The human body is also hygienic dead ends. So which parts of the body are the dirtiest? 1, scalp Studies have found that there are about 1 million microorganisms per square centimeter of scalp, the most of which are follicular lipid mites, they like to make their home within the epidermis of the scalp, combining in groups to form a “large family”, working together to suck the sebaceous glands secretion of lipids for a living, the end result is Hair loss. To fight them, in addition to washing your hair regularly, it is best to comb your hair with a comb every morning and evening, which stimulates the scalp and allows it to ventilate. 2, oral cavity The mouth is the place where food must pass, but did you know that there are more than 100 million microorganisms per square centimeter in our mouth, of which there are good flora, but also a significant portion of bad microorganisms, which are the culprits of bad breath. They live between the teeth and on the tongue and produce unpleasant sulfur compounds while breaking down food residues and saliva. Keep your mouth clean and hygienic, brush your teeth carefully in the morning and evening, remember to floss your teeth before brushing, and clean your tongue after brushing, the bacteria left on your tongue will also destroy your breath. 3, armpit In a crowded bus or subway, you may have more than once to appreciate the unbearable smell! It emanates from the armpits and pollutes the surrounding air with impunity. The microorganisms hiding in the armpits are as high as 1-10 billion per square centimeter. The sweat itself does not have an odor, it is the armpit “regulars” – rod-shaped flora nourished by the fatty acids secreted by the skin, which reproduce and breed a large number of bacteria, resulting in an unpleasant odor. Armpit sweating is not a disease, as long as you bathe regularly, change clothes can be eliminated, underwear is best to choose cotton clothing. 4, intestinal tract There are more than 400 kinds of bacteria residing in the intestinal tract. Escherichia coli in the intestine is a good tenant in the human inn, it helps us digest and is also an integral part of our defense system. But outside the gut, Escherichia coli can cause disease, and if it “slips” into food, it can cause nausea, vomiting and diarrhea. To protect the intestinal tract, it is recommended to drink 1-2 bottles of yogurt every day, in which the probiotics can inhibit the bad flora from dominating the intestinal tract and help the good flora gain control of the intestinal tract. In addition, adhere to moderate exercise, often do push-ups, abdominal rubbing, etc., can prevent intestinal aging.