From the Guidelines
Kefir is a fermented milk drink that contains multiple strains of beneficial bacteria and yeasts, making it a diverse probiotic source with various health benefits, including improved digestion and enhanced immune function, as supported by recent studies 1.
Definition and Composition of Kefir
Kefir is made by adding kefir grains, a combination of bacteria and yeasts, to milk, typically from cows, goats, or sheep. The fermentation process creates a tangy, slightly effervescent beverage with a consistency between milk and yogurt.
Health Benefits of Kefir
The health benefits of kefir include:
- Improved digestion
- Enhanced immune function
- Potential antimicrobial properties Kefir is also rich in nutrients like protein, calcium, B vitamins, and vitamin K2, as noted in studies on probiotics and gut health 1.
Consumption and Preparation of Kefir
Kefir can be consumed plain or used in various recipes, such as smoothies, overnight oats, or as a substitute for buttermilk. Commercial kefir is widely available, but it can also be made at home by obtaining kefir grains and fermenting milk for 24-48 hours at room temperature.
Recent Studies on Kefir and Probiotics
Recent studies, such as those published in Gut Microbes 1 and Cell Host and Microbe 1, highlight the importance of probiotics and fermented foods, including kefir, in maintaining gut health and preventing various diseases. These studies support the potential benefits of kefir in improving digestion, enhancing immune function, and promoting overall health.
From the Research
Definition and Composition of Kefir
- Kefir is a fermented milk product created through the symbiotic fermentation of milk by lactic acid bacteria and yeasts contained within an exopolysaccharide and protein complex called a kefir grain 2, 3.
- The nutritional composition of kefir varies according to the milk composition, the microbiological composition of the grains used, the time/temperature of fermentation and storage conditions 2.
- Kefir is a complex fermented dairy product containing more than 50 species of probiotic bacteria and yeast 4.
Health Benefits of Kefir
- Kefir has been associated with a range of health benefits, including improved digestion and tolerance to lactose, antibacterial effect, hypocholesterolaemic effect, control of plasma glucose, anti-hypertensive effect, anti-inflammatory effect, antioxidant activity, anti-carcinogenic activity, anti-allergenic activity and healing effects 2.
- Kefir has been shown to have multiple properties conferring health benefits, including antiobesity, anti-hepatic steatosis, antioxidative, antiallergenic, antitumor, anti-inflammatory, cholesterol-lowering, constipation-alleviating, and antimicrobial properties 4.
- The health benefits of kefir can be attributed to the micro-organisms present in kefir and/or to the metabolites synthesized by them during milk fermentation 5.
Microbiological Composition of Kefir
- Kefir grains are built up by a complex community of lactic acid and acetic acid bacteria and yeasts confined in a matrix of proteins and polysaccharides 5.
- The use of both culture-dependent and independent methods has made possible to determine the micro-organisms that constitute the kefir ecosystem 5.
- Bifidobacteria and lactobacilli, which are present in kefir, are Gram-positive lactic acid-producing bacteria constituting a major part of the intestinal microflora in humans and other mammals 6.