“You Could Be in Serious Trouble If You Just Drink Water as Soon as You Wake Up”... Jung Ga-eun Shares a Cautionary Note, With a “20-Something Figure” [Health Talk]

[Financial News] A glass of lukewarm water after waking is considered one of the signature healthy habits for kick-starting the metabolism. But claims that there is a step people must take before drinking water have drawn growing attention to oral bacteria.
Broadcaster Jung Ga-eun, 48, recently shared on her YouTube channel the morning health routine she has followed for 20 years. In the video, Jung said, “As soon as I wake up in the morning, I drink lukewarm water,” but stressed, “It can be a serious problem if you just drink it without brushing your teeth. You’re swallowing the bacteria that built up overnight.” She also drew attention by showing off her slim, toned figure and youthful looks in a tight yoga outfit.

As Jung Ga-eun explained, the oral environment changes rapidly during sleep. Saliva normally washes away food debris in the mouth and helps keep bacteria from multiplying through its antimicrobial substances, serving as a natural cleansing mechanism.
During sleep, however, saliva production drops significantly, leaving the mouth dry. As a result, anaerobic bacteria such as Streptococcus mutans and Jinjiballiseu bacteria, which cause plaque buildup, gum inflammation and bad breath, multiply exponentially. This is also why people often have particularly bad breath or a coated feeling in their mouths when they wake up.

So, will you really be in “serious trouble” if you drink water without brushing your teeth?
According to medical experts, most of the oral bacteria that grow in the mouth overnight are killed by highly acidic stomach acid (gastric juice), even if they travel down to the stomach with water. Therefore, a healthy adult is unlikely to develop an acute infection or a life-threatening illness just because they happened to drink water first thing in the morning.
However, if harmful bacteria in the mouth enter the airways or lungs of older or infirm people, or people with chronic illnesses and weakened immune systems, they can pose a risk of aspiration pneumonia. Patients with severe gum inflammation or periodontal disease should also take care, as harmful oral bacteria can enter the bloodstream and place a burden on the body.
Experts advise that even without brushing every time—which can be a hassle—gently rinsing the mouth two or three times with lukewarm water and spitting it out before drinking clean water can effectively remove most harmful substances and the unpleasant bacterial film.
They also recommend slowly sipping lukewarm water at around 30–40 degrees Celsius, close to body temperature, rather than cold water, to reduce irritation to the stomach and help maintain body temperature and blood circulation.
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