Kefir
What is Kefir?
Kefir is a fermented drink (dairy or non-dairy) that can provide a variety of nutrients and beneficial gut bacteria. It has been shown to significantly improve bowel movements and may decrease inflammatory responses and allergy development through the intestinal immune system.
Kefir comes from the Turkish word ‘keyif’ meaning the ‘good feeling’ that is often associated with its consumption.
Water kefir grains, used to ferment milk into the kefir beverage, contain many beneficial bacteria and yeast [6].
Kefir is made by fermenting the sugars in milk, but can be made with other milk sources or nondairy milk, fruits, and vegetables [6, 2].
The fermented food characteristics of kefir include antioxidant, antimicrobial, and antifungal properties which fight harmful molecules as well as outcompete unwanted bacteria in the gut [4, 2].
The Food & Agriculture Organization (FAO) and World Health Organization (WHO) outline that kefir grains must have 10 million CFU/g of bacteria and 10 thousand CFU/g of yeast minimum [4].
Kefir has been shown to alleviate constipation and reduce the need for laxatives in some patients due to its probiotic properties [9].
Both milk and soy kefir beverages have been shown to lower bad cholesterol levels associated with heart disease [8, 2].
DISCLAIMER: Due to the fermenting process, some ethanol is produced, though typically 0.02-2% alcohol by volume. Kefir is not recommended to kids under 2 years old. Some recommendations say that as a general rule, kids age three and up can drink their age in ounces safely on a daily basis.
Nutrient Breakdown
Kefr is a great source of healthy gut bacteria, protein, calcium, and vitamin A. Plain dairy kefir contains:
The fermentation process of milk with kefir grains results in increased availability of vitamins, amino acids, and healthy gut bacteria [1]. Many varieties of kefir drinks exist with varying amounts of added fruit flavors, sugars, and milk fat levels. Additionally, some kefir products have enriched vitamin A and D3.
Types of Kefir
Cow, goat, or sheep milk kefir
Non-dairy
Kefir Alternatives
Fermented beverages
Yakult
Fermented dairy products (yogurt)
Fermented soy products (tempeh, miso, natto)
Fermented vegetables (kimchi, sauerkraut)
See the Fermented Foods note for more suggestions on fermented alternatives for kefir. If your child won’t eat fermented foods, consider a probiotic supplement.
Food Reactions
The body can respond to foods in many different ways including food allergies, food sensitivities, or food intolerances. If you suspect a food reaction, you can either choose to avoid the food or seek food reaction testing. Click here more information on the difference in types of food reactions and testing options.
DISCLAIMER: Always consult with your pediatrician and/or your Registered Dietitian to help you test for a food reaction or to aid you in making individualized dietary changes.
Kefir & Autism in the Research
Constipation
Kefir has been studied as a treatment for constipation in those with mental or physical disabilities. Both the powdered milk and powdered kefir were shown to alleviate some individuals symptoms, alluding that components of regular milk are also beneficial [7]. Results were seen in patients with chronic, but not severe constipation.
Another related study focused on daily consumption of the kefir as a beverage: showing significant improvement of stool consistency, frequency, and reduction of laxative use due to the addition of the probiotic in the diet [9].
Cholesterol
The fermentation process of kefir results in lowered cholesterol levels of the milk product [2].
Bacteria present in both milk and soy kefir were shown to reduce blood cholesterol levels in animal models independent of assigned diet, specifically lowering the LDL cholesterol associated with heart disease [8, 2].
Anti-allergenic Effects
Gut microbes are now seen as an important factor in allergy or asthma development: type and level of bacteria can reduce prevalence [2].
Specific bacteria and yeast studied in kefir can decrease inflammatory responses and allergy development through the intestinal immune system [2].
Kefir vs Yogurt
Kefir beverages are produced differently than yogurt, therefore have differing probiotic communities [5].
Fermented dairy products can be better tolerated than regular milk for individuals with lactose malabsorption. While kefir contains more lactose enzyme than yogurt, studies have shown their effects are similar [4, 5].
Non-dairy Kefir
Water kefir is made from water, sugar, and kefir grains, although there are limited studies on the functions of this non-dairy kefir option [4].
A honey-based kefir beverage study showed the characteristics passed the FAO/WHO qualities of probiotic, antimicrobial, and antioxidant activity proving it is a viable option for vegans, vegetarians, or lactose intolerant individuals [3].
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[1] Baschali A, Tsakalidou E, Kyriacou A, Karavasiloglou N, Matalas AL. Traditional low-alcoholic and non-alcoholic fermented beverages consumed in European countries: a neglected food group. Nutr Res Rev. 2017;30(1):1-24.
[2] Bourrie BC, Willing BP, Cotter PD. The Microbiota and Health Promoting Characteristics of the Fermented Beverage Kefir. Front Microbiol. 2016;7:647.
[3] De oliveira coelho B, Fiorda-mello F, De melo pereira GV, et al. In Vitro Probiotic Properties and DNA Protection Activity of Yeast and Lactic Acid Bacteria Isolated from A Honey-Based Kefir Beverage. Foods. 2019;8(10)
[4] Dimidi E, Cox SR, Rossi M, Whelan K. Fermented Foods: Definitions and Characteristics, Impact on the Gut Microbiota and Effects on Gastrointestinal Health and Disease. Nutrients. 2019;11(8)
[5] Hertzler SR, Clancy SM. Kefir improves lactose digestion and tolerance in adults with lactose maldigestion. J Am Diet Assoc. 2003;103(5):582-7.
[6] Koh WY, Utra U, Rosma A, Effarizah ME, Rosli WIW, Park YH. Development of a novel fermented pumpkin-based beverage inoculated with water kefir grains: a response surface methodology approach. Food Sci Biotechnol. 2018;27(2):525-535.
[7] Maki, R.; Matsukawa, M.; Matsuduka, A.; Hashinaga, M.; Anai, H.; Yamaoka, Y.; Hanada, K.; Fujii, C. Therapeutic effect of lyophilized, Kefir-fermented milk on constipation among persons with mental and physical disabilities. Jpn. J. Nurs. Sci. 2018, 15, 218–225.
[8] Slattery C, Cotter PD, O'toole PW. Analysis of Health Benefits Conferred by Species from Kefir. Nutrients. 2019;11(6)
[9] Turan, I.; Dedeli, O.; Bor, S.; Ilter, T. Effects of a kefir supplement on symptoms, colonic transit, and bowel satisfaction score in patients with chronic constipation: A pilot study. Turk. J. Gastroenterol. 2014, 25, 650–656.
Authors
Sarah Reale, Dietetics Student
Brittyn Coleman, MS, RDN/LD, CLT
