Kefir is a living culture, a complex symbiosis of more than 30 microflora that form grains or cauliflower-like structures in the milk. Microorganisms present in the grains include lactic acid bacteria, Lactococcus lactis subsp. lactis, Streptococcus thermophilus, Lb delbrueckii subsp. bulgaricus, Lb helveticus, Lb casei subsp. pseudoplantarum and Lb brevis, a variety of yeasts, such as Kluyveromyces, Torulopsis, and Saccharomyces, acetic acid bacteria among others. They give kefir excellent keeping qualities by keeping putrifying bacteria that might otherwise colonise the milk at bay. They've been shown to inhibit both salmonella and E. Coli in laboratory tests.
Milk Kefir versus Yogurt
Milk kefir and yogurt are not identical, although have a lot in common. They both have creamy-but-tart tastes and are traditionally made from dairy (both can be made with alternatives, such as rice milk, nut milk and coconut milk). They also both have plenty of protein, calcium, B vitamins, potassium, and probiotics.
However, kefir typically has more protein and more probiotics. Kefir is also thinner and is best as a drink, whereas yogurt has a thicker consistency.
Kefir and yogurt are made differently. Kefir ferments at room temperature, while many types of yogurt start culturing under heat. Kefir contains a larger number of different types of healthy bacteria, and it’s better for the gastrointestinal tract because of this. Kefir’s active yeast also has more nutritional benefits than that of yogurt.
Milk kefir is nutrient-dense, with plenty of protein, B vitamins, potassium, and calcium. Calcium helps to build strong bones, protein builds strong muscles, and potassium is essential for heart health. But the probiotics are the strongest health benefit that kefir has to offer. According to the Mayo Clinic, probiotics can help to improve the healthy bacteria ratio in the gastrointestinal tract’s environment, treat or prevent diarrhea, especially following antibiotic treatment, treat irritable bowel syndrome, reduce or prevent gastrointestinal infections, prevent and treat vaginal infections, and prevent and treat urinary tract infections.
One study found that mice who consumed kefir for seven days experienced anti-inflammatory and healing effects. Another study found that kefir may be beneficial in lowering cholesterol and stimulating the immune system.
Side Effects, Precautions, and When Not to Take Milk Kefir
Despite its superior health benefits, some people develop constipation and abdominal cramping when consuming kefir, particularly when they just start a kefir regiment. Adjustment in gut microflora might be one of the reasons for this. Consult your doctor if you have AIDS or other conditions that weaken the immune system, or if you have autoimmune diseases before using kefir.
Kefir is generally safe for young children between 1 and 5 years of age to consume kefir. However, children under 1 year of age should not have cows' milk products, and stick with breast milk, which is really high in natural probiotics.
Because kefir is fermented, most people who are lactose intolerant can actually drink kefir. However, kefir is made with caseins (milk protein), which some people eliminate from their diet. If you have eliminated caseins from your diet, try another probiotic instead, such as water kefir, kombucha, jun, kanji, kimchi or other fermented vegetables.
What the Research Say
Most, if not all, of the research about kefir is positive. One study found that kefir possessed strong antimicrobial, anti-inflammatory, antioxidant, and anti-tumor properties. Research has shown that kefir may also help improve the digestive system in multiple ways, including direct pathogen inhibition and the increased production of beneficial bacteria. It may even be effective in treating peptic ulcers. Note that the human microbiome is an exciting areas of scientific discovery that’s still in the early stages.
Milk kefir and probiotics, in general, may help with certain conditions listed below.
Arthritis - If you have an inflammatory type of arthritis, probiotics may be especially important. The beneficial bacteria appear to have an impact on inflammation, reducing common biomarkers of inflammation, including C-reactive protein.
Irritable Bowel Syndrome - probiotics help balance gut health
Chronic fatigue - chronic fatigue is often linked to overgrowth of Candida Albicans, and controlling the population with probiotics sounds like the way to go.
Weight gain - Candida overgrowth is often thought to cause sugar craving and over consumption, and it makes perfectly sense that the exist links between gut health, absorption, metabolism, sugar and food cravings (read here and here).
Depression - Researches have been done to study the link of gut microflora and depression, and how probiotics may help cure depression.
Skin Health - Research has been done to study the link between gut-brain-skin, and found the benefits of oral probiotics for skin health.
Immunity - Emerging insights into the interactions between probiotics and host receptors have demonstrated the ability of probiotics to modulate gene expression and cellular differentiation of the immune system.