Since four thousand years the human race is using lactic bacterias for the fermentation of foods. These bacterias are used in the whole world, in particular in milk products such as yogurt, cheese, butter and kefir.
The actions of lactic acid bacteria are species and strain specific, and depend on sufficient numbers of bacteria being available in the intestines. The difficulty in identifying and classifying strains has complicated research, since benefits may only pertain to particular strains.
Nevertheless, lactic acid bacteria have a number of well-established benefits. They can improve lactose digestion, play a role in preventing and treating diarrhea and act on the immune system, helping the body to resist and fight infection.
Canada’s Food Guide
The Canada Food Guide recommends consuming yogurt and kefir to achieve or maintain a healthy lifestyle. Indeed, it is recommended for anyone aged 19 and over, according to age and gender, to consume between 2 and 3 servings of milk and alternatives a day. For example, one serving of yogurt or kefir represents 175 g (3/4 cup), a 2-liter jar of yogurt therefore contains 10 servings.
Fermentation of yogurt is one of the oldest methods practiced by human beings in order to transform milk into products. Its beneficial influence on human health and nutrition has existed in many civilizations and has been known for thousands of years.
Yogurt is one of the best-known of the foods that contain lactic bacteria. It is defined as a coagulated milk product that results from the fermentation of lactic acid in milk by Lactobacillus delbrueckii subspecies bulgaricus (L. bulgaricus) and Streptococcus salivarius subspecies thermophilus (S. thermophilus). Indeed, fermentation of the sugar found in milk (lactose) by these bacteria produces lactic acid, which acts on milk proteins to give yogurt its texture and its characteristics. Other lactic acid bacteria species, such as probiotic bacteria belonging to the Bifidobacterium and Lactobacillus genera, are also used to give yogurt unique characteristics.
As starter cultures for yogurt production, lactic acid bacteria species display symbiotic relations during their growth in milk. Thus, a carefully selected mixture of bacteria species is used to complement each other and to achieve a remarkable efficiency in health benefits.
The benefits of yogurt and lactic acid-producing bacteria such as yogurt species have been investigated in numerous studies in recent years. Studies showed promising health benefits for certain gastrointestinal conditions, including lactose intolerance, constipation, diarrheal diseases, colon cancer, inflammatory bowel disease, Helicobacter pylori infection, and allergies. Patients with any of these conditions could possibly benefit from the consumption of yogurt. The benefits of yogurt consumption to gastrointestinal function are related to effects mediated through the gut microflora, bowel transit, and enhancement of immune responses.
Probiotics are microbial food supplement with beneficial effects on the consumers. They are defined as live microorganisms that, when administered in adequate amounts, confer a beneficial effect on the health of the host. Most probiotics are actually lactic acid-producing bacteria and are normally consumed in the form of yogurt, fermented milks (such as kefir) or other fermented foods. The main benefit of probiotics is to improve the intestinal tract health.
Indeed, the intestinal microbial flora consists of diverse bacterial species that inhabit the gastrointestinal tract. These good bacteria are integral to the origin, development and regulation of the immune system, protection of the body from infection, and maintenance of intestinal metabolic equilibrium. So, probiotics improve the intestinal health tract by adhering and colonizing the gastrointestinal tract, interacting with a wide range of specific human epithelial cells, thus modulating and improving the immunity of the gastrointestinal tract.
In addition, some of the beneficial effects of lactic acid bacteria consumption include: reducing symptoms of lactose intolerance, synthesizing and enhancing the bioavailability of nutrients, enhancing the immune systems, decreasing the prevalence of allergy in susceptible individuals, controlling symptoms of inflammation/arthritis, controlling hypertension and reducing the risk of certain cancer.
Kefir is an acidic fermented milk beverage that originated from the Caucasus region, thousands of years ago. It is produced from kefir grains, which are a cluster of active microorganisms (bacteria and yeasts) held together in a white gelatinous matrix that look like small cauliflowers. Kefir has a uniform creamy consistence, it is slightly carbonated and it presents a small amount of alcohol, produced by the yeasts.
Kefir is actually considered an example of probiotic mixture of bacteria and yeasts. Today, traditional authentic kefir can be prepared by culturing pasteurized milk with kefir starters at home. The main species of bacteria found in kefir belong to the genera of Lactococcus, Lactobacillus, Leuconostoc and Acetobacter, while yeasts are mainly Kluyveromyces marxianus and Saccharomyces cerevisiae.
A vast variety of different species of good microorganisms are found in kefir. This is why it is actually so healthy. Because kefir is such a balanced and nourishing food, it contributes to a healthy immune system and has been used to help patients suffering from different disorders.
Kefir is easily digested and it provides beneficial bacteria and yeast, many bioactive ingredients or nutrients, vitamins and minerals, and complete and partially digested proteins as well; which give it unique health benefits. Kefir is reported to have various health benefits such as anti-tumour, anti-inflammatory, anti-neoplastic (inhibiting or preventing the development of abnormal biological tissue or organ) and pro-digestive effects. It has been shown to control several cellular types of cancer.
The regular use of kefir can help relieve intestinal disorders, promote bowel movement, reduce flatulence and create a healthier digestive system. Its excellent nutritional content offers healing and health-maintenance benefits to people in every type of condition.
All the different microorganisms found in kefir participate together to the elaboration of a fresh, thirsty, active and delectable fermented milk, every species delivering a specific characteristic or flavor, contributing to the unique aspect of kefir.