Tissier found that bifidobacteria are dominant in the gut microbiota of breast-fed babies and he observed clinical benefits from treating diarrhea in infants with bifidobacteria.

During an outbreak of shigellosis in 1917, German professor Alfred Nissle isolated a strain of Escherichia coli from the feces of a soldier who was not affected by the disease. Methods of treating infectious diseases were needed at that time when antibiotics were not yet available, and Nissle used the E. coli Nissle 1917 strain in acute gastrointestinal infectious salmonellosis and shigellosis.

In 1920, Rettger and Cheplin reported that Metchnikoff's "Bulgarian Bacillus", later called Lactobacillus delbrueckii subsp. bulgaricus, could not live in the human intestine.

Contrasting antibiotics, probiotics were defined as microbially derived factors that stimulate the growth of other microorganisms. In 1989 Roy Fuller suggested a definition of probiotics that has been widely used: "A live microbial feed supplement which beneficially affects the host animal by improving its intestinal microbial balance." Fuller's definition emphasizes the requirement of viability for probiotics and introduces the aspect of a beneficial effect on the host.

The term "probiotic" originally referred to microorganisms that have effects on other microorganisms. The conception of probiotics involved the notion that substances secreted by one microorganism stimulated the growth of another microorganism. The term was used againto describe tissue extracts that stimulated microbial growth. The term probiotics was taken up by Parker, who defined the concept as, "Organisms and substances that have a beneficial effect on the host animal by contributing to its intestinal microbial balance."

In the following decades, intestinal lactic acid bacterial species with alleged health beneficial properties were introduced as probiotics, including Lactobacillus rhamnosus, Lactobacillus casei, and Lactobacillus johnsonii.

Types of Probiotics

Many types of bacteria are classified as probiotics. They all have different benefits, but most come from two groups. Ask your doctor about which might best help you.

• Lactobacillus may be the most common probiotic. It’s the one you’ll find in yogurt and other fermented foods. Different strains can help with diarrhea and may help with people who can’t digest lactose, the sugar in milk.
• Bifidobacterium can be found in some dairy products. It may help ease the symptoms of irritable bowel syndrome and some other conditions.
• Saccharomyces boulardii is a yeast found in probiotics. It appears to help fight diarrhea and other digestive problems.

How to Use Probiotics Safely

The FDA regulates probiotics like foods, not like medications. Unlike drug companies, makers of probiotic supplements don't have to show their products are safe or that they work.

In general, probiotic foods and supplements are thought to be safe for most people, though some people with immune system problems or other serious health conditions shouldn't take them.

In some cases, mild side effects might include an upset stomach, diarrhea, gas, and bloating for the first couple of days after you start taking them. They may also trigger allergic reactions. Stop taking them and talk to your doctor if you have problems.

Side effects of Probiotics

The manipulation of the gut microbiota is complex and may cause bacteria-host interactions. Though probiotics are considered safe, some have concerns about their safety in certain cases. Some people, such as those with immunodeficiency, short bowel syndrome, central venous catheters, cardiac valve disease and premature infants, may be at higher risk for adverse events.

In severely ill people with inflammatory bowel disease there is a risk of the passage of viable bacteria from the gastrointestinal tract to the internal organs (bacterial translocation) as a consequence of bacteremia, which can cause adverse health consequences.

Rarely, consumption of probiotics by children with lowered immune system function or who are already critically ill may result in bacteremia or fungemia (i.e., bacteria or fungi in the blood), which can lead to sepsis, a potentially fatal disease.

It has been suggested that Lactobacillus contributes to obesity in humans, but no evidence of this relationship has been found

Effectiveness of Probiotics

 Researchers have studied probiotics to find out whether they might help prevent or treat a variety of health problems, including:

• Digestive disorders such as diarrhea caused by infections, antibiotic-associated diarrhea, irritable bowel syndrome, and inflammatory bowel disease
• Allergic disorders such as atopic dermatitis (eczema) and allergic rhinitis (hay fever)
• Tooth decay, periodontal disease, and other oral health problems
• Colic in infants
• Liver disease
• The common cold
• Prevention of necrotizing enterocolitis in very low birth weight infants.

There’s preliminary evidence that some probiotics are helpful in preventing diarrhea caused by infections and antibiotics and in improving symptoms of irritable bowel syndrome, but more needs to be learned. We still don’t know which probiotics are helpful and which are not.

We also don’t know how much of the probiotic people would have to take or who would most likely benefit from taking probiotics. Even for the conditions that have been studied the most, researchers are still working toward finding the answers to these questions.

Probiotics are not all alike. For example, if a specific kind of Lactobacillus helps prevent an illness, that doesn’t necessarily mean that another kind of Lactobacillus would have the same effect or that any of the Bifidobacterium probiotics would do the same thing.

Although some probiotics have shown promise in research studies, strong scientific evidence to support specific uses of probiotics for most health conditions is lacking. The U.S. Food and Drug Administration (FDA) has not approved any probiotics for preventing or treating any health problem.

Some experts have cautioned that the rapid growth in marketing and use of probiotics may have outpaced scientific research for many of their proposed uses and benefits.

The dietary sources of Probiotics

Probiotics which are usually beneficial bacteria  provide all sorts of powerful benefits for human body and brain. They may improve digestive health, reduce depression and promote heart health. Some evidence suggests they may even give better-looking skin. Getting probiotics from supplements is popular, but you can also get them from fermented foods.

Here is a list of 11 probiotic foods that are super healthy. 

• Yogurt is one of the best sources of probiotics, which are friendly bacteria that can improve your health. It is made from milk that has been fermented by friendly bacteria, mainly lactic acid bacteria and bifidobacteria
•  Kefir is a fermented probiotic milk drink. It is made by adding kefir grains to cow's or goat's milk.
• Sauerkraut is finely shredded cabbage that has been fermented by lactic acid bacteria. 
• Tempeh is a fermented soybean product. It forms a firm patty whose flavor is described as nutty, earthy or similar to a mushroom
•  Kimchi is a fermented, spicy Korean side dish.
•  Miso is a Japanese seasoning. It is traditionally made by fermenting soybeans with salt and a type of fungus called koji. Kombucha is a fermented black or green tea drink. 
• Pickles (also known as gherkins) are cucumbers that have been pickled in a solution of salt and water. 
• Traditional Buttermilk actually refers to a range of fermented dairy drinks.  
•  Natto is another fermented soybean product, like tempeh and miso. It contains a bacterial strain called Bacillus subtilis.
• Although most types of cheese are fermented, it does not mean that all of them contain probiotics.

Global consumption of Probiotics

In 2015, the global retail market value for probiotics was US$41 billion, including sales of probiotic supplements, fermented milk products, and yogurt, which alone accounted for 75% of total consumption.

Innovation in probiotic products in 2015 was mainly from supplements, which produced US$4 billion and was projected to grow 37% globally by 2020. Consumption of yogurt products in China has increased by 20% per year since 2014.