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Probiotics are live microorganisms that can be found in fermented foods and cultured milk, and are widely used for the preparation of infant food. They are well-known as “health friendly bacteria”, which exhibit various health beneficial properties such as prevention of bowel diseases, improving the immune system, improving lactose intolerance and intestinal microbial balance, exhibiting anti hypercholesterolemic and
antihypertensive effects, alleviation of postmenopausal disorders, and reducing traveller’s diarrhoea. Recent studies have also been focused on their uses in treating skin and oral diseases. In addition to that, modulation of the gut-brain by probiotics has been suggested as a novel therapeutic solution for anxiety and depression1.

There are many microorganisms that could potentially function as probiotic, of which Lactobacillus and Bifidobacterium species are the most commonly used.

Mechanism of action

The efficacy of a probiotic effect often depends on the mechanism by which they exert their activity. By and large, to treat a disease, the probiotics follow a set of mechanisms, which is discussed in this review. The effective performance of the probiotic depends on their strong adherence and colonization of the human gut, which in turn improves the host immune system. The mechanism of adherence is still under investigation, but Lactobacillus plantarum has been shown to exhibit a mannose specific adhesion by which it can adhere to human colonic cells. Once the probiotic adheres to the cell, various biological activities take place, which primarily include the release of cytokines and chemokines. These then exert their secondary activity such as stimulation of mucosal and systemic host immunity2.

Functions of probiotics

Probiotics have adverse functions. They may help:

  • improve immune function
  • protect against hostile bacteria to prevent infection
  • improve digestion and absorption of food and nutrients.

Under normal or “balanced” conditions, friendly bacteria in the gut outnumber the unfriendly ones. Probiotics can act as gut-beneficial bacteria that create a physical barrier against unfriendly bacteria. Probiotics can also help offset the bacterial imbalance caused by taking antibiotics. Antibiotics kill good bacteria along with the harmful ones, often leading to gas, cramping or diarrhoea. Potential benefits of probiotics have been seen in the treatment or prevention of many conditions such as diarrhoea, irritable bowel syndrome, ulcerative colitis, and Crohn’s disease.

Probiotics may help breakdown protein and fat in the digestive tract — a valuable benefit to help infants, toddlers or patients who need to build strength throughout and after an illness.

Probiotics and Gastrointestinal Health
Probiotics have been shown to have a positive impact on a variety of gastrointestinal disorders. They are used routinely in the health care setting to reduce diarrhea associated with taking antibiotics in both adults and children. Certain probiotics may help manage symptoms of irritable bowel syndrome and may also inhibit the growth of Helicobacter pylori, bacteria that colonize the stomach and can cause ulcers and stomach cancer.

Probiotics and Lactose Intolerance
People with lactose intolerance can often consume yogurt with few symptoms because of the probiotics it contains. These probiotics help digest the lactose in the small intestine before it reaches the colon. In addition, the yogurt starter cultures Lactobacillus bulgaricus and Streptococcus thermophilus help break down the lactose. Yogurt is a good way for people with lactose intolerance to consume the recommended servings of dairy without experiencing uncomfortable symptoms.

Probiotics and Immunity
A healthy immune system is important for everyone, and probiotics may play a role in improving its function. One study of adults that consumed a yogurt drink with several bacterial strains showed that consumption of the probiotics significantly reduced the incidence of upper respiratory infections and flu-like symptoms. In preschool children, a diet that included daily probiotic consumption led to reduced cold and flu symptoms and a decrease in missed school days due to illness.

Probiotics and Chronic Disease Risk
A growing body of evidence shows that the gut microbiota may play an important role in the development of obesity, obesity-associated inflammation and insulin resistance. Obesity and type 2 diabetes are associated with changes in gut microbiota. Whether or not these changes impact weight or disease risk is the subject of scientific research, but the potential for using probiotics in weight management and disease prevention is positive.

Probiotics and Mental Health
The impact of probiotic consumption on mental health is one of the newer areas of probiotic research. Researchers believe that the link between the gut and the brain, known as the “gut-brain axis,” affects both physical and mental health. Probiotics are being studied for their ability to reduce anxiety, relieve stress and improve mental outlook.

Researchers are just beginning to explore the effect of probiotics on many other aspects of human health. In the meantime, probiotic-rich foods can safely become part of a daily eating pattern, with the potential to have an impact beyond the nutrients provided.

Sources of probiotics

Fermented or cultured dairy products are a major source of probiotics. Other sources of probiotics include miso, tempeh, soy beverages, buttermilk, fermented milk. The bacteria either occur naturally in these foods or have been added during preparation. Probiotics are also available as dietary supplements in capsule, tablet or powder-form.

Here are the most common strains of probiotics:

Lactobacillus acidophilus
Lactobacillus bulgaricus
Lactobacillus casei
Lactobacillus gasseri
Lactobacillus plantarum
Bifidobacterium bifidum
Bifidobacterium lactis
Bifidobacterium longum
Enterococcus faecium
Saccharomyces boulardii

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  • A dedicated nutritionist with Masters in Nutrition and 6 years of experience in the healthcare field. With a diploma in Wellness coaching and Diabetes Eductaion, Ms. Fiza is compassionate about health & fitness. She is well versed in diet, lifestyle counselling and making positive changes in the lives of her clients/patients.

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