You need to replenish the beneficial bacteria in your gut everyday to keep yourself healthy and free from harmful bacteria. Since most probiotic bacteria are flushed out in the stool, you need to consume them everyday
Yakult and yoghurt are both cultured dairy products made from milk fermented with live bacteria. However Yakult contain 6.5 billion live bacteria that reach our intestine alive. Also the strain of bacteria Lactobacillus casei strain Shirota is unique and different from the strain of bacteria found in yoghurt and dahi.
Yes everyone should consume probiotics to stay healthy. Our intestines have more than 100 trillion bacteria that play an important role in maintaining good health and well being. Of these organisms some are beneficial while others are harmful. For maintaining good health it is important that the beneficial bacteria outnumber the harmful ones. However often due to stress, infection, irregular diet, indiscriminate use of antibiotics, ageing etc this balance gets disturbed and the beneficial organisms decrease in number. This results in ill health which often manifests as indigestion, constipation, diarrhoea and sometimes in more serious diseases such as IBS (Irritable Bowel Syndrome), IBD (Inflammatory Bowel Disease) etc. Regular consumption of probiotics helps to restore the balance of the gut flora, improve our digestive health and build immunity.