What is Kefir
Kefir is a product derived from milk - it retains a small part of the initial lactose and is not produced by coagulation of casein proteins - and therefore considered a full-fledged dairy product. It is a good source of high biological value proteins, calcium, phosphorus and vitamins - especially of the B group, in particular vitamin B2 (riboflavin) and vitamin A. Produced from whole milk, it also has a modest amount of saturated fat and cholesterol. Thanks to the activity of the microorganisms present inside the kefir, it is a food well tolerated by the lactose intolerant and, above all, an ally for the well-being of the gastro-intestinal tract.
In the kitchen, natural kefir can be used in the preparation of cakes, biscuits, bread and dough for focaccia and pizzas, as it promotes leavening and makes them softer. Also ideal in the savory version, as a sauce to accompany vegetables, meats and fish. In this case, kefir facilitates digestion, because it favors the assimilation of animal proteins.
, infusing the milk with kefir grains, which are a starchy matrix containing a symbiotic community of lactic acid bacteria, acetic bacteria and yeast. Kefir has many health benefits, including lowering cholesterol, reducing inflammation and exercising an antioxidant effect. In common with other probiotics, kefir also has antimicrobial properties, high calcium and phosphorus content. constituents of bone hydroxyapatite. It is also a valid ally during growth and in old age; the need for these minerals also increases during pregnancy and breastfeeding.
Kefir is rich in folic acid (vitamin B9), an essential supplement not only for pregnant women, but also during menopause, as an excellent defense against osteoporosis and mood swings.
When to limit the consumption of Kefir
The consumption of Kefir should be significantly reduced, or avoided, in case of hyperchlorhydria and hypochlorhydria, stomach acid, gastritis, ulcer and gastroesophageal reflux disease, in most cases associated with hiatal hernia. It can also alter the alvus of people with irritable bowel and colitis, making their symptoms worse.
were able to produce this substance, called tryptophol acetate, but for the first time a yeast has been discovered that produces it.
The researchers found that tryptophol acetate interferes with "quorum sensing" - a form of microbial communication - in several pathogenic bacteria. In quorum detection, bacteria release signaling molecules into the surrounding environment. When the molecules reach a particular concentration, they trigger changes in gene expression in bacteria of the same species. These changes allow pathogenic bacteria to coordinate their activity based on their number. This coordination is necessary for some bacteria to defend themselves or attack their hosts.
In some cases, when they reach a certain density, microbes can join together to form a slimy, protective coating, or "biofilm," on a surface.
Inhibited pathogenic bacteria
In laboratory cultures, the researchers found that tryptophol acetate had an inhibitory effect on the action of several pathogenic bacteria.
Some of the species tested were:
- Pseudomonas aeruginosa, which causes pneumonia when it infects the lungs.
- S. enterica, responsible for food poisoning.
- Staphylococcus aureus, which can trigger sepsis, among other life-threatening infections.
- V. cholerae, which causes cholera.
These results would be the first demonstration that the virulence of human pathogenic bacteria could be mitigated by molecules secreted in probiotic milk products, such as yogurt or kefir.
Scientists specifically focused on the effect of tryptopol acetate on V. cholerae. They found that the substance blocked quorum sensing in this bacterium, and reduced its virulence by modifying the expression of the bacterial genes that control quorum detection. The researchers pointed out that this type of interference in bacterial communication may be common in environments. complexes in which many different microorganisms live together, such as in probiotic food or in the human intestine.
