(1) At a suitable temperature, Lactobacillus grows and reproduces in fresh milk, and lactose in milk is decomposed into lactic acid. Lactic acid can change the neutral or alkaline environment in the intestine into acidity, thus destroying and inhibiting the growth and reproduction of spoilage bacteria in the intestine, and protecting the human body from and alleviating the invasion of toxic substances. This is because the spoilage bacteria in the intestine can move a lot in neutral or weakly alkaline environment, which not only decomposes protein in the intestine, but also produces some toxic substances, such as indole, phenol and fecal odor. These toxic substances affect health, especially lead to premature aging of the nervous system.
Yogurt can promote gastric peristalsis, stimulate gastric acid secretion, enhance the digestive ability of gastrointestinal tract and improve the metabolism of the body.
③ Lactic acid bacteria can produce an antibiotic in the process of growth and development, which can inhibit and destroy the growth of many pathogenic bacteria, such as mycobacterium tuberculosis. Therefore, it has preventive and adjuvant therapeutic effects on some diseases.
(4) Lactic acid can increase intestinal beneficial bacteria and inhibit spoilage bacteria, so it can prevent toxic substances produced by decomposing protein by spoilage bacteria from accumulating in the body, thus preventing the occurrence of some cancers.
⑤ Free amino acids and peptides increased after milk was fermented by lactic acid bacteria. The content of free amino acids is about 4 times that of milk, and the content of essential amino acids is about 4 times that of milk.
⑥ After milk is acted by lactic acid bacteria, its fat structure becomes easier to be digested and absorbed by human body. Among them, calcium becomes calcium lactate, which not only helps yogurt to form clots, but also makes calcium easily absorbed by human body, which is of great benefit to the prevention and treatment of osteoporosis in the elderly.
⑦ The contents of vitamins A, B 1, B2 and C in yogurt are similar to those in milk. However, the content of folic acid is 1 times higher than that of milk, and the content of choline is obviously increased, which has obvious effect on preventing fat oxidation and high cholesterol concentration in the body.
(8) Due to the decline of metabolic function of the elderly, the colon and rectum atrophy and intestinal mucus secretion decrease, which is easy to cause constipation. Yogurt has a laxative effect, so it has a preventive effect on senile constipation. In addition, yogurt is nutritious and easy to digest and absorb, so it is an ideal healthy food for the elderly.
Therefore, yogurt can make people healthy and live longer, and long-term enjoyment can prolong life.